xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision b8b350af)
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_host.h>
14 #include <scsi/scsi_request.h>
15 
16 struct Scsi_Host;
17 struct scsi_driver;
18 
19 /*
20  * MAX_COMMAND_SIZE is:
21  * The longest fixed-length SCSI CDB as per the SCSI standard.
22  * fixed-length means: commands that their size can be determined
23  * by their opcode and the CDB does not carry a length specifier, (unlike
24  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
25  * true and the SCSI standard also defines extended commands and
26  * vendor specific commands that can be bigger than 16 bytes. The kernel
27  * will support these using the same infrastructure used for VARLEN CDB's.
28  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
29  * supports without specifying a cmd_len by ULD's
30  */
31 #define MAX_COMMAND_SIZE 16
32 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
33 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
34 #endif
35 
36 struct scsi_data_buffer {
37 	struct sg_table table;
38 	unsigned length;
39 };
40 
41 /* embedded in scsi_cmnd */
42 struct scsi_pointer {
43 	char *ptr;		/* data pointer */
44 	int this_residual;	/* left in this buffer */
45 	struct scatterlist *buffer;	/* which buffer */
46 	int buffers_residual;	/* how many buffers left */
47 
48         dma_addr_t dma_handle;
49 
50 	volatile int Status;
51 	volatile int Message;
52 	volatile int have_data_in;
53 	volatile int sent_command;
54 	volatile int phase;
55 };
56 
57 /* for scmd->flags */
58 #define SCMD_TAGGED		(1 << 0)
59 #define SCMD_INITIALIZED	(1 << 1)
60 #define SCMD_LAST		(1 << 2)
61 /* flags preserved across unprep / reprep */
62 #define SCMD_PRESERVED_FLAGS	(SCMD_INITIALIZED)
63 
64 /* for scmd->state */
65 #define SCMD_STATE_COMPLETE	0
66 #define SCMD_STATE_INFLIGHT	1
67 
68 struct scsi_cmnd {
69 	struct scsi_request req;
70 	struct scsi_device *device;
71 	struct list_head eh_entry; /* entry for the host 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 
94 	unsigned short cmd_len;
95 	enum dma_data_direction sc_data_direction;
96 
97 	/* These elements define the operation we are about to perform */
98 	unsigned char *cmnd;
99 
100 
101 	/* These elements define the operation we ultimately want to perform */
102 	struct scsi_data_buffer sdb;
103 	struct scsi_data_buffer *prot_sdb;
104 
105 	unsigned underflow;	/* Return error if less than
106 				   this amount is transferred */
107 
108 	unsigned transfersize;	/* How much we are guaranteed to
109 				   transfer with each SCSI transfer
110 				   (ie, between disconnect /
111 				   reconnects.   Probably == sector
112 				   size */
113 
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 	/* Low-level done function - can be used by low-level driver to point
121 	 *        to completion function.  Not used by mid/upper level code. */
122 	void (*scsi_done) (struct scsi_cmnd *);
123 
124 	/*
125 	 * The following fields can be written to by the host specific code.
126 	 * Everything else should be left alone.
127 	 */
128 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
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 	int flags;		/* Command flags */
140 	unsigned long state;	/* Command completion state */
141 
142 	unsigned int extra_len;	/* length of alignment and padding */
143 };
144 
145 /* Variant of blk_mq_rq_from_pdu() that verifies the type of its argument. */
146 static inline struct request *scsi_cmd_to_rq(struct scsi_cmnd *scmd)
147 {
148 	return blk_mq_rq_from_pdu(scmd);
149 }
150 
151 /*
152  * Return the driver private allocation behind the command.
153  * Only works if cmd_size is set in the host template.
154  */
155 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
156 {
157 	return cmd + 1;
158 }
159 
160 /* make sure not to use it with passthrough commands */
161 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
162 {
163 	struct request *rq = scsi_cmd_to_rq(cmd);
164 
165 	return *(struct scsi_driver **)rq->rq_disk->private_data;
166 }
167 
168 extern void scsi_finish_command(struct scsi_cmnd *cmd);
169 
170 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
171 				 size_t *offset, size_t *len);
172 extern void scsi_kunmap_atomic_sg(void *virt);
173 
174 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
175 void scsi_free_sgtables(struct scsi_cmnd *cmd);
176 
177 #ifdef CONFIG_SCSI_DMA
178 extern int scsi_dma_map(struct scsi_cmnd *cmd);
179 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
180 #else /* !CONFIG_SCSI_DMA */
181 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
182 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
183 #endif /* !CONFIG_SCSI_DMA */
184 
185 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
186 {
187 	return cmd->sdb.table.nents;
188 }
189 
190 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
191 {
192 	return cmd->sdb.table.sgl;
193 }
194 
195 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
196 {
197 	return cmd->sdb.length;
198 }
199 
200 static inline void scsi_set_resid(struct scsi_cmnd *cmd, unsigned int resid)
201 {
202 	cmd->req.resid_len = resid;
203 }
204 
205 static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
206 {
207 	return cmd->req.resid_len;
208 }
209 
210 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
211 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
212 
213 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
214 					   void *buf, int buflen)
215 {
216 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
217 				   buf, buflen);
218 }
219 
220 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
221 					 void *buf, int buflen)
222 {
223 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
224 				 buf, buflen);
225 }
226 
227 static inline sector_t scsi_get_sector(struct scsi_cmnd *scmd)
228 {
229 	return blk_rq_pos(scsi_cmd_to_rq(scmd));
230 }
231 
232 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
233 {
234 	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
235 
236 	return blk_rq_pos(scsi_cmd_to_rq(scmd)) >> shift;
237 }
238 
239 static inline unsigned int scsi_logical_block_count(struct scsi_cmnd *scmd)
240 {
241 	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
242 
243 	return blk_rq_bytes(scsi_cmd_to_rq(scmd)) >> shift;
244 }
245 
246 /*
247  * The operations below are hints that tell the controller driver how
248  * to handle I/Os with DIF or similar types of protection information.
249  */
250 enum scsi_prot_operations {
251 	/* Normal I/O */
252 	SCSI_PROT_NORMAL = 0,
253 
254 	/* OS-HBA: Protected, HBA-Target: Unprotected */
255 	SCSI_PROT_READ_INSERT,
256 	SCSI_PROT_WRITE_STRIP,
257 
258 	/* OS-HBA: Unprotected, HBA-Target: Protected */
259 	SCSI_PROT_READ_STRIP,
260 	SCSI_PROT_WRITE_INSERT,
261 
262 	/* OS-HBA: Protected, HBA-Target: Protected */
263 	SCSI_PROT_READ_PASS,
264 	SCSI_PROT_WRITE_PASS,
265 };
266 
267 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
268 {
269 	scmd->prot_op = op;
270 }
271 
272 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
273 {
274 	return scmd->prot_op;
275 }
276 
277 enum scsi_prot_flags {
278 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
279 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
280 	SCSI_PROT_REF_CHECK		= 1 << 2,
281 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
282 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
283 };
284 
285 /*
286  * The controller usually does not know anything about the target it
287  * is communicating with.  However, when DIX is enabled the controller
288  * must be know target type so it can verify the protection
289  * information passed along with the I/O.
290  */
291 enum scsi_prot_target_type {
292 	SCSI_PROT_DIF_TYPE0 = 0,
293 	SCSI_PROT_DIF_TYPE1,
294 	SCSI_PROT_DIF_TYPE2,
295 	SCSI_PROT_DIF_TYPE3,
296 };
297 
298 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
299 {
300 	scmd->prot_type = type;
301 }
302 
303 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
304 {
305 	return scmd->prot_type;
306 }
307 
308 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
309 {
310 	struct request *rq = blk_mq_rq_from_pdu(scmd);
311 
312 	return t10_pi_ref_tag(rq);
313 }
314 
315 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
316 {
317 	return scmd->device->sector_size;
318 }
319 
320 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
321 {
322 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
323 }
324 
325 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
326 {
327 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
328 }
329 
330 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
331 {
332 	return cmd->prot_sdb;
333 }
334 
335 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
336 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
337 
338 static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
339 {
340 	cmd->result = (cmd->result & 0xffffff00) | status;
341 }
342 
343 static inline u8 get_status_byte(struct scsi_cmnd *cmd)
344 {
345 	return cmd->result & 0xff;
346 }
347 
348 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
349 {
350 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
351 }
352 
353 static inline u8 get_host_byte(struct scsi_cmnd *cmd)
354 {
355 	return (cmd->result >> 16) & 0xff;
356 }
357 
358 /**
359  * scsi_msg_to_host_byte() - translate message byte
360  *
361  * Translate the SCSI parallel message byte to a matching
362  * host byte setting. A message of COMMAND_COMPLETE indicates
363  * a successful command execution, any other message indicate
364  * an error. As the messages themselves only have a meaning
365  * for the SCSI parallel protocol this function translates
366  * them into a matching host byte value for SCSI EH.
367  */
368 static inline void scsi_msg_to_host_byte(struct scsi_cmnd *cmd, u8 msg)
369 {
370 	switch (msg) {
371 	case COMMAND_COMPLETE:
372 		break;
373 	case ABORT_TASK_SET:
374 		set_host_byte(cmd, DID_ABORT);
375 		break;
376 	case TARGET_RESET:
377 		set_host_byte(cmd, DID_RESET);
378 		break;
379 	default:
380 		set_host_byte(cmd, DID_ERROR);
381 		break;
382 	}
383 }
384 
385 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
386 {
387 	unsigned int xfer_len = scmd->sdb.length;
388 	unsigned int prot_interval = scsi_prot_interval(scmd);
389 
390 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
391 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
392 
393 	return xfer_len;
394 }
395 
396 extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
397 			     u8 key, u8 asc, u8 ascq);
398 
399 #endif /* _SCSI_SCSI_CMND_H */
400