1 files changed, 9 insertions, 136 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index a109ccbda9ca..3587ac3fe3f3 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -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;
 }