[PATCH v2 14/21] scsi: libfc, csiostor: Change to sg_copy_buffer in two drivers

Logan Gunthorpe
2017-04-25T18:21:01Z

These two drivers appear to duplicate the functionality of
sg_copy_buffer. So we clean them up to use the common code.

This helps us remove a couple of instances that would otherwise be
slightly tricky sg_map usages.

Signed-off-by: Logan Gunthorpe <logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
Cc: Johannes Thumshirn <jth-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
drivers/scsi/csiostor/csio_scsi.c | 54 +++------------------------------------
drivers/scsi/libfc/fc_libfc.c | 49 ++++++++---------------------------
2 files changed, 14 insertions(+), 89 deletions(-)

diff --git a/drivers/scsi/csiostor/csio_scsi.c b/drivers/scsi/csiostor/csio_scsi.c
index a1ff75f..bd9d062 100644
--- a/drivers/scsi/csiostor/csio_scsi.c
+++ b/drivers/scsi/csiostor/csio_scsi.c
@@ -1489,60 +1489,14 @@ static inline uint32_t
csio_scsi_copy_to_sgl(struct csio_hw *hw, struct csio_ioreq *req)
{
struct scsi_cmnd *scmnd = (struct scsi_cmnd *)csio_scsi_cmnd(req);
- struct scatterlist *sg;
- uint32_t bytes_left;
- uint32_t bytes_copy;
- uint32_t buf_off = 0;
- uint32_t start_off = 0;
- uint32_t sg_off = 0;
- void *sg_addr;
- void *buf_addr;
struct csio_dma_buf *dma_buf;
+ size_t copied;

- bytes_left = scsi_bufflen(scmnd);
- sg = scsi_sglist(scmnd);
dma_buf = (struct csio_dma_buf *)csio_list_next(&req->gen_list);
+ copied = sg_copy_from_buffer(scsi_sglist(scmnd), scsi_sg_count(scmnd),
+ dma_buf->vaddr, scsi_bufflen(scmnd));

- /* Copy data from driver buffer to SGs of SCSI CMD */
- while (bytes_left > 0 && sg && dma_buf) {
- if (buf_off >= dma_buf->len) {
- buf_off = 0;
- dma_buf = (struct csio_dma_buf *)
- csio_list_next(dma_buf);
- continue;
- }
-
- if (start_off >= sg->length) {
- start_off -= sg->length;
- sg = sg_next(sg);
- continue;
- }
-
- buf_addr = dma_buf->vaddr + buf_off;
- sg_off = sg->offset + start_off;
- bytes_copy = min((dma_buf->len - buf_off),
- sg->length - start_off);
- bytes_copy = min((uint32_t)(PAGE_SIZE - (sg_off & ~PAGE_MASK)),
- bytes_copy);
-
- sg_addr = kmap_atomic(sg_page(sg) + (sg_off >> PAGE_SHIFT));
- if (!sg_addr) {
- csio_err(hw, "failed to kmap sg:%p of ioreq:%p\n",
- sg, req);
- break;
- }
-
- csio_dbg(hw, "copy_to_sgl:sg_addr %p sg_off %d buf %p len %d\n",
- sg_addr, sg_off, buf_addr, bytes_copy);
- memcpy(sg_addr + (sg_off & ~PAGE_MASK), buf_addr, bytes_copy);
- kunmap_atomic(sg_addr);
-
- start_off += bytes_copy;
- buf_off += bytes_copy;
- bytes_left -= bytes_copy;
- }
-
- if (bytes_left > 0)
+ if (copied != scsi_bufflen(scmnd))
return DID_ERROR;
else
return DID_OK;
diff --git a/drivers/scsi/libfc/fc_libfc.c b/drivers/scsi/libfc/fc_libfc.c
index d623d08..ce0805a 100644
--- a/drivers/scsi/libfc/fc_libfc.c
+++ b/drivers/scsi/libfc/fc_libfc.c
@@ -113,45 +113,16 @@ u32 fc_copy_buffer_to_sglist(void *buf, size_t len,
u32 *nents, size_t *offset,
u32 *crc)
{
- size_t remaining = len;
- u32 copy_len = 0;
-
- while (remaining > 0 && sg) {
- size_t off, sg_bytes;
- void *page_addr;
-
- if (*offset >= sg->length) {
- /*
- * Check for end and drop resources
- * from the last iteration.
- */
- if (!(*nents))
- break;
- --(*nents);
- *offset -= sg->length;
- sg = sg_next(sg);
- continue;
- }
- sg_bytes = min(remaining, sg->length - *offset);
-
- /*
- * The scatterlist item may be bigger than PAGE_SIZE,
- * but we are limited to mapping PAGE_SIZE at a time.
- */
- off = *offset + sg->offset;
- sg_bytes = min(sg_bytes,
- (size_t)(PAGE_SIZE - (off & ~PAGE_MASK)));
- page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT));
- if (crc)
- *crc = crc32(*crc, buf, sg_bytes);
- memcpy((char *)page_addr + (off & ~PAGE_MASK), buf, sg_bytes);
- kunmap_atomic(page_addr);
- buf += sg_bytes;
- *offset += sg_bytes;
- remaining -= sg_bytes;
- copy_len += sg_bytes;
- }
- return copy_len;
+ size_t copied;
+
+ copied = sg_pcopy_from_buffer(sg, sg_nents(sg),
+ buf, len, *offset);
+
+ *offset += copied;
+ if (crc)
+ *crc = crc32(*crc, buf, copied);
+
+ return copied;
}

/**
--
2.1.4