xref: /linux/include/scsi/scsi_cmnd.h (revision e1c4c5436b4ad579762fbe78bfabc8aef59bd5b1)
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 
14 struct 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 
30 struct scsi_data_buffer {
31 	struct sg_table table;
32 	unsigned length;
33 };
34 
35 /* embedded in scsi_cmnd */
36 struct 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 /* flags preserved across unprep / reprep */
56 #define SCMD_PRESERVED_FLAGS	(SCMD_INITIALIZED)
57 
58 /* for scmd->state */
59 #define SCMD_STATE_COMPLETE	0
60 #define SCMD_STATE_INFLIGHT	1
61 
62 enum scsi_cmnd_submitter {
63 	SUBMITTED_BY_BLOCK_LAYER = 0,
64 	SUBMITTED_BY_SCSI_ERROR_HANDLER = 1,
65 	SUBMITTED_BY_SCSI_RESET_IOCTL = 2,
66 } __packed;
67 
68 struct scsi_cmnd {
69 	struct scsi_device *device;
70 	struct list_head eh_entry; /* entry for the host eh_abort_list/eh_cmd_q */
71 	struct delayed_work abort_work;
72 
73 	struct rcu_head rcu;
74 
75 	int eh_eflags;		/* Used by error handlr */
76 
77 	int budget_token;
78 
79 	/*
80 	 * This is set to jiffies as it was when the command was first
81 	 * allocated.  It is used to time how long the command has
82 	 * been outstanding
83 	 */
84 	unsigned long jiffies_at_alloc;
85 
86 	int retries;
87 	int allowed;
88 
89 	unsigned char prot_op;
90 	unsigned char prot_type;
91 	unsigned char prot_flags;
92 	enum scsi_cmnd_submitter submitter;
93 
94 	unsigned short cmd_len;
95 	enum dma_data_direction sc_data_direction;
96 
97 	unsigned char cmnd[32]; /* SCSI CDB */
98 
99 	/* These elements define the operation we ultimately want to perform */
100 	struct scsi_data_buffer sdb;
101 	struct scsi_data_buffer *prot_sdb;
102 
103 	unsigned underflow;	/* Return error if less than
104 				   this amount is transferred */
105 
106 	unsigned transfersize;	/* How much we are guaranteed to
107 				   transfer with each SCSI transfer
108 				   (ie, between disconnect /
109 				   reconnects.   Probably == sector
110 				   size */
111 	unsigned resid_len;	/* residual count */
112 	unsigned sense_len;
113 	unsigned char *sense_buffer;
114 				/* obtained by REQUEST SENSE when
115 				 * CHECK CONDITION is received on original
116 				 * command (auto-sense). Length must be
117 				 * SCSI_SENSE_BUFFERSIZE bytes. */
118 
119 	int flags;		/* Command flags */
120 	unsigned long state;	/* Command completion state */
121 
122 	unsigned int extra_len;	/* length of alignment and padding */
123 
124 	/*
125 	 * The fields below can be modified by the LLD but the fields above
126 	 * must not be modified.
127 	 */
128 
129 	unsigned char *host_scribble;	/* The host adapter is allowed to
130 					 * call scsi_malloc and get some memory
131 					 * and hang it here.  The host adapter
132 					 * is also expected to call scsi_free
133 					 * to release this memory.  (The memory
134 					 * obtained by scsi_malloc is guaranteed
135 					 * to be at an address < 16Mb). */
136 
137 	int result;		/* Status code from lower level driver */
138 };
139 
140 /* Variant of blk_mq_rq_from_pdu() that verifies the type of its argument. */
141 static inline struct request *scsi_cmd_to_rq(struct scsi_cmnd *scmd)
142 {
143 	return blk_mq_rq_from_pdu(scmd);
144 }
145 
146 /*
147  * Return the driver private allocation behind the command.
148  * Only works if cmd_size is set in the host template.
149  */
150 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
151 {
152 	return cmd + 1;
153 }
154 
155 void scsi_done(struct scsi_cmnd *cmd);
156 void scsi_done_direct(struct scsi_cmnd *cmd);
157 
158 extern void scsi_finish_command(struct scsi_cmnd *cmd);
159 
160 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
161 				 size_t *offset, size_t *len);
162 extern void scsi_kunmap_atomic_sg(void *virt);
163 
164 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
165 void scsi_free_sgtables(struct scsi_cmnd *cmd);
166 
167 #ifdef CONFIG_SCSI_DMA
168 extern int scsi_dma_map(struct scsi_cmnd *cmd);
169 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
170 #else /* !CONFIG_SCSI_DMA */
171 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
172 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
173 #endif /* !CONFIG_SCSI_DMA */
174 
175 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
176 {
177 	return cmd->sdb.table.nents;
178 }
179 
180 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
181 {
182 	return cmd->sdb.table.sgl;
183 }
184 
185 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
186 {
187 	return cmd->sdb.length;
188 }
189 
190 static inline void scsi_set_resid(struct scsi_cmnd *cmd, unsigned int resid)
191 {
192 	cmd->resid_len = resid;
193 }
194 
195 static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
196 {
197 	return cmd->resid_len;
198 }
199 
200 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
201 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
202 
203 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
204 					   const void *buf, int buflen)
205 {
206 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
207 				   buf, buflen);
208 }
209 
210 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
211 					 void *buf, int buflen)
212 {
213 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
214 				 buf, buflen);
215 }
216 
217 static inline sector_t scsi_get_sector(struct scsi_cmnd *scmd)
218 {
219 	return blk_rq_pos(scsi_cmd_to_rq(scmd));
220 }
221 
222 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
223 {
224 	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
225 
226 	return blk_rq_pos(scsi_cmd_to_rq(scmd)) >> shift;
227 }
228 
229 static inline unsigned int scsi_logical_block_count(struct scsi_cmnd *scmd)
230 {
231 	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
232 
233 	return blk_rq_bytes(scsi_cmd_to_rq(scmd)) >> shift;
234 }
235 
236 /*
237  * The operations below are hints that tell the controller driver how
238  * to handle I/Os with DIF or similar types of protection information.
239  */
240 enum scsi_prot_operations {
241 	/* Normal I/O */
242 	SCSI_PROT_NORMAL = 0,
243 
244 	/* OS-HBA: Protected, HBA-Target: Unprotected */
245 	SCSI_PROT_READ_INSERT,
246 	SCSI_PROT_WRITE_STRIP,
247 
248 	/* OS-HBA: Unprotected, HBA-Target: Protected */
249 	SCSI_PROT_READ_STRIP,
250 	SCSI_PROT_WRITE_INSERT,
251 
252 	/* OS-HBA: Protected, HBA-Target: Protected */
253 	SCSI_PROT_READ_PASS,
254 	SCSI_PROT_WRITE_PASS,
255 };
256 
257 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
258 {
259 	scmd->prot_op = op;
260 }
261 
262 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
263 {
264 	return scmd->prot_op;
265 }
266 
267 enum scsi_prot_flags {
268 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
269 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
270 	SCSI_PROT_REF_CHECK		= 1 << 2,
271 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
272 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
273 };
274 
275 /*
276  * The controller usually does not know anything about the target it
277  * is communicating with.  However, when DIX is enabled the controller
278  * must be know target type so it can verify the protection
279  * information passed along with the I/O.
280  */
281 enum scsi_prot_target_type {
282 	SCSI_PROT_DIF_TYPE0 = 0,
283 	SCSI_PROT_DIF_TYPE1,
284 	SCSI_PROT_DIF_TYPE2,
285 	SCSI_PROT_DIF_TYPE3,
286 };
287 
288 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
289 {
290 	scmd->prot_type = type;
291 }
292 
293 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
294 {
295 	return scmd->prot_type;
296 }
297 
298 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
299 {
300 	struct request *rq = blk_mq_rq_from_pdu(scmd);
301 
302 	return t10_pi_ref_tag(rq);
303 }
304 
305 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
306 {
307 	return scmd->device->sector_size;
308 }
309 
310 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
311 {
312 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
313 }
314 
315 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
316 {
317 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
318 }
319 
320 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
321 {
322 	return cmd->prot_sdb;
323 }
324 
325 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
326 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
327 
328 static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
329 {
330 	cmd->result = (cmd->result & 0xffffff00) | status;
331 }
332 
333 static inline u8 get_status_byte(struct scsi_cmnd *cmd)
334 {
335 	return cmd->result & 0xff;
336 }
337 
338 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
339 {
340 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
341 }
342 
343 static inline u8 get_host_byte(struct scsi_cmnd *cmd)
344 {
345 	return (cmd->result >> 16) & 0xff;
346 }
347 
348 /**
349  * scsi_msg_to_host_byte() - translate message byte
350  *
351  * Translate the SCSI parallel message byte to a matching
352  * host byte setting. A message of COMMAND_COMPLETE indicates
353  * a successful command execution, any other message indicate
354  * an error. As the messages themselves only have a meaning
355  * for the SCSI parallel protocol this function translates
356  * them into a matching host byte value for SCSI EH.
357  */
358 static inline void scsi_msg_to_host_byte(struct scsi_cmnd *cmd, u8 msg)
359 {
360 	switch (msg) {
361 	case COMMAND_COMPLETE:
362 		break;
363 	case ABORT_TASK_SET:
364 		set_host_byte(cmd, DID_ABORT);
365 		break;
366 	case TARGET_RESET:
367 		set_host_byte(cmd, DID_RESET);
368 		break;
369 	default:
370 		set_host_byte(cmd, DID_ERROR);
371 		break;
372 	}
373 }
374 
375 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
376 {
377 	unsigned int xfer_len = scmd->sdb.length;
378 	unsigned int prot_interval = scsi_prot_interval(scmd);
379 
380 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
381 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
382 
383 	return xfer_len;
384 }
385 
386 extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
387 			     u8 key, u8 asc, u8 ascq);
388 
389 struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf,
390 				   blk_mq_req_flags_t flags);
391 
392 #endif /* _SCSI_SCSI_CMND_H */
393