1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _SCSI_SCSI_CMND_H
3#define _SCSI_SCSI_CMND_H
4
5#include <linux/dma-mapping.h>
6#include <linux/blkdev.h>
7#include <linux/t10-pi.h>
8#include <linux/list.h>
9#include <linux/types.h>
10#include <linux/timer.h>
11#include <linux/scatterlist.h>
12#include <scsi/scsi_device.h>
13
14struct Scsi_Host;
15
16/*
17 * MAX_COMMAND_SIZE is:
18 * The longest fixed-length SCSI CDB as per the SCSI standard.
19 * fixed-length means: commands that their size can be determined
20 * by their opcode and the CDB does not carry a length specifier, (unlike
21 * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
22 * true and the SCSI standard also defines extended commands and
23 * vendor specific commands that can be bigger than 16 bytes. The kernel
24 * will support these using the same infrastructure used for VARLEN CDB's.
25 * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
26 * supports without specifying a cmd_len by ULD's
27 */
28#define MAX_COMMAND_SIZE 16
29
30struct scsi_data_buffer {
31 struct sg_table table;
32 unsigned length;
33};
34
35/* embedded in scsi_cmnd */
36struct scsi_pointer {
37 char *ptr; /* data pointer */
38 int this_residual; /* left in this buffer */
39 struct scatterlist *buffer; /* which buffer */
40 int buffers_residual; /* how many buffers left */
41
42 dma_addr_t dma_handle;
43
44 volatile int Status;
45 volatile int Message;
46 volatile int have_data_in;
47 volatile int sent_command;
48 volatile int phase;
49};
50
51/* for scmd->flags */
52#define SCMD_TAGGED (1 << 0)
53#define SCMD_INITIALIZED (1 << 1)
54#define SCMD_LAST (1 << 2)
55/*
56 * libata uses SCSI EH to fetch sense data for successful commands.
57 * SCSI EH should not overwrite scmd->result when SCMD_FORCE_EH_SUCCESS is set.
58 */
59#define SCMD_FORCE_EH_SUCCESS (1 << 3)
60#define SCMD_FAIL_IF_RECOVERING (1 << 4)
61/* flags preserved across unprep / reprep */
62#define SCMD_PRESERVED_FLAGS (SCMD_INITIALIZED | SCMD_FAIL_IF_RECOVERING)
63
64/* for scmd->state */
65#define SCMD_STATE_COMPLETE 0
66#define SCMD_STATE_INFLIGHT 1
67
68enum scsi_cmnd_submitter {
69 SUBMITTED_BY_BLOCK_LAYER = 0,
70 SUBMITTED_BY_SCSI_ERROR_HANDLER = 1,
71 SUBMITTED_BY_SCSI_RESET_IOCTL = 2,
72} __packed;
73
74struct scsi_cmnd {
75 struct scsi_device *device;
76 struct list_head eh_entry; /* entry for the host eh_abort_list/eh_cmd_q */
77 struct delayed_work abort_work;
78
79 struct rcu_head rcu;
80
81 int eh_eflags; /* Used by error handlr */
82
83 int budget_token;
84
85 /*
86 * This is set to jiffies as it was when the command was first
87 * allocated. It is used to time how long the command has
88 * been outstanding
89 */
90 unsigned long jiffies_at_alloc;
91
92 int retries;
93 int allowed;
94
95 unsigned char prot_op;
96 unsigned char prot_type;
97 unsigned char prot_flags;
98 enum scsi_cmnd_submitter submitter;
99
100 unsigned short cmd_len;
101 enum dma_data_direction sc_data_direction;
102
103 unsigned char cmnd[32]; /* SCSI CDB */
104
105 /* These elements define the operation we ultimately want to perform */
106 struct scsi_data_buffer sdb;
107 struct scsi_data_buffer *prot_sdb;
108
109 unsigned underflow; /* Return error if less than
110 this amount is transferred */
111
112 unsigned transfersize; /* How much we are guaranteed to
113 transfer with each SCSI transfer
114 (ie, between disconnect /
115 reconnects. Probably == sector
116 size */
117 unsigned resid_len; /* residual count */
118 unsigned sense_len;
119 unsigned char *sense_buffer;
120 /* obtained by REQUEST SENSE when
121 * CHECK CONDITION is received on original
122 * command (auto-sense). Length must be
123 * SCSI_SENSE_BUFFERSIZE bytes. */
124
125 int flags; /* Command flags */
126 unsigned long state; /* Command completion state */
127
128 unsigned int extra_len; /* length of alignment and padding */
129
130 /*
131 * The fields below can be modified by the LLD but the fields above
132 * must not be modified.
133 */
134
135 unsigned char *host_scribble; /* The host adapter is allowed to
136 * call scsi_malloc and get some memory
137 * and hang it here. The host adapter
138 * is also expected to call scsi_free
139 * to release this memory. (The memory
140 * obtained by scsi_malloc is guaranteed
141 * to be at an address < 16Mb). */
142
143 int result; /* Status code from lower level driver */
144};
145
146/* Variant of blk_mq_rq_from_pdu() that verifies the type of its argument. */
147static inline struct request *scsi_cmd_to_rq(struct scsi_cmnd *scmd)
148{
149 return blk_mq_rq_from_pdu(pdu: scmd);
150}
151
152/*
153 * Return the driver private allocation behind the command.
154 * Only works if cmd_size is set in the host template.
155 */
156static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
157{
158 return cmd + 1;
159}
160
161void scsi_done(struct scsi_cmnd *cmd);
162void scsi_done_direct(struct scsi_cmnd *cmd);
163
164extern void scsi_finish_command(struct scsi_cmnd *cmd);
165
166extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
167 size_t *offset, size_t *len);
168extern void scsi_kunmap_atomic_sg(void *virt);
169
170blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
171void scsi_free_sgtables(struct scsi_cmnd *cmd);
172
173#ifdef CONFIG_SCSI_DMA
174extern int scsi_dma_map(struct scsi_cmnd *cmd);
175extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
176#else /* !CONFIG_SCSI_DMA */
177static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
178static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
179#endif /* !CONFIG_SCSI_DMA */
180
181static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
182{
183 return cmd->sdb.table.nents;
184}
185
186static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
187{
188 return cmd->sdb.table.sgl;
189}
190
191static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
192{
193 return cmd->sdb.length;
194}
195
196static inline void scsi_set_resid(struct scsi_cmnd *cmd, unsigned int resid)
197{
198 cmd->resid_len = resid;
199}
200
201static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
202{
203 return cmd->resid_len;
204}
205
206#define scsi_for_each_sg(cmd, sg, nseg, __i) \
207 for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
208
209static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
210 const void *buf, int buflen)
211{
212 return sg_copy_from_buffer(sgl: scsi_sglist(cmd), nents: scsi_sg_count(cmd),
213 buf, buflen);
214}
215
216static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
217 void *buf, int buflen)
218{
219 return sg_copy_to_buffer(sgl: scsi_sglist(cmd), nents: scsi_sg_count(cmd),
220 buf, buflen);
221}
222
223static inline sector_t scsi_get_sector(struct scsi_cmnd *scmd)
224{
225 return blk_rq_pos(rq: scsi_cmd_to_rq(scmd));
226}
227
228static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
229{
230 unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
231
232 return blk_rq_pos(rq: scsi_cmd_to_rq(scmd)) >> shift;
233}
234
235static inline unsigned int scsi_logical_block_count(struct scsi_cmnd *scmd)
236{
237 unsigned int shift = ilog2(scmd->device->sector_size);
238
239 return blk_rq_bytes(rq: scsi_cmd_to_rq(scmd)) >> shift;
240}
241
242/*
243 * The operations below are hints that tell the controller driver how
244 * to handle I/Os with DIF or similar types of protection information.
245 */
246enum scsi_prot_operations {
247 /* Normal I/O */
248 SCSI_PROT_NORMAL = 0,
249
250 /* OS-HBA: Protected, HBA-Target: Unprotected */
251 SCSI_PROT_READ_INSERT,
252 SCSI_PROT_WRITE_STRIP,
253
254 /* OS-HBA: Unprotected, HBA-Target: Protected */
255 SCSI_PROT_READ_STRIP,
256 SCSI_PROT_WRITE_INSERT,
257
258 /* OS-HBA: Protected, HBA-Target: Protected */
259 SCSI_PROT_READ_PASS,
260 SCSI_PROT_WRITE_PASS,
261};
262
263static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
264{
265 scmd->prot_op = op;
266}
267
268static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
269{
270 return scmd->prot_op;
271}
272
273enum scsi_prot_flags {
274 SCSI_PROT_TRANSFER_PI = 1 << 0,
275 SCSI_PROT_GUARD_CHECK = 1 << 1,
276 SCSI_PROT_REF_CHECK = 1 << 2,
277 SCSI_PROT_REF_INCREMENT = 1 << 3,
278 SCSI_PROT_IP_CHECKSUM = 1 << 4,
279};
280
281/*
282 * The controller usually does not know anything about the target it
283 * is communicating with. However, when DIX is enabled the controller
284 * must be know target type so it can verify the protection
285 * information passed along with the I/O.
286 */
287enum scsi_prot_target_type {
288 SCSI_PROT_DIF_TYPE0 = 0,
289 SCSI_PROT_DIF_TYPE1,
290 SCSI_PROT_DIF_TYPE2,
291 SCSI_PROT_DIF_TYPE3,
292};
293
294static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
295{
296 scmd->prot_type = type;
297}
298
299static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
300{
301 return scmd->prot_type;
302}
303
304static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
305{
306 struct request *rq = blk_mq_rq_from_pdu(pdu: scmd);
307
308 return t10_pi_ref_tag(rq);
309}
310
311static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
312{
313 return scmd->device->sector_size;
314}
315
316static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
317{
318 return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
319}
320
321static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
322{
323 return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
324}
325
326static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
327{
328 return cmd->prot_sdb;
329}
330
331#define scsi_for_each_prot_sg(cmd, sg, nseg, __i) \
332 for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
333
334static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
335{
336 cmd->result = (cmd->result & 0xffffff00) | status;
337}
338
339static inline u8 get_status_byte(struct scsi_cmnd *cmd)
340{
341 return cmd->result & 0xff;
342}
343
344static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
345{
346 cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
347}
348
349static inline u8 get_host_byte(struct scsi_cmnd *cmd)
350{
351 return (cmd->result >> 16) & 0xff;
352}
353
354/**
355 * scsi_msg_to_host_byte() - translate message byte
356 * @cmd: the SCSI command
357 * @msg: the SCSI parallel message byte to translate
358 *
359 * Translate the SCSI parallel message byte to a matching
360 * host byte setting. A message of COMMAND_COMPLETE indicates
361 * a successful command execution, any other message indicate
362 * an error. As the messages themselves only have a meaning
363 * for the SCSI parallel protocol this function translates
364 * them into a matching host byte value for SCSI EH.
365 */
366static inline void scsi_msg_to_host_byte(struct scsi_cmnd *cmd, u8 msg)
367{
368 switch (msg) {
369 case COMMAND_COMPLETE:
370 break;
371 case ABORT_TASK_SET:
372 set_host_byte(cmd, status: DID_ABORT);
373 break;
374 case TARGET_RESET:
375 set_host_byte(cmd, status: DID_RESET);
376 break;
377 default:
378 set_host_byte(cmd, status: DID_ERROR);
379 break;
380 }
381}
382
383static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
384{
385 unsigned int xfer_len = scmd->sdb.length;
386 unsigned int prot_interval = scsi_prot_interval(scmd);
387
388 if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
389 xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
390
391 return xfer_len;
392}
393
394extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
395 u8 key, u8 asc, u8 ascq);
396
397struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf,
398 blk_mq_req_flags_t flags);
399
400#endif /* _SCSI_SCSI_CMND_H */
401