diff options
Diffstat (limited to 'drivers/scsi/libfc/fc_libfc.c')
| -rw-r--r-- | drivers/scsi/libfc/fc_libfc.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/drivers/scsi/libfc/fc_libfc.c b/drivers/scsi/libfc/fc_libfc.c new file mode 100644 index 000000000000..39f4b6ab04b4 --- /dev/null +++ b/drivers/scsi/libfc/fc_libfc.c @@ -0,0 +1,134 @@ +/* + * 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; +} |