From: Robert Love <robert.w.love@intel.com>
To: James.Bottomley@HansenPartnership.com, linux-scsi@vger.kernel.org
Cc: Robert Love <robert.w.love@intel.com>
Subject: [PATCH 22/54] libfc: Add routine to copy data from a buffer to a SG list
Date: Tue, 03 Nov 2009 11:47:28 -0800 [thread overview]
Message-ID: <20091103194728.4085.79895.stgit@localhost.localdomain> (raw)
In-Reply-To: <20091103194530.4085.37963.stgit@localhost.localdomain>
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>
---
drivers/scsi/libfc/fc_fcp.c | 56 +++++++-------------------------------
drivers/scsi/libfc/fc_libfc.c | 60 +++++++++++++++++++++++++++++++++++++++++
drivers/scsi/libfc/fc_libfc.h | 8 +++++
3 files changed, 78 insertions(+), 46 deletions(-)
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 @@ static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
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 @@ static void fc_fcp_recv_data(struct fc_fcp_pkt *fsp, struct fc_frame *fp)
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;
-
- 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;
- }
+ nents = scsi_sg_count(sc);
- 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:
diff --git a/drivers/scsi/libfc/fc_libfc.c b/drivers/scsi/libfc/fc_libfc.c
index 01418ae..295eafb 100644
--- a/drivers/scsi/libfc/fc_libfc.c
+++ b/drivers/scsi/libfc/fc_libfc.c
@@ -72,3 +72,63 @@ static void __exit libfc_exit(void)
fc_destroy_rport();
}
module_exit(libfc_exit);
+
+/**
+ * fc_copy_buffer_to_sglist() - This routine copies the data of a buffer
+ * into a scatter-gather list (SG list).
+ *
+ * @buf: pointer to the data buffer.
+ * @len: the byte-length of the data buffer.
+ * @sg: pointer to the pointer of the SG list.
+ * @nents: pointer to the remaining number of entries in the SG list.
+ * @offset: pointer to the current offset in the SG list.
+ * @km_type: dedicated page table slot type for kmap_atomic.
+ * @crc: pointer to the 32-bit crc value.
+ * If crc is NULL, CRC is not calculated.
+ */
+u32 fc_copy_buffer_to_sglist(void *buf, size_t len,
+ struct scatterlist *sg,
+ u32 *nents, size_t *offset,
+ enum km_type km_type, 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),
+ km_type);
+ if (crc)
+ *crc = crc32(*crc, buf, sg_bytes);
+ memcpy((char *)page_addr + (off & ~PAGE_MASK), buf, sg_bytes);
+ kunmap_atomic(page_addr, km_type);
+ buf += sg_bytes;
+ *offset += sg_bytes;
+ remaining -= sg_bytes;
+ copy_len += sg_bytes;
+ }
+ return copy_len;
+}
diff --git a/drivers/scsi/libfc/fc_libfc.h b/drivers/scsi/libfc/fc_libfc.h
index 0530149..e4b5e92 100644
--- a/drivers/scsi/libfc/fc_libfc.h
+++ b/drivers/scsi/libfc/fc_libfc.h
@@ -101,4 +101,12 @@ void fc_destroy_fcp(void);
*/
const char *fc_els_resp_type(struct fc_frame *);
+/*
+ * Copies a buffer into an sg list
+ */
+u32 fc_copy_buffer_to_sglist(void *buf, size_t len,
+ struct scatterlist *sg,
+ u32 *nents, size_t *offset,
+ enum km_type km_type, u32 *crc);
+
#endif /* _FC_LIBFC_H_ */
next prev parent reply other threads:[~2009-11-03 19:47 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-03 19:45 [PATCH 00/54] libfc, libfcoe, fcoe and fnic updates for 2.6.33 Robert Love
2009-11-03 19:45 ` [PATCH 01/54] fnic: Allocate OS interrupt resources just before enabling interrupts Robert Love
2009-11-03 19:45 ` [PATCH 02/54] fcoe: Increase FCOE_MAX_LUN to 0xFFFF (65535) Robert Love
2009-11-03 19:45 ` [PATCH 03/54] libfc: Move non-common routines and prototypes out of libfc.h Robert Love
2009-11-03 19:45 ` [PATCH 04/54] libfc: Remove fc_fcp_complete Robert Love
2009-11-03 19:45 ` [PATCH 05/54] libfc: Add libfc/fc_libfc.[ch] for libfc internal routines Robert Love
2009-11-03 19:46 ` [PATCH 06/54] libfc: Move libfc_init and libfc_exit to fc_libfc.c Robert Love
2009-11-03 19:46 ` [PATCH 07/54] libfc: changes to libfc_host_alloc to consolidate initialization with allocation Robert Love
2009-11-03 19:46 ` [PATCH 08/54] libfc: add some generic NPIV support routines to libfc Robert Love
2009-11-03 19:46 ` [PATCH 09/54] libfc: vport link handling and fc_vport state managment Robert Love
2009-11-03 19:46 ` [PATCH 10/54] libfc, libfcoe: FDISC ELS for NPIV Robert Love
2009-11-03 19:46 ` [PATCH 11/54] libfcoe, fcoe: libfcoe NPIV support Robert Love
2009-11-03 19:46 ` [PATCH 12/54] fcoe: add a separate scsi transport template for NPIV vports Robert Love
2009-11-03 19:46 ` [PATCH 13/54] fcoe: NPIV vport create/destroy Robert Love
2009-11-03 19:46 ` [PATCH 14/54] libfc: RPN_ID is obsolete and unnecessary Robert Love
2009-11-03 19:46 ` [PATCH 15/54] libfc: RNN_ID may be required before RSNN_NN with some switches Robert Love
2009-11-03 19:46 ` [PATCH 16/54] libfc: Register Symbolic Node Name (RSNN_NN) Robert Love
2009-11-03 19:47 ` [PATCH 17/54] libfc: Register Symbolic Port Name (RSPN_ID) Robert Love
2009-11-03 19:47 ` [PATCH 18/54] libfc: combine name server registration response handlers Robert Love
2009-11-03 19:47 ` [PATCH 19/54] libfc: combine name server registration request functions Robert Love
2009-11-03 19:47 ` [PATCH 20/54] fcoe: vport symbolic name support Robert Love
2009-11-03 19:47 ` [PATCH 21/54] libfc: Export FC headers Robert Love
2009-11-03 19:47 ` Robert Love [this message]
2009-11-03 19:47 ` [PATCH 23/54] libfc, fcoe: Add FC passthrough support Robert Love
2009-11-03 19:47 ` [PATCH 24/54] libfc: Formatting cleanups across libfc Robert Love
2009-11-03 19:47 ` [PATCH 25/54] libfcoe: formatting and comment cleanups Robert Love
2009-11-03 19:47 ` [PATCH 26/54] fcoe: Formatting cleanups and commenting Robert Love
2009-11-03 19:47 ` [PATCH 27/54] fcoe, libfc: use single frame allocation API Robert Love
2009-11-03 19:48 ` [PATCH 28/54] libfc: reduce can_queue for all FCP frame allocation failures Robert Love
2009-11-03 19:48 ` [PATCH 29/54] libfc: adds can_queue ramp up Robert Love
2009-11-03 19:48 ` [PATCH 30/54] libfcoe: Allow FIP to be disabled by the driver Robert Love
2009-11-03 19:48 ` [PATCH 31/54] libfcoe: fip: use SCSI host number to identify debug messages Robert Love
2009-11-03 19:48 ` [PATCH 32/54] libfcoe: fip: allow FIP receive to be called from IRQ Robert Love
2009-11-03 19:48 ` [PATCH 33/54] libfcoe: FIP should report link to libfc whether selected or not Robert Love
2009-11-03 19:48 ` [PATCH 34/54] libfcoe: don't send ELS in FIP mode if no FCF selected Robert Love
2009-11-03 19:48 ` [PATCH 35/54] fcoe: remove extra function decalrations Robert Love
2009-11-03 19:48 ` [PATCH 36/54] fcoe: add check to fail gracefully in bonding mode Robert Love
2009-11-03 19:48 ` [PATCH 37/54] libfc: fix RNN_ID smashing skb payload Robert Love
2009-11-03 19:48 ` [PATCH 38/54] libfc: fix symbolic name registrations smashing skb data Robert Love
2009-11-03 19:49 ` [PATCH 39/54] libfc: fix fc_els_resp_type to correct display of CT responses Robert Love
2009-11-03 19:49 ` [PATCH 40/54] libfc: add set_fid function to libfc template Robert Love
2009-11-03 19:49 ` [PATCH 41/54] libfc: add host number to lport link up/down messages Robert Love
2009-11-03 19:49 ` [PATCH 42/54] libfcoe: fcoe: simplify receive FLOGI response Robert Love
2009-11-03 19:49 ` [PATCH 43/54] fnic: Add FIP support to the fnic driver Robert Love
2009-11-03 19:49 ` [PATCH 44/54] libfc: register FC4 features with the FC switch Robert Love
2009-11-03 19:49 ` [PATCH 45/54] fnic: enable bsg pass-thru for fcping Robert Love
2009-11-03 19:49 ` [PATCH 46/54] fcoe: Fix checking san mac address Robert Love
2009-11-03 19:49 ` [PATCH 47/54] fcoe: Fix getting san mac for VLAN interface Robert Love
2009-11-03 19:49 ` [PATCH 48/54] fcoe: Fix setting lport's WWNN/WWPN to use san mac address Robert Love
2009-11-03 19:49 ` [PATCH 49/54] libfc: do not use DID_NO_CONNECT for pkt alloc failures Robert Love
2009-11-03 19:49 ` [PATCH 50/54] fcoe: Fix using VLAN ID in creating lport's WWWN/WWPN Robert Love
2009-11-03 19:50 ` [PATCH 51/54] libfc, fcoe: fixes for highmem skb linearize panics Robert Love
2009-11-03 19:50 ` [PATCH 52/54] libfc: fix an issue of pending exch/es after i/f destroyed or rmmod fcoe Robert Love
2009-11-03 19:50 ` [PATCH 53/54] libfcoe: Do not pad FIP keep-alive to full frame size Robert Love
2009-11-03 19:50 ` [PATCH 54/54] libfc fcoe: increase ELS and CT timeouts Robert Love
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