block: add support for IO CPU affinity

[linux-2.6-omap-h63xx.git] / include / linux / bio.h

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 0933a14e641423f523d8ed7a56ef7f2a6b849e5c..13aba20edb2d9b8030e7338934d5fdf9d0b97021 100644 (file)
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -26,21 +26,8 @@
 
 #ifdef CONFIG_BLOCK
 
-/* Platforms may set this to teach the BIO layer about IOMMU hardware. */
 #include <asm/io.h>
 
-#if defined(BIO_VMERGE_MAX_SIZE) && defined(BIO_VMERGE_BOUNDARY)
-#define BIOVEC_VIRT_START_SIZE(x) (bvec_to_phys(x) & (BIO_VMERGE_BOUNDARY - 1))
-#define BIOVEC_VIRT_OVERSIZE(x)        ((x) > BIO_VMERGE_MAX_SIZE)
-#else
-#define BIOVEC_VIRT_START_SIZE(x)      0
-#define BIOVEC_VIRT_OVERSIZE(x)                0
-#endif
-
-#ifndef BIO_VMERGE_BOUNDARY
-#define BIO_VMERGE_BOUNDARY    0
-#endif
-
 #define BIO_DEBUG
 
 #ifdef BIO_DEBUG
@@ -88,25 +75,14 @@ struct bio {
        /* Number of segments in this BIO after
         * physical address coalescing is performed.
         */
-       unsigned short          bi_phys_segments;
-
-       /* Number of segments after physical and DMA remapping
-        * hardware coalescing is performed.
-        */
-       unsigned short          bi_hw_segments;
+       unsigned int            bi_phys_segments;
 
        unsigned int            bi_size;        /* residual I/O count */
 
-       /*
-        * To keep track of the max hw size, we account for the
-        * sizes of the first and last virtually mergeable segments
-        * in this bio
-        */
-       unsigned int            bi_hw_front_size;
-       unsigned int            bi_hw_back_size;
-
        unsigned int            bi_max_vecs;    /* max bvl_vecs we can hold */
 
+       unsigned int            bi_comp_cpu;    /* completion CPU */
+
        struct bio_vec          *bi_io_vec;     /* the actual vec list */
 
        bio_end_io_t            *bi_end_io;
@@ -126,11 +102,12 @@ struct bio {
 #define BIO_UPTODATE   0       /* ok after I/O completion */
 #define BIO_RW_BLOCK   1       /* RW_AHEAD set, and read/write would block */
 #define BIO_EOF                2       /* out-out-bounds error */
-#define BIO_SEG_VALID  3       /* nr_hw_seg valid */
+#define BIO_SEG_VALID  3       /* bi_phys_segments valid */
 #define BIO_CLONED     4       /* doesn't own data */
 #define BIO_BOUNCED    5       /* bio is a bounce bio */
 #define BIO_USER_MAPPED 6      /* contains user pages */
 #define BIO_EOPNOTSUPP 7       /* not supported */
+#define BIO_CPU_AFFINE 8       /* complete bio on same CPU as submitted */
 #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag)))
 
 /*
@@ -149,13 +126,16 @@ struct bio {
  * bit 2 -- barrier
  * bit 3 -- fail fast, don't want low level driver retries
  * bit 4 -- synchronous I/O hint: the block layer will unplug immediately
+ * bit 5 -- metadata request
+ * bit 6 -- discard sectors
  */
-#define BIO_RW         0
-#define BIO_RW_AHEAD   1
+#define BIO_RW         0       /* Must match RW in req flags (blkdev.h) */
+#define BIO_RW_AHEAD   1       /* Must match FAILFAST in req flags */
 #define BIO_RW_BARRIER 2
 #define BIO_RW_FAILFAST        3
 #define BIO_RW_SYNC    4
 #define BIO_RW_META    5
+#define BIO_RW_DISCARD 6
 
 /*
  * upper 16 bits of bi_rw define the io priority of this bio
@@ -185,14 +165,15 @@ struct bio {
 #define bio_failfast(bio)      ((bio)->bi_rw & (1 << BIO_RW_FAILFAST))
 #define bio_rw_ahead(bio)      ((bio)->bi_rw & (1 << BIO_RW_AHEAD))
 #define bio_rw_meta(bio)       ((bio)->bi_rw & (1 << BIO_RW_META))
-#define bio_empty_barrier(bio) (bio_barrier(bio) && !(bio)->bi_size)
+#define bio_discard(bio)       ((bio)->bi_rw & (1 << BIO_RW_DISCARD))
+#define bio_empty_barrier(bio) (bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))
 
 static inline unsigned int bio_cur_sectors(struct bio *bio)
 {
        if (bio->bi_vcnt)
                return bio_iovec(bio)->bv_len >> 9;
-
-       return 0;
+       else /* dataless requests such as discard */
+               return bio->bi_size >> 9;
 }
 
 static inline void *bio_data(struct bio *bio)
@@ -236,8 +217,6 @@ static inline void *bio_data(struct bio *bio)
        ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
 #endif
 
-#define BIOVEC_VIRT_MERGEABLE(vec1, vec2)      \
-       ((((bvec_to_phys((vec1)) + (vec1)->bv_len) | bvec_to_phys((vec2))) & (BIO_VMERGE_BOUNDARY - 1)) == 0)
 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
        (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
@@ -335,7 +314,6 @@ extern void bio_free(struct bio *, struct bio_set *);
 extern void bio_endio(struct bio *, int);
 struct request_queue;
 extern int bio_phys_segments(struct request_queue *, struct bio *);
-extern int bio_hw_segments(struct request_queue *, struct bio *);
 
 extern void __bio_clone(struct bio *, struct bio *);
 extern struct bio *bio_clone(struct bio *, gfp_t);
@@ -367,6 +345,14 @@ void zero_fill_bio(struct bio *bio);
 extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
 extern unsigned int bvec_nr_vecs(unsigned short idx);
 
+/*
+ * Allow queuer to specify a completion CPU for this bio
+ */
+static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
+{
+       bio->bi_comp_cpu = cpu;
+}
+
 /*
  * bio_set is used to allow other portions of the IO system to
  * allocate their own private memory pools for bio and iovec structures.
@@ -445,6 +431,14 @@ static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
        __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
 #define bio_kunmap_irq(buf,flags)      __bio_kunmap_irq(buf, flags)
 
+/*
+ * Check whether this bio carries any data or not. A NULL bio is allowed.
+ */
+static inline int bio_has_data(struct bio *bio)
+{
+       return bio && bio->bi_io_vec != NULL;
+}
+
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 
 #define bip_vec_idx(bip, idx)  (&(bip->bip_vec[(idx)]))