1 // SPDX-License-Identifier: GPL-2.0
3 * SCSI functions used by both the initiator and the target code.
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>
15 MODULE_DESCRIPTION("SCSI functions used by both the initiator and the target code");
16 MODULE_LICENSE("GPL v2");
18 /* Command group 3 is reserved and should never be used. */
19 const unsigned char scsi_command_size_tbl[8] = {
20 6, 10, 10, 12, 16, 12, 10, 10
22 EXPORT_SYMBOL(scsi_command_size_tbl);
24 /* NB: These are exposed through /proc/scsi/scsi and form part of the ABI.
25 * You may not alter any existing entry (although adding new ones is
26 * encouraged once assigned by ANSI/INCITS T10).
28 static const char *const scsi_device_types[] = {
53 * scsi_device_type - Return 17-char string indicating device type.
54 * @type: type number to look up
56 const char *scsi_device_type(unsigned type)
59 return "Well-known LUN ";
62 if (type >= ARRAY_SIZE(scsi_device_types))
64 return scsi_device_types[type];
66 EXPORT_SYMBOL(scsi_device_type);
68 enum pr_type scsi_pr_type_to_block(enum scsi_pr_type type)
71 case SCSI_PR_WRITE_EXCLUSIVE:
72 return PR_WRITE_EXCLUSIVE;
73 case SCSI_PR_EXCLUSIVE_ACCESS:
74 return PR_EXCLUSIVE_ACCESS;
75 case SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY:
76 return PR_WRITE_EXCLUSIVE_REG_ONLY;
77 case SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY:
78 return PR_EXCLUSIVE_ACCESS_REG_ONLY;
79 case SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS:
80 return PR_WRITE_EXCLUSIVE_ALL_REGS;
81 case SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS:
82 return PR_EXCLUSIVE_ACCESS_ALL_REGS;
87 EXPORT_SYMBOL_GPL(scsi_pr_type_to_block);
89 enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type)
92 case PR_WRITE_EXCLUSIVE:
93 return SCSI_PR_WRITE_EXCLUSIVE;
94 case PR_EXCLUSIVE_ACCESS:
95 return SCSI_PR_EXCLUSIVE_ACCESS;
96 case PR_WRITE_EXCLUSIVE_REG_ONLY:
97 return SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY;
98 case PR_EXCLUSIVE_ACCESS_REG_ONLY:
99 return SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY;
100 case PR_WRITE_EXCLUSIVE_ALL_REGS:
101 return SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS;
102 case PR_EXCLUSIVE_ACCESS_ALL_REGS:
103 return SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS;
108 EXPORT_SYMBOL_GPL(block_pr_type_to_scsi);
111 * scsilun_to_int - convert a scsi_lun to an int
112 * @scsilun: struct scsi_lun to be converted.
115 * Convert @scsilun from a struct scsi_lun to a four-byte host byte-ordered
116 * integer, and return the result. The caller must check for
117 * truncation before using this function.
120 * For a description of the LUN format, post SCSI-3 see the SCSI
121 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
123 * Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function
124 * returns the integer: 0x0b03d204
126 * This encoding will return a standard integer LUN for LUNs smaller
127 * than 256, which typically use a single level LUN structure with
128 * addressing method 0.
130 u64 scsilun_to_int(struct scsi_lun *scsilun)
136 for (i = 0; i < sizeof(lun); i += 2)
137 lun = lun | (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) |
138 ((u64)scsilun->scsi_lun[i + 1] << (i * 8)));
141 EXPORT_SYMBOL(scsilun_to_int);
144 * int_to_scsilun - reverts an int into a scsi_lun
145 * @lun: integer to be reverted
146 * @scsilun: struct scsi_lun to be set.
149 * Reverts the functionality of the scsilun_to_int, which packed
150 * an 8-byte lun value into an int. This routine unpacks the int
151 * back into the lun value.
154 * Given an integer : 0x0b03d204, this function returns a
155 * struct scsi_lun of: d2 04 0b 03 00 00 00 00
158 void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)
162 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
164 for (i = 0; i < sizeof(lun); i += 2) {
165 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
166 scsilun->scsi_lun[i+1] = lun & 0xFF;
170 EXPORT_SYMBOL(int_to_scsilun);
173 * scsi_normalize_sense - normalize main elements from either fixed or
174 * descriptor sense data format into a common format.
176 * @sense_buffer: byte array containing sense data returned by device
177 * @sb_len: number of valid bytes in sense_buffer
178 * @sshdr: pointer to instance of structure that common
179 * elements are written to.
182 * The "main elements" from sense data are: response_code, sense_key,
183 * asc, ascq and additional_length (only for descriptor format).
185 * Typically this function can be called after a device has
186 * responded to a SCSI command with the CHECK_CONDITION status.
189 * true if valid sense data information found, else false;
191 bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
192 struct scsi_sense_hdr *sshdr)
194 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
196 if (!sense_buffer || !sb_len)
199 sshdr->response_code = (sense_buffer[0] & 0x7f);
201 if (!scsi_sense_valid(sshdr))
204 if (sshdr->response_code >= 0x72) {
209 sshdr->sense_key = (sense_buffer[1] & 0xf);
211 sshdr->asc = sense_buffer[2];
213 sshdr->ascq = sense_buffer[3];
215 sshdr->additional_length = sense_buffer[7];
221 sshdr->sense_key = (sense_buffer[2] & 0xf);
223 sb_len = min(sb_len, sense_buffer[7] + 8);
225 sshdr->asc = sense_buffer[12];
227 sshdr->ascq = sense_buffer[13];
233 EXPORT_SYMBOL(scsi_normalize_sense);
236 * scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
237 * @sense_buffer: byte array of descriptor format sense data
238 * @sb_len: number of valid bytes in sense_buffer
239 * @desc_type: value of descriptor type to find
240 * (e.g. 0 -> information)
243 * only valid when sense data is in descriptor format
246 * pointer to start of (first) descriptor if found else NULL
248 const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
251 int add_sen_len, add_len, desc_len, k;
254 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
256 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
258 add_sen_len = (add_sen_len < (sb_len - 8)) ?
259 add_sen_len : (sb_len - 8);
260 descp = &sense_buffer[8];
261 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
263 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
264 desc_len = add_len + 2;
265 if (descp[0] == desc_type)
267 if (add_len < 0) // short descriptor ??
272 EXPORT_SYMBOL(scsi_sense_desc_find);
275 * scsi_build_sense_buffer - build sense data in a buffer
276 * @desc: Sense format (non-zero == descriptor format,
278 * @buf: Where to build sense data
280 * @asc: Additional sense code
281 * @ascq: Additional sense code qualifier
284 void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
287 buf[0] = 0x72; /* descriptor, current */
293 buf[0] = 0x70; /* fixed, current */
300 EXPORT_SYMBOL(scsi_build_sense_buffer);
303 * scsi_set_sense_information - set the information field in a
304 * formatted sense data buffer
305 * @buf: Where to build sense data
306 * @buf_len: buffer length
307 * @info: 64-bit information value to be set
310 * 0 on success or -EINVAL for invalid sense buffer length
312 int scsi_set_sense_information(u8 *buf, int buf_len, u64 info)
314 if ((buf[0] & 0x7f) == 0x72) {
318 ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0);
324 if (buf_len < len + 0xc)
325 /* Not enough room for info */
330 ucp[2] = 0x80; /* Valid bit */
332 put_unaligned_be64(info, &ucp[4]);
333 } else if ((buf[0] & 0x7f) == 0x70) {
335 * Only set the 'VALID' bit if we can represent the value
336 * correctly; otherwise just fill out the lower bytes and
337 * clear the 'VALID' flag.
339 if (info <= 0xffffffffUL)
343 put_unaligned_be32((u32)info, &buf[3]);
348 EXPORT_SYMBOL(scsi_set_sense_information);
351 * scsi_set_sense_field_pointer - set the field pointer sense key
352 * specific information in a formatted sense data buffer
353 * @buf: Where to build sense data
354 * @buf_len: buffer length
355 * @fp: field pointer to be set
356 * @bp: bit pointer to be set
357 * @cd: command/data bit
360 * 0 on success or -EINVAL for invalid sense buffer length
362 int scsi_set_sense_field_pointer(u8 *buf, int buf_len, u16 fp, u8 bp, bool cd)
366 if ((buf[0] & 0x7f) == 0x72) {
368 ucp = (char *)scsi_sense_desc_find(buf, len + 8, 2);
374 if (buf_len < len + 8)
375 /* Not enough room for info */
380 ucp[4] = 0x80; /* Valid bit */
385 put_unaligned_be16(fp, &ucp[5]);
386 } else if ((buf[0] & 0x7f) == 0x70) {
396 put_unaligned_be16(fp, &buf[16]);
401 EXPORT_SYMBOL(scsi_set_sense_field_pointer);