/*
* 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;
}
