mirror of
https://github.com/torvalds/linux.git
synced 2024-12-23 03:11:46 +00:00
5868287460
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>
135 lines
3.4 KiB
C
135 lines
3.4 KiB
C
/*
|
|
* Copyright(c) 2009 Intel Corporation. All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms and conditions of the GNU General Public License,
|
|
* version 2, as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|
|
* more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along with
|
|
* this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*
|
|
* Maintained at www.Open-FCoE.org
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/types.h>
|
|
#include <linux/scatterlist.h>
|
|
#include <linux/crc32.h>
|
|
|
|
#include <scsi/libfc.h>
|
|
|
|
#include "fc_libfc.h"
|
|
|
|
MODULE_AUTHOR("Open-FCoE.org");
|
|
MODULE_DESCRIPTION("libfc");
|
|
MODULE_LICENSE("GPL v2");
|
|
|
|
unsigned int fc_debug_logging;
|
|
module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR);
|
|
MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");
|
|
|
|
/**
|
|
* libfc_init() - Initialize libfc.ko
|
|
*/
|
|
static int __init libfc_init(void)
|
|
{
|
|
int rc = 0;
|
|
|
|
rc = fc_setup_fcp();
|
|
if (rc)
|
|
return rc;
|
|
|
|
rc = fc_setup_exch_mgr();
|
|
if (rc)
|
|
goto destroy_pkt_cache;
|
|
|
|
rc = fc_setup_rport();
|
|
if (rc)
|
|
goto destroy_em;
|
|
|
|
return rc;
|
|
destroy_em:
|
|
fc_destroy_exch_mgr();
|
|
destroy_pkt_cache:
|
|
fc_destroy_fcp();
|
|
return rc;
|
|
}
|
|
module_init(libfc_init);
|
|
|
|
/**
|
|
* libfc_exit() - Tear down libfc.ko
|
|
*/
|
|
static void __exit libfc_exit(void)
|
|
{
|
|
fc_destroy_fcp();
|
|
fc_destroy_exch_mgr();
|
|
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;
|
|
}
|