libata: convert to using sg helpers

This converts libata to using the sg helpers for looking up sg
elements, instead of doing it manually.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 68699b3e799843249086f7ae4f944b6dd893fe1a..e52c33180e4246079e318f3b7e00aae6295e404f 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1410,7 +1410,7 @@ static void ata_qc_complete_internal(struct ata_queued_cmd *qc)
  */
 unsigned ata_exec_internal_sg(struct ata_device *dev,
                              struct ata_taskfile *tf, const u8 *cdb,
-                             int dma_dir, struct scatterlist *sg,
+                             int dma_dir, struct scatterlist *sgl,
                              unsigned int n_elem, unsigned long timeout)
 {
        struct ata_link *link = dev->link;
@@ -1472,11 +1472,12 @@ unsigned ata_exec_internal_sg(struct ata_device *dev,
        qc->dma_dir = dma_dir;
        if (dma_dir != DMA_NONE) {
                unsigned int i, buflen = 0;
+               struct scatterlist *sg;
 
-               for (i = 0; i < n_elem; i++)
-                       buflen += sg[i].length;
+               for_each_sg(sgl, sg, n_elem, i)
+                       buflen += sg->length;
 
-               ata_sg_init(qc, sg, n_elem);
+               ata_sg_init(qc, sgl, n_elem);
                qc->nbytes = buflen;
        }
 
@@ -4292,7 +4293,7 @@ void ata_sg_clean(struct ata_queued_cmd *qc)
                if (qc->n_elem)
                        dma_unmap_sg(ap->dev, sg, qc->n_elem, dir);
                /* restore last sg */
-               sg[qc->orig_n_elem - 1].length += qc->pad_len;
+               sg_last(sg, qc->orig_n_elem)->length += qc->pad_len;
                if (pad_buf) {
                        struct scatterlist *psg = &qc->pad_sgent;
                        void *addr = kmap_atomic(psg->page, KM_IRQ0);
@@ -4547,6 +4548,7 @@ void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen)
        qc->orig_n_elem = 1;
        qc->buf_virt = buf;
        qc->nbytes = buflen;
+       qc->cursg = qc->__sg;
 
        sg_init_one(&qc->sgent, buf, buflen);
 }
@@ -4572,6 +4574,7 @@ void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
        qc->__sg = sg;
        qc->n_elem = n_elem;
        qc->orig_n_elem = n_elem;
+       qc->cursg = qc->__sg;
 }
 
 /**
@@ -4661,7 +4664,7 @@ static int ata_sg_setup(struct ata_queued_cmd *qc)
 {
        struct ata_port *ap = qc->ap;
        struct scatterlist *sg = qc->__sg;
-       struct scatterlist *lsg = &sg[qc->n_elem - 1];
+       struct scatterlist *lsg = sg_last(qc->__sg, qc->n_elem);
        int n_elem, pre_n_elem, dir, trim_sg = 0;
 
        VPRINTK("ENTER, ata%u\n", ap->print_id);
@@ -4825,7 +4828,6 @@ void ata_data_xfer_noirq(struct ata_device *adev, unsigned char *buf,
 static void ata_pio_sector(struct ata_queued_cmd *qc)
 {
        int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
-       struct scatterlist *sg = qc->__sg;
        struct ata_port *ap = qc->ap;
        struct page *page;
        unsigned int offset;
@@ -4834,8 +4836,8 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
        if (qc->curbytes == qc->nbytes - qc->sect_size)
                ap->hsm_task_state = HSM_ST_LAST;
 
-       page = sg[qc->cursg].page;
-       offset = sg[qc->cursg].offset + qc->cursg_ofs;
+       page = qc->cursg->page;
+       offset = qc->cursg->offset + qc->cursg_ofs;
 
        /* get the current page and offset */
        page = nth_page(page, (offset >> PAGE_SHIFT));
@@ -4863,8 +4865,8 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
        qc->curbytes += qc->sect_size;
        qc->cursg_ofs += qc->sect_size;
 
-       if (qc->cursg_ofs == (&sg[qc->cursg])->length) {
-               qc->cursg++;
+       if (qc->cursg_ofs == qc->cursg->length) {
+               qc->cursg = sg_next(qc->cursg);
                qc->cursg_ofs = 0;
        }
 }
@@ -4959,7 +4961,7 @@ static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
                ap->hsm_task_state = HSM_ST_LAST;
 
 next_sg:
-       if (unlikely(qc->cursg >= qc->n_elem)) {
+       if (unlikely(qc->cursg == sg_last(qc->__sg, qc->n_elem))) {
                /*
                 * The end of qc->sg is reached and the device expects
                 * more data to transfer. In order not to overrun qc->sg
@@ -4982,7 +4984,7 @@ next_sg:
                return;
        }
 
-       sg = &qc->__sg[qc->cursg];
+       sg = qc->cursg;
 
        page = sg->page;
        offset = sg->offset + qc->cursg_ofs;
@@ -5021,7 +5023,7 @@ next_sg:
        qc->cursg_ofs += count;
 
        if (qc->cursg_ofs == sg->length) {
-               qc->cursg++;
+               qc->cursg = sg_next(qc->cursg);
                qc->cursg_ofs = 0;
        }
 

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 229a9ff9f9241995e5e22ef4ead50394c76f3bb3..377e6d4d9be38664320510c77fddc4c5d9cd95ba 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -29,7 +29,7 @@
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/dma-mapping.h>
-#include <asm/scatterlist.h>
+#include <linux/scatterlist.h>
 #include <linux/io.h>
 #include <linux/ata.h>
 #include <linux/workqueue.h>
@@ -416,6 +416,7 @@ struct ata_queued_cmd {
        unsigned long           flags;          /* ATA_QCFLAG_xxx */
        unsigned int            tag;
        unsigned int            n_elem;
+       unsigned int            n_iter;
        unsigned int            orig_n_elem;
 
        int                     dma_dir;
@@ -426,7 +427,7 @@ struct ata_queued_cmd {
        unsigned int            nbytes;
        unsigned int            curbytes;
 
-       unsigned int            cursg;
+       struct scatterlist      *cursg;
        unsigned int            cursg_ofs;
 
        struct scatterlist      sgent;
@@ -1043,7 +1044,7 @@ ata_sg_is_last(struct scatterlist *sg, struct ata_queued_cmd *qc)
                return 1;
        if (qc->pad_len)
                return 0;
-       if (((sg - qc->__sg) + 1) == qc->n_elem)
+       if (qc->n_iter == qc->n_elem)
                return 1;
        return 0;
 }
@@ -1051,6 +1052,7 @@ ata_sg_is_last(struct scatterlist *sg, struct ata_queued_cmd *qc)
 static inline struct scatterlist *
 ata_qc_first_sg(struct ata_queued_cmd *qc)
 {
+       qc->n_iter = 0;
        if (qc->n_elem)
                return qc->__sg;
        if (qc->pad_len)
@@ -1063,8 +1065,8 @@ ata_qc_next_sg(struct scatterlist *sg, struct ata_queued_cmd *qc)
 {
        if (sg == &qc->pad_sgent)
                return NULL;
-       if (++sg - qc->__sg < qc->n_elem)
-               return sg;
+       if (++qc->n_iter < qc->n_elem)
+               return sg_next(sg);
        if (qc->pad_len)
                return &qc->pad_sgent;
        return NULL;
@@ -1309,9 +1311,11 @@ static inline void ata_qc_reinit(struct ata_queued_cmd *qc)
        qc->dma_dir = DMA_NONE;
        qc->__sg = NULL;
        qc->flags = 0;
-       qc->cursg = qc->cursg_ofs = 0;
+       qc->cursg = NULL;
+       qc->cursg_ofs = 0;
        qc->nbytes = qc->curbytes = 0;
        qc->n_elem = 0;
+       qc->n_iter = 0;
        qc->err_mask = 0;
        qc->pad_len = 0;
        qc->sect_size = ATA_SECT_SIZE;