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_LICENSE("GPL v2");
17 /* Command group 3 is reserved and should never be used. */
18 const unsigned char scsi_command_size_tbl[8] = {
19 6, 10, 10, 12, 16, 12, 10, 10
21 EXPORT_SYMBOL(scsi_command_size_tbl);
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).
27 static const char *const scsi_device_types[] = {
52 * scsi_device_type - Return 17-char string indicating device type.
53 * @type: type number to look up
55 const char *scsi_device_type(unsigned type)
58 return "Well-known LUN ";
61 if (type >= ARRAY_SIZE(scsi_device_types))
63 return scsi_device_types[type];
65 EXPORT_SYMBOL(scsi_device_type);
67 enum pr_type scsi_pr_type_to_block(enum scsi_pr_type 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;
86 EXPORT_SYMBOL_GPL(scsi_pr_type_to_block);
88 enum scsi_pr_type block_pr_type_to_scsi(enum pr_type 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;
107 EXPORT_SYMBOL_GPL(block_pr_type_to_scsi);
110 * scsilun_to_int - convert a scsi_lun to an int
111 * @scsilun: struct scsi_lun to be converted.
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.
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.
122 * Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function
123 * returns the integer: 0x0b03d204
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.
129 u64 scsilun_to_int(struct scsi_lun *scsilun)
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)));
140 EXPORT_SYMBOL(scsilun_to_int);
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.
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.
153 * Given an integer : 0x0b03d204, this function returns a
154 * struct scsi_lun of: d2 04 0b 03 00 00 00 00
157 void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)
161 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
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;
169 EXPORT_SYMBOL(int_to_scsilun);
172 * scsi_normalize_sense - normalize main elements from either fixed or
173 * descriptor sense data format into a common format.
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.
181 * The "main elements" from sense data are: response_code, sense_key,
182 * asc, ascq and additional_length (only for descriptor format).
184 * Typically this function can be called after a device has
185 * responded to a SCSI command with the CHECK_CONDITION status.
188 * true if valid sense data information found, else false;
190 bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
191 struct scsi_sense_hdr *sshdr)
193 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
195 if (!sense_buffer || !sb_len)
198 sshdr->response_code = (sense_buffer[0] & 0x7f);
200 if (!scsi_sense_valid(sshdr))
203 if (sshdr->response_code >= 0x72) {
208 sshdr->sense_key = (sense_buffer[1] & 0xf);
210 sshdr->asc = sense_buffer[2];
212 sshdr->ascq = sense_buffer[3];
214 sshdr->additional_length = sense_buffer[7];
220 sshdr->sense_key = (sense_buffer[2] & 0xf);
222 sb_len = min(sb_len, sense_buffer[7] + 8);
224 sshdr->asc = sense_buffer[12];
226 sshdr->ascq = sense_buffer[13];
232 EXPORT_SYMBOL(scsi_normalize_sense);
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)
242 * only valid when sense data is in descriptor format
245 * pointer to start of (first) descriptor if found else NULL
247 const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
250 int add_sen_len, add_len, desc_len, k;
253 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
255 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
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) {
262 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
263 desc_len = add_len + 2;
264 if (descp[0] == desc_type)
266 if (add_len < 0) // short descriptor ??
271 EXPORT_SYMBOL(scsi_sense_desc_find);
274 * scsi_build_sense_buffer - build sense data in a buffer
275 * @desc: Sense format (non-zero == descriptor format,
277 * @buf: Where to build sense data
279 * @asc: Additional sense code
280 * @ascq: Additional sense code qualifier
283 void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
286 buf[0] = 0x72; /* descriptor, current */
292 buf[0] = 0x70; /* fixed, current */
299 EXPORT_SYMBOL(scsi_build_sense_buffer);
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
309 * 0 on success or -EINVAL for invalid sense buffer length
311 int scsi_set_sense_information(u8 *buf, int buf_len, u64 info)
313 if ((buf[0] & 0x7f) == 0x72) {
317 ucp = (char *)scsi_sense_desc_find(buf, len + 8, 0);
323 if (buf_len < len + 0xc)
324 /* Not enough room for info */
329 ucp[2] = 0x80; /* Valid bit */
331 put_unaligned_be64(info, &ucp[4]);
332 } else if ((buf[0] & 0x7f) == 0x70) {
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.
338 if (info <= 0xffffffffUL)
342 put_unaligned_be32((u32)info, &buf[3]);
347 EXPORT_SYMBOL(scsi_set_sense_information);
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
359 * 0 on success or -EINVAL for invalid sense buffer length
361 int scsi_set_sense_field_pointer(u8 *buf, int buf_len, u16 fp, u8 bp, bool cd)
365 if ((buf[0] & 0x7f) == 0x72) {
367 ucp = (char *)scsi_sense_desc_find(buf, len + 8, 2);
373 if (buf_len < len + 8)
374 /* Not enough room for info */
379 ucp[4] = 0x80; /* Valid bit */
384 put_unaligned_be16(fp, &ucp[5]);
385 } else if ((buf[0] & 0x7f) == 0x70) {
395 put_unaligned_be16(fp, &buf[16]);
400 EXPORT_SYMBOL(scsi_set_sense_field_pointer);