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 @@ | |||
1 | /* | ||
2 | * Copyright(c) 2009 Intel Corporation. All rights reserved. | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or modify it | ||
5 | * under the terms and conditions of the GNU General Public License, | ||
6 | * version 2, as published by the Free Software Foundation. | ||
7 | * | ||
8 | * This program is distributed in the hope it will be useful, but WITHOUT | ||
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | ||
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | ||
11 | * more details. | ||
12 | * | ||
13 | * You should have received a copy of the GNU General Public License along with | ||
14 | * this program; if not, write to the Free Software Foundation, Inc., | ||
15 | * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. | ||
16 | * | ||
17 | * Maintained at www.Open-FCoE.org | ||
18 | */ | ||
19 | |||
20 | #include <linux/kernel.h> | ||
21 | #include <linux/types.h> | ||
22 | #include <linux/scatterlist.h> | ||
23 | #include <linux/crc32.h> | ||
24 | |||
25 | #include <scsi/libfc.h> | ||
26 | |||
27 | #include "fc_libfc.h" | ||
28 | |||
29 | MODULE_AUTHOR("Open-FCoE.org"); | ||
30 | MODULE_DESCRIPTION("libfc"); | ||
31 | MODULE_LICENSE("GPL v2"); | ||
32 | |||
33 | unsigned int fc_debug_logging; | ||
34 | module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR); | ||
35 | MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels"); | ||
36 | |||
37 | /** | ||
38 | * libfc_init() - Initialize libfc.ko | ||
39 | */ | ||
40 | static int __init libfc_init(void) | ||
41 | { | ||
42 | int rc = 0; | ||
43 | |||
44 | rc = fc_setup_fcp(); | ||
45 | if (rc) | ||
46 | return rc; | ||
47 | |||
48 | rc = fc_setup_exch_mgr(); | ||
49 | if (rc) | ||
50 | goto destroy_pkt_cache; | ||
51 | |||
52 | rc = fc_setup_rport(); | ||
53 | if (rc) | ||
54 | goto destroy_em; | ||
55 | |||
56 | return rc; | ||
57 | destroy_em: | ||
58 | fc_destroy_exch_mgr(); | ||
59 | destroy_pkt_cache: | ||
60 | fc_destroy_fcp(); | ||
61 | return rc; | ||
62 | } | ||
63 | module_init(libfc_init); | ||
64 | |||
65 | /** | ||
66 | * libfc_exit() - Tear down libfc.ko | ||
67 | */ | ||
68 | static void __exit libfc_exit(void) | ||
69 | { | ||
70 | fc_destroy_fcp(); | ||
71 | fc_destroy_exch_mgr(); | ||
72 | fc_destroy_rport(); | ||
73 | } | ||
74 | module_exit(libfc_exit); | ||
75 | |||
76 | /** | ||
77 | * fc_copy_buffer_to_sglist() - This routine copies the data of a buffer | ||
78 | * into a scatter-gather list (SG list). | ||
79 | * | ||
80 | * @buf: pointer to the data buffer. | ||
81 | * @len: the byte-length of the data buffer. | ||
82 | * @sg: pointer to the pointer of the SG list. | ||
83 | * @nents: pointer to the remaining number of entries in the SG list. | ||
84 | * @offset: pointer to the current offset in the SG list. | ||
85 | * @km_type: dedicated page table slot type for kmap_atomic. | ||
86 | * @crc: pointer to the 32-bit crc value. | ||
87 | * If crc is NULL, CRC is not calculated. | ||
88 | */ | ||
89 | u32 fc_copy_buffer_to_sglist(void *buf, size_t len, | ||
90 | struct scatterlist *sg, | ||
91 | u32 *nents, size_t *offset, | ||
92 | enum km_type km_type, u32 *crc) | ||
93 | { | ||
94 | size_t remaining = len; | ||
95 | u32 copy_len = 0; | ||
96 | |||
97 | while (remaining > 0 && sg) { | ||
98 | size_t off, sg_bytes; | ||
99 | void *page_addr; | ||
100 | |||
101 | if (*offset >= sg->length) { | ||
102 | /* | ||
103 | * Check for end and drop resources | ||
104 | * from the last iteration. | ||
105 | */ | ||
106 | if (!(*nents)) | ||
107 | break; | ||
108 | --(*nents); | ||
109 | *offset -= sg->length; | ||
110 | sg = sg_next(sg); | ||
111 | continue; | ||
112 | } | ||
113 | sg_bytes = min(remaining, sg->length - *offset); | ||
114 | |||
115 | /* | ||
116 | * The scatterlist item may be bigger than PAGE_SIZE, | ||
117 | * but we are limited to mapping PAGE_SIZE at a time. | ||
118 | */ | ||
119 | off = *offset + sg->offset; | ||
120 | sg_bytes = min(sg_bytes, | ||
121 | (size_t)(PAGE_SIZE - (off & ~PAGE_MASK))); | ||
122 | page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT), | ||
123 | km_type); | ||
124 | if (crc) | ||
125 | *crc = crc32(*crc, buf, sg_bytes); | ||
126 | memcpy((char *)page_addr + (off & ~PAGE_MASK), buf, sg_bytes); | ||
127 | kunmap_atomic(page_addr, km_type); | ||
128 | buf += sg_bytes; | ||
129 | *offset += sg_bytes; | ||
130 | remaining -= sg_bytes; | ||
131 | copy_len += sg_bytes; | ||
132 | } | ||
133 | return copy_len; | ||
134 | } | ||