]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/ide/ide-tape.c
ide-tape: remove tape->merge_stage
[linux-2.6-omap-h63xx.git] / drivers / ide / ide-tape.c
index 43e0e05577763b4bcd166dc4d14128dd94dac9d2..29870c415110ad0bc3cf2d4bf76791ebfe0d5763 100644 (file)
@@ -72,26 +72,6 @@ enum {
 #endif
 
 /**************************** Tunable parameters *****************************/
-
-
-/*
- * Pipelined mode parameters.
- *
- * We try to use the minimum number of stages which is enough to keep the tape
- * constantly streaming. To accomplish that, we implement a feedback loop around
- * the maximum number of stages:
- *
- * We start from MIN maximum stages (we will not even use MIN stages if we don't
- * need them), increment it by RATE*(MAX-MIN) whenever we sense that the
- * pipeline is empty, until we reach the optimum value or until we reach MAX.
- *
- * Setting the following parameter to 0 is illegal: the pipelined mode cannot be
- * disabled (idetape_calculate_speeds() divides by tape->max_stages.)
- */
-#define IDETAPE_MIN_PIPELINE_STAGES      1
-#define IDETAPE_MAX_PIPELINE_STAGES    400
-#define IDETAPE_INCREASE_STAGES_RATE    20
-
 /*
  * After each failed packet command we issue a request sense command and retry
  * the packet command IDETAPE_MAX_PC_RETRIES times.
@@ -181,56 +161,59 @@ struct idetape_bh {
        char *b_data;
 };
 
-typedef struct idetape_packet_command_s {
-       /* Actual packet bytes */
-       u8 c[12];
-       /* On each retry, we increment retries */
-       int retries;
-       /* Error code */
-       int error;
-       /* Bytes to transfer */
-       int request_transfer;
-       /* Bytes actually transferred */
-       int actually_transferred;
-       /* Size of our data buffer */
-       int buffer_size;
-       struct idetape_bh *bh;
-       char *b_data;
-       int b_count;
-       /* Data buffer */
-       u8 *buffer;
-       /* Pointer into the above buffer */
-       u8 *current_position;
-       /* Called when this packet command is completed */
-       ide_startstop_t (*callback) (ide_drive_t *);
-       /* Temporary buffer */
-       u8 pc_buffer[IDETAPE_PC_BUFFER_SIZE];
-       /* Status/Action bit flags: long for set_bit */
-       unsigned long flags;
-} idetape_pc_t;
+/* Tape door status */
+#define DOOR_UNLOCKED                  0
+#define DOOR_LOCKED                    1
+#define DOOR_EXPLICITLY_LOCKED         2
+
+/* Some defines for the SPACE command */
+#define IDETAPE_SPACE_OVER_FILEMARK    1
+#define IDETAPE_SPACE_TO_EOD           3
+
+/* Some defines for the LOAD UNLOAD command */
+#define IDETAPE_LU_LOAD_MASK           1
+#define IDETAPE_LU_RETENSION_MASK      2
+#define IDETAPE_LU_EOT_MASK            4
 
 /*
- *     Packet command flag bits.
+ * Special requests for our block device strategy routine.
+ *
+ * In order to service a character device command, we add special requests to
+ * the tail of our block device request queue and wait for their completion.
  */
-/* Set when an error is considered normal - We won't retry */
-#define        PC_ABORT                        0
-/* 1 When polling for DSC on a media access command */
-#define PC_WAIT_FOR_DSC                        1
-/* 1 when we prefer to use DMA if possible */
-#define PC_DMA_RECOMMENDED             2
-/* 1 while DMA in progress */
-#define        PC_DMA_IN_PROGRESS              3
-/* 1 when encountered problem during DMA */
-#define        PC_DMA_ERROR                    4
-/* Data direction */
-#define        PC_WRITING                      5
-
-/* A pipeline stage. */
-typedef struct idetape_stage_s {
-       struct request rq;                      /* The corresponding request */
-       struct idetape_bh *bh;                  /* The data buffers */
-       struct idetape_stage_s *next;           /* Pointer to the next stage */
-} idetape_stage_t;
+
+enum {
+       REQ_IDETAPE_PC1         = (1 << 0), /* packet command (first stage) */
+       REQ_IDETAPE_PC2         = (1 << 1), /* packet command (second stage) */
+       REQ_IDETAPE_READ        = (1 << 2),
+       REQ_IDETAPE_WRITE       = (1 << 3),
+};
+
+/* Error codes returned in rq->errors to the higher part of the driver. */
+#define IDETAPE_ERROR_GENERAL          101
+#define IDETAPE_ERROR_FILEMARK         102
+#define IDETAPE_ERROR_EOD              103
+
+/* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
+#define IDETAPE_BLOCK_DESCRIPTOR       0
+#define IDETAPE_CAPABILITIES_PAGE      0x2a
+
+/* Tape flag bits values. */
+enum {
+       IDETAPE_FLAG_IGNORE_DSC         = (1 << 0),
+       /* 0 When the tape position is unknown */
+       IDETAPE_FLAG_ADDRESS_VALID      = (1 << 1),
+       /* Device already opened */
+       IDETAPE_FLAG_BUSY               = (1 << 2),
+       /* Attempt to auto-detect the current user block size */
+       IDETAPE_FLAG_DETECT_BS          = (1 << 3),
+       /* Currently on a filemark */
+       IDETAPE_FLAG_FILEMARK           = (1 << 4),
+       /* DRQ interrupt device */
+       IDETAPE_FLAG_DRQ_INTERRUPT      = (1 << 5),
+       /* 0 = no tape is loaded, so we don't rewind after ejecting */
+       IDETAPE_FLAG_MEDIUM_PRESENT     = (1 << 6),
+};
 
 /*
  * Most of our global data which we need to save even as we leave the driver due
@@ -258,11 +241,11 @@ typedef struct ide_tape_obj {
         *      retry, to get detailed information on what went wrong.
         */
        /* Current packet command */
-       idetape_pc_t *pc;
+       struct ide_atapi_pc *pc;
        /* Last failed packet command */
-       idetape_pc_t *failed_pc;
+       struct ide_atapi_pc *failed_pc;
        /* Packet command stack */
-       idetape_pc_t pc_stack[IDETAPE_PC_STACK];
+       struct ide_atapi_pc pc_stack[IDETAPE_PC_STACK];
        /* Next free packet command storage space */
        int pc_stack_index;
        struct request rq_stack[IDETAPE_PC_STACK];
@@ -275,9 +258,7 @@ typedef struct ide_tape_obj {
         * While polling for DSC we use postponed_rq to postpone the current
         * request so that ide.c will be able to service pending requests on the
         * other device. Note that at most we will have only one DSC (usually
-        * data transfer) request in the device request queue. Additional
-        * requests can be queued in our internal pipeline, but they will be
-        * visible to ide.c only one at a time.
+        * data transfer) request in the device request queue.
         */
        struct request *postponed_rq;
        /* The time in which we started polling for DSC */
@@ -317,43 +298,20 @@ typedef struct ide_tape_obj {
         * At most, there is only one ide-tape originated data transfer request
         * in the device request queue. This allows ide.c to easily service
         * requests from the other device when we postpone our active request.
-        * In the pipelined operation mode, we use our internal pipeline
-        * structure to hold more data requests. The data buffer size is chosen
-        * based on the tape's recommendation.
         */
-       /* ptr to the request which is waiting in the device request queue */
-       struct request *active_data_rq;
+
        /* Data buffer size chosen based on the tape's recommendation */
-       int stage_size;
-       idetape_stage_t *merge_stage;
-       int merge_stage_size;
+       int buffer_size;
+       /* merge buffer */
+       struct idetape_bh *merge_bh;
+       /* size of the merge buffer */
+       int merge_bh_size;
+       /* pointer to current buffer head within the merge buffer */
        struct idetape_bh *bh;
        char *b_data;
        int b_count;
 
-       /*
-        * Pipeline parameters.
-        *
-        * To accomplish non-pipelined mode, we simply set the following
-        * variables to zero (or NULL, where appropriate).
-        */
-       /* Number of currently used stages */
-       int nr_stages;
-       /* Number of pending stages */
-       int nr_pending_stages;
-       /* We will not allocate more than this number of stages */
-       int max_stages, min_pipeline, max_pipeline;
-       /* The first stage which will be removed from the pipeline */
-       idetape_stage_t *first_stage;
-       /* The currently active stage */
-       idetape_stage_t *active_stage;
-       /* Will be serviced after the currently active request */
-       idetape_stage_t *next_stage;
-       /* New requests will be added to the pipeline here */
-       idetape_stage_t *last_stage;
-       /* Optional free stage which we can use */
-       idetape_stage_t *cache_stage;
-       int pages_per_stage;
+       int pages_per_buffer;
        /* Wasted space in each stage */
        int excess_bh_size;
 
@@ -374,45 +332,6 @@ typedef struct ide_tape_obj {
        /* the tape is write protected (hardware or opened as read-only) */
        char write_prot;
 
-       /*
-        * Limit the number of times a request can be postponed, to avoid an
-        * infinite postpone deadlock.
-        */
-       int postpone_cnt;
-
-       /*
-        * Measures number of frames:
-        *
-        * 1. written/read to/from the driver pipeline (pipeline_head).
-        * 2. written/read to/from the tape buffers (idetape_bh).
-        * 3. written/read by the tape to/from the media (tape_head).
-        */
-       int pipeline_head;
-       int buffer_head;
-       int tape_head;
-       int last_tape_head;
-
-       /* Speed control at the tape buffers input/output */
-       unsigned long insert_time;
-       int insert_size;
-       int insert_speed;
-       int max_insert_speed;
-       int measure_insert_time;
-
-       /* Speed regulation negative feedback loop */
-       int speed_control;
-       int pipeline_head_speed;
-       int controlled_pipeline_head_speed;
-       int uncontrolled_pipeline_head_speed;
-       int controlled_last_pipeline_head;
-       unsigned long uncontrolled_pipeline_head_time;
-       unsigned long controlled_pipeline_head_time;
-       int controlled_previous_pipeline_head;
-       int uncontrolled_previous_pipeline_head;
-       unsigned long controlled_previous_head_time;
-       unsigned long uncontrolled_previous_head_time;
-       int restart_speed_control_req;
-
        u32 debug_mask;
 } idetape_tape_t;
 
@@ -446,58 +365,6 @@ static void ide_tape_put(struct ide_tape_obj *tape)
        mutex_unlock(&idetape_ref_mutex);
 }
 
-/* Tape door status */
-#define DOOR_UNLOCKED                  0
-#define DOOR_LOCKED                    1
-#define DOOR_EXPLICITLY_LOCKED         2
-
-/*
- *     Tape flag bits values.
- */
-#define IDETAPE_IGNORE_DSC             0
-#define IDETAPE_ADDRESS_VALID          1       /* 0 When the tape position is unknown */
-#define IDETAPE_BUSY                   2       /* Device already opened */
-#define IDETAPE_PIPELINE_ERROR         3       /* Error detected in a pipeline stage */
-#define IDETAPE_DETECT_BS              4       /* Attempt to auto-detect the current user block size */
-#define IDETAPE_FILEMARK               5       /* Currently on a filemark */
-#define IDETAPE_DRQ_INTERRUPT          6       /* DRQ interrupt device */
-#define IDETAPE_READ_ERROR             7
-#define IDETAPE_PIPELINE_ACTIVE                8       /* pipeline active */
-/* 0 = no tape is loaded, so we don't rewind after ejecting */
-#define IDETAPE_MEDIUM_PRESENT         9
-
-/* Some defines for the SPACE command */
-#define IDETAPE_SPACE_OVER_FILEMARK    1
-#define IDETAPE_SPACE_TO_EOD           3
-
-/* Some defines for the LOAD UNLOAD command */
-#define IDETAPE_LU_LOAD_MASK           1
-#define IDETAPE_LU_RETENSION_MASK      2
-#define IDETAPE_LU_EOT_MASK            4
-
-/*
- * Special requests for our block device strategy routine.
- *
- * In order to service a character device command, we add special requests to
- * the tail of our block device request queue and wait for their completion.
- */
-
-enum {
-       REQ_IDETAPE_PC1         = (1 << 0), /* packet command (first stage) */
-       REQ_IDETAPE_PC2         = (1 << 1), /* packet command (second stage) */
-       REQ_IDETAPE_READ        = (1 << 2),
-       REQ_IDETAPE_WRITE       = (1 << 3),
-};
-
-/* Error codes returned in rq->errors to the higher part of the driver. */
-#define        IDETAPE_ERROR_GENERAL           101
-#define        IDETAPE_ERROR_FILEMARK          102
-#define        IDETAPE_ERROR_EOD               103
-
-/* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
-#define IDETAPE_BLOCK_DESCRIPTOR       0
-#define        IDETAPE_CAPABILITIES_PAGE       0x2a
-
 /*
  * The variables below are used for the character device interface. Additional
  * state variables are defined in our ide_drive_t structure.
@@ -518,17 +385,7 @@ static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
        return tape;
 }
 
-/*
- * Too bad. The drive wants to send us data which we are not ready to accept.
- * Just throw it away.
- */
-static void idetape_discard_data(ide_drive_t *drive, unsigned int bcount)
-{
-       while (bcount--)
-               (void) HWIF(drive)->INB(IDE_DATA_REG);
-}
-
-static void idetape_input_buffers(ide_drive_t *drive, idetape_pc_t *pc,
+static void idetape_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
                                  unsigned int bcount)
 {
        struct idetape_bh *bh = pc->bh;
@@ -538,7 +395,7 @@ static void idetape_input_buffers(ide_drive_t *drive, idetape_pc_t *pc,
                if (bh == NULL) {
                        printk(KERN_ERR "ide-tape: bh == NULL in "
                                "idetape_input_buffers\n");
-                       idetape_discard_data(drive, bcount);
+                       ide_atapi_discard_data(drive, bcount);
                        return;
                }
                count = min(
@@ -557,7 +414,7 @@ static void idetape_input_buffers(ide_drive_t *drive, idetape_pc_t *pc,
        pc->bh = bh;
 }
 
-static void idetape_output_buffers(ide_drive_t *drive, idetape_pc_t *pc,
+static void idetape_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
                                   unsigned int bcount)
 {
        struct idetape_bh *bh = pc->bh;
@@ -585,13 +442,13 @@ static void idetape_output_buffers(ide_drive_t *drive, idetape_pc_t *pc,
        }
 }
 
-static void idetape_update_buffers(idetape_pc_t *pc)
+static void idetape_update_buffers(struct ide_atapi_pc *pc)
 {
        struct idetape_bh *bh = pc->bh;
        int count;
-       unsigned int bcount = pc->actually_transferred;
+       unsigned int bcount = pc->xferred;
 
-       if (test_bit(PC_WRITING, &pc->flags))
+       if (pc->flags & PC_FLAG_WRITING)
                return;
        while (bcount) {
                if (bh == NULL) {
@@ -614,7 +471,7 @@ static void idetape_update_buffers(idetape_pc_t *pc)
  *     driver. A storage space for a maximum of IDETAPE_PC_STACK packet
  *     commands is allocated at initialization time.
  */
-static idetape_pc_t *idetape_next_pc_storage(ide_drive_t *drive)
+static struct ide_atapi_pc *idetape_next_pc_storage(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
 
@@ -649,14 +506,14 @@ static struct request *idetape_next_rq_storage(ide_drive_t *drive)
        return (&tape->rq_stack[tape->rq_stack_index++]);
 }
 
-static void idetape_init_pc(idetape_pc_t *pc)
+static void idetape_init_pc(struct ide_atapi_pc *pc)
 {
        memset(pc->c, 0, 12);
        pc->retries = 0;
        pc->flags = 0;
-       pc->request_transfer = 0;
-       pc->buffer = pc->pc_buffer;
-       pc->buffer_size = IDETAPE_PC_BUFFER_SIZE;
+       pc->req_xfer = 0;
+       pc->buf = pc->pc_buf;
+       pc->buf_size = IDETAPE_PC_BUFFER_SIZE;
        pc->bh = NULL;
        pc->b_data = NULL;
 }
@@ -668,7 +525,7 @@ static void idetape_init_pc(idetape_pc_t *pc)
 static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t *pc = tape->failed_pc;
+       struct ide_atapi_pc *pc = tape->failed_pc;
 
        tape->sense_key = sense[2] & 0xF;
        tape->asc       = sense[12];
@@ -677,9 +534,9 @@ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
        debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
                 pc->c[0], tape->sense_key, tape->asc, tape->ascq);
 
-       /* Correct pc->actually_transferred by asking the tape.  */
-       if (test_bit(PC_DMA_ERROR, &pc->flags)) {
-               pc->actually_transferred = pc->request_transfer -
+       /* Correct pc->xferred by asking the tape.       */
+       if (pc->flags & PC_FLAG_DMA_ERROR) {
+               pc->xferred = pc->req_xfer -
                        tape->blk_size *
                        be32_to_cpu(get_unaligned((u32 *)&sense[3]));
                idetape_update_buffers(pc);
@@ -697,153 +554,61 @@ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
                        /* don't report an error, everything's ok */
                        pc->error = 0;
                        /* don't retry read/write */
-                       set_bit(PC_ABORT, &pc->flags);
+                       pc->flags |= PC_FLAG_ABORT;
                }
        }
        if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
                pc->error = IDETAPE_ERROR_FILEMARK;
-               set_bit(PC_ABORT, &pc->flags);
+               pc->flags |= PC_FLAG_ABORT;
        }
        if (pc->c[0] == WRITE_6) {
                if ((sense[2] & 0x40) || (tape->sense_key == 0xd
                     && tape->asc == 0x0 && tape->ascq == 0x2)) {
                        pc->error = IDETAPE_ERROR_EOD;
-                       set_bit(PC_ABORT, &pc->flags);
+                       pc->flags |= PC_FLAG_ABORT;
                }
        }
        if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
                if (tape->sense_key == 8) {
                        pc->error = IDETAPE_ERROR_EOD;
-                       set_bit(PC_ABORT, &pc->flags);
+                       pc->flags |= PC_FLAG_ABORT;
                }
-               if (!test_bit(PC_ABORT, &pc->flags) &&
-                   pc->actually_transferred)
+               if (!(pc->flags & PC_FLAG_ABORT) &&
+                   pc->xferred)
                        pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
        }
 }
 
-static void idetape_activate_next_stage(ide_drive_t *drive)
+/* Free data buffers completely. */
+static void ide_tape_kfree_buffer(idetape_tape_t *tape)
 {
-       idetape_tape_t *tape = drive->driver_data;
-       idetape_stage_t *stage = tape->next_stage;
-       struct request *rq = &stage->rq;
+       struct idetape_bh *prev_bh, *bh = tape->merge_bh;
 
-       debug_log(DBG_PROCS, "Enter %s\n", __func__);
+       while (bh) {
+               u32 size = bh->b_size;
 
-       if (stage == NULL) {
-               printk(KERN_ERR "ide-tape: bug: Trying to activate a non"
-                               " existing stage\n");
-               return;
-       }
+               while (size) {
+                       unsigned int order = fls(size >> PAGE_SHIFT)-1;
 
-       rq->rq_disk = tape->disk;
-       rq->buffer = NULL;
-       rq->special = (void *)stage->bh;
-       tape->active_data_rq = rq;
-       tape->active_stage = stage;
-       tape->next_stage = stage->next;
-}
-
-/* Free a stage along with its related buffers completely. */
-static void __idetape_kfree_stage(idetape_stage_t *stage)
-{
-       struct idetape_bh *prev_bh, *bh = stage->bh;
-       int size;
-
-       while (bh != NULL) {
-               if (bh->b_data != NULL) {
-                       size = (int) bh->b_size;
-                       while (size > 0) {
-                               free_page((unsigned long) bh->b_data);
-                               size -= PAGE_SIZE;
-                               bh->b_data += PAGE_SIZE;
-                       }
+                       if (bh->b_data)
+                               free_pages((unsigned long)bh->b_data, order);
+
+                       size &= (order-1);
+                       bh->b_data += (1 << order) * PAGE_SIZE;
                }
                prev_bh = bh;
                bh = bh->b_reqnext;
                kfree(prev_bh);
        }
-       kfree(stage);
-}
-
-static void idetape_kfree_stage(idetape_tape_t *tape, idetape_stage_t *stage)
-{
-       __idetape_kfree_stage(stage);
-}
-
-/*
- * Remove tape->first_stage from the pipeline. The caller should avoid race
- * conditions.
- */
-static void idetape_remove_stage_head(ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       idetape_stage_t *stage;
-
-       debug_log(DBG_PROCS, "Enter %s\n", __func__);
-
-       if (tape->first_stage == NULL) {
-               printk(KERN_ERR "ide-tape: bug: tape->first_stage is NULL\n");
-               return;
-       }
-       if (tape->active_stage == tape->first_stage) {
-               printk(KERN_ERR "ide-tape: bug: Trying to free our active "
-                               "pipeline stage\n");
-               return;
-       }
-       stage = tape->first_stage;
-       tape->first_stage = stage->next;
-       idetape_kfree_stage(tape, stage);
-       tape->nr_stages--;
-       if (tape->first_stage == NULL) {
-               tape->last_stage = NULL;
-               if (tape->next_stage != NULL)
-                       printk(KERN_ERR "ide-tape: bug: tape->next_stage !="
-                                       " NULL\n");
-               if (tape->nr_stages)
-                       printk(KERN_ERR "ide-tape: bug: nr_stages should be 0 "
-                                       "now\n");
-       }
-}
-
-/*
- * This will free all the pipeline stages starting from new_last_stage->next
- * to the end of the list, and point tape->last_stage to new_last_stage.
- */
-static void idetape_abort_pipeline(ide_drive_t *drive,
-                                  idetape_stage_t *new_last_stage)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       idetape_stage_t *stage = new_last_stage->next;
-       idetape_stage_t *nstage;
-
-       debug_log(DBG_PROCS, "%s: Enter %s\n", tape->name, __func__);
-
-       while (stage) {
-               nstage = stage->next;
-               idetape_kfree_stage(tape, stage);
-               --tape->nr_stages;
-               --tape->nr_pending_stages;
-               stage = nstage;
-       }
-       if (new_last_stage)
-               new_last_stage->next = NULL;
-       tape->last_stage = new_last_stage;
-       tape->next_stage = NULL;
+       kfree(tape->merge_bh);
 }
 
-/*
- * Finish servicing a request and insert a pending pipeline request into the
- * main device queue.
- */
 static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
 {
        struct request *rq = HWGROUP(drive)->rq;
        idetape_tape_t *tape = drive->driver_data;
        unsigned long flags;
        int error;
-       int remove_stage = 0;
-       idetape_stage_t *active_stage;
 
        debug_log(DBG_PROCS, "Enter %s\n", __func__);
 
@@ -863,56 +628,8 @@ static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
 
        spin_lock_irqsave(&tape->lock, flags);
 
-       /* The request was a pipelined data transfer request */
-       if (tape->active_data_rq == rq) {
-               active_stage = tape->active_stage;
-               tape->active_stage = NULL;
-               tape->active_data_rq = NULL;
-               tape->nr_pending_stages--;
-               if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
-                       remove_stage = 1;
-                       if (error) {
-                               set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
-                               if (error == IDETAPE_ERROR_EOD)
-                                       idetape_abort_pipeline(drive,
-                                                               active_stage);
-                       }
-               } else if (rq->cmd[0] & REQ_IDETAPE_READ) {
-                       if (error == IDETAPE_ERROR_EOD) {
-                               set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
-                               idetape_abort_pipeline(drive, active_stage);
-                       }
-               }
-               if (tape->next_stage != NULL) {
-                       idetape_activate_next_stage(drive);
-
-                       /* Insert the next request into the request queue. */
-                       (void)ide_do_drive_cmd(drive, tape->active_data_rq,
-                                               ide_end);
-               } else if (!error) {
-                       /*
-                        * This is a part of the feedback loop which tries to
-                        * find the optimum number of stages. We are starting
-                        * from a minimum maximum number of stages, and if we
-                        * sense that the pipeline is empty, we try to increase
-                        * it, until we reach the user compile time memory
-                        * limit.
-                        */
-                       int i = (tape->max_pipeline - tape->min_pipeline) / 10;
-
-                       tape->max_stages += max(i, 1);
-                       tape->max_stages = max(tape->max_stages,
-                                               tape->min_pipeline);
-                       tape->max_stages = min(tape->max_stages,
-                                               tape->max_pipeline);
-               }
-       }
        ide_end_drive_cmd(drive, 0, 0);
 
-       if (remove_stage)
-               idetape_remove_stage_head(drive);
-       if (tape->active_data_rq == NULL)
-               clear_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
        spin_unlock_irqrestore(&tape->lock, flags);
        return 0;
 }
@@ -924,7 +641,7 @@ static ide_startstop_t idetape_request_sense_callback(ide_drive_t *drive)
        debug_log(DBG_PROCS, "Enter %s\n", __func__);
 
        if (!tape->pc->error) {
-               idetape_analyze_error(drive, tape->pc->buffer);
+               idetape_analyze_error(drive, tape->pc->buf);
                idetape_end_request(drive, 1, 0);
        } else {
                printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - "
@@ -934,13 +651,13 @@ static ide_startstop_t idetape_request_sense_callback(ide_drive_t *drive)
        return ide_stopped;
 }
 
-static void idetape_create_request_sense_cmd(idetape_pc_t *pc)
+static void idetape_create_request_sense_cmd(struct ide_atapi_pc *pc)
 {
        idetape_init_pc(pc);
        pc->c[0] = REQUEST_SENSE;
        pc->c[4] = 20;
-       pc->request_transfer = 20;
-       pc->callback = &idetape_request_sense_callback;
+       pc->req_xfer = 20;
+       pc->idetape_callback = &idetape_request_sense_callback;
 }
 
 static void idetape_init_rq(struct request *rq, u8 cmd)
@@ -965,7 +682,7 @@ static void idetape_init_rq(struct request *rq, u8 cmd)
  * handling functions should queue request to the lower level part and wait for
  * their completion using idetape_queue_pc_tail or idetape_queue_rw_tail.
  */
-static void idetape_queue_pc_head(ide_drive_t *drive, idetape_pc_t *pc,
+static void idetape_queue_pc_head(ide_drive_t *drive, struct ide_atapi_pc *pc,
                                  struct request *rq)
 {
        struct ide_tape_obj *tape = drive->driver_data;
@@ -984,14 +701,14 @@ static void idetape_queue_pc_head(ide_drive_t *drive, idetape_pc_t *pc,
 static ide_startstop_t idetape_retry_pc (ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t *pc;
+       struct ide_atapi_pc *pc;
        struct request *rq;
 
        (void)ide_read_error(drive);
        pc = idetape_next_pc_storage(drive);
        rq = idetape_next_rq_storage(drive);
        idetape_create_request_sense_cmd(pc);
-       set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
+       set_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags);
        idetape_queue_pc_head(drive, pc, rq);
        return ide_stopped;
 }
@@ -1010,7 +727,7 @@ static void idetape_postpone_request(ide_drive_t *drive)
        ide_stall_queue(drive, tape->dsc_poll_freq);
 }
 
-typedef void idetape_io_buf(ide_drive_t *, idetape_pc_t *, unsigned int);
+typedef void idetape_io_buf(ide_drive_t *, struct ide_atapi_pc *, unsigned int);
 
 /*
  * This is the usual interrupt handler which will be called during a packet
@@ -1023,7 +740,7 @@ static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
 {
        ide_hwif_t *hwif = drive->hwif;
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t *pc = tape->pc;
+       struct ide_atapi_pc *pc = tape->pc;
        xfer_func_t *xferfunc;
        idetape_io_buf *iobuf;
        unsigned int temp;
@@ -1038,8 +755,8 @@ static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
        /* Clear the interrupt */
        stat = ide_read_status(drive);
 
-       if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
-               if (hwif->ide_dma_end(drive) || (stat & ERR_STAT)) {
+       if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
+               if (hwif->dma_ops->dma_end(drive) || (stat & ERR_STAT)) {
                        /*
                         * A DMA error is sometimes expected. For example,
                         * if the tape is crossing a filemark during a
@@ -1061,9 +778,9 @@ static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
                         * data transfer will occur, but no DMA error.
                         * (AS, 19 Apr 2001)
                         */
-                       set_bit(PC_DMA_ERROR, &pc->flags);
+                       pc->flags |= PC_FLAG_DMA_ERROR;
                } else {
-                       pc->actually_transferred = pc->request_transfer;
+                       pc->xferred = pc->req_xfer;
                        idetape_update_buffers(pc);
                }
                debug_log(DBG_PROCS, "DMA finished\n");
@@ -1073,9 +790,9 @@ static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
        /* No more interrupts */
        if ((stat & DRQ_STAT) == 0) {
                debug_log(DBG_SENSE, "Packet command completed, %d bytes"
-                               " transferred\n", pc->actually_transferred);
+                               " transferred\n", pc->xferred);
 
-               clear_bit(PC_DMA_IN_PROGRESS, &pc->flags);
+               pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
                local_irq_enable();
 
 #if SIMULATE_ERRORS
@@ -1088,7 +805,7 @@ static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
 #endif
                if ((stat & ERR_STAT) && pc->c[0] == REQUEST_SENSE)
                        stat &= ~ERR_STAT;
-               if ((stat & ERR_STAT) || test_bit(PC_DMA_ERROR, &pc->flags)) {
+               if ((stat & ERR_STAT) || (pc->flags & PC_FLAG_DMA_ERROR)) {
                        /* Error detected */
                        debug_log(DBG_ERR, "%s: I/O error\n", tape->name);
 
@@ -1104,7 +821,7 @@ static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
                        return idetape_retry_pc(drive);
                }
                pc->error = 0;
-               if (test_bit(PC_WAIT_FOR_DSC, &pc->flags) &&
+               if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) &&
                    (stat & SEEK_STAT) == 0) {
                        /* Media access command */
                        tape->dsc_polling_start = jiffies;
@@ -1117,9 +834,11 @@ static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
                if (tape->failed_pc == pc)
                        tape->failed_pc = NULL;
                /* Command finished - Call the callback function */
-               return pc->callback(drive);
+               return pc->idetape_callback(drive);
        }
-       if (test_and_clear_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
+
+       if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
+               pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
                printk(KERN_ERR "ide-tape: The tape wants to issue more "
                                "interrupts in DMA mode\n");
                printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n");
@@ -1127,16 +846,16 @@ static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
                return ide_do_reset(drive);
        }
        /* Get the number of bytes to transfer on this interrupt. */
-       bcount = (hwif->INB(IDE_BCOUNTH_REG) << 8) |
-                 hwif->INB(IDE_BCOUNTL_REG);
+       bcount = (hwif->INB(hwif->io_ports.lbah_addr) << 8) |
+                 hwif->INB(hwif->io_ports.lbam_addr);
 
-       ireason = hwif->INB(IDE_IREASON_REG);
+       ireason = hwif->INB(hwif->io_ports.nsect_addr);
 
        if (ireason & CD) {
                printk(KERN_ERR "ide-tape: CoD != 0 in %s\n", __func__);
                return ide_do_reset(drive);
        }
-       if (((ireason & IO) == IO) == test_bit(PC_WRITING, &pc->flags)) {
+       if (((ireason & IO) == IO) == !!(pc->flags & PC_FLAG_WRITING)) {
                /* Hopefully, we will never get here */
                printk(KERN_ERR "ide-tape: We wanted to %s, ",
                                (ireason & IO) ? "Write" : "Read");
@@ -1144,15 +863,15 @@ static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
                                (ireason & IO) ? "Read" : "Write");
                return ide_do_reset(drive);
        }
-       if (!test_bit(PC_WRITING, &pc->flags)) {
+       if (!(pc->flags & PC_FLAG_WRITING)) {
                /* Reading - Check that we have enough space */
-               temp = pc->actually_transferred + bcount;
-               if (temp > pc->request_transfer) {
-                       if (temp > pc->buffer_size) {
+               temp = pc->xferred + bcount;
+               if (temp > pc->req_xfer) {
+                       if (temp > pc->buf_size) {
                                printk(KERN_ERR "ide-tape: The tape wants to "
                                        "send us more data than expected "
                                        "- discarding data\n");
-                               idetape_discard_data(drive, bcount);
+                               ide_atapi_discard_data(drive, bcount);
                                ide_set_handler(drive, &idetape_pc_intr,
                                                IDETAPE_WAIT_CMD, NULL);
                                return ide_started;
@@ -1170,11 +889,11 @@ static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
        if (pc->bh)
                iobuf(drive, pc, bcount);
        else
-               xferfunc(drive, pc->current_position, bcount);
+               xferfunc(drive, pc->cur_pos, bcount);
 
        /* Update the current position */
-       pc->actually_transferred += bcount;
-       pc->current_position += bcount;
+       pc->xferred += bcount;
+       pc->cur_pos += bcount;
 
        debug_log(DBG_SENSE, "[cmd %x] transferred %d bytes on that intr.\n",
                        pc->c[0], bcount);
@@ -1224,7 +943,7 @@ static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive)
 {
        ide_hwif_t *hwif = drive->hwif;
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t *pc = tape->pc;
+       struct ide_atapi_pc *pc = tape->pc;
        int retries = 100;
        ide_startstop_t startstop;
        u8 ireason;
@@ -1234,12 +953,12 @@ static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive)
                                "yet DRQ isn't asserted\n");
                return startstop;
        }
-       ireason = hwif->INB(IDE_IREASON_REG);
+       ireason = hwif->INB(hwif->io_ports.nsect_addr);
        while (retries-- && ((ireason & CD) == 0 || (ireason & IO))) {
                printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing "
                                "a packet command, retrying\n");
                udelay(100);
-               ireason = hwif->INB(IDE_IREASON_REG);
+               ireason = hwif->INB(hwif->io_ports.nsect_addr);
                if (retries == 0) {
                        printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while "
                                        "issuing a packet command, ignoring\n");
@@ -1256,15 +975,16 @@ static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive)
        ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
 #ifdef CONFIG_BLK_DEV_IDEDMA
        /* Begin DMA, if necessary */
-       if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags))
-               hwif->dma_start(drive);
+       if (pc->flags & PC_FLAG_DMA_IN_PROGRESS)
+               hwif->dma_ops->dma_start(drive);
 #endif
        /* Send the actual packet */
        HWIF(drive)->atapi_output_bytes(drive, pc->c, 12);
        return ide_started;
 }
 
-static ide_startstop_t idetape_issue_pc(ide_drive_t *drive, idetape_pc_t *pc)
+static ide_startstop_t idetape_issue_pc(ide_drive_t *drive,
+               struct ide_atapi_pc *pc)
 {
        ide_hwif_t *hwif = drive->hwif;
        idetape_tape_t *tape = drive->driver_data;
@@ -1283,13 +1003,13 @@ static ide_startstop_t idetape_issue_pc(ide_drive_t *drive, idetape_pc_t *pc)
        tape->pc = pc;
 
        if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
-           test_bit(PC_ABORT, &pc->flags)) {
+               (pc->flags & PC_FLAG_ABORT)) {
                /*
                 * We will "abort" retrying a packet command in case legitimate
                 * error code was received (crossing a filemark, or end of the
                 * media, for example).
                 */
-               if (!test_bit(PC_ABORT, &pc->flags)) {
+               if (!(pc->flags & PC_FLAG_ABORT)) {
                        if (!(pc->c[0] == TEST_UNIT_READY &&
                              tape->sense_key == 2 && tape->asc == 4 &&
                             (tape->ascq == 1 || tape->ascq == 8))) {
@@ -1304,36 +1024,38 @@ static ide_startstop_t idetape_issue_pc(ide_drive_t *drive, idetape_pc_t *pc)
                        pc->error = IDETAPE_ERROR_GENERAL;
                }
                tape->failed_pc = NULL;
-               return pc->callback(drive);
+               return pc->idetape_callback(drive);
        }
        debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
 
        pc->retries++;
        /* We haven't transferred any data yet */
-       pc->actually_transferred = 0;
-       pc->current_position = pc->buffer;
+       pc->xferred = 0;
+       pc->cur_pos = pc->buf;
        /* Request to transfer the entire buffer at once */
-       bcount = pc->request_transfer;
+       bcount = pc->req_xfer;
 
-       if (test_and_clear_bit(PC_DMA_ERROR, &pc->flags)) {
+       if (pc->flags & PC_FLAG_DMA_ERROR) {
+               pc->flags &= ~PC_FLAG_DMA_ERROR;
                printk(KERN_WARNING "ide-tape: DMA disabled, "
                                "reverting to PIO\n");
                ide_dma_off(drive);
        }
-       if (test_bit(PC_DMA_RECOMMENDED, &pc->flags) && drive->using_dma)
-               dma_ok = !hwif->dma_setup(drive);
+       if ((pc->flags & PC_FLAG_DMA_RECOMMENDED) && drive->using_dma)
+               dma_ok = !hwif->dma_ops->dma_setup(drive);
 
        ide_pktcmd_tf_load(drive, IDE_TFLAG_NO_SELECT_MASK |
                           IDE_TFLAG_OUT_DEVICE, bcount, dma_ok);
 
-       if (dma_ok)                     /* Will begin DMA later */
-               set_bit(PC_DMA_IN_PROGRESS, &pc->flags);
-       if (test_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags)) {
+       if (dma_ok)
+               /* Will begin DMA later */
+               pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
+       if (test_bit(IDETAPE_FLAG_DRQ_INTERRUPT, &tape->flags)) {
                ide_execute_command(drive, WIN_PACKETCMD, &idetape_transfer_pc,
                                    IDETAPE_WAIT_CMD, NULL);
                return ide_started;
        } else {
-               hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
+               hwif->OUTB(WIN_PACKETCMD, hwif->io_ports.command_addr);
                return idetape_transfer_pc(drive);
        }
 }
@@ -1349,7 +1071,7 @@ static ide_startstop_t idetape_pc_callback(ide_drive_t *drive)
 }
 
 /* A mode sense command is used to "sense" tape parameters. */
-static void idetape_create_mode_sense_cmd(idetape_pc_t *pc, u8 page_code)
+static void idetape_create_mode_sense_cmd(struct ide_atapi_pc *pc, u8 page_code)
 {
        idetape_init_pc(pc);
        pc->c[0] = MODE_SENSE;
@@ -1368,81 +1090,18 @@ static void idetape_create_mode_sense_cmd(idetape_pc_t *pc, u8 page_code)
        /* We will just discard data in that case */
        pc->c[4] = 255;
        if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
-               pc->request_transfer = 12;
+               pc->req_xfer = 12;
        else if (page_code == IDETAPE_CAPABILITIES_PAGE)
-               pc->request_transfer = 24;
+               pc->req_xfer = 24;
        else
-               pc->request_transfer = 50;
-       pc->callback = &idetape_pc_callback;
-}
-
-static void idetape_calculate_speeds(ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-
-       if (time_after(jiffies,
-                       tape->controlled_pipeline_head_time + 120 * HZ)) {
-               tape->controlled_previous_pipeline_head =
-                       tape->controlled_last_pipeline_head;
-               tape->controlled_previous_head_time =
-                       tape->controlled_pipeline_head_time;
-               tape->controlled_last_pipeline_head = tape->pipeline_head;
-               tape->controlled_pipeline_head_time = jiffies;
-       }
-       if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ))
-               tape->controlled_pipeline_head_speed = (tape->pipeline_head -
-                               tape->controlled_last_pipeline_head) * 32 * HZ /
-                               (jiffies - tape->controlled_pipeline_head_time);
-       else if (time_after(jiffies, tape->controlled_previous_head_time))
-               tape->controlled_pipeline_head_speed = (tape->pipeline_head -
-                               tape->controlled_previous_pipeline_head) * 32 *
-                       HZ / (jiffies - tape->controlled_previous_head_time);
-
-       if (tape->nr_pending_stages < tape->max_stages/*- 1 */) {
-               /* -1 for read mode error recovery */
-               if (time_after(jiffies, tape->uncontrolled_previous_head_time +
-                                       10 * HZ)) {
-                       tape->uncontrolled_pipeline_head_time = jiffies;
-                       tape->uncontrolled_pipeline_head_speed =
-                               (tape->pipeline_head -
-                                tape->uncontrolled_previous_pipeline_head) *
-                               32 * HZ / (jiffies -
-                                       tape->uncontrolled_previous_head_time);
-               }
-       } else {
-               tape->uncontrolled_previous_head_time = jiffies;
-               tape->uncontrolled_previous_pipeline_head = tape->pipeline_head;
-               if (time_after(jiffies, tape->uncontrolled_pipeline_head_time +
-                                       30 * HZ))
-                       tape->uncontrolled_pipeline_head_time = jiffies;
-
-       }
-       tape->pipeline_head_speed = max(tape->uncontrolled_pipeline_head_speed,
-                                       tape->controlled_pipeline_head_speed);
-
-       if (tape->speed_control == 1) {
-               if (tape->nr_pending_stages >= tape->max_stages / 2)
-                       tape->max_insert_speed = tape->pipeline_head_speed +
-                               (1100 - tape->pipeline_head_speed) * 2 *
-                               (tape->nr_pending_stages - tape->max_stages / 2)
-                               / tape->max_stages;
-               else
-                       tape->max_insert_speed = 500 +
-                               (tape->pipeline_head_speed - 500) * 2 *
-                               tape->nr_pending_stages / tape->max_stages;
-
-               if (tape->nr_pending_stages >= tape->max_stages * 99 / 100)
-                       tape->max_insert_speed = 5000;
-       } else
-               tape->max_insert_speed = tape->speed_control;
-
-       tape->max_insert_speed = max(tape->max_insert_speed, 500);
+               pc->req_xfer = 50;
+       pc->idetape_callback = &idetape_pc_callback;
 }
 
 static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t *pc = tape->pc;
+       struct ide_atapi_pc *pc = tape->pc;
        u8 stat;
 
        stat = ide_read_status(drive);
@@ -1463,27 +1122,17 @@ static ide_startstop_t idetape_media_access_finished(ide_drive_t *drive)
                pc->error = IDETAPE_ERROR_GENERAL;
                tape->failed_pc = NULL;
        }
-       return pc->callback(drive);
+       return pc->idetape_callback(drive);
 }
 
 static ide_startstop_t idetape_rw_callback(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
        struct request *rq = HWGROUP(drive)->rq;
-       int blocks = tape->pc->actually_transferred / tape->blk_size;
+       int blocks = tape->pc->xferred / tape->blk_size;
 
        tape->avg_size += blocks * tape->blk_size;
-       tape->insert_size += blocks * tape->blk_size;
-       if (tape->insert_size > 1024 * 1024)
-               tape->measure_insert_time = 1;
-       if (tape->measure_insert_time) {
-               tape->measure_insert_time = 0;
-               tape->insert_time = jiffies;
-               tape->insert_size = 0;
-       }
-       if (time_after(jiffies, tape->insert_time))
-               tape->insert_speed = tape->insert_size / 1024 * HZ /
-                                       (jiffies - tape->insert_time);
+
        if (time_after_eq(jiffies, tape->avg_time + HZ)) {
                tape->avg_speed = tape->avg_size * HZ /
                                (jiffies - tape->avg_time) / 1024;
@@ -1502,47 +1151,49 @@ static ide_startstop_t idetape_rw_callback(ide_drive_t *drive)
        return ide_stopped;
 }
 
-static void idetape_create_read_cmd(idetape_tape_t *tape, idetape_pc_t *pc,
+static void idetape_create_read_cmd(idetape_tape_t *tape,
+               struct ide_atapi_pc *pc,
                unsigned int length, struct idetape_bh *bh)
 {
        idetape_init_pc(pc);
        pc->c[0] = READ_6;
        put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
        pc->c[1] = 1;
-       pc->callback = &idetape_rw_callback;
+       pc->idetape_callback = &idetape_rw_callback;
        pc->bh = bh;
        atomic_set(&bh->b_count, 0);
-       pc->buffer = NULL;
-       pc->buffer_size = length * tape->blk_size;
-       pc->request_transfer = pc->buffer_size;
-       if (pc->request_transfer == tape->stage_size)
-               set_bit(PC_DMA_RECOMMENDED, &pc->flags);
+       pc->buf = NULL;
+       pc->buf_size = length * tape->blk_size;
+       pc->req_xfer = pc->buf_size;
+       if (pc->req_xfer == tape->buffer_size)
+               pc->flags |= PC_FLAG_DMA_RECOMMENDED;
 }
 
-static void idetape_create_write_cmd(idetape_tape_t *tape, idetape_pc_t *pc,
+static void idetape_create_write_cmd(idetape_tape_t *tape,
+               struct ide_atapi_pc *pc,
                unsigned int length, struct idetape_bh *bh)
 {
        idetape_init_pc(pc);
        pc->c[0] = WRITE_6;
        put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
        pc->c[1] = 1;
-       pc->callback = &idetape_rw_callback;
-       set_bit(PC_WRITING, &pc->flags);
+       pc->idetape_callback = &idetape_rw_callback;
+       pc->flags |= PC_FLAG_WRITING;
        pc->bh = bh;
        pc->b_data = bh->b_data;
        pc->b_count = atomic_read(&bh->b_count);
-       pc->buffer = NULL;
-       pc->buffer_size = length * tape->blk_size;
-       pc->request_transfer = pc->buffer_size;
-       if (pc->request_transfer == tape->stage_size)
-               set_bit(PC_DMA_RECOMMENDED, &pc->flags);
+       pc->buf = NULL;
+       pc->buf_size = length * tape->blk_size;
+       pc->req_xfer = pc->buf_size;
+       if (pc->req_xfer == tape->buffer_size)
+               pc->flags |= PC_FLAG_DMA_RECOMMENDED;
 }
 
 static ide_startstop_t idetape_do_request(ide_drive_t *drive,
                                          struct request *rq, sector_t block)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t *pc = NULL;
+       struct ide_atapi_pc *pc = NULL;
        struct request *postponed_rq = tape->postponed_rq;
        u8 stat;
 
@@ -1579,18 +1230,14 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
        stat = ide_read_status(drive);
 
        if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2))
-               set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
+               set_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags);
 
        if (drive->post_reset == 1) {
-               set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
+               set_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags);
                drive->post_reset = 0;
        }
 
-       if (time_after(jiffies, tape->insert_time))
-               tape->insert_speed = tape->insert_size / 1024 * HZ /
-                                       (jiffies - tape->insert_time);
-       idetape_calculate_speeds(drive);
-       if (!test_and_clear_bit(IDETAPE_IGNORE_DSC, &tape->flags) &&
+       if (!test_and_clear_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags) &&
            (stat & SEEK_STAT) == 0) {
                if (postponed_rq == NULL) {
                        tape->dsc_polling_start = jiffies;
@@ -1613,23 +1260,19 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
                return ide_stopped;
        }
        if (rq->cmd[0] & REQ_IDETAPE_READ) {
-               tape->buffer_head++;
-               tape->postpone_cnt = 0;
                pc = idetape_next_pc_storage(drive);
                idetape_create_read_cmd(tape, pc, rq->current_nr_sectors,
                                        (struct idetape_bh *)rq->special);
                goto out;
        }
        if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
-               tape->buffer_head++;
-               tape->postpone_cnt = 0;
                pc = idetape_next_pc_storage(drive);
                idetape_create_write_cmd(tape, pc, rq->current_nr_sectors,
                                         (struct idetape_bh *)rq->special);
                goto out;
        }
        if (rq->cmd[0] & REQ_IDETAPE_PC1) {
-               pc = (idetape_pc_t *) rq->buffer;
+               pc = (struct ide_atapi_pc *) rq->buffer;
                rq->cmd[0] &= ~(REQ_IDETAPE_PC1);
                rq->cmd[0] |= REQ_IDETAPE_PC2;
                goto out;
@@ -1643,111 +1286,91 @@ out:
        return idetape_issue_pc(drive, pc);
 }
 
-/* Pipeline related functions */
-static inline int idetape_pipeline_active(idetape_tape_t *tape)
-{
-       int rc1, rc2;
-
-       rc1 = test_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
-       rc2 = (tape->active_data_rq != NULL);
-       return rc1;
-}
-
 /*
- * The function below uses __get_free_page to allocate a pipeline stage, along
- * with all the necessary small buffers which together make a buffer of size
- * tape->stage_size (or a bit more). We attempt to combine sequential pages as
+ * The function below uses __get_free_pages to allocate a data buffer of size
+ * tape->buffer_size (or a bit more). We attempt to combine sequential pages as
  * much as possible.
  *
- * It returns a pointer to the new allocated stage, or NULL if we can't (or
- * don't want to) allocate a stage.
- *
- * Pipeline stages are optional and are used to increase performance. If we
- * can't allocate them, we'll manage without them.
+ * It returns a pointer to the newly allocated buffer, or NULL in case of
+ * failure.
  */
-static idetape_stage_t *__idetape_kmalloc_stage(idetape_tape_t *tape, int full,
-                                               int clear)
+static struct idetape_bh *ide_tape_kmalloc_buffer(idetape_tape_t *tape,
+                                                 int full, int clear)
 {
-       idetape_stage_t *stage;
-       struct idetape_bh *prev_bh, *bh;
-       int pages = tape->pages_per_stage;
+       struct idetape_bh *prev_bh, *bh, *merge_bh;
+       int pages = tape->pages_per_buffer;
+       unsigned int order, b_allocd;
        char *b_data = NULL;
 
-       stage = kmalloc(sizeof(idetape_stage_t), GFP_KERNEL);
-       if (!stage)
-               return NULL;
-       stage->next = NULL;
-
-       stage->bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
-       bh = stage->bh;
+       merge_bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
+       bh = merge_bh;
        if (bh == NULL)
                goto abort;
-       bh->b_reqnext = NULL;
-       bh->b_data = (char *) __get_free_page(GFP_KERNEL);
+
+       order = fls(pages) - 1;
+       bh->b_data = (char *) __get_free_pages(GFP_KERNEL, order);
        if (!bh->b_data)
                goto abort;
+       b_allocd = (1 << order) * PAGE_SIZE;
+       pages &= (order-1);
+
        if (clear)
-               memset(bh->b_data, 0, PAGE_SIZE);
-       bh->b_size = PAGE_SIZE;
+               memset(bh->b_data, 0, b_allocd);
+       bh->b_reqnext = NULL;
+       bh->b_size = b_allocd;
        atomic_set(&bh->b_count, full ? bh->b_size : 0);
 
-       while (--pages) {
-               b_data = (char *) __get_free_page(GFP_KERNEL);
+       while (pages) {
+               order = fls(pages) - 1;
+               b_data = (char *) __get_free_pages(GFP_KERNEL, order);
                if (!b_data)
                        goto abort;
+               b_allocd = (1 << order) * PAGE_SIZE;
+
                if (clear)
-                       memset(b_data, 0, PAGE_SIZE);
-               if (bh->b_data == b_data + PAGE_SIZE) {
-                       bh->b_size += PAGE_SIZE;
-                       bh->b_data -= PAGE_SIZE;
+                       memset(b_data, 0, b_allocd);
+
+               /* newly allocated page frames below buffer header or ...*/
+               if (bh->b_data == b_data + b_allocd) {
+                       bh->b_size += b_allocd;
+                       bh->b_data -= b_allocd;
                        if (full)
-                               atomic_add(PAGE_SIZE, &bh->b_count);
+                               atomic_add(b_allocd, &bh->b_count);
                        continue;
                }
+               /* they are above the header */
                if (b_data == bh->b_data + bh->b_size) {
-                       bh->b_size += PAGE_SIZE;
+                       bh->b_size += b_allocd;
                        if (full)
-                               atomic_add(PAGE_SIZE, &bh->b_count);
+                               atomic_add(b_allocd, &bh->b_count);
                        continue;
                }
                prev_bh = bh;
                bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
                if (!bh) {
-                       free_page((unsigned long) b_data);
+                       free_pages((unsigned long) b_data, order);
                        goto abort;
                }
                bh->b_reqnext = NULL;
                bh->b_data = b_data;
-               bh->b_size = PAGE_SIZE;
+               bh->b_size = b_allocd;
                atomic_set(&bh->b_count, full ? bh->b_size : 0);
                prev_bh->b_reqnext = bh;
+
+               pages &= (order-1);
        }
+
        bh->b_size -= tape->excess_bh_size;
        if (full)
                atomic_sub(tape->excess_bh_size, &bh->b_count);
-       return stage;
+       return merge_bh;
 abort:
-       __idetape_kfree_stage(stage);
+       ide_tape_kfree_buffer(tape);
        return NULL;
 }
 
-static idetape_stage_t *idetape_kmalloc_stage(idetape_tape_t *tape)
-{
-       idetape_stage_t *cache_stage = tape->cache_stage;
-
-       debug_log(DBG_PROCS, "Enter %s\n", __func__);
-
-       if (tape->nr_stages >= tape->max_stages)
-               return NULL;
-       if (cache_stage != NULL) {
-               tape->cache_stage = NULL;
-               return cache_stage;
-       }
-       return __idetape_kmalloc_stage(tape, 0, 0);
-}
-
 static int idetape_copy_stage_from_user(idetape_tape_t *tape,
-               idetape_stage_t *stage, const char __user *buf, int n)
+                                       const char __user *buf, int n)
 {
        struct idetape_bh *bh = tape->bh;
        int count;
@@ -1779,7 +1402,7 @@ static int idetape_copy_stage_from_user(idetape_tape_t *tape,
 }
 
 static int idetape_copy_stage_to_user(idetape_tape_t *tape, char __user *buf,
-               idetape_stage_t *stage, int n)
+                                     int n)
 {
        struct idetape_bh *bh = tape->bh;
        int count;
@@ -1810,11 +1433,11 @@ static int idetape_copy_stage_to_user(idetape_tape_t *tape, char __user *buf,
        return ret;
 }
 
-static void idetape_init_merge_stage(idetape_tape_t *tape)
+static void idetape_init_merge_buffer(idetape_tape_t *tape)
 {
-       struct idetape_bh *bh = tape->merge_stage->bh;
+       struct idetape_bh *bh = tape->merge_bh;
+       tape->bh = tape->merge_bh;
 
-       tape->bh = bh;
        if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
                atomic_set(&bh->b_count, 0);
        else {
@@ -1823,65 +1446,10 @@ static void idetape_init_merge_stage(idetape_tape_t *tape)
        }
 }
 
-static void idetape_switch_buffers(idetape_tape_t *tape, idetape_stage_t *stage)
-{
-       struct idetape_bh *tmp;
-
-       tmp = stage->bh;
-       stage->bh = tape->merge_stage->bh;
-       tape->merge_stage->bh = tmp;
-       idetape_init_merge_stage(tape);
-}
-
-/* Add a new stage at the end of the pipeline. */
-static void idetape_add_stage_tail(ide_drive_t *drive, idetape_stage_t *stage)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       unsigned long flags;
-
-       debug_log(DBG_PROCS, "Enter %s\n", __func__);
-
-       spin_lock_irqsave(&tape->lock, flags);
-       stage->next = NULL;
-       if (tape->last_stage != NULL)
-               tape->last_stage->next = stage;
-       else
-               tape->first_stage = stage;
-               tape->next_stage  = stage;
-       tape->last_stage = stage;
-       if (tape->next_stage == NULL)
-               tape->next_stage = tape->last_stage;
-       tape->nr_stages++;
-       tape->nr_pending_stages++;
-       spin_unlock_irqrestore(&tape->lock, flags);
-}
-
-/* Install a completion in a pending request and sleep until it is serviced. The
- * caller should ensure that the request will not be serviced before we install
- * the completion (usually by disabling interrupts).
- */
-static void idetape_wait_for_request(ide_drive_t *drive, struct request *rq)
-{
-       DECLARE_COMPLETION_ONSTACK(wait);
-       idetape_tape_t *tape = drive->driver_data;
-
-       if (rq == NULL || !blk_special_request(rq)) {
-               printk(KERN_ERR "ide-tape: bug: Trying to sleep on non-valid"
-                                " request\n");
-               return;
-       }
-       rq->end_io_data = &wait;
-       rq->end_io = blk_end_sync_rq;
-       spin_unlock_irq(&tape->lock);
-       wait_for_completion(&wait);
-       /* The stage and its struct request have been deallocated */
-       spin_lock_irq(&tape->lock);
-}
-
 static ide_startstop_t idetape_read_position_callback(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       u8 *readpos = tape->pc->buffer;
+       u8 *readpos = tape->pc->buf;
 
        debug_log(DBG_PROCS, "Enter %s\n", __func__);
 
@@ -1894,7 +1462,7 @@ static ide_startstop_t idetape_read_position_callback(ide_drive_t *drive)
                if (readpos[0] & 0x4) {
                        printk(KERN_INFO "ide-tape: Block location is unknown"
                                         "to the tape\n");
-                       clear_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
+                       clear_bit(IDETAPE_FLAG_ADDRESS_VALID, &tape->flags);
                        idetape_end_request(drive, 0, 0);
                } else {
                        debug_log(DBG_SENSE, "Block Location - %u\n",
@@ -1903,7 +1471,7 @@ static ide_startstop_t idetape_read_position_callback(ide_drive_t *drive)
                        tape->partition = readpos[1];
                        tape->first_frame =
                                be32_to_cpu(*(u32 *)&readpos[4]);
-                       set_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
+                       set_bit(IDETAPE_FLAG_ADDRESS_VALID, &tape->flags);
                        idetape_end_request(drive, 1, 0);
                }
        } else {
@@ -1917,20 +1485,20 @@ static ide_startstop_t idetape_read_position_callback(ide_drive_t *drive)
  * writing a filemark otherwise.
  */
 static void idetape_create_write_filemark_cmd(ide_drive_t *drive,
-               idetape_pc_t *pc, int write_filemark)
+               struct ide_atapi_pc *pc, int write_filemark)
 {
        idetape_init_pc(pc);
        pc->c[0] = WRITE_FILEMARKS;
        pc->c[4] = write_filemark;
-       set_bit(PC_WAIT_FOR_DSC, &pc->flags);
-       pc->callback = &idetape_pc_callback;
+       pc->flags |= PC_FLAG_WAIT_FOR_DSC;
+       pc->idetape_callback = &idetape_pc_callback;
 }
 
-static void idetape_create_test_unit_ready_cmd(idetape_pc_t *pc)
+static void idetape_create_test_unit_ready_cmd(struct ide_atapi_pc *pc)
 {
        idetape_init_pc(pc);
        pc->c[0] = TEST_UNIT_READY;
-       pc->callback = &idetape_pc_callback;
+       pc->idetape_callback = &idetape_pc_callback;
 }
 
 /*
@@ -1946,7 +1514,7 @@ static void idetape_create_test_unit_ready_cmd(idetape_pc_t *pc)
  * to the request list without waiting for it to be serviced! In that case, we
  * usually use idetape_queue_pc_head().
  */
-static int __idetape_queue_pc_tail(ide_drive_t *drive, idetape_pc_t *pc)
+static int idetape_queue_pc_tail(ide_drive_t *drive, struct ide_atapi_pc *pc)
 {
        struct ide_tape_obj *tape = drive->driver_data;
        struct request rq;
@@ -1957,28 +1525,28 @@ static int __idetape_queue_pc_tail(ide_drive_t *drive, idetape_pc_t *pc)
        return ide_do_drive_cmd(drive, &rq, ide_wait);
 }
 
-static void idetape_create_load_unload_cmd(ide_drive_t *drive, idetape_pc_t *pc,
-               int cmd)
+static void idetape_create_load_unload_cmd(ide_drive_t *drive,
+               struct ide_atapi_pc *pc, int cmd)
 {
        idetape_init_pc(pc);
        pc->c[0] = START_STOP;
        pc->c[4] = cmd;
-       set_bit(PC_WAIT_FOR_DSC, &pc->flags);
-       pc->callback = &idetape_pc_callback;
+       pc->flags |= PC_FLAG_WAIT_FOR_DSC;
+       pc->idetape_callback = &idetape_pc_callback;
 }
 
 static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        int load_attempted = 0;
 
        /* Wait for the tape to become ready */
-       set_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
+       set_bit(IDETAPE_FLAG_MEDIUM_PRESENT, &tape->flags);
        timeout += jiffies;
        while (time_before(jiffies, timeout)) {
                idetape_create_test_unit_ready_cmd(&pc);
-               if (!__idetape_queue_pc_tail(drive, &pc))
+               if (!idetape_queue_pc_tail(drive, &pc))
                        return 0;
                if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
                    || (tape->asc == 0x3A)) {
@@ -1987,7 +1555,7 @@ static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
                                return -ENOMEDIUM;
                        idetape_create_load_unload_cmd(drive, &pc,
                                                        IDETAPE_LU_LOAD_MASK);
-                       __idetape_queue_pc_tail(drive, &pc);
+                       idetape_queue_pc_tail(drive, &pc);
                        load_attempted = 1;
                /* not about to be ready */
                } else if (!(tape->sense_key == 2 && tape->asc == 4 &&
@@ -1998,14 +1566,9 @@ static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
        return -EIO;
 }
 
-static int idetape_queue_pc_tail(ide_drive_t *drive, idetape_pc_t *pc)
-{
-       return __idetape_queue_pc_tail(drive, pc);
-}
-
 static int idetape_flush_tape_buffers(ide_drive_t *drive)
 {
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        int rc;
 
        idetape_create_write_filemark_cmd(drive, &pc, 0);
@@ -2016,18 +1579,18 @@ static int idetape_flush_tape_buffers(ide_drive_t *drive)
        return 0;
 }
 
-static void idetape_create_read_position_cmd(idetape_pc_t *pc)
+static void idetape_create_read_position_cmd(struct ide_atapi_pc *pc)
 {
        idetape_init_pc(pc);
        pc->c[0] = READ_POSITION;
-       pc->request_transfer = 20;
-       pc->callback = &idetape_read_position_callback;
+       pc->req_xfer = 20;
+       pc->idetape_callback = &idetape_read_position_callback;
 }
 
 static int idetape_read_position(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        int position;
 
        debug_log(DBG_PROCS, "Enter %s\n", __func__);
@@ -2039,7 +1602,8 @@ static int idetape_read_position(ide_drive_t *drive)
        return position;
 }
 
-static void idetape_create_locate_cmd(ide_drive_t *drive, idetape_pc_t *pc,
+static void idetape_create_locate_cmd(ide_drive_t *drive,
+               struct ide_atapi_pc *pc,
                unsigned int block, u8 partition, int skip)
 {
        idetape_init_pc(pc);
@@ -2047,12 +1611,12 @@ static void idetape_create_locate_cmd(ide_drive_t *drive, idetape_pc_t *pc,
        pc->c[1] = 2;
        put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
        pc->c[8] = partition;
-       set_bit(PC_WAIT_FOR_DSC, &pc->flags);
-       pc->callback = &idetape_pc_callback;
+       pc->flags |= PC_FLAG_WAIT_FOR_DSC;
+       pc->idetape_callback = &idetape_pc_callback;
 }
 
-static int idetape_create_prevent_cmd(ide_drive_t *drive, idetape_pc_t *pc,
-                                     int prevent)
+static int idetape_create_prevent_cmd(ide_drive_t *drive,
+               struct ide_atapi_pc *pc, int prevent)
 {
        idetape_tape_t *tape = drive->driver_data;
 
@@ -2063,54 +1627,25 @@ static int idetape_create_prevent_cmd(ide_drive_t *drive, idetape_pc_t *pc,
        idetape_init_pc(pc);
        pc->c[0] = ALLOW_MEDIUM_REMOVAL;
        pc->c[4] = prevent;
-       pc->callback = &idetape_pc_callback;
+       pc->idetape_callback = &idetape_pc_callback;
        return 1;
 }
 
-static int __idetape_discard_read_pipeline(ide_drive_t *drive)
+static void __ide_tape_discard_merge_buffer(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       unsigned long flags;
-       int cnt;
 
        if (tape->chrdev_dir != IDETAPE_DIR_READ)
-               return 0;
+               return;
 
-       /* Remove merge stage. */
-       cnt = tape->merge_stage_size / tape->blk_size;
-       if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
-               ++cnt;          /* Filemarks count as 1 sector */
-       tape->merge_stage_size = 0;
-       if (tape->merge_stage != NULL) {
-               __idetape_kfree_stage(tape->merge_stage);
-               tape->merge_stage = NULL;
+       clear_bit(IDETAPE_FLAG_FILEMARK, &tape->flags);
+       tape->merge_bh_size = 0;
+       if (tape->merge_bh != NULL) {
+               ide_tape_kfree_buffer(tape);
+               tape->merge_bh = NULL;
        }
 
-       /* Clear pipeline flags. */
-       clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
        tape->chrdev_dir = IDETAPE_DIR_NONE;
-
-       /* Remove pipeline stages. */
-       if (tape->first_stage == NULL)
-               return 0;
-
-       spin_lock_irqsave(&tape->lock, flags);
-       tape->next_stage = NULL;
-       if (idetape_pipeline_active(tape))
-               idetape_wait_for_request(drive, tape->active_data_rq);
-       spin_unlock_irqrestore(&tape->lock, flags);
-
-       while (tape->first_stage != NULL) {
-               struct request *rq_ptr = &tape->first_stage->rq;
-
-               cnt += rq_ptr->nr_sectors - rq_ptr->current_nr_sectors;
-               if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
-                       ++cnt;
-               idetape_remove_stage_head(drive);
-       }
-       tape->nr_pending_stages = 0;
-       tape->max_stages = tape->min_pipeline;
-       return cnt;
 }
 
 /*
@@ -2124,10 +1659,10 @@ static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
 {
        idetape_tape_t *tape = drive->driver_data;
        int retval;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
 
        if (tape->chrdev_dir == IDETAPE_DIR_READ)
-               __idetape_discard_read_pipeline(drive);
+               __ide_tape_discard_merge_buffer(drive);
        idetape_wait_ready(drive, 60 * 5 * HZ);
        idetape_create_locate_cmd(drive, &pc, block, partition, skip);
        retval = idetape_queue_pc_tail(drive, &pc);
@@ -2138,20 +1673,19 @@ static int idetape_position_tape(ide_drive_t *drive, unsigned int block,
        return (idetape_queue_pc_tail(drive, &pc));
 }
 
-static void idetape_discard_read_pipeline(ide_drive_t *drive,
+static void ide_tape_discard_merge_buffer(ide_drive_t *drive,
                                          int restore_position)
 {
        idetape_tape_t *tape = drive->driver_data;
-       int cnt;
        int seek, position;
 
-       cnt = __idetape_discard_read_pipeline(drive);
+       __ide_tape_discard_merge_buffer(drive);
        if (restore_position) {
                position = idetape_read_position(drive);
-               seek = position > cnt ? position - cnt : 0;
+               seek = position > 0 ? position : 0;
                if (idetape_position_tape(drive, seek, 0, 0)) {
                        printk(KERN_INFO "ide-tape: %s: position_tape failed in"
-                                        " discard_pipeline()\n", tape->name);
+                                        " %s\n", tape->name, __func__);
                        return;
                }
        }
@@ -2169,12 +1703,6 @@ static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks,
 
        debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);
 
-       if (idetape_pipeline_active(tape)) {
-               printk(KERN_ERR "ide-tape: bug: the pipeline is active in %s\n",
-                               __func__);
-               return (0);
-       }
-
        idetape_init_rq(&rq, cmd);
        rq.rq_disk = tape->disk;
        rq.special = (void *)bh;
@@ -2186,192 +1714,83 @@ static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks,
        if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0)
                return 0;
 
-       if (tape->merge_stage)
-               idetape_init_merge_stage(tape);
+       if (tape->merge_bh)
+               idetape_init_merge_buffer(tape);
        if (rq.errors == IDETAPE_ERROR_GENERAL)
                return -EIO;
        return (tape->blk_size * (blocks-rq.current_nr_sectors));
 }
 
-/* start servicing the pipeline stages, starting from tape->next_stage. */
-static void idetape_plug_pipeline(ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-
-       if (tape->next_stage == NULL)
-               return;
-       if (!idetape_pipeline_active(tape)) {
-               set_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
-               idetape_activate_next_stage(drive);
-               (void) ide_do_drive_cmd(drive, tape->active_data_rq, ide_end);
-       }
-}
-
-static void idetape_create_inquiry_cmd(idetape_pc_t *pc)
+static void idetape_create_inquiry_cmd(struct ide_atapi_pc *pc)
 {
        idetape_init_pc(pc);
        pc->c[0] = INQUIRY;
        pc->c[4] = 254;
-       pc->request_transfer = 254;
-       pc->callback = &idetape_pc_callback;
+       pc->req_xfer = 254;
+       pc->idetape_callback = &idetape_pc_callback;
 }
 
-static void idetape_create_rewind_cmd(ide_drive_t *drive, idetape_pc_t *pc)
+static void idetape_create_rewind_cmd(ide_drive_t *drive,
+               struct ide_atapi_pc *pc)
 {
        idetape_init_pc(pc);
        pc->c[0] = REZERO_UNIT;
-       set_bit(PC_WAIT_FOR_DSC, &pc->flags);
-       pc->callback = &idetape_pc_callback;
+       pc->flags |= PC_FLAG_WAIT_FOR_DSC;
+       pc->idetape_callback = &idetape_pc_callback;
 }
 
-static void idetape_create_erase_cmd(idetape_pc_t *pc)
+static void idetape_create_erase_cmd(struct ide_atapi_pc *pc)
 {
        idetape_init_pc(pc);
        pc->c[0] = ERASE;
        pc->c[1] = 1;
-       set_bit(PC_WAIT_FOR_DSC, &pc->flags);
-       pc->callback = &idetape_pc_callback;
+       pc->flags |= PC_FLAG_WAIT_FOR_DSC;
+       pc->idetape_callback = &idetape_pc_callback;
 }
 
-static void idetape_create_space_cmd(idetape_pc_t *pc, int count, u8 cmd)
+static void idetape_create_space_cmd(struct ide_atapi_pc *pc, int count, u8 cmd)
 {
        idetape_init_pc(pc);
        pc->c[0] = SPACE;
        put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
        pc->c[1] = cmd;
-       set_bit(PC_WAIT_FOR_DSC, &pc->flags);
-       pc->callback = &idetape_pc_callback;
+       pc->flags |= PC_FLAG_WAIT_FOR_DSC;
+       pc->idetape_callback = &idetape_pc_callback;
 }
 
-static void idetape_wait_first_stage(ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       unsigned long flags;
-
-       if (tape->first_stage == NULL)
-               return;
-       spin_lock_irqsave(&tape->lock, flags);
-       if (tape->active_stage == tape->first_stage)
-               idetape_wait_for_request(drive, tape->active_data_rq);
-       spin_unlock_irqrestore(&tape->lock, flags);
-}
-
-/*
- * Try to add a character device originated write request to our pipeline. In
- * case we don't succeed, we revert to non-pipelined operation mode for this
- * request. In order to accomplish that, we
- *
- * 1. Try to allocate a new pipeline stage.
- * 2. If we can't, wait for more and more requests to be serviced and try again
- * each time.
- * 3. If we still can't allocate a stage, fallback to non-pipelined operation
- * mode for this request.
- */
+/* Queue up a character device originated write request. */
 static int idetape_add_chrdev_write_request(ide_drive_t *drive, int blocks)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_stage_t *new_stage;
-       unsigned long flags;
-       struct request *rq;
 
        debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
 
-       /* Attempt to allocate a new stage. Beware possible race conditions. */
-       while ((new_stage = idetape_kmalloc_stage(tape)) == NULL) {
-               spin_lock_irqsave(&tape->lock, flags);
-               if (idetape_pipeline_active(tape)) {
-                       idetape_wait_for_request(drive, tape->active_data_rq);
-                       spin_unlock_irqrestore(&tape->lock, flags);
-               } else {
-                       spin_unlock_irqrestore(&tape->lock, flags);
-                       idetape_plug_pipeline(drive);
-                       if (idetape_pipeline_active(tape))
-                               continue;
-                       /*
-                        * The machine is short on memory. Fallback to non-
-                        * pipelined operation mode for this request.
-                        */
-                       return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
-                                               blocks, tape->merge_stage->bh);
-               }
-       }
-       rq = &new_stage->rq;
-       idetape_init_rq(rq, REQ_IDETAPE_WRITE);
-       /* Doesn't actually matter - We always assume sequential access */
-       rq->sector = tape->first_frame;
-       rq->current_nr_sectors = blocks;
-       rq->nr_sectors = blocks;
-
-       idetape_switch_buffers(tape, new_stage);
-       idetape_add_stage_tail(drive, new_stage);
-       tape->pipeline_head++;
-       idetape_calculate_speeds(drive);
-
-       /*
-        * Estimate whether the tape has stopped writing by checking if our
-        * write pipeline is currently empty. If we are not writing anymore,
-        * wait for the pipeline to be almost completely full (90%) before
-        * starting to service requests, so that we will be able to keep up with
-        * the higher speeds of the tape.
-        */
-       if (!idetape_pipeline_active(tape)) {
-               if (tape->nr_stages >= tape->max_stages * 9 / 10 ||
-                       tape->nr_stages >= tape->max_stages -
-                       tape->uncontrolled_pipeline_head_speed * 3 * 1024 /
-                       tape->blk_size) {
-                       tape->measure_insert_time = 1;
-                       tape->insert_time = jiffies;
-                       tape->insert_size = 0;
-                       tape->insert_speed = 0;
-                       idetape_plug_pipeline(drive);
-               }
-       }
-       if (test_and_clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
-               /* Return a deferred error */
-               return -EIO;
-       return blocks;
+       return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE,
+                                    blocks, tape->merge_bh);
 }
 
-/*
- * Wait until all pending pipeline requests are serviced. Typically called on
- * device close.
- */
-static void idetape_wait_for_pipeline(ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       unsigned long flags;
-
-       while (tape->next_stage || idetape_pipeline_active(tape)) {
-               idetape_plug_pipeline(drive);
-               spin_lock_irqsave(&tape->lock, flags);
-               if (idetape_pipeline_active(tape))
-                       idetape_wait_for_request(drive, tape->active_data_rq);
-               spin_unlock_irqrestore(&tape->lock, flags);
-       }
-}
-
-static void idetape_empty_write_pipeline(ide_drive_t *drive)
+static void ide_tape_flush_merge_buffer(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
        int blocks, min;
        struct idetape_bh *bh;
 
        if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
-               printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline,"
+               printk(KERN_ERR "ide-tape: bug: Trying to empty merge buffer"
                                " but we are not writing.\n");
                return;
        }
-       if (tape->merge_stage_size > tape->stage_size) {
+       if (tape->merge_bh_size > tape->buffer_size) {
                printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n");
-               tape->merge_stage_size = tape->stage_size;
+               tape->merge_bh_size = tape->buffer_size;
        }
-       if (tape->merge_stage_size) {
-               blocks = tape->merge_stage_size / tape->blk_size;
-               if (tape->merge_stage_size % tape->blk_size) {
+       if (tape->merge_bh_size) {
+               blocks = tape->merge_bh_size / tape->blk_size;
+               if (tape->merge_bh_size % tape->blk_size) {
                        unsigned int i;
 
                        blocks++;
-                       i = tape->blk_size - tape->merge_stage_size %
+                       i = tape->blk_size - tape->merge_bh_size %
                                tape->blk_size;
                        bh = tape->bh->b_reqnext;
                        while (bh) {
@@ -2395,74 +1814,33 @@ static void idetape_empty_write_pipeline(ide_drive_t *drive)
                        }
                }
                (void) idetape_add_chrdev_write_request(drive, blocks);
-               tape->merge_stage_size = 0;
+               tape->merge_bh_size = 0;
        }
-       idetape_wait_for_pipeline(drive);
-       if (tape->merge_stage != NULL) {
-               __idetape_kfree_stage(tape->merge_stage);
-               tape->merge_stage = NULL;
+       if (tape->merge_bh != NULL) {
+               ide_tape_kfree_buffer(tape);
+               tape->merge_bh = NULL;
        }
-       clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
        tape->chrdev_dir = IDETAPE_DIR_NONE;
-
-       /*
-        * On the next backup, perform the feedback loop again. (I don't want to
-        * keep sense information between backups, as some systems are
-        * constantly on, and the system load can be totally different on the
-        * next backup).
-        */
-       tape->max_stages = tape->min_pipeline;
-       if (tape->first_stage != NULL ||
-           tape->next_stage != NULL ||
-           tape->last_stage != NULL ||
-           tape->nr_stages != 0) {
-               printk(KERN_ERR "ide-tape: ide-tape pipeline bug, "
-                       "first_stage %p, next_stage %p, "
-                       "last_stage %p, nr_stages %d\n",
-                       tape->first_stage, tape->next_stage,
-                       tape->last_stage, tape->nr_stages);
-       }
 }
 
-static void idetape_restart_speed_control(ide_drive_t *drive)
+static int idetape_init_read(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-
-       tape->restart_speed_control_req = 0;
-       tape->pipeline_head = 0;
-       tape->controlled_last_pipeline_head = 0;
-       tape->controlled_previous_pipeline_head = 0;
-       tape->uncontrolled_previous_pipeline_head = 0;
-       tape->controlled_pipeline_head_speed = 5000;
-       tape->pipeline_head_speed = 5000;
-       tape->uncontrolled_pipeline_head_speed = 0;
-       tape->controlled_pipeline_head_time =
-               tape->uncontrolled_pipeline_head_time = jiffies;
-       tape->controlled_previous_head_time =
-               tape->uncontrolled_previous_head_time = jiffies;
-}
-
-static int idetape_init_read(ide_drive_t *drive, int max_stages)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       idetape_stage_t *new_stage;
-       struct request rq;
        int bytes_read;
-       u16 blocks = *(u16 *)&tape->caps[12];
 
        /* Initialize read operation */
        if (tape->chrdev_dir != IDETAPE_DIR_READ) {
                if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
-                       idetape_empty_write_pipeline(drive);
+                       ide_tape_flush_merge_buffer(drive);
                        idetape_flush_tape_buffers(drive);
                }
-               if (tape->merge_stage || tape->merge_stage_size) {
-                       printk(KERN_ERR "ide-tape: merge_stage_size should be"
+               if (tape->merge_bh || tape->merge_bh_size) {
+                       printk(KERN_ERR "ide-tape: merge_bh_size should be"
                                         " 0 now\n");
-                       tape->merge_stage_size = 0;
+                       tape->merge_bh_size = 0;
                }
-               tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0);
-               if (!tape->merge_stage)
+               tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0);
+               if (!tape->merge_bh)
                        return -ENOMEM;
                tape->chrdev_dir = IDETAPE_DIR_READ;
 
@@ -2475,94 +1853,34 @@ static int idetape_init_read(ide_drive_t *drive, int max_stages)
                if (drive->dsc_overlap) {
                        bytes_read = idetape_queue_rw_tail(drive,
                                                        REQ_IDETAPE_READ, 0,
-                                                       tape->merge_stage->bh);
+                                                       tape->merge_bh);
                        if (bytes_read < 0) {
-                               __idetape_kfree_stage(tape->merge_stage);
-                               tape->merge_stage = NULL;
+                               ide_tape_kfree_buffer(tape);
+                               tape->merge_bh = NULL;
                                tape->chrdev_dir = IDETAPE_DIR_NONE;
                                return bytes_read;
                        }
                }
        }
-       if (tape->restart_speed_control_req)
-               idetape_restart_speed_control(drive);
-       idetape_init_rq(&rq, REQ_IDETAPE_READ);
-       rq.sector = tape->first_frame;
-       rq.nr_sectors = blocks;
-       rq.current_nr_sectors = blocks;
-       if (!test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags) &&
-           tape->nr_stages < max_stages) {
-               new_stage = idetape_kmalloc_stage(tape);
-               while (new_stage != NULL) {
-                       new_stage->rq = rq;
-                       idetape_add_stage_tail(drive, new_stage);
-                       if (tape->nr_stages >= max_stages)
-                               break;
-                       new_stage = idetape_kmalloc_stage(tape);
-               }
-       }
-       if (!idetape_pipeline_active(tape)) {
-               if (tape->nr_pending_stages >= 3 * max_stages / 4) {
-                       tape->measure_insert_time = 1;
-                       tape->insert_time = jiffies;
-                       tape->insert_size = 0;
-                       tape->insert_speed = 0;
-                       idetape_plug_pipeline(drive);
-               }
-       }
+
        return 0;
 }
 
-/*
- * Called from idetape_chrdev_read() to service a character device read request
- * and add read-ahead requests to our pipeline.
- */
+/* called from idetape_chrdev_read() to service a chrdev read request. */
 static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks)
 {
        idetape_tape_t *tape = drive->driver_data;
-       unsigned long flags;
-       struct request *rq_ptr;
-       int bytes_read;
 
        debug_log(DBG_PROCS, "Enter %s, %d blocks\n", __func__, blocks);
 
        /* If we are at a filemark, return a read length of 0 */
-       if (test_bit(IDETAPE_FILEMARK, &tape->flags))
+       if (test_bit(IDETAPE_FLAG_FILEMARK, &tape->flags))
                return 0;
 
-       /* Wait for the next block to reach the head of the pipeline. */
-       idetape_init_read(drive, tape->max_stages);
-       if (tape->first_stage == NULL) {
-               if (test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
-                       return 0;
-               return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks,
-                                       tape->merge_stage->bh);
-       }
-       idetape_wait_first_stage(drive);
-       rq_ptr = &tape->first_stage->rq;
-       bytes_read = tape->blk_size * (rq_ptr->nr_sectors -
-                                       rq_ptr->current_nr_sectors);
-       rq_ptr->nr_sectors = 0;
-       rq_ptr->current_nr_sectors = 0;
+       idetape_init_read(drive);
 
-       if (rq_ptr->errors == IDETAPE_ERROR_EOD)
-               return 0;
-       else {
-               idetape_switch_buffers(tape, tape->first_stage);
-               if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
-                       set_bit(IDETAPE_FILEMARK, &tape->flags);
-               spin_lock_irqsave(&tape->lock, flags);
-               idetape_remove_stage_head(drive);
-               spin_unlock_irqrestore(&tape->lock, flags);
-               tape->pipeline_head++;
-               idetape_calculate_speeds(drive);
-       }
-       if (bytes_read > blocks * tape->blk_size) {
-               printk(KERN_ERR "ide-tape: bug: trying to return more bytes"
-                               " than requested\n");
-               bytes_read = blocks * tape->blk_size;
-       }
-       return (bytes_read);
+       return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks,
+                                    tape->merge_bh);
 }
 
 static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
@@ -2574,8 +1892,8 @@ static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
        while (bcount) {
                unsigned int count;
 
-               bh = tape->merge_stage->bh;
-               count = min(tape->stage_size, bcount);
+               bh = tape->merge_bh;
+               count = min(tape->buffer_size, bcount);
                bcount -= count;
                blocks = count / tape->blk_size;
                while (count) {
@@ -2586,31 +1904,10 @@ static void idetape_pad_zeros(ide_drive_t *drive, int bcount)
                        bh = bh->b_reqnext;
                }
                idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks,
-                                     tape->merge_stage->bh);
+                                     tape->merge_bh);
        }
 }
 
-static int idetape_pipeline_size(ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-       idetape_stage_t *stage;
-       struct request *rq;
-       int size = 0;
-
-       idetape_wait_for_pipeline(drive);
-       stage = tape->first_stage;
-       while (stage != NULL) {
-               rq = &stage->rq;
-               size += tape->blk_size * (rq->nr_sectors -
-                               rq->current_nr_sectors);
-               if (rq->errors == IDETAPE_ERROR_FILEMARK)
-                       size += tape->blk_size;
-               stage = stage->next;
-       }
-       size += tape->merge_stage_size;
-       return size;
-}
-
 /*
  * Rewinds the tape to the Beginning Of the current Partition (BOP). We
  * currently support only one partition.
@@ -2618,7 +1915,7 @@ static int idetape_pipeline_size(ide_drive_t *drive)
 static int idetape_rewind_tape(ide_drive_t *drive)
 {
        int retval;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        idetape_tape_t *tape;
        tape = drive->driver_data;
 
@@ -2656,11 +1953,10 @@ static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
                if (copy_from_user(&config, argp, sizeof(config)))
                        return -EFAULT;
                tape->best_dsc_rw_freq = config.dsc_rw_frequency;
-               tape->max_stages = config.nr_stages;
                break;
        case 0x0350:
                config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
-               config.nr_stages = tape->max_stages;
+               config.nr_stages = 1;
                if (copy_to_user(argp, &config, sizeof(config)))
                        return -EFAULT;
                break;
@@ -2670,19 +1966,11 @@ static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
        return 0;
 }
 
-/*
- * The function below is now a bit more complicated than just passing the
- * command to the tape since we may have crossed some filemarks during our
- * pipelined read-ahead mode. As a minor side effect, the pipeline enables us to
- * support MTFSFM when the filemark is in our internal pipeline even if the tape
- * doesn't support spacing over filemarks in the reverse direction.
- */
 static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
                                        int mt_count)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
-       unsigned long flags;
+       struct ide_atapi_pc pc;
        int retval, count = 0;
        int sprev = !!(tape->caps[4] & 0x20);
 
@@ -2695,47 +1983,12 @@ static int idetape_space_over_filemarks(ide_drive_t *drive, short mt_op,
        }
 
        if (tape->chrdev_dir == IDETAPE_DIR_READ) {
-               /* its a read-ahead buffer, scan it for crossed filemarks. */
-               tape->merge_stage_size = 0;
-               if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
+               tape->merge_bh_size = 0;
+               if (test_and_clear_bit(IDETAPE_FLAG_FILEMARK, &tape->flags))
                        ++count;
-               while (tape->first_stage != NULL) {
-                       if (count == mt_count) {
-                               if (mt_op == MTFSFM)
-                                       set_bit(IDETAPE_FILEMARK, &tape->flags);
-                               return 0;
-                       }
-                       spin_lock_irqsave(&tape->lock, flags);
-                       if (tape->first_stage == tape->active_stage) {
-                               /*
-                                * We have reached the active stage in the read
-                                * pipeline. There is no point in allowing the
-                                * drive to continue reading any farther, so we
-                                * stop the pipeline.
-                                *
-                                * This section should be moved to a separate
-                                * subroutine because similar operations are
-                                * done in __idetape_discard_read_pipeline(),
-                                * for example.
-                                */
-                               tape->next_stage = NULL;
-                               spin_unlock_irqrestore(&tape->lock, flags);
-                               idetape_wait_first_stage(drive);
-                               tape->next_stage = tape->first_stage->next;
-                       } else
-                               spin_unlock_irqrestore(&tape->lock, flags);
-                       if (tape->first_stage->rq.errors ==
-                                       IDETAPE_ERROR_FILEMARK)
-                               ++count;
-                       idetape_remove_stage_head(drive);
-               }
-               idetape_discard_read_pipeline(drive, 0);
+               ide_tape_discard_merge_buffer(drive, 0);
        }
 
-       /*
-        * The filemark was not found in our internal pipeline; now we can issue
-        * the space command.
-        */
        switch (mt_op) {
        case MTFSF:
        case MTBSF:
@@ -2786,32 +2039,30 @@ static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
        debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
 
        if (tape->chrdev_dir != IDETAPE_DIR_READ) {
-               if (test_bit(IDETAPE_DETECT_BS, &tape->flags))
+               if (test_bit(IDETAPE_FLAG_DETECT_BS, &tape->flags))
                        if (count > tape->blk_size &&
                            (count % tape->blk_size) == 0)
                                tape->user_bs_factor = count / tape->blk_size;
        }
-       rc = idetape_init_read(drive, tape->max_stages);
+       rc = idetape_init_read(drive);
        if (rc < 0)
                return rc;
        if (count == 0)
                return (0);
-       if (tape->merge_stage_size) {
-               actually_read = min((unsigned int)(tape->merge_stage_size),
+       if (tape->merge_bh_size) {
+               actually_read = min((unsigned int)(tape->merge_bh_size),
                                    (unsigned int)count);
-               if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage,
-                                              actually_read))
+               if (idetape_copy_stage_to_user(tape, buf, actually_read))
                        ret = -EFAULT;
                buf += actually_read;
-               tape->merge_stage_size -= actually_read;
+               tape->merge_bh_size -= actually_read;
                count -= actually_read;
        }
-       while (count >= tape->stage_size) {
+       while (count >= tape->buffer_size) {
                bytes_read = idetape_add_chrdev_read_request(drive, ctl);
                if (bytes_read <= 0)
                        goto finish;
-               if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage,
-                                              bytes_read))
+               if (idetape_copy_stage_to_user(tape, buf, bytes_read))
                        ret = -EFAULT;
                buf += bytes_read;
                count -= bytes_read;
@@ -2822,14 +2073,13 @@ static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
                if (bytes_read <= 0)
                        goto finish;
                temp = min((unsigned long)count, (unsigned long)bytes_read);
-               if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage,
-                                              temp))
+               if (idetape_copy_stage_to_user(tape, buf, temp))
                        ret = -EFAULT;
                actually_read += temp;
-               tape->merge_stage_size = bytes_read-temp;
+               tape->merge_bh_size = bytes_read-temp;
        }
 finish:
-       if (!actually_read && test_bit(IDETAPE_FILEMARK, &tape->flags)) {
+       if (!actually_read && test_bit(IDETAPE_FLAG_FILEMARK, &tape->flags)) {
                debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);
 
                idetape_space_over_filemarks(drive, MTFSF, 1);
@@ -2857,17 +2107,17 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
        /* Initialize write operation */
        if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
                if (tape->chrdev_dir == IDETAPE_DIR_READ)
-                       idetape_discard_read_pipeline(drive, 1);
-               if (tape->merge_stage || tape->merge_stage_size) {
-                       printk(KERN_ERR "ide-tape: merge_stage_size "
+                       ide_tape_discard_merge_buffer(drive, 1);
+               if (tape->merge_bh || tape->merge_bh_size) {
+                       printk(KERN_ERR "ide-tape: merge_bh_size "
                                "should be 0 now\n");
-                       tape->merge_stage_size = 0;
+                       tape->merge_bh_size = 0;
                }
-               tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0);
-               if (!tape->merge_stage)
+               tape->merge_bh = ide_tape_kmalloc_buffer(tape, 0, 0);
+               if (!tape->merge_bh)
                        return -ENOMEM;
                tape->chrdev_dir = IDETAPE_DIR_WRITE;
-               idetape_init_merge_stage(tape);
+               idetape_init_merge_buffer(tape);
 
                /*
                 * Issue a write 0 command to ensure that DSC handshake is
@@ -2878,10 +2128,10 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
                if (drive->dsc_overlap) {
                        ssize_t retval = idetape_queue_rw_tail(drive,
                                                        REQ_IDETAPE_WRITE, 0,
-                                                       tape->merge_stage->bh);
+                                                       tape->merge_bh);
                        if (retval < 0) {
-                               __idetape_kfree_stage(tape->merge_stage);
-                               tape->merge_stage = NULL;
+                               ide_tape_kfree_buffer(tape);
+                               tape->merge_bh = NULL;
                                tape->chrdev_dir = IDETAPE_DIR_NONE;
                                return retval;
                        }
@@ -2889,56 +2139,51 @@ static ssize_t idetape_chrdev_write(struct file *file, const char __user *buf,
        }
        if (count == 0)
                return (0);
-       if (tape->restart_speed_control_req)
-               idetape_restart_speed_control(drive);
-       if (tape->merge_stage_size) {
-               if (tape->merge_stage_size >= tape->stage_size) {
+       if (tape->merge_bh_size) {
+               if (tape->merge_bh_size >= tape->buffer_size) {
                        printk(KERN_ERR "ide-tape: bug: merge buf too big\n");
-                       tape->merge_stage_size = 0;
+                       tape->merge_bh_size = 0;
                }
                actually_written = min((unsigned int)
-                               (tape->stage_size - tape->merge_stage_size),
+                               (tape->buffer_size - tape->merge_bh_size),
                                (unsigned int)count);
-               if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf,
-                                                actually_written))
+               if (idetape_copy_stage_from_user(tape, buf, actually_written))
                                ret = -EFAULT;
                buf += actually_written;
-               tape->merge_stage_size += actually_written;
+               tape->merge_bh_size += actually_written;
                count -= actually_written;
 
-               if (tape->merge_stage_size == tape->stage_size) {
+               if (tape->merge_bh_size == tape->buffer_size) {
                        ssize_t retval;
-                       tape->merge_stage_size = 0;
+                       tape->merge_bh_size = 0;
                        retval = idetape_add_chrdev_write_request(drive, ctl);
                        if (retval <= 0)
                                return (retval);
                }
        }
-       while (count >= tape->stage_size) {
+       while (count >= tape->buffer_size) {
                ssize_t retval;
-               if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf,
-                                                tape->stage_size))
+               if (idetape_copy_stage_from_user(tape, buf, tape->buffer_size))
                        ret = -EFAULT;
-               buf += tape->stage_size;
-               count -= tape->stage_size;
+               buf += tape->buffer_size;
+               count -= tape->buffer_size;
                retval = idetape_add_chrdev_write_request(drive, ctl);
-               actually_written += tape->stage_size;
+               actually_written += tape->buffer_size;
                if (retval <= 0)
                        return (retval);
        }
        if (count) {
                actually_written += count;
-               if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf,
-                                                count))
+               if (idetape_copy_stage_from_user(tape, buf, count))
                        ret = -EFAULT;
-               tape->merge_stage_size += count;
+               tape->merge_bh_size += count;
        }
        return ret ? ret : actually_written;
 }
 
 static int idetape_write_filemark(ide_drive_t *drive)
 {
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
 
        /* Write a filemark */
        idetape_create_write_filemark_cmd(drive, &pc, 1);
@@ -2955,8 +2200,7 @@ static int idetape_write_filemark(ide_drive_t *drive)
  *
  * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
  * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
- * usually not supported (it is supported in the rare case in which we crossed
- * the filemark during our read-ahead pipelined operation mode).
+ * usually not supported.
  *
  * The following commands are currently not supported:
  *
@@ -2966,13 +2210,12 @@ static int idetape_write_filemark(ide_drive_t *drive)
 static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        int i, retval;
 
        debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
                        mt_op, mt_count);
 
-       /* Commands which need our pipelined read-ahead stages. */
        switch (mt_op) {
        case MTFSF:
        case MTFSFM:
@@ -2989,7 +2232,7 @@ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
        case MTWEOF:
                if (tape->write_prot)
                        return -EACCES;
-               idetape_discard_read_pipeline(drive, 1);
+               ide_tape_discard_merge_buffer(drive, 1);
                for (i = 0; i < mt_count; i++) {
                        retval = idetape_write_filemark(drive);
                        if (retval)
@@ -2997,12 +2240,12 @@ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
                }
                return 0;
        case MTREW:
-               idetape_discard_read_pipeline(drive, 0);
+               ide_tape_discard_merge_buffer(drive, 0);
                if (idetape_rewind_tape(drive))
                        return -EIO;
                return 0;
        case MTLOAD:
-               idetape_discard_read_pipeline(drive, 0);
+               ide_tape_discard_merge_buffer(drive, 0);
                idetape_create_load_unload_cmd(drive, &pc,
                                               IDETAPE_LU_LOAD_MASK);
                return idetape_queue_pc_tail(drive, &pc);
@@ -3017,18 +2260,18 @@ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
                                if (!idetape_queue_pc_tail(drive, &pc))
                                        tape->door_locked = DOOR_UNLOCKED;
                }
-               idetape_discard_read_pipeline(drive, 0);
+               ide_tape_discard_merge_buffer(drive, 0);
                idetape_create_load_unload_cmd(drive, &pc,
                                              !IDETAPE_LU_LOAD_MASK);
                retval = idetape_queue_pc_tail(drive, &pc);
                if (!retval)
-                       clear_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
+                       clear_bit(IDETAPE_FLAG_MEDIUM_PRESENT, &tape->flags);
                return retval;
        case MTNOP:
-               idetape_discard_read_pipeline(drive, 0);
+               ide_tape_discard_merge_buffer(drive, 0);
                return idetape_flush_tape_buffers(drive);
        case MTRETEN:
-               idetape_discard_read_pipeline(drive, 0);
+               ide_tape_discard_merge_buffer(drive, 0);
                idetape_create_load_unload_cmd(drive, &pc,
                        IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
                return idetape_queue_pc_tail(drive, &pc);
@@ -3045,16 +2288,16 @@ static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
                            mt_count % tape->blk_size)
                                return -EIO;
                        tape->user_bs_factor = mt_count / tape->blk_size;
-                       clear_bit(IDETAPE_DETECT_BS, &tape->flags);
+                       clear_bit(IDETAPE_FLAG_DETECT_BS, &tape->flags);
                } else
-                       set_bit(IDETAPE_DETECT_BS, &tape->flags);
+                       set_bit(IDETAPE_FLAG_DETECT_BS, &tape->flags);
                return 0;
        case MTSEEK:
-               idetape_discard_read_pipeline(drive, 0);
+               ide_tape_discard_merge_buffer(drive, 0);
                return idetape_position_tape(drive,
                        mt_count * tape->user_bs_factor, tape->partition, 0);
        case MTSETPART:
-               idetape_discard_read_pipeline(drive, 0);
+               ide_tape_discard_merge_buffer(drive, 0);
                return idetape_position_tape(drive, 0, mt_count, 0);
        case MTFSR:
        case MTBSR:
@@ -3099,13 +2342,12 @@ static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
 
        debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
 
-       tape->restart_speed_control_req = 1;
        if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
-               idetape_empty_write_pipeline(drive);
+               ide_tape_flush_merge_buffer(drive);
                idetape_flush_tape_buffers(drive);
        }
        if (cmd == MTIOCGET || cmd == MTIOCPOS) {
-               block_offset = idetape_pipeline_size(drive) /
+               block_offset = tape->merge_bh_size /
                        (tape->blk_size * tape->user_bs_factor);
                position = idetape_read_position(drive);
                if (position < 0)
@@ -3137,7 +2379,7 @@ static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
                return 0;
        default:
                if (tape->chrdev_dir == IDETAPE_DIR_READ)
-                       idetape_discard_read_pipeline(drive, 1);
+                       ide_tape_discard_merge_buffer(drive, 1);
                return idetape_blkdev_ioctl(drive, cmd, arg);
        }
 }
@@ -3149,7 +2391,7 @@ static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
 static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
 
        idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
        if (idetape_queue_pc_tail(drive, &pc)) {
@@ -3161,10 +2403,10 @@ static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
                }
                return;
        }
-       tape->blk_size = (pc.buffer[4 + 5] << 16) +
-                               (pc.buffer[4 + 6] << 8)  +
-                                pc.buffer[4 + 7];
-       tape->drv_write_prot = (pc.buffer[2] & 0x80) >> 7;
+       tape->blk_size = (pc.buf[4 + 5] << 16) +
+                               (pc.buf[4 + 6] << 8)  +
+                                pc.buf[4 + 7];
+       tape->drv_write_prot = (pc.buf[2] & 0x80) >> 7;
 }
 
 static int idetape_chrdev_open(struct inode *inode, struct file *filp)
@@ -3172,7 +2414,7 @@ static int idetape_chrdev_open(struct inode *inode, struct file *filp)
        unsigned int minor = iminor(inode), i = minor & ~0xc0;
        ide_drive_t *drive;
        idetape_tape_t *tape;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        int retval;
 
        if (i >= MAX_HWIFS * MAX_DRIVES)
@@ -3195,25 +2437,22 @@ static int idetape_chrdev_open(struct inode *inode, struct file *filp)
 
        filp->private_data = tape;
 
-       if (test_and_set_bit(IDETAPE_BUSY, &tape->flags)) {
+       if (test_and_set_bit(IDETAPE_FLAG_BUSY, &tape->flags)) {
                retval = -EBUSY;
                goto out_put_tape;
        }
 
        retval = idetape_wait_ready(drive, 60 * HZ);
        if (retval) {
-               clear_bit(IDETAPE_BUSY, &tape->flags);
+               clear_bit(IDETAPE_FLAG_BUSY, &tape->flags);
                printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
                goto out_put_tape;
        }
 
        idetape_read_position(drive);
-       if (!test_bit(IDETAPE_ADDRESS_VALID, &tape->flags))
+       if (!test_bit(IDETAPE_FLAG_ADDRESS_VALID, &tape->flags))
                (void)idetape_rewind_tape(drive);
 
-       if (tape->chrdev_dir != IDETAPE_DIR_READ)
-               clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
-
        /* Read block size and write protect status from drive. */
        ide_tape_get_bsize_from_bdesc(drive);
 
@@ -3227,7 +2466,7 @@ static int idetape_chrdev_open(struct inode *inode, struct file *filp)
        if (tape->write_prot) {
                if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
                    (filp->f_flags & O_ACCMODE) == O_RDWR) {
-                       clear_bit(IDETAPE_BUSY, &tape->flags);
+                       clear_bit(IDETAPE_FLAG_BUSY, &tape->flags);
                        retval = -EROFS;
                        goto out_put_tape;
                }
@@ -3242,8 +2481,6 @@ static int idetape_chrdev_open(struct inode *inode, struct file *filp)
                        }
                }
        }
-       idetape_restart_speed_control(drive);
-       tape->restart_speed_control_req = 0;
        return 0;
 
 out_put_tape:
@@ -3255,13 +2492,13 @@ static void idetape_write_release(ide_drive_t *drive, unsigned int minor)
 {
        idetape_tape_t *tape = drive->driver_data;
 
-       idetape_empty_write_pipeline(drive);
-       tape->merge_stage = __idetape_kmalloc_stage(tape, 1, 0);
-       if (tape->merge_stage != NULL) {
+       ide_tape_flush_merge_buffer(drive);
+       tape->merge_bh = ide_tape_kmalloc_buffer(tape, 1, 0);
+       if (tape->merge_bh != NULL) {
                idetape_pad_zeros(drive, tape->blk_size *
                                (tape->user_bs_factor - 1));
-               __idetape_kfree_stage(tape->merge_stage);
-               tape->merge_stage = NULL;
+               ide_tape_kfree_buffer(tape);
+               tape->merge_bh = NULL;
        }
        idetape_write_filemark(drive);
        idetape_flush_tape_buffers(drive);
@@ -3272,7 +2509,7 @@ static int idetape_chrdev_release(struct inode *inode, struct file *filp)
 {
        struct ide_tape_obj *tape = ide_tape_f(filp);
        ide_drive_t *drive = tape->drive;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        unsigned int minor = iminor(inode);
 
        lock_kernel();
@@ -3284,15 +2521,10 @@ static int idetape_chrdev_release(struct inode *inode, struct file *filp)
                idetape_write_release(drive, minor);
        if (tape->chrdev_dir == IDETAPE_DIR_READ) {
                if (minor < 128)
-                       idetape_discard_read_pipeline(drive, 1);
-               else
-                       idetape_wait_for_pipeline(drive);
-       }
-       if (tape->cache_stage != NULL) {
-               __idetape_kfree_stage(tape->cache_stage);
-               tape->cache_stage = NULL;
+                       ide_tape_discard_merge_buffer(drive, 1);
        }
-       if (minor < 128 && test_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags))
+
+       if (minor < 128 && test_bit(IDETAPE_FLAG_MEDIUM_PRESENT, &tape->flags))
                (void) idetape_rewind_tape(drive);
        if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
                if (tape->door_locked == DOOR_LOCKED) {
@@ -3302,7 +2534,7 @@ static int idetape_chrdev_release(struct inode *inode, struct file *filp)
                        }
                }
        }
-       clear_bit(IDETAPE_BUSY, &tape->flags);
+       clear_bit(IDETAPE_FLAG_BUSY, &tape->flags);
        ide_tape_put(tape);
        unlock_kernel();
        return 0;
@@ -3350,7 +2582,7 @@ static int idetape_identify_device(ide_drive_t *drive)
 static void idetape_get_inquiry_results(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        char fw_rev[6], vendor_id[10], product_id[18];
 
        idetape_create_inquiry_cmd(&pc);
@@ -3359,9 +2591,9 @@ static void idetape_get_inquiry_results(ide_drive_t *drive)
                                tape->name);
                return;
        }
-       memcpy(vendor_id, &pc.buffer[8], 8);
-       memcpy(product_id, &pc.buffer[16], 16);
-       memcpy(fw_rev, &pc.buffer[32], 4);
+       memcpy(vendor_id, &pc.buf[8], 8);
+       memcpy(product_id, &pc.buf[16], 16);
+       memcpy(fw_rev, &pc.buf[32], 4);
 
        ide_fixstring(vendor_id, 10, 0);
        ide_fixstring(product_id, 18, 0);
@@ -3378,7 +2610,7 @@ static void idetape_get_inquiry_results(ide_drive_t *drive)
 static void idetape_get_mode_sense_results(ide_drive_t *drive)
 {
        idetape_tape_t *tape = drive->driver_data;
-       idetape_pc_t pc;
+       struct ide_atapi_pc pc;
        u8 *caps;
        u8 speed, max_speed;
 
@@ -3392,7 +2624,7 @@ static void idetape_get_mode_sense_results(ide_drive_t *drive)
                put_unaligned(6*52, (u16 *)&tape->caps[16]);
                return;
        }
-       caps = pc.buffer + 4 + pc.buffer[3];
+       caps = pc.buf + 4 + pc.buf[3];
 
        /* convert to host order and save for later use */
        speed = be16_to_cpu(*(u16 *)&caps[14]);
@@ -3428,33 +2660,15 @@ static void idetape_add_settings(ide_drive_t *drive)
 
        ide_add_setting(drive, "buffer", SETTING_READ, TYPE_SHORT, 0, 0xffff,
                        1, 2, (u16 *)&tape->caps[16], NULL);
-       ide_add_setting(drive, "pipeline_min", SETTING_RW, TYPE_INT, 1, 0xffff,
-                       tape->stage_size / 1024, 1, &tape->min_pipeline, NULL);
-       ide_add_setting(drive, "pipeline", SETTING_RW, TYPE_INT, 1, 0xffff,
-                       tape->stage_size / 1024, 1, &tape->max_stages, NULL);
-       ide_add_setting(drive, "pipeline_max", SETTING_RW, TYPE_INT, 1, 0xffff,
-                       tape->stage_size / 1024, 1, &tape->max_pipeline, NULL);
-       ide_add_setting(drive, "pipeline_used", SETTING_READ, TYPE_INT, 0,
-                       0xffff, tape->stage_size / 1024, 1, &tape->nr_stages,
-                       NULL);
-       ide_add_setting(drive, "pipeline_pending", SETTING_READ, TYPE_INT, 0,
-                       0xffff, tape->stage_size / 1024, 1,
-                       &tape->nr_pending_stages, NULL);
        ide_add_setting(drive, "speed", SETTING_READ, TYPE_SHORT, 0, 0xffff,
                        1, 1, (u16 *)&tape->caps[14], NULL);
-       ide_add_setting(drive, "stage", SETTING_READ, TYPE_INT, 0, 0xffff, 1,
-                       1024, &tape->stage_size, NULL);
+       ide_add_setting(drive, "buffer_size", SETTING_READ, TYPE_INT, 0, 0xffff,
+                       1, 1024, &tape->buffer_size, NULL);
        ide_add_setting(drive, "tdsc", SETTING_RW, TYPE_INT, IDETAPE_DSC_RW_MIN,
                        IDETAPE_DSC_RW_MAX, 1000, HZ, &tape->best_dsc_rw_freq,
                        NULL);
        ide_add_setting(drive, "dsc_overlap", SETTING_RW, TYPE_BYTE, 0, 1, 1,
                        1, &drive->dsc_overlap, NULL);
-       ide_add_setting(drive, "pipeline_head_speed_c", SETTING_READ, TYPE_INT,
-                       0, 0xffff, 1, 1, &tape->controlled_pipeline_head_speed,
-                       NULL);
-       ide_add_setting(drive, "pipeline_head_speed_u", SETTING_READ, TYPE_INT,
-                       0, 0xffff, 1, 1,
-                       &tape->uncontrolled_pipeline_head_speed, NULL);
        ide_add_setting(drive, "avg_speed", SETTING_READ, TYPE_INT, 0, 0xffff,
                        1, 1, &tape->avg_speed, NULL);
        ide_add_setting(drive, "debug_mask", SETTING_RW, TYPE_INT, 0, 0xffff, 1,
@@ -3477,11 +2691,10 @@ static inline void idetape_add_settings(ide_drive_t *drive) { ; }
  */
 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
 {
-       unsigned long t1, tmid, tn, t;
+       unsigned long t;
        int speed;
-       int stage_size;
+       int buffer_size;
        u8 gcw[2];
-       struct sysinfo si;
        u16 *ctl = (u16 *)&tape->caps[12];
 
        spin_lock_init(&tape->lock);
@@ -3500,65 +2713,33 @@ static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
        tape->name[2] = '0' + minor;
        tape->chrdev_dir = IDETAPE_DIR_NONE;
        tape->pc = tape->pc_stack;
-       tape->max_insert_speed = 10000;
-       tape->speed_control = 1;
        *((unsigned short *) &gcw) = drive->id->config;
 
        /* Command packet DRQ type */
        if (((gcw[0] & 0x60) >> 5) == 1)
-               set_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags);
-
-       tape->min_pipeline = 10;
-       tape->max_pipeline = 10;
-       tape->max_stages   = 10;
+               set_bit(IDETAPE_FLAG_DRQ_INTERRUPT, &tape->flags);
 
        idetape_get_inquiry_results(drive);
        idetape_get_mode_sense_results(drive);
        ide_tape_get_bsize_from_bdesc(drive);
        tape->user_bs_factor = 1;
-       tape->stage_size = *ctl * tape->blk_size;
-       while (tape->stage_size > 0xffff) {
+       tape->buffer_size = *ctl * tape->blk_size;
+       while (tape->buffer_size > 0xffff) {
                printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
                *ctl /= 2;
-               tape->stage_size = *ctl * tape->blk_size;
+               tape->buffer_size = *ctl * tape->blk_size;
        }
-       stage_size = tape->stage_size;
-       tape->pages_per_stage = stage_size / PAGE_SIZE;
-       if (stage_size % PAGE_SIZE) {
-               tape->pages_per_stage++;
-               tape->excess_bh_size = PAGE_SIZE - stage_size % PAGE_SIZE;
+       buffer_size = tape->buffer_size;
+       tape->pages_per_buffer = buffer_size / PAGE_SIZE;
+       if (buffer_size % PAGE_SIZE) {
+               tape->pages_per_buffer++;
+               tape->excess_bh_size = PAGE_SIZE - buffer_size % PAGE_SIZE;
        }
 
-       /* Select the "best" DSC read/write polling freq and pipeline size. */
+       /* select the "best" DSC read/write polling freq */
        speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
 
-       tape->max_stages = speed * 1000 * 10 / tape->stage_size;
-
-       /* Limit memory use for pipeline to 10% of physical memory */
-       si_meminfo(&si);
-       if (tape->max_stages * tape->stage_size >
-                       si.totalram * si.mem_unit / 10)
-               tape->max_stages =
-                       si.totalram * si.mem_unit / (10 * tape->stage_size);
-
-       tape->max_stages   = min(tape->max_stages, IDETAPE_MAX_PIPELINE_STAGES);
-       tape->min_pipeline = min(tape->max_stages, IDETAPE_MIN_PIPELINE_STAGES);
-       tape->max_pipeline =
-               min(tape->max_stages * 2, IDETAPE_MAX_PIPELINE_STAGES);
-       if (tape->max_stages == 0) {
-               tape->max_stages   = 1;
-               tape->min_pipeline = 1;
-               tape->max_pipeline = 1;
-       }
-
-       t1 = (tape->stage_size * HZ) / (speed * 1000);
-       tmid = (*(u16 *)&tape->caps[16] * 32 * HZ) / (speed * 125);
-       tn = (IDETAPE_FIFO_THRESHOLD * tape->stage_size * HZ) / (speed * 1000);
-
-       if (tape->max_stages)
-               t = tn;
-       else
-               t = t1;
+       t = (IDETAPE_FIFO_THRESHOLD * tape->buffer_size * HZ) / (speed * 1000);
 
        /*
         * Ensure that the number we got makes sense; limit it within
@@ -3568,11 +2749,10 @@ static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
                                min_t(unsigned long, t, IDETAPE_DSC_RW_MAX),
                                IDETAPE_DSC_RW_MIN);
        printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
-               "%dkB pipeline, %lums tDSC%s\n",
+               "%lums tDSC%s\n",
                drive->name, tape->name, *(u16 *)&tape->caps[14],
-               (*(u16 *)&tape->caps[16] * 512) / tape->stage_size,
-               tape->stage_size / 1024,
-               tape->max_stages * tape->stage_size / 1024,
+               (*(u16 *)&tape->caps[16] * 512) / tape->buffer_size,
+               tape->buffer_size / 1024,
                tape->best_dsc_rw_freq * 1000 / HZ,
                drive->using_dma ? ", DMA":"");
 
@@ -3596,7 +2776,7 @@ static void ide_tape_release(struct kref *kref)
        ide_drive_t *drive = tape->drive;
        struct gendisk *g = tape->disk;
 
-       BUG_ON(tape->first_stage != NULL || tape->merge_stage_size);
+       BUG_ON(tape->merge_bh_size);
 
        drive->dsc_overlap = 0;
        drive->driver_data = NULL;
@@ -3765,11 +2945,6 @@ static int ide_tape_probe(ide_drive_t *drive)
        g->fops = &idetape_block_ops;
        ide_register_region(g);
 
-       printk(KERN_WARNING "It is possible that this driver does not have any"
-               " users anymore and, as a result, it will be REMOVED soon."
-               " Please notify Bart <bzolnier@gmail.com> or Boris"
-               " <petkovbb@gmail.com> in case you still need it.\n");
-
        return 0;
 
 out_free_tape: