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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SCSI functions used by both the initiator and the target code.
4 */
5
6#include <linux/bug.h>
7#include <linux/kernel.h>
8#include <linux/string.h>
9#include <linux/errno.h>
10#include <linux/module.h>
11#include <uapi/linux/pr.h>
12#include <asm/unaligned.h>
13#include <scsi/scsi_common.h>
14
15MODULE_LICENSE("GPL v2");
16
17/* Command group 3 is reserved and should never be used. */
18const unsigned char scsi_command_size_tbl[8] = {
19 6, 10, 10, 12, 16, 12, 10, 10
20};
21EXPORT_SYMBOL(scsi_command_size_tbl);
22
23/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
24 * You may not alter any existing entry (although adding new ones is
25 * encouraged once assigned by ANSI/INCITS T10).
26 */
27static const char *const scsi_device_types[] = {
28 "Direct-Access ",
29 "Sequential-Access",
30 "Printer ",
31 "Processor ",
32 "WORM ",
33 "CD-ROM ",
34 "Scanner ",
35 "Optical Device ",
36 "Medium Changer ",
37 "Communications ",
38 "ASC IT8 ",
39 "ASC IT8 ",
40 "RAID ",
41 "Enclosure ",
42 "Direct-Access-RBC",
43 "Optical card ",
44 "Bridge controller",
45 "Object storage ",
46 "Automation/Drive ",
47 "Security Manager ",
48 "Direct-Access-ZBC",
49};
50
51/**
52 * scsi_device_type - Return 17-char string indicating device type.
53 * @type: type number to look up
54 */
55const char *scsi_device_type(unsigned type)
56{
57 if (type == 0x1e)
58 return "Well-known LUN ";
59 if (type == 0x1f)
60 return "No Device ";
61 if (type >= ARRAY_SIZE(scsi_device_types))
62 return "Unknown ";
63 return scsi_device_types[type];
64}
65EXPORT_SYMBOL(scsi_device_type);
66
67enum pr_type scsi_pr_type_to_block(enum scsi_pr_type type)
68{
69 switch (type) {
70 case SCSI_PR_WRITE_EXCLUSIVE:
71 return PR_WRITE_EXCLUSIVE;
72 case SCSI_PR_EXCLUSIVE_ACCESS:
73 return PR_EXCLUSIVE_ACCESS;
74 case SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY:
75 return PR_WRITE_EXCLUSIVE_REG_ONLY;
76 case SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY:
77 return PR_EXCLUSIVE_ACCESS_REG_ONLY;
78 case SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS:
79 return PR_WRITE_EXCLUSIVE_ALL_REGS;
80 case SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS:
81 return PR_EXCLUSIVE_ACCESS_ALL_REGS;
82 }
83
84 return 0;
85}
86EXPORT_SYMBOL_GPL(scsi_pr_type_to_block);
87
88enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
89{
90 switch (type) {
91 case PR_WRITE_EXCLUSIVE:
92 return SCSI_PR_WRITE_EXCLUSIVE;
93 case PR_EXCLUSIVE_ACCESS:
94 return SCSI_PR_EXCLUSIVE_ACCESS;
95 case PR_WRITE_EXCLUSIVE_REG_ONLY:
96 return SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY;
97 case PR_EXCLUSIVE_ACCESS_REG_ONLY:
98 return SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY;
99 case PR_WRITE_EXCLUSIVE_ALL_REGS:
100 return SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS;
101 case PR_EXCLUSIVE_ACCESS_ALL_REGS:
102 return SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS;
103 }
104
105 return 0;
106}
107EXPORT_SYMBOL_GPL(block_pr_type_to_scsi);
108
109/**
110 * scsilun_to_int - convert a scsi_lun to an int
111 * @scsilun: struct scsi_lun to be converted.
112 *
113 * Description:
114 * Convert @scsilun from a struct scsi_lun to a four-byte host byte-ordered
115 * integer, and return the result. The caller must check for
116 * truncation before using this function.
117 *
118 * Notes:
119 * For a description of the LUN format, post SCSI-3 see the SCSI
120 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
121 *
122 * Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function
123 * returns the integer: 0x0b03d204
124 *
125 * This encoding will return a standard integer LUN for LUNs smaller
126 * than 256, which typically use a single level LUN structure with
127 * addressing method 0.
128 */
129u64 scsilun_to_int(struct scsi_lun *scsilun)
130{
131 int i;
132 u64 lun;
133
134 lun = 0;
135 for (i = 0; i < sizeof(lun); i += 2)
136 lun = lun | (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) |
137 ((u64)scsilun->scsi_lun[i + 1] << (i * 8)));
138 return lun;
139}
140EXPORT_SYMBOL(scsilun_to_int);
141
142/**
143 * int_to_scsilun - reverts an int into a scsi_lun
144 * @lun: integer to be reverted
145 * @scsilun: struct scsi_lun to be set.
146 *
147 * Description:
148 * Reverts the functionality of the scsilun_to_int, which packed
149 * an 8-byte lun value into an int. This routine unpacks the int
150 * back into the lun value.
151 *
152 * Notes:
153 * Given an integer : 0x0b03d204, this function returns a
154 * struct scsi_lun of: d2 04 0b 03 00 00 00 00
155 *
156 */
157void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)
158{
159 int i;
160
161 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
162
163 for (i = 0; i < sizeof(lun); i += 2) {
164 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
165 scsilun->scsi_lun[i+1] = lun & 0xFF;
166 lun = lun >> 16;
167 }
168}
169EXPORT_SYMBOL(int_to_scsilun);
170
171/**
172 * scsi_normalize_sense - normalize main elements from either fixed or
173 * descriptor sense data format into a common format.
174 *
175 * @sense_buffer: byte array containing sense data returned by device
176 * @sb_len: number of valid bytes in sense_buffer
177 * @sshdr: pointer to instance of structure that common
178 * elements are written to.
179 *
180 * Notes:
181 * The "main elements" from sense data are: response_code, sense_key,
182 * asc, ascq and additional_length (only for descriptor format).
183 *
184 * Typically this function can be called after a device has
185 * responded to a SCSI command with the CHECK_CONDITION status.
186 *
187 * Return value:
188 * true if valid sense data information found, else false;
189 */
190bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
191 struct scsi_sense_hdr *sshdr)
192{
193 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
194
195 if (!sense_buffer || !sb_len)
196 return false;
197
198 sshdr->response_code = (sense_buffer[0] & 0x7f);
199
200 if (!scsi_sense_valid(sshdr))
201 return false;
202
203 if (sshdr->response_code >= 0x72) {
204 /*
205 * descriptor format
206 */
207 if (sb_len > 1)
208 sshdr->sense_key = (sense_buffer[1] & 0xf);
209 if (sb_len > 2)
210 sshdr->asc = sense_buffer[2];
211 if (sb_len > 3)
212 sshdr->ascq = sense_buffer[3];
213 if (sb_len > 7)
214 sshdr->additional_length = sense_buffer[7];
215 } else {
216 /*
217 * fixed format
218 */
219 if (sb_len > 2)
220 sshdr->sense_key = (sense_buffer[2] & 0xf);
221 if (sb_len > 7) {
222 sb_len = min(sb_len, sense_buffer[7] + 8);
223 if (sb_len > 12)
224 sshdr->asc = sense_buffer[12];
225 if (sb_len > 13)
226 sshdr->ascq = sense_buffer[13];
227 }
228 }
229
230 return true;
231}
232EXPORT_SYMBOL(scsi_normalize_sense);
233
234/**
235 * scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
236 * @sense_buffer: byte array of descriptor format sense data
237 * @sb_len: number of valid bytes in sense_buffer
238 * @desc_type: value of descriptor type to find
239 * (e.g. 0 -> information)
240 *
241 * Notes:
242 * only valid when sense data is in descriptor format
243 *
244 * Return value:
245 * pointer to start of (first) descriptor if found else NULL
246 */
247const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
248 int desc_type)
249{
250 int add_sen_len, add_len, desc_len, k;
251 const u8 * descp;
252
253 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
254 return NULL;
255 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
256 return NULL;
257 add_sen_len = (add_sen_len < (sb_len - 8)) ?
258 add_sen_len : (sb_len - 8);
259 descp = &sense_buffer[8];
260 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
261 descp += desc_len;
262 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
263 desc_len = add_len + 2;
264 if (descp[0] == desc_type)
265 return descp;
266 if (add_len < 0) // short descriptor ??
267 break;
268 }
269 return NULL;
270}
271EXPORT_SYMBOL(scsi_sense_desc_find);
272
273/**
274 * scsi_build_sense_buffer - build sense data in a buffer
275 * @desc: Sense format (non-zero == descriptor format,
276 * 0 == fixed format)
277 * @buf: Where to build sense data
278 * @key: Sense key
279 * @asc: Additional sense code
280 * @ascq: Additional sense code qualifier
281 *
282 **/
283void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
284{
285 if (desc) {
286 buf[0] = 0x72; /* descriptor, current */
287 buf[1] = key;
288 buf[2] = asc;
289 buf[3] = ascq;
290 buf[7] = 0;
291 } else {
292 buf[0] = 0x70; /* fixed, current */
293 buf[2] = key;
294 buf[7] = 0xa;
295 buf[12] = asc;
296 buf[13] = ascq;
297 }
298}
299EXPORT_SYMBOL(scsi_build_sense_buffer);
300
301/**
302 * scsi_set_sense_information - set the information field in a
303 * formatted sense data buffer
304 * @buf: Where to build sense data
305 * @buf_len: buffer length
306 * @info: 64-bit information value to be set
307 *
308 * Return value:
309 * 0 on success or -EINVAL for invalid sense buffer length
310 **/
311int scsi_set_sense_information(u8 *buf, int buf_len, u64 info)
312{
313 if ((buf[0] & 0x7f) == 0x72) {
314 u8 *ucp, len;
315
316 len = buf[7];
317 ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0);
318 if (!ucp) {
319 buf[7] = len + 0xc;
320 ucp = buf + 8 + len;
321 }
322
323 if (buf_len < len + 0xc)
324 /* Not enough room for info */
325 return -EINVAL;
326
327 ucp[0] = 0;
328 ucp[1] = 0xa;
329 ucp[2] = 0x80; /* Valid bit */
330 ucp[3] = 0;
331 put_unaligned_be64(info, &ucp[4]);
332 } else if ((buf[0] & 0x7f) == 0x70) {
333 /*
334 * Only set the 'VALID' bit if we can represent the value
335 * correctly; otherwise just fill out the lower bytes and
336 * clear the 'VALID' flag.
337 */
338 if (info <= 0xffffffffUL)
339 buf[0] |= 0x80;
340 else
341 buf[0] &= 0x7f;
342 put_unaligned_be32((u32)info, &buf[3]);
343 }
344
345 return 0;
346}
347EXPORT_SYMBOL(scsi_set_sense_information);
348
349/**
350 * scsi_set_sense_field_pointer - set the field pointer sense key
351 * specific information in a formatted sense data buffer
352 * @buf: Where to build sense data
353 * @buf_len: buffer length
354 * @fp: field pointer to be set
355 * @bp: bit pointer to be set
356 * @cd: command/data bit
357 *
358 * Return value:
359 * 0 on success or -EINVAL for invalid sense buffer length
360 */
361int scsi_set_sense_field_pointer(u8 *buf, int buf_len, u16 fp, u8 bp, bool cd)
362{
363 u8 *ucp, len;
364
365 if ((buf[0] & 0x7f) == 0x72) {
366 len = buf[7];
367 ucp = (char *)scsi_sense_desc_find(buf, len + 8, 2);
368 if (!ucp) {
369 buf[7] = len + 8;
370 ucp = buf + 8 + len;
371 }
372
373 if (buf_len < len + 8)
374 /* Not enough room for info */
375 return -EINVAL;
376
377 ucp[0] = 2;
378 ucp[1] = 6;
379 ucp[4] = 0x80; /* Valid bit */
380 if (cd)
381 ucp[4] |= 0x40;
382 if (bp < 0x8)
383 ucp[4] |= 0x8 | bp;
384 put_unaligned_be16(fp, &ucp[5]);
385 } else if ((buf[0] & 0x7f) == 0x70) {
386 len = buf[7];
387 if (len < 18)
388 buf[7] = 18;
389
390 buf[15] = 0x80;
391 if (cd)
392 buf[15] |= 0x40;
393 if (bp < 0x8)
394 buf[15] |= 0x8 | bp;
395 put_unaligned_be16(fp, &buf[16]);
396 }
397
398 return 0;
399}
400EXPORT_SYMBOL(scsi_set_sense_field_pointer);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SCSI functions used by both the initiator and the target code.
4 */
5
6#include <linux/bug.h>
7#include <linux/kernel.h>
8#include <linux/string.h>
9#include <linux/errno.h>
10#include <linux/module.h>
11#include <asm/unaligned.h>
12#include <scsi/scsi_common.h>
13
14MODULE_LICENSE("GPL v2");
15
16/* Command group 3 is reserved and should never be used. */
17const unsigned char scsi_command_size_tbl[8] = {
18 6, 10, 10, 12, 16, 12, 10, 10
19};
20EXPORT_SYMBOL(scsi_command_size_tbl);
21
22/* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
23 * You may not alter any existing entry (although adding new ones is
24 * encouraged once assigned by ANSI/INCITS T10).
25 */
26static const char *const scsi_device_types[] = {
27 "Direct-Access ",
28 "Sequential-Access",
29 "Printer ",
30 "Processor ",
31 "WORM ",
32 "CD-ROM ",
33 "Scanner ",
34 "Optical Device ",
35 "Medium Changer ",
36 "Communications ",
37 "ASC IT8 ",
38 "ASC IT8 ",
39 "RAID ",
40 "Enclosure ",
41 "Direct-Access-RBC",
42 "Optical card ",
43 "Bridge controller",
44 "Object storage ",
45 "Automation/Drive ",
46 "Security Manager ",
47 "Direct-Access-ZBC",
48};
49
50/**
51 * scsi_device_type - Return 17-char string indicating device type.
52 * @type: type number to look up
53 */
54const char *scsi_device_type(unsigned type)
55{
56 if (type == 0x1e)
57 return "Well-known LUN ";
58 if (type == 0x1f)
59 return "No Device ";
60 if (type >= ARRAY_SIZE(scsi_device_types))
61 return "Unknown ";
62 return scsi_device_types[type];
63}
64EXPORT_SYMBOL(scsi_device_type);
65
66/**
67 * scsilun_to_int - convert a scsi_lun to an int
68 * @scsilun: struct scsi_lun to be converted.
69 *
70 * Description:
71 * Convert @scsilun from a struct scsi_lun to a four-byte host byte-ordered
72 * integer, and return the result. The caller must check for
73 * truncation before using this function.
74 *
75 * Notes:
76 * For a description of the LUN format, post SCSI-3 see the SCSI
77 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
78 *
79 * Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function
80 * returns the integer: 0x0b03d204
81 *
82 * This encoding will return a standard integer LUN for LUNs smaller
83 * than 256, which typically use a single level LUN structure with
84 * addressing method 0.
85 */
86u64 scsilun_to_int(struct scsi_lun *scsilun)
87{
88 int i;
89 u64 lun;
90
91 lun = 0;
92 for (i = 0; i < sizeof(lun); i += 2)
93 lun = lun | (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) |
94 ((u64)scsilun->scsi_lun[i + 1] << (i * 8)));
95 return lun;
96}
97EXPORT_SYMBOL(scsilun_to_int);
98
99/**
100 * int_to_scsilun - reverts an int into a scsi_lun
101 * @lun: integer to be reverted
102 * @scsilun: struct scsi_lun to be set.
103 *
104 * Description:
105 * Reverts the functionality of the scsilun_to_int, which packed
106 * an 8-byte lun value into an int. This routine unpacks the int
107 * back into the lun value.
108 *
109 * Notes:
110 * Given an integer : 0x0b03d204, this function returns a
111 * struct scsi_lun of: d2 04 0b 03 00 00 00 00
112 *
113 */
114void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)
115{
116 int i;
117
118 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
119
120 for (i = 0; i < sizeof(lun); i += 2) {
121 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
122 scsilun->scsi_lun[i+1] = lun & 0xFF;
123 lun = lun >> 16;
124 }
125}
126EXPORT_SYMBOL(int_to_scsilun);
127
128/**
129 * scsi_normalize_sense - normalize main elements from either fixed or
130 * descriptor sense data format into a common format.
131 *
132 * @sense_buffer: byte array containing sense data returned by device
133 * @sb_len: number of valid bytes in sense_buffer
134 * @sshdr: pointer to instance of structure that common
135 * elements are written to.
136 *
137 * Notes:
138 * The "main elements" from sense data are: response_code, sense_key,
139 * asc, ascq and additional_length (only for descriptor format).
140 *
141 * Typically this function can be called after a device has
142 * responded to a SCSI command with the CHECK_CONDITION status.
143 *
144 * Return value:
145 * true if valid sense data information found, else false;
146 */
147bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
148 struct scsi_sense_hdr *sshdr)
149{
150 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
151
152 if (!sense_buffer || !sb_len)
153 return false;
154
155 sshdr->response_code = (sense_buffer[0] & 0x7f);
156
157 if (!scsi_sense_valid(sshdr))
158 return false;
159
160 if (sshdr->response_code >= 0x72) {
161 /*
162 * descriptor format
163 */
164 if (sb_len > 1)
165 sshdr->sense_key = (sense_buffer[1] & 0xf);
166 if (sb_len > 2)
167 sshdr->asc = sense_buffer[2];
168 if (sb_len > 3)
169 sshdr->ascq = sense_buffer[3];
170 if (sb_len > 7)
171 sshdr->additional_length = sense_buffer[7];
172 } else {
173 /*
174 * fixed format
175 */
176 if (sb_len > 2)
177 sshdr->sense_key = (sense_buffer[2] & 0xf);
178 if (sb_len > 7) {
179 sb_len = (sb_len < (sense_buffer[7] + 8)) ?
180 sb_len : (sense_buffer[7] + 8);
181 if (sb_len > 12)
182 sshdr->asc = sense_buffer[12];
183 if (sb_len > 13)
184 sshdr->ascq = sense_buffer[13];
185 }
186 }
187
188 return true;
189}
190EXPORT_SYMBOL(scsi_normalize_sense);
191
192/**
193 * scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
194 * @sense_buffer: byte array of descriptor format sense data
195 * @sb_len: number of valid bytes in sense_buffer
196 * @desc_type: value of descriptor type to find
197 * (e.g. 0 -> information)
198 *
199 * Notes:
200 * only valid when sense data is in descriptor format
201 *
202 * Return value:
203 * pointer to start of (first) descriptor if found else NULL
204 */
205const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
206 int desc_type)
207{
208 int add_sen_len, add_len, desc_len, k;
209 const u8 * descp;
210
211 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
212 return NULL;
213 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
214 return NULL;
215 add_sen_len = (add_sen_len < (sb_len - 8)) ?
216 add_sen_len : (sb_len - 8);
217 descp = &sense_buffer[8];
218 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
219 descp += desc_len;
220 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
221 desc_len = add_len + 2;
222 if (descp[0] == desc_type)
223 return descp;
224 if (add_len < 0) // short descriptor ??
225 break;
226 }
227 return NULL;
228}
229EXPORT_SYMBOL(scsi_sense_desc_find);
230
231/**
232 * scsi_build_sense_buffer - build sense data in a buffer
233 * @desc: Sense format (non-zero == descriptor format,
234 * 0 == fixed format)
235 * @buf: Where to build sense data
236 * @key: Sense key
237 * @asc: Additional sense code
238 * @ascq: Additional sense code qualifier
239 *
240 **/
241void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
242{
243 if (desc) {
244 buf[0] = 0x72; /* descriptor, current */
245 buf[1] = key;
246 buf[2] = asc;
247 buf[3] = ascq;
248 buf[7] = 0;
249 } else {
250 buf[0] = 0x70; /* fixed, current */
251 buf[2] = key;
252 buf[7] = 0xa;
253 buf[12] = asc;
254 buf[13] = ascq;
255 }
256}
257EXPORT_SYMBOL(scsi_build_sense_buffer);
258
259/**
260 * scsi_set_sense_information - set the information field in a
261 * formatted sense data buffer
262 * @buf: Where to build sense data
263 * @buf_len: buffer length
264 * @info: 64-bit information value to be set
265 *
266 * Return value:
267 * 0 on success or -EINVAL for invalid sense buffer length
268 **/
269int scsi_set_sense_information(u8 *buf, int buf_len, u64 info)
270{
271 if ((buf[0] & 0x7f) == 0x72) {
272 u8 *ucp, len;
273
274 len = buf[7];
275 ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0);
276 if (!ucp) {
277 buf[7] = len + 0xc;
278 ucp = buf + 8 + len;
279 }
280
281 if (buf_len < len + 0xc)
282 /* Not enough room for info */
283 return -EINVAL;
284
285 ucp[0] = 0;
286 ucp[1] = 0xa;
287 ucp[2] = 0x80; /* Valid bit */
288 ucp[3] = 0;
289 put_unaligned_be64(info, &ucp[4]);
290 } else if ((buf[0] & 0x7f) == 0x70) {
291 /*
292 * Only set the 'VALID' bit if we can represent the value
293 * correctly; otherwise just fill out the lower bytes and
294 * clear the 'VALID' flag.
295 */
296 if (info <= 0xffffffffUL)
297 buf[0] |= 0x80;
298 else
299 buf[0] &= 0x7f;
300 put_unaligned_be32((u32)info, &buf[3]);
301 }
302
303 return 0;
304}
305EXPORT_SYMBOL(scsi_set_sense_information);
306
307/**
308 * scsi_set_sense_field_pointer - set the field pointer sense key
309 * specific information in a formatted sense data buffer
310 * @buf: Where to build sense data
311 * @buf_len: buffer length
312 * @fp: field pointer to be set
313 * @bp: bit pointer to be set
314 * @cd: command/data bit
315 *
316 * Return value:
317 * 0 on success or -EINVAL for invalid sense buffer length
318 */
319int scsi_set_sense_field_pointer(u8 *buf, int buf_len, u16 fp, u8 bp, bool cd)
320{
321 u8 *ucp, len;
322
323 if ((buf[0] & 0x7f) == 0x72) {
324 len = buf[7];
325 ucp = (char *)scsi_sense_desc_find(buf, len + 8, 2);
326 if (!ucp) {
327 buf[7] = len + 8;
328 ucp = buf + 8 + len;
329 }
330
331 if (buf_len < len + 8)
332 /* Not enough room for info */
333 return -EINVAL;
334
335 ucp[0] = 2;
336 ucp[1] = 6;
337 ucp[4] = 0x80; /* Valid bit */
338 if (cd)
339 ucp[4] |= 0x40;
340 if (bp < 0x8)
341 ucp[4] |= 0x8 | bp;
342 put_unaligned_be16(fp, &ucp[5]);
343 } else if ((buf[0] & 0x7f) == 0x70) {
344 len = buf[7];
345 if (len < 18)
346 buf[7] = 18;
347
348 buf[15] = 0x80;
349 if (cd)
350 buf[15] |= 0x40;
351 if (bp < 0x8)
352 buf[15] |= 0x8 | bp;
353 put_unaligned_be16(fp, &buf[16]);
354 }
355
356 return 0;
357}
358EXPORT_SYMBOL(scsi_set_sense_field_pointer);