xref: /linux/include/scsi/scsi_cmnd.h (revision 68550cbc6129159b7a6434796b721e8b66ee12f6)
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 #include <scsi/scsi_request.h>
14 
15 struct Scsi_Host;
16 struct scsi_driver;
17 
18 /*
19  * MAX_COMMAND_SIZE is:
20  * The longest fixed-length SCSI CDB as per the SCSI standard.
21  * fixed-length means: commands that their size can be determined
22  * by their opcode and the CDB does not carry a length specifier, (unlike
23  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
24  * true and the SCSI standard also defines extended commands and
25  * vendor specific commands that can be bigger than 16 bytes. The kernel
26  * will support these using the same infrastructure used for VARLEN CDB's.
27  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
28  * supports without specifying a cmd_len by ULD's
29  */
30 #define MAX_COMMAND_SIZE 16
31 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
32 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
33 #endif
34 
35 struct scsi_data_buffer {
36 	struct sg_table table;
37 	unsigned length;
38 };
39 
40 /* embedded in scsi_cmnd */
41 struct scsi_pointer {
42 	char *ptr;		/* data pointer */
43 	int this_residual;	/* left in this buffer */
44 	struct scatterlist *buffer;	/* which buffer */
45 	int buffers_residual;	/* how many buffers left */
46 
47         dma_addr_t dma_handle;
48 
49 	volatile int Status;
50 	volatile int Message;
51 	volatile int have_data_in;
52 	volatile int sent_command;
53 	volatile int phase;
54 };
55 
56 /* for scmd->flags */
57 #define SCMD_TAGGED		(1 << 0)
58 #define SCMD_INITIALIZED	(1 << 1)
59 #define SCMD_LAST		(1 << 2)
60 /* flags preserved across unprep / reprep */
61 #define SCMD_PRESERVED_FLAGS	(SCMD_INITIALIZED)
62 
63 /* for scmd->state */
64 #define SCMD_STATE_COMPLETE	0
65 #define SCMD_STATE_INFLIGHT	1
66 
67 enum scsi_cmnd_submitter {
68 	SUBMITTED_BY_BLOCK_LAYER = 0,
69 	SUBMITTED_BY_SCSI_ERROR_HANDLER = 1,
70 	SUBMITTED_BY_SCSI_RESET_IOCTL = 2,
71 } __packed;
72 
73 struct scsi_cmnd {
74 	struct scsi_request req;
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 	/* These elements define the operation we are about to perform */
104 	unsigned char *cmnd;
105 
106 
107 	/* These elements define the operation we ultimately want to perform */
108 	struct scsi_data_buffer sdb;
109 	struct scsi_data_buffer *prot_sdb;
110 
111 	unsigned underflow;	/* Return error if less than
112 				   this amount is transferred */
113 
114 	unsigned transfersize;	/* How much we are guaranteed to
115 				   transfer with each SCSI transfer
116 				   (ie, between disconnect /
117 				   reconnects.   Probably == sector
118 				   size */
119 
120 	unsigned char *sense_buffer;
121 				/* obtained by REQUEST SENSE when
122 				 * CHECK CONDITION is received on original
123 				 * command (auto-sense). Length must be
124 				 * SCSI_SENSE_BUFFERSIZE bytes. */
125 
126 	/*
127 	 * The following fields can be written to by the host specific code.
128 	 * Everything else should be left alone.
129 	 */
130 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
131 
132 	unsigned char *host_scribble;	/* The host adapter is allowed to
133 					 * call scsi_malloc and get some memory
134 					 * and hang it here.  The host adapter
135 					 * is also expected to call scsi_free
136 					 * to release this memory.  (The memory
137 					 * obtained by scsi_malloc is guaranteed
138 					 * to be at an address < 16Mb). */
139 
140 	int result;		/* Status code from lower level driver */
141 	int flags;		/* Command flags */
142 	unsigned long state;	/* Command completion state */
143 
144 	unsigned int extra_len;	/* length of alignment and padding */
145 };
146 
147 /* Variant of blk_mq_rq_from_pdu() that verifies the type of its argument. */
148 static inline struct request *scsi_cmd_to_rq(struct scsi_cmnd *scmd)
149 {
150 	return blk_mq_rq_from_pdu(scmd);
151 }
152 
153 /*
154  * Return the driver private allocation behind the command.
155  * Only works if cmd_size is set in the host template.
156  */
157 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
158 {
159 	return cmd + 1;
160 }
161 
162 /* make sure not to use it with passthrough commands */
163 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
164 {
165 	struct request *rq = scsi_cmd_to_rq(cmd);
166 
167 	return *(struct scsi_driver **)rq->rq_disk->private_data;
168 }
169 
170 void scsi_done(struct scsi_cmnd *cmd);
171 
172 extern void scsi_finish_command(struct scsi_cmnd *cmd);
173 
174 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
175 				 size_t *offset, size_t *len);
176 extern void scsi_kunmap_atomic_sg(void *virt);
177 
178 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
179 void scsi_free_sgtables(struct scsi_cmnd *cmd);
180 
181 #ifdef CONFIG_SCSI_DMA
182 extern int scsi_dma_map(struct scsi_cmnd *cmd);
183 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
184 #else /* !CONFIG_SCSI_DMA */
185 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
186 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
187 #endif /* !CONFIG_SCSI_DMA */
188 
189 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
190 {
191 	return cmd->sdb.table.nents;
192 }
193 
194 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
195 {
196 	return cmd->sdb.table.sgl;
197 }
198 
199 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
200 {
201 	return cmd->sdb.length;
202 }
203 
204 static inline void scsi_set_resid(struct scsi_cmnd *cmd, unsigned int resid)
205 {
206 	cmd->req.resid_len = resid;
207 }
208 
209 static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
210 {
211 	return cmd->req.resid_len;
212 }
213 
214 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
215 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
216 
217 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
218 					   void *buf, int buflen)
219 {
220 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
221 				   buf, buflen);
222 }
223 
224 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
225 					 void *buf, int buflen)
226 {
227 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
228 				 buf, buflen);
229 }
230 
231 static inline sector_t scsi_get_sector(struct scsi_cmnd *scmd)
232 {
233 	return blk_rq_pos(scsi_cmd_to_rq(scmd));
234 }
235 
236 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
237 {
238 	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
239 
240 	return blk_rq_pos(scsi_cmd_to_rq(scmd)) >> shift;
241 }
242 
243 static inline unsigned int scsi_logical_block_count(struct scsi_cmnd *scmd)
244 {
245 	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
246 
247 	return blk_rq_bytes(scsi_cmd_to_rq(scmd)) >> shift;
248 }
249 
250 /*
251  * The operations below are hints that tell the controller driver how
252  * to handle I/Os with DIF or similar types of protection information.
253  */
254 enum scsi_prot_operations {
255 	/* Normal I/O */
256 	SCSI_PROT_NORMAL = 0,
257 
258 	/* OS-HBA: Protected, HBA-Target: Unprotected */
259 	SCSI_PROT_READ_INSERT,
260 	SCSI_PROT_WRITE_STRIP,
261 
262 	/* OS-HBA: Unprotected, HBA-Target: Protected */
263 	SCSI_PROT_READ_STRIP,
264 	SCSI_PROT_WRITE_INSERT,
265 
266 	/* OS-HBA: Protected, HBA-Target: Protected */
267 	SCSI_PROT_READ_PASS,
268 	SCSI_PROT_WRITE_PASS,
269 };
270 
271 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
272 {
273 	scmd->prot_op = op;
274 }
275 
276 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
277 {
278 	return scmd->prot_op;
279 }
280 
281 enum scsi_prot_flags {
282 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
283 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
284 	SCSI_PROT_REF_CHECK		= 1 << 2,
285 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
286 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
287 };
288 
289 /*
290  * The controller usually does not know anything about the target it
291  * is communicating with.  However, when DIX is enabled the controller
292  * must be know target type so it can verify the protection
293  * information passed along with the I/O.
294  */
295 enum scsi_prot_target_type {
296 	SCSI_PROT_DIF_TYPE0 = 0,
297 	SCSI_PROT_DIF_TYPE1,
298 	SCSI_PROT_DIF_TYPE2,
299 	SCSI_PROT_DIF_TYPE3,
300 };
301 
302 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
303 {
304 	scmd->prot_type = type;
305 }
306 
307 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
308 {
309 	return scmd->prot_type;
310 }
311 
312 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
313 {
314 	struct request *rq = blk_mq_rq_from_pdu(scmd);
315 
316 	return t10_pi_ref_tag(rq);
317 }
318 
319 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
320 {
321 	return scmd->device->sector_size;
322 }
323 
324 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
325 {
326 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
327 }
328 
329 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
330 {
331 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
332 }
333 
334 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
335 {
336 	return cmd->prot_sdb;
337 }
338 
339 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
340 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
341 
342 static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
343 {
344 	cmd->result = (cmd->result & 0xffffff00) | status;
345 }
346 
347 static inline u8 get_status_byte(struct scsi_cmnd *cmd)
348 {
349 	return cmd->result & 0xff;
350 }
351 
352 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
353 {
354 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
355 }
356 
357 static inline u8 get_host_byte(struct scsi_cmnd *cmd)
358 {
359 	return (cmd->result >> 16) & 0xff;
360 }
361 
362 /**
363  * scsi_msg_to_host_byte() - translate message byte
364  *
365  * Translate the SCSI parallel message byte to a matching
366  * host byte setting. A message of COMMAND_COMPLETE indicates
367  * a successful command execution, any other message indicate
368  * an error. As the messages themselves only have a meaning
369  * for the SCSI parallel protocol this function translates
370  * them into a matching host byte value for SCSI EH.
371  */
372 static inline void scsi_msg_to_host_byte(struct scsi_cmnd *cmd, u8 msg)
373 {
374 	switch (msg) {
375 	case COMMAND_COMPLETE:
376 		break;
377 	case ABORT_TASK_SET:
378 		set_host_byte(cmd, DID_ABORT);
379 		break;
380 	case TARGET_RESET:
381 		set_host_byte(cmd, DID_RESET);
382 		break;
383 	default:
384 		set_host_byte(cmd, DID_ERROR);
385 		break;
386 	}
387 }
388 
389 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
390 {
391 	unsigned int xfer_len = scmd->sdb.length;
392 	unsigned int prot_interval = scsi_prot_interval(scmd);
393 
394 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
395 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
396 
397 	return xfer_len;
398 }
399 
400 extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
401 			     u8 key, u8 asc, u8 ascq);
402 
403 struct request *scsi_alloc_request(struct request_queue *q,
404 		unsigned int op, blk_mq_req_flags_t flags);
405 
406 #endif /* _SCSI_SCSI_CMND_H */
407