xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision be2b81b5)
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 #define SCMD_FAIL_IF_RECOVERING	(1 << 4)
56 /* flags preserved across unprep / reprep */
57 #define SCMD_PRESERVED_FLAGS	(SCMD_INITIALIZED | SCMD_FAIL_IF_RECOVERING)
58 
59 /* for scmd->state */
60 #define SCMD_STATE_COMPLETE	0
61 #define SCMD_STATE_INFLIGHT	1
62 
63 enum scsi_cmnd_submitter {
64 	SUBMITTED_BY_BLOCK_LAYER = 0,
65 	SUBMITTED_BY_SCSI_ERROR_HANDLER = 1,
66 	SUBMITTED_BY_SCSI_RESET_IOCTL = 2,
67 } __packed;
68 
69 struct scsi_cmnd {
70 	struct scsi_device *device;
71 	struct list_head eh_entry; /* entry for the host eh_abort_list/eh_cmd_q */
72 	struct delayed_work abort_work;
73 
74 	struct rcu_head rcu;
75 
76 	int eh_eflags;		/* Used by error handlr */
77 
78 	int budget_token;
79 
80 	/*
81 	 * This is set to jiffies as it was when the command was first
82 	 * allocated.  It is used to time how long the command has
83 	 * been outstanding
84 	 */
85 	unsigned long jiffies_at_alloc;
86 
87 	int retries;
88 	int allowed;
89 
90 	unsigned char prot_op;
91 	unsigned char prot_type;
92 	unsigned char prot_flags;
93 	enum scsi_cmnd_submitter submitter;
94 
95 	unsigned short cmd_len;
96 	enum dma_data_direction sc_data_direction;
97 
98 	unsigned char cmnd[32]; /* SCSI CDB */
99 
100 	/* These elements define the operation we ultimately want to perform */
101 	struct scsi_data_buffer sdb;
102 	struct scsi_data_buffer *prot_sdb;
103 
104 	unsigned underflow;	/* Return error if less than
105 				   this amount is transferred */
106 
107 	unsigned transfersize;	/* How much we are guaranteed to
108 				   transfer with each SCSI transfer
109 				   (ie, between disconnect /
110 				   reconnects.   Probably == sector
111 				   size */
112 	unsigned resid_len;	/* residual count */
113 	unsigned sense_len;
114 	unsigned char *sense_buffer;
115 				/* obtained by REQUEST SENSE when
116 				 * CHECK CONDITION is received on original
117 				 * command (auto-sense). Length must be
118 				 * SCSI_SENSE_BUFFERSIZE bytes. */
119 
120 	int flags;		/* Command flags */
121 	unsigned long state;	/* Command completion state */
122 
123 	unsigned int extra_len;	/* length of alignment and padding */
124 
125 	/*
126 	 * The fields below can be modified by the LLD but the fields above
127 	 * must not be modified.
128 	 */
129 
130 	unsigned char *host_scribble;	/* The host adapter is allowed to
131 					 * call scsi_malloc and get some memory
132 					 * and hang it here.  The host adapter
133 					 * is also expected to call scsi_free
134 					 * to release this memory.  (The memory
135 					 * obtained by scsi_malloc is guaranteed
136 					 * to be at an address < 16Mb). */
137 
138 	int result;		/* Status code from lower level driver */
139 };
140 
141 /* Variant of blk_mq_rq_from_pdu() that verifies the type of its argument. */
142 static inline struct request *scsi_cmd_to_rq(struct scsi_cmnd *scmd)
143 {
144 	return blk_mq_rq_from_pdu(scmd);
145 }
146 
147 /*
148  * Return the driver private allocation behind the command.
149  * Only works if cmd_size is set in the host template.
150  */
151 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
152 {
153 	return cmd + 1;
154 }
155 
156 void scsi_done(struct scsi_cmnd *cmd);
157 void scsi_done_direct(struct scsi_cmnd *cmd);
158 
159 extern void scsi_finish_command(struct scsi_cmnd *cmd);
160 
161 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
162 				 size_t *offset, size_t *len);
163 extern void scsi_kunmap_atomic_sg(void *virt);
164 
165 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
166 void scsi_free_sgtables(struct scsi_cmnd *cmd);
167 
168 #ifdef CONFIG_SCSI_DMA
169 extern int scsi_dma_map(struct scsi_cmnd *cmd);
170 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
171 #else /* !CONFIG_SCSI_DMA */
172 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
173 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
174 #endif /* !CONFIG_SCSI_DMA */
175 
176 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
177 {
178 	return cmd->sdb.table.nents;
179 }
180 
181 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
182 {
183 	return cmd->sdb.table.sgl;
184 }
185 
186 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
187 {
188 	return cmd->sdb.length;
189 }
190 
191 static inline void scsi_set_resid(struct scsi_cmnd *cmd, unsigned int resid)
192 {
193 	cmd->resid_len = resid;
194 }
195 
196 static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
197 {
198 	return cmd->resid_len;
199 }
200 
201 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
202 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
203 
204 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
205 					   const void *buf, int buflen)
206 {
207 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
208 				   buf, buflen);
209 }
210 
211 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
212 					 void *buf, int buflen)
213 {
214 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
215 				 buf, buflen);
216 }
217 
218 static inline sector_t scsi_get_sector(struct scsi_cmnd *scmd)
219 {
220 	return blk_rq_pos(scsi_cmd_to_rq(scmd));
221 }
222 
223 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
224 {
225 	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
226 
227 	return blk_rq_pos(scsi_cmd_to_rq(scmd)) >> shift;
228 }
229 
230 static inline unsigned int scsi_logical_block_count(struct scsi_cmnd *scmd)
231 {
232 	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
233 
234 	return blk_rq_bytes(scsi_cmd_to_rq(scmd)) >> shift;
235 }
236 
237 /*
238  * The operations below are hints that tell the controller driver how
239  * to handle I/Os with DIF or similar types of protection information.
240  */
241 enum scsi_prot_operations {
242 	/* Normal I/O */
243 	SCSI_PROT_NORMAL = 0,
244 
245 	/* OS-HBA: Protected, HBA-Target: Unprotected */
246 	SCSI_PROT_READ_INSERT,
247 	SCSI_PROT_WRITE_STRIP,
248 
249 	/* OS-HBA: Unprotected, HBA-Target: Protected */
250 	SCSI_PROT_READ_STRIP,
251 	SCSI_PROT_WRITE_INSERT,
252 
253 	/* OS-HBA: Protected, HBA-Target: Protected */
254 	SCSI_PROT_READ_PASS,
255 	SCSI_PROT_WRITE_PASS,
256 };
257 
258 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
259 {
260 	scmd->prot_op = op;
261 }
262 
263 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
264 {
265 	return scmd->prot_op;
266 }
267 
268 enum scsi_prot_flags {
269 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
270 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
271 	SCSI_PROT_REF_CHECK		= 1 << 2,
272 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
273 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
274 };
275 
276 /*
277  * The controller usually does not know anything about the target it
278  * is communicating with.  However, when DIX is enabled the controller
279  * must be know target type so it can verify the protection
280  * information passed along with the I/O.
281  */
282 enum scsi_prot_target_type {
283 	SCSI_PROT_DIF_TYPE0 = 0,
284 	SCSI_PROT_DIF_TYPE1,
285 	SCSI_PROT_DIF_TYPE2,
286 	SCSI_PROT_DIF_TYPE3,
287 };
288 
289 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
290 {
291 	scmd->prot_type = type;
292 }
293 
294 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
295 {
296 	return scmd->prot_type;
297 }
298 
299 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
300 {
301 	struct request *rq = blk_mq_rq_from_pdu(scmd);
302 
303 	return t10_pi_ref_tag(rq);
304 }
305 
306 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
307 {
308 	return scmd->device->sector_size;
309 }
310 
311 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
312 {
313 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
314 }
315 
316 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
317 {
318 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
319 }
320 
321 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
322 {
323 	return cmd->prot_sdb;
324 }
325 
326 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
327 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
328 
329 static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
330 {
331 	cmd->result = (cmd->result & 0xffffff00) | status;
332 }
333 
334 static inline u8 get_status_byte(struct scsi_cmnd *cmd)
335 {
336 	return cmd->result & 0xff;
337 }
338 
339 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
340 {
341 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
342 }
343 
344 static inline u8 get_host_byte(struct scsi_cmnd *cmd)
345 {
346 	return (cmd->result >> 16) & 0xff;
347 }
348 
349 /**
350  * scsi_msg_to_host_byte() - translate message byte
351  *
352  * Translate the SCSI parallel message byte to a matching
353  * host byte setting. A message of COMMAND_COMPLETE indicates
354  * a successful command execution, any other message indicate
355  * an error. As the messages themselves only have a meaning
356  * for the SCSI parallel protocol this function translates
357  * them into a matching host byte value for SCSI EH.
358  */
359 static inline void scsi_msg_to_host_byte(struct scsi_cmnd *cmd, u8 msg)
360 {
361 	switch (msg) {
362 	case COMMAND_COMPLETE:
363 		break;
364 	case ABORT_TASK_SET:
365 		set_host_byte(cmd, DID_ABORT);
366 		break;
367 	case TARGET_RESET:
368 		set_host_byte(cmd, DID_RESET);
369 		break;
370 	default:
371 		set_host_byte(cmd, DID_ERROR);
372 		break;
373 	}
374 }
375 
376 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
377 {
378 	unsigned int xfer_len = scmd->sdb.length;
379 	unsigned int prot_interval = scsi_prot_interval(scmd);
380 
381 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
382 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
383 
384 	return xfer_len;
385 }
386 
387 extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
388 			     u8 key, u8 asc, u8 ascq);
389 
390 struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf,
391 				   blk_mq_req_flags_t flags);
392 
393 #endif /* _SCSI_SCSI_CMND_H */
394