[SCSI] libfc: Add routine to copy data from a buffer to a SG list
When handling the multi-frame responses of fc pass-thru requests,
a code segment similar to fc_fcp_recv_data (routine to receive
inbound SCSI data) is used in the response handler. This patch
is to add a routine, called fc_copy_buffer_to_sglist(), to handle
the common function of copying data from a buffer to a scatter-
gather list in order to avoid code duplication.
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c
index 866f78a..98279fe 100644
--- a/drivers/scsi/libfc/fc_fcp.c
+++ b/drivers/scsi/libfc/fc_fcp.c
@@ -323,7 +323,7 @@
size_t len;
void *buf;
struct scatterlist *sg;
- size_t remaining;
+ u32 nents;
fh = fc_frame_header_get(fp);
offset = ntohl(fh->fh_parm_offset);
@@ -347,55 +347,19 @@
if (offset != fsp->xfer_len)
fsp->state |= FC_SRB_DISCONTIG;
- crc = 0;
- if (fr_flags(fp) & FCPHF_CRC_UNCHECKED)
- crc = crc32(~0, (u8 *) fh, sizeof(*fh));
-
sg = scsi_sglist(sc);
- remaining = len;
+ nents = scsi_sg_count(sc);
- while (remaining > 0 && sg) {
- size_t off;
- void *page_addr;
- size_t sg_bytes;
-
- if (offset >= sg->length) {
- 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),
- KM_SOFTIRQ0);
- if (!page_addr)
- break; /* XXX panic? */
-
- if (fr_flags(fp) & FCPHF_CRC_UNCHECKED)
- crc = crc32(crc, buf, sg_bytes);
- memcpy((char *)page_addr + (off & ~PAGE_MASK), buf,
- sg_bytes);
-
- kunmap_atomic(page_addr, KM_SOFTIRQ0);
- buf += sg_bytes;
- offset += sg_bytes;
- remaining -= sg_bytes;
- copy_len += sg_bytes;
- }
-
- if (fr_flags(fp) & FCPHF_CRC_UNCHECKED) {
+ if (!(fr_flags(fp) & FCPHF_CRC_UNCHECKED)) {
+ copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
+ &offset, KM_SOFTIRQ0, NULL);
+ } else {
+ crc = crc32(~0, (u8 *) fh, sizeof(*fh));
+ copy_len = fc_copy_buffer_to_sglist(buf, len, sg, &nents,
+ &offset, KM_SOFTIRQ0, &crc);
buf = fc_frame_payload_get(fp, 0);
- if (len % 4) {
+ if (len % 4)
crc = crc32(crc, buf + len, 4 - (len % 4));
- len += 4 - (len % 4);
- }
if (~crc != le32_to_cpu(fr_crc(fp))) {
crc_err: