libata: add ata_sg_is_last() helper, use it in several drivers
diff --git a/drivers/scsi/pdc_adma.c b/drivers/scsi/pdc_adma.c
index 53b8db4..c6825da 100644
--- a/drivers/scsi/pdc_adma.c
+++ b/drivers/scsi/pdc_adma.c
@@ -293,14 +293,14 @@
static int adma_fill_sg(struct ata_queued_cmd *qc)
{
- struct scatterlist *sg = qc->sg;
+ struct scatterlist *sg;
struct ata_port *ap = qc->ap;
struct adma_port_priv *pp = ap->private_data;
u8 *buf = pp->pkt;
- int nelem, i = (2 + buf[3]) * 8;
+ int i = (2 + buf[3]) * 8;
u8 pFLAGS = pORD | ((qc->tf.flags & ATA_TFLAG_WRITE) ? pDIRO : 0);
- for (nelem = 0; nelem < qc->n_elem; nelem++,sg++) {
+ ata_for_each_sg(sg, qc) {
u32 addr;
u32 len;
@@ -312,7 +312,7 @@
*(__le32 *)(buf + i) = cpu_to_le32(len);
i += 4;
- if ((nelem + 1) == qc->n_elem)
+ if (ata_sg_is_last(sg, qc))
pFLAGS |= pEND;
buf[i++] = pFLAGS;
buf[i++] = qc->dev->dma_mode & 0xf;
diff --git a/drivers/scsi/sata_mv.c b/drivers/scsi/sata_mv.c
index d457f56..be7c378 100644
--- a/drivers/scsi/sata_mv.c
+++ b/drivers/scsi/sata_mv.c
@@ -785,22 +785,24 @@
static void mv_fill_sg(struct ata_queued_cmd *qc)
{
struct mv_port_priv *pp = qc->ap->private_data;
- unsigned int i;
+ unsigned int i = 0;
+ struct scatterlist *sg;
- for (i = 0; i < qc->n_elem; i++) {
+ ata_for_each_sg(sg, qc) {
u32 sg_len;
dma_addr_t addr;
- addr = sg_dma_address(&qc->sg[i]);
- sg_len = sg_dma_len(&qc->sg[i]);
+ addr = sg_dma_address(sg);
+ sg_len = sg_dma_len(sg);
pp->sg_tbl[i].addr = cpu_to_le32(addr & 0xffffffff);
pp->sg_tbl[i].addr_hi = cpu_to_le32((addr >> 16) >> 16);
assert(0 == (sg_len & ~MV_DMA_BOUNDARY));
pp->sg_tbl[i].flags_size = cpu_to_le32(sg_len);
- }
- if (0 < qc->n_elem) {
- pp->sg_tbl[qc->n_elem - 1].flags_size |= EPRD_FLAG_END_OF_TBL;
+ if (ata_sg_is_last(sg, qc))
+ pp->sg_tbl[i].flags_size |= cpu_to_le32(EPRD_FLAG_END_OF_TBL);
+
+ i++;
}
}
diff --git a/drivers/scsi/sata_sil24.c b/drivers/scsi/sata_sil24.c
index 1985781..e16d181 100644
--- a/drivers/scsi/sata_sil24.c
+++ b/drivers/scsi/sata_sil24.c
@@ -416,15 +416,20 @@
static inline void sil24_fill_sg(struct ata_queued_cmd *qc,
struct sil24_cmd_block *cb)
{
- struct scatterlist *sg = qc->sg;
struct sil24_sge *sge = cb->sge;
- unsigned i;
+ struct scatterlist *sg;
+ unsigned int idx = 0;
- for (i = 0; i < qc->n_elem; i++, sg++, sge++) {
+ ata_for_each_sg(sg, qc) {
sge->addr = cpu_to_le64(sg_dma_address(sg));
sge->cnt = cpu_to_le32(sg_dma_len(sg));
- sge->flags = 0;
- sge->flags = i < qc->n_elem - 1 ? 0 : cpu_to_le32(SGE_TRM);
+ if (ata_sg_is_last(sg, qc))
+ sge->flags = cpu_to_le32(SGE_TRM);
+ else
+ sge->flags = 0;
+
+ sge++;
+ idx++;
}
}
diff --git a/include/linux/libata.h b/include/linux/libata.h
index d3f58a7..d3dfefe 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -480,6 +480,18 @@
#endif /* CONFIG_PCI */
+static inline int
+ata_sg_is_last(struct scatterlist *sg, struct ata_queued_cmd *qc)
+{
+ if (sg == &qc->pad_sgent)
+ return 1;
+ if (qc->pad_len)
+ return 0;
+ if (((sg - qc->__sg) + 1) == qc->n_elem)
+ return 1;
+ return 0;
+}
+
static inline struct scatterlist *
ata_qc_next_sg(struct scatterlist *sg, struct ata_queued_cmd *qc)
{