]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/ata/libata-core.c
libata: eliminate the home grown dma padding in favour of
[linux-2.6-omap-h63xx.git] / drivers / ata / libata-core.c
index a109ccbda9caec7ac7fbc3e9770e28850772c6eb..3587ac3fe3f394bb2e9113672f1d165876ce6a6a 100644 (file)
@@ -4493,30 +4493,13 @@ void ata_sg_clean(struct ata_queued_cmd *qc)
        struct ata_port *ap = qc->ap;
        struct scatterlist *sg = qc->sg;
        int dir = qc->dma_dir;
-       void *pad_buf = NULL;
 
        WARN_ON(sg == NULL);
 
-       VPRINTK("unmapping %u sg elements\n", qc->mapped_n_elem);
+       VPRINTK("unmapping %u sg elements\n", qc->n_elem);
 
-       /* if we padded the buffer out to 32-bit bound, and data
-        * xfer direction is from-device, we must copy from the
-        * pad buffer back into the supplied buffer
-        */
-       if (qc->pad_len && !(qc->tf.flags & ATA_TFLAG_WRITE))
-               pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
-
-       if (qc->mapped_n_elem)
-               dma_unmap_sg(ap->dev, sg, qc->mapped_n_elem, dir);
-       /* restore last sg */
-       if (qc->last_sg)
-               *qc->last_sg = qc->saved_last_sg;
-       if (pad_buf) {
-               struct scatterlist *psg = &qc->extra_sg[1];
-               void *addr = kmap_atomic(sg_page(psg), KM_IRQ0);
-               memcpy(addr + psg->offset, pad_buf, qc->pad_len);
-               kunmap_atomic(addr, KM_IRQ0);
-       }
+       if (qc->n_elem)
+               dma_unmap_sg(ap->dev, sg, qc->n_elem, dir);
 
        qc->flags &= ~ATA_QCFLAG_DMAMAP;
        qc->sg = NULL;
@@ -4767,97 +4750,6 @@ void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
        qc->cursg = qc->sg;
 }
 
-static unsigned int ata_sg_setup_extra(struct ata_queued_cmd *qc,
-                                      unsigned int *n_elem_extra,
-                                      unsigned int *nbytes_extra)
-{
-       struct ata_port *ap = qc->ap;
-       unsigned int n_elem = qc->n_elem;
-       struct scatterlist *lsg, *copy_lsg = NULL, *tsg = NULL, *esg = NULL;
-
-       *n_elem_extra = 0;
-       *nbytes_extra = 0;
-
-       /* needs padding? */
-       qc->pad_len = qc->nbytes & 3;
-
-       if (likely(!qc->pad_len))
-               return n_elem;
-
-       /* locate last sg and save it */
-       lsg = sg_last(qc->sg, n_elem);
-       qc->last_sg = lsg;
-       qc->saved_last_sg = *lsg;
-
-       sg_init_table(qc->extra_sg, ARRAY_SIZE(qc->extra_sg));
-
-       if (qc->pad_len) {
-               struct scatterlist *psg = &qc->extra_sg[1];
-               void *pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
-               unsigned int offset;
-
-               WARN_ON(qc->dev->class != ATA_DEV_ATAPI);
-
-               memset(pad_buf, 0, ATA_DMA_PAD_SZ);
-
-               /* psg->page/offset are used to copy to-be-written
-                * data in this function or read data in ata_sg_clean.
-                */
-               offset = lsg->offset + lsg->length - qc->pad_len;
-               sg_set_page(psg, nth_page(sg_page(lsg), offset >> PAGE_SHIFT),
-                           qc->pad_len, offset_in_page(offset));
-
-               if (qc->tf.flags & ATA_TFLAG_WRITE) {
-                       void *addr = kmap_atomic(sg_page(psg), KM_IRQ0);
-                       memcpy(pad_buf, addr + psg->offset, qc->pad_len);
-                       kunmap_atomic(addr, KM_IRQ0);
-               }
-
-               sg_dma_address(psg) = ap->pad_dma + (qc->tag * ATA_DMA_PAD_SZ);
-               sg_dma_len(psg) = ATA_DMA_PAD_SZ;
-
-               /* Trim the last sg entry and chain the original and
-                * padding sg lists.
-                *
-                * Because chaining consumes one sg entry, one extra
-                * sg entry is allocated and the last sg entry is
-                * copied to it if the length isn't zero after padded
-                * amount is removed.
-                *
-                * If the last sg entry is completely replaced by
-                * padding sg entry, the first sg entry is skipped
-                * while chaining.
-                */
-               lsg->length -= qc->pad_len;
-               if (lsg->length) {
-                       copy_lsg = &qc->extra_sg[0];
-                       tsg = &qc->extra_sg[0];
-               } else {
-                       n_elem--;
-                       tsg = &qc->extra_sg[1];
-               }
-
-               esg = &qc->extra_sg[1];
-
-               (*n_elem_extra)++;
-               (*nbytes_extra) += 4 - qc->pad_len;
-       }
-
-       if (copy_lsg)
-               sg_set_page(copy_lsg, sg_page(lsg), lsg->length, lsg->offset);
-
-       sg_chain(lsg, 1, tsg);
-       sg_mark_end(esg);
-
-       /* sglist can't start with chaining sg entry, fast forward */
-       if (qc->sg == lsg) {
-               qc->sg = tsg;
-               qc->cursg = tsg;
-       }
-
-       return n_elem;
-}
-
 /**
  *     ata_sg_setup - DMA-map the scatter-gather table associated with a command.
  *     @qc: Command with scatter-gather table to be mapped.
@@ -4874,26 +4766,17 @@ static unsigned int ata_sg_setup_extra(struct ata_queued_cmd *qc,
 static int ata_sg_setup(struct ata_queued_cmd *qc)
 {
        struct ata_port *ap = qc->ap;
-       unsigned int n_elem, n_elem_extra, nbytes_extra;
+       unsigned int n_elem;
 
        VPRINTK("ENTER, ata%u\n", ap->print_id);
 
-       n_elem = ata_sg_setup_extra(qc, &n_elem_extra, &nbytes_extra);
+       n_elem = dma_map_sg(ap->dev, qc->sg, qc->n_elem, qc->dma_dir);
+       if (n_elem < 1)
+               return -1;
 
-       if (n_elem) {
-               n_elem = dma_map_sg(ap->dev, qc->sg, n_elem, qc->dma_dir);
-               if (n_elem < 1) {
-                       /* restore last sg */
-                       if (qc->last_sg)
-                               *qc->last_sg = qc->saved_last_sg;
-                       return -1;
-               }
-               DPRINTK("%d sg elements mapped\n", n_elem);
-       }
+       DPRINTK("%d sg elements mapped\n", n_elem);
 
-       qc->n_elem = qc->mapped_n_elem = n_elem;
-       qc->n_elem += n_elem_extra;
-       qc->nbytes += nbytes_extra;
+       qc->n_elem = n_elem;
        qc->flags |= ATA_QCFLAG_DMAMAP;
 
        return 0;
@@ -5962,9 +5845,6 @@ void ata_qc_issue(struct ata_queued_cmd *qc)
         */
        BUG_ON(ata_is_data(prot) && (!qc->sg || !qc->n_elem || !qc->nbytes));
 
-       /* ata_sg_setup() may update nbytes */
-       qc->raw_nbytes = qc->nbytes;
-
        if (ata_is_dma(prot) || (ata_is_pio(prot) &&
                                 (ap->flags & ATA_FLAG_PIO_DMA)))
                if (ata_sg_setup(qc))
@@ -6573,19 +6453,12 @@ void ata_host_resume(struct ata_host *host)
 int ata_port_start(struct ata_port *ap)
 {
        struct device *dev = ap->dev;
-       int rc;
 
        ap->prd = dmam_alloc_coherent(dev, ATA_PRD_TBL_SZ, &ap->prd_dma,
                                      GFP_KERNEL);
        if (!ap->prd)
                return -ENOMEM;
 
-       rc = ata_pad_alloc(ap, dev);
-       if (rc)
-               return rc;
-
-       DPRINTK("prd alloc, virt %p, dma %llx\n", ap->prd,
-               (unsigned long long)ap->prd_dma);
        return 0;
 }