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Bart Van Assche07e38422015-05-08 10:07:48 +02001/*
2 * SCSI functions used by both the initiator and the target code.
3 */
4
5#include <linux/bug.h>
6#include <linux/kernel.h>
7#include <linux/string.h>
Sagi Grimbergf5a8b3a2015-07-15 10:55:37 +03008#include <linux/errno.h>
Sagi Grimberg7708c162015-07-08 17:58:52 +03009#include <asm/unaligned.h>
Bart Van Assche07e38422015-05-08 10:07:48 +020010#include <scsi/scsi_common.h>
11
12/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
13 * You may not alter any existing entry (although adding new ones is
14 * encouraged once assigned by ANSI/INCITS T10
15 */
16static const char *const scsi_device_types[] = {
17 "Direct-Access ",
18 "Sequential-Access",
19 "Printer ",
20 "Processor ",
21 "WORM ",
22 "CD-ROM ",
23 "Scanner ",
24 "Optical Device ",
25 "Medium Changer ",
26 "Communications ",
27 "ASC IT8 ",
28 "ASC IT8 ",
29 "RAID ",
30 "Enclosure ",
31 "Direct-Access-RBC",
32 "Optical card ",
33 "Bridge controller",
34 "Object storage ",
35 "Automation/Drive ",
36 "Security Manager ",
37 "Direct-Access-ZBC",
38};
39
40/**
41 * scsi_device_type - Return 17 char string indicating device type.
42 * @type: type number to look up
43 */
44const char *scsi_device_type(unsigned type)
45{
46 if (type == 0x1e)
47 return "Well-known LUN ";
48 if (type == 0x1f)
49 return "No Device ";
50 if (type >= ARRAY_SIZE(scsi_device_types))
51 return "Unknown ";
52 return scsi_device_types[type];
53}
54EXPORT_SYMBOL(scsi_device_type);
55
56/**
57 * scsilun_to_int - convert a scsi_lun to an int
58 * @scsilun: struct scsi_lun to be converted.
59 *
60 * Description:
61 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
62 * integer, and return the result. The caller must check for
63 * truncation before using this function.
64 *
65 * Notes:
66 * For a description of the LUN format, post SCSI-3 see the SCSI
67 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
68 *
69 * Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function
70 * returns the integer: 0x0b03d204
71 *
72 * This encoding will return a standard integer LUN for LUNs smaller
73 * than 256, which typically use a single level LUN structure with
74 * addressing method 0.
75 */
76u64 scsilun_to_int(struct scsi_lun *scsilun)
77{
78 int i;
79 u64 lun;
80
81 lun = 0;
82 for (i = 0; i < sizeof(lun); i += 2)
83 lun = lun | (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) |
84 ((u64)scsilun->scsi_lun[i + 1] << (i * 8)));
85 return lun;
86}
87EXPORT_SYMBOL(scsilun_to_int);
88
89/**
90 * int_to_scsilun - reverts an int into a scsi_lun
91 * @lun: integer to be reverted
92 * @scsilun: struct scsi_lun to be set.
93 *
94 * Description:
95 * Reverts the functionality of the scsilun_to_int, which packed
96 * an 8-byte lun value into an int. This routine unpacks the int
97 * back into the lun value.
98 *
99 * Notes:
100 * Given an integer : 0x0b03d204, this function returns a
101 * struct scsi_lun of: d2 04 0b 03 00 00 00 00
102 *
103 */
104void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)
105{
106 int i;
107
108 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
109
110 for (i = 0; i < sizeof(lun); i += 2) {
111 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
112 scsilun->scsi_lun[i+1] = lun & 0xFF;
113 lun = lun >> 16;
114 }
115}
116EXPORT_SYMBOL(int_to_scsilun);
117
118/**
119 * scsi_normalize_sense - normalize main elements from either fixed or
120 * descriptor sense data format into a common format.
121 *
122 * @sense_buffer: byte array containing sense data returned by device
123 * @sb_len: number of valid bytes in sense_buffer
124 * @sshdr: pointer to instance of structure that common
125 * elements are written to.
126 *
127 * Notes:
128 * The "main elements" from sense data are: response_code, sense_key,
129 * asc, ascq and additional_length (only for descriptor format).
130 *
131 * Typically this function can be called after a device has
132 * responded to a SCSI command with the CHECK_CONDITION status.
133 *
134 * Return value:
135 * true if valid sense data information found, else false;
136 */
137bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
138 struct scsi_sense_hdr *sshdr)
139{
140 if (!sense_buffer || !sb_len)
141 return false;
142
143 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
144
145 sshdr->response_code = (sense_buffer[0] & 0x7f);
146
147 if (!scsi_sense_valid(sshdr))
148 return false;
149
150 if (sshdr->response_code >= 0x72) {
151 /*
152 * descriptor format
153 */
154 if (sb_len > 1)
155 sshdr->sense_key = (sense_buffer[1] & 0xf);
156 if (sb_len > 2)
157 sshdr->asc = sense_buffer[2];
158 if (sb_len > 3)
159 sshdr->ascq = sense_buffer[3];
160 if (sb_len > 7)
161 sshdr->additional_length = sense_buffer[7];
162 } else {
163 /*
164 * fixed format
165 */
166 if (sb_len > 2)
167 sshdr->sense_key = (sense_buffer[2] & 0xf);
168 if (sb_len > 7) {
169 sb_len = (sb_len < (sense_buffer[7] + 8)) ?
170 sb_len : (sense_buffer[7] + 8);
171 if (sb_len > 12)
172 sshdr->asc = sense_buffer[12];
173 if (sb_len > 13)
174 sshdr->ascq = sense_buffer[13];
175 }
176 }
177
178 return true;
179}
180EXPORT_SYMBOL(scsi_normalize_sense);
Sagi Grimberg7708c162015-07-08 17:58:52 +0300181
182/**
183 * scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
184 * @sense_buffer: byte array of descriptor format sense data
185 * @sb_len: number of valid bytes in sense_buffer
186 * @desc_type: value of descriptor type to find
187 * (e.g. 0 -> information)
188 *
189 * Notes:
190 * only valid when sense data is in descriptor format
191 *
192 * Return value:
193 * pointer to start of (first) descriptor if found else NULL
194 */
195const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
196 int desc_type)
197{
198 int add_sen_len, add_len, desc_len, k;
199 const u8 * descp;
200
201 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
202 return NULL;
203 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
204 return NULL;
205 add_sen_len = (add_sen_len < (sb_len - 8)) ?
206 add_sen_len : (sb_len - 8);
207 descp = &sense_buffer[8];
208 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
209 descp += desc_len;
210 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
211 desc_len = add_len + 2;
212 if (descp[0] == desc_type)
213 return descp;
214 if (add_len < 0) // short descriptor ??
215 break;
216 }
217 return NULL;
218}
219EXPORT_SYMBOL(scsi_sense_desc_find);
220
221/**
222 * scsi_build_sense_buffer - build sense data in a buffer
223 * @desc: Sense format (non zero == descriptor format,
224 * 0 == fixed format)
225 * @buf: Where to build sense data
226 * @key: Sense key
227 * @asc: Additional sense code
228 * @ascq: Additional sense code qualifier
229 *
230 **/
231void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
232{
233 if (desc) {
234 buf[0] = 0x72; /* descriptor, current */
235 buf[1] = key;
236 buf[2] = asc;
237 buf[3] = ascq;
238 buf[7] = 0;
239 } else {
240 buf[0] = 0x70; /* fixed, current */
241 buf[2] = key;
242 buf[7] = 0xa;
243 buf[12] = asc;
244 buf[13] = ascq;
245 }
246}
247EXPORT_SYMBOL(scsi_build_sense_buffer);
248
249/**
250 * scsi_set_sense_information - set the information field in a
251 * formatted sense data buffer
252 * @buf: Where to build sense data
Sagi Grimbergf5a8b3a2015-07-15 10:55:37 +0300253 * @buf_len: buffer length
Sagi Grimberg7708c162015-07-08 17:58:52 +0300254 * @info: 64-bit information value to be set
255 *
Sagi Grimbergf5a8b3a2015-07-15 10:55:37 +0300256 * Return value:
257 * 0 on success or EINVAL for invalid sense buffer length
Sagi Grimberg7708c162015-07-08 17:58:52 +0300258 **/
Sagi Grimbergf5a8b3a2015-07-15 10:55:37 +0300259int scsi_set_sense_information(u8 *buf, int buf_len, u64 info)
Sagi Grimberg7708c162015-07-08 17:58:52 +0300260{
261 if ((buf[0] & 0x7f) == 0x72) {
262 u8 *ucp, len;
263
264 len = buf[7];
265 ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0);
266 if (!ucp) {
Sagi Grimberg12306b42015-07-15 10:55:36 +0300267 buf[7] = len + 0xc;
Sagi Grimberg7708c162015-07-08 17:58:52 +0300268 ucp = buf + 8 + len;
269 }
Sagi Grimbergf5a8b3a2015-07-15 10:55:37 +0300270
271 if (buf_len < len + 0xc)
272 /* Not enough room for info */
273 return -EINVAL;
274
Sagi Grimberg7708c162015-07-08 17:58:52 +0300275 ucp[0] = 0;
276 ucp[1] = 0xa;
277 ucp[2] = 0x80; /* Valid bit */
278 ucp[3] = 0;
279 put_unaligned_be64(info, &ucp[4]);
280 } else if ((buf[0] & 0x7f) == 0x70) {
281 buf[0] |= 0x80;
282 put_unaligned_be64(info, &buf[3]);
283 }
Sagi Grimbergf5a8b3a2015-07-15 10:55:37 +0300284
285 return 0;
Sagi Grimberg7708c162015-07-08 17:58:52 +0300286}
287EXPORT_SYMBOL(scsi_set_sense_information);