void ata_sg_clean(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
- struct scatterlist *sg = qc->__sg;
+ struct scatterlist *sg = qc->sg;
int dir = qc->dma_dir;
void *pad_buf = NULL;
- WARN_ON(!(qc->flags & ATA_QCFLAG_DMAMAP));
WARN_ON(sg == NULL);
- VPRINTK("unmapping %u sg elements\n", qc->n_elem);
+ VPRINTK("unmapping %u sg elements\n", qc->mapped_n_elem);
/* if we padded the buffer out to 32-bit bound, and data
* xfer direction is from-device, we must copy from the
if (qc->pad_len && !(qc->tf.flags & ATA_TFLAG_WRITE))
pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
- if (qc->n_elem)
- dma_unmap_sg(ap->dev, sg, qc->n_elem, dir);
+ if (qc->mapped_n_elem)
+ dma_unmap_sg(ap->dev, sg, qc->mapped_n_elem, dir);
/* restore last sg */
- sg_last(sg, qc->orig_n_elem)->length += qc->pad_len;
+ if (qc->last_sg)
+ *qc->last_sg = qc->saved_last_sg;
if (pad_buf) {
- struct scatterlist *psg = &qc->pad_sgent;
+ 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);
}
qc->flags &= ~ATA_QCFLAG_DMAMAP;
- qc->__sg = NULL;
+ qc->sg = NULL;
}
/**
{
struct ata_port *ap = qc->ap;
struct scatterlist *sg;
- unsigned int idx;
+ unsigned int si, pi;
- WARN_ON(qc->__sg == NULL);
- WARN_ON(qc->n_elem == 0 && qc->pad_len == 0);
-
- idx = 0;
- ata_for_each_sg(sg, qc) {
+ pi = 0;
+ for_each_sg(qc->sg, sg, qc->n_elem, si) {
u32 addr, offset;
u32 sg_len, len;
if ((offset + sg_len) > 0x10000)
len = 0x10000 - offset;
- ap->prd[idx].addr = cpu_to_le32(addr);
- ap->prd[idx].flags_len = cpu_to_le32(len & 0xffff);
- VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", idx, addr, len);
+ ap->prd[pi].addr = cpu_to_le32(addr);
+ ap->prd[pi].flags_len = cpu_to_le32(len & 0xffff);
+ VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", pi, addr, len);
- idx++;
+ pi++;
sg_len -= len;
addr += len;
}
}
- if (idx)
- ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
+ ap->prd[pi - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
}
/**
{
struct ata_port *ap = qc->ap;
struct scatterlist *sg;
- unsigned int idx;
-
- WARN_ON(qc->__sg == NULL);
- WARN_ON(qc->n_elem == 0 && qc->pad_len == 0);
+ unsigned int si, pi;
- idx = 0;
- ata_for_each_sg(sg, qc) {
+ pi = 0;
+ for_each_sg(qc->sg, sg, qc->n_elem, si) {
u32 addr, offset;
u32 sg_len, len, blen;
len = 0x10000 - offset;
blen = len & 0xffff;
- ap->prd[idx].addr = cpu_to_le32(addr);
+ ap->prd[pi].addr = cpu_to_le32(addr);
if (blen == 0) {
/* Some PATA chipsets like the CS5530 can't
cope with 0x0000 meaning 64K as the spec says */
- ap->prd[idx].flags_len = cpu_to_le32(0x8000);
+ ap->prd[pi].flags_len = cpu_to_le32(0x8000);
blen = 0x8000;
- ap->prd[++idx].addr = cpu_to_le32(addr + 0x8000);
+ ap->prd[++pi].addr = cpu_to_le32(addr + 0x8000);
}
- ap->prd[idx].flags_len = cpu_to_le32(blen);
- VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", idx, addr, len);
+ ap->prd[pi].flags_len = cpu_to_le32(blen);
+ VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", pi, addr, len);
- idx++;
+ pi++;
sg_len -= len;
addr += len;
}
}
- if (idx)
- ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
+ ap->prd[pi - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
}
/**
* LOCKING:
* spin_lock_irqsave(host lock)
*/
-
void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
unsigned int n_elem)
{
- qc->flags |= ATA_QCFLAG_DMAMAP;
- qc->__sg = sg;
+ qc->sg = sg;
qc->n_elem = n_elem;
- qc->orig_n_elem = n_elem;
- qc->cursg = qc->__sg;
+ qc->cursg = qc->sg;
}
-/**
- * ata_sg_setup - DMA-map the scatter-gather table associated with a command.
- * @qc: Command with scatter-gather table to be mapped.
- *
- * DMA-map the scatter-gather table associated with queued_cmd @qc.
- *
- * LOCKING:
- * spin_lock_irqsave(host lock)
- *
- * RETURNS:
- * Zero on success, negative on error.
- *
- */
-
-static int ata_sg_setup(struct ata_queued_cmd *qc)
+static unsigned int ata_sg_setup_extra(struct ata_queued_cmd *qc,
+ unsigned int *n_elem_extra)
{
struct ata_port *ap = qc->ap;
- struct scatterlist *sg = qc->__sg;
- struct scatterlist *lsg = sg_last(qc->__sg, qc->n_elem);
- int n_elem, pre_n_elem, dir, trim_sg = 0;
+ unsigned int n_elem = qc->n_elem;
+ struct scatterlist *lsg, *copy_lsg = NULL, *tsg = NULL, *esg = NULL;
- VPRINTK("ENTER, ata%u\n", ap->print_id);
- WARN_ON(!(qc->flags & ATA_QCFLAG_DMAMAP));
+ *n_elem_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));
- /* we must lengthen transfers to end on a 32-bit boundary */
- qc->pad_len = lsg->length & 3;
if (qc->pad_len) {
+ struct scatterlist *psg = &qc->extra_sg[1];
void *pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
- struct scatterlist *psg = &qc->pad_sgent;
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
+ /* 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_init_table(psg, 1);
sg_set_page(psg, nth_page(sg_page(lsg), offset >> PAGE_SHIFT),
- qc->pad_len, offset_in_page(offset));
+ qc->pad_len, offset_in_page(offset));
if (qc->tf.flags & ATA_TFLAG_WRITE) {
void *addr = kmap_atomic(sg_page(psg), KM_IRQ0);
sg_dma_address(psg) = ap->pad_dma + (qc->tag * ATA_DMA_PAD_SZ);
sg_dma_len(psg) = ATA_DMA_PAD_SZ;
- /* trim last sg */
+
+ /* 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 == 0)
- trim_sg = 1;
+ 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];
- DPRINTK("padding done, sg[%d].length=%u pad_len=%u\n",
- qc->n_elem - 1, lsg->length, qc->pad_len);
+ (*n_elem_extra)++;
}
- pre_n_elem = qc->n_elem;
- if (trim_sg && pre_n_elem)
- pre_n_elem--;
+ if (copy_lsg)
+ sg_set_page(copy_lsg, sg_page(lsg), lsg->length, lsg->offset);
- if (!pre_n_elem) {
- n_elem = 0;
- goto skip_map;
+ 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;
}
- dir = qc->dma_dir;
- n_elem = dma_map_sg(ap->dev, sg, pre_n_elem, dir);
- if (n_elem < 1) {
- /* restore last sg */
- lsg->length += qc->pad_len;
- return -1;
+ 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.
+ *
+ * DMA-map the scatter-gather table associated with queued_cmd @qc.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host lock)
+ *
+ * RETURNS:
+ * Zero on success, negative on error.
+ *
+ */
+static int ata_sg_setup(struct ata_queued_cmd *qc)
+{
+ struct ata_port *ap = qc->ap;
+ unsigned int n_elem, n_elem_extra;
+
+ VPRINTK("ENTER, ata%u\n", ap->print_id);
+
+ n_elem = ata_sg_setup_extra(qc, &n_elem_extra);
+
+ 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;
-skip_map:
- qc->n_elem = n_elem;
+ qc->flags |= ATA_QCFLAG_DMAMAP;
return 0;
}
qc->flags |= ATA_QCFLAG_ACTIVE;
ap->qc_active |= 1 << qc->tag;
+ /* We guarantee to LLDs that they will have at least one
+ * non-zero sg if the command is a data command.
+ */
+ BUG_ON(ata_is_data(prot) && (!qc->sg || !qc->n_elem || !qc->nbytes));
+
if (ata_is_dma(prot) || (ata_is_pio(prot) &&
- (ap->flags & ATA_FLAG_PIO_DMA))) {
+ (ap->flags & ATA_FLAG_PIO_DMA)))
if (ata_sg_setup(qc))
goto sg_err;
- } else
- qc->flags &= ATA_QCFLAG_DMAMAP;
/* if device is sleeping, schedule softreset and abort the link */
if (unlikely(qc->dev->flags & ATA_DFLAG_SLEEPING)) {
return;
sg_err:
- qc->flags &= ~ATA_QCFLAG_DMAMAP;
qc->err_mask |= AC_ERR_SYSTEM;
err:
ata_qc_complete(qc);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff