xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision 92cc94ad)
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 char tag;	/* SCSI-II queued command tag */
143 	unsigned int extra_len;	/* length of alignment and padding */
144 };
145 
146 /* Variant of blk_mq_rq_from_pdu() that verifies the type of its argument. */
147 static inline struct request *scsi_cmd_to_rq(struct scsi_cmnd *scmd)
148 {
149 	return blk_mq_rq_from_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  */
156 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
157 {
158 	return cmd + 1;
159 }
160 
161 /* make sure not to use it with passthrough commands */
162 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
163 {
164 	struct request *rq = scsi_cmd_to_rq(cmd);
165 
166 	return *(struct scsi_driver **)rq->rq_disk->private_data;
167 }
168 
169 extern void scsi_finish_command(struct scsi_cmnd *cmd);
170 
171 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
172 				 size_t *offset, size_t *len);
173 extern void scsi_kunmap_atomic_sg(void *virt);
174 
175 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
176 void scsi_free_sgtables(struct scsi_cmnd *cmd);
177 
178 #ifdef CONFIG_SCSI_DMA
179 extern int scsi_dma_map(struct scsi_cmnd *cmd);
180 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
181 #else /* !CONFIG_SCSI_DMA */
182 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
183 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
184 #endif /* !CONFIG_SCSI_DMA */
185 
186 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
187 {
188 	return cmd->sdb.table.nents;
189 }
190 
191 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
192 {
193 	return cmd->sdb.table.sgl;
194 }
195 
196 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
197 {
198 	return cmd->sdb.length;
199 }
200 
201 static inline void scsi_set_resid(struct scsi_cmnd *cmd, unsigned int resid)
202 {
203 	cmd->req.resid_len = resid;
204 }
205 
206 static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
207 {
208 	return cmd->req.resid_len;
209 }
210 
211 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
212 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
213 
214 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
215 					   void *buf, int buflen)
216 {
217 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
218 				   buf, buflen);
219 }
220 
221 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
222 					 void *buf, int buflen)
223 {
224 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
225 				 buf, buflen);
226 }
227 
228 static inline sector_t scsi_get_sector(struct scsi_cmnd *scmd)
229 {
230 	return blk_rq_pos(scsi_cmd_to_rq(scmd));
231 }
232 
233 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
234 {
235 	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
236 
237 	return blk_rq_pos(scsi_cmd_to_rq(scmd)) >> shift;
238 }
239 
240 static inline unsigned int scsi_logical_block_count(struct scsi_cmnd *scmd)
241 {
242 	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
243 
244 	return blk_rq_bytes(scsi_cmd_to_rq(scmd)) >> shift;
245 }
246 
247 /*
248  * The operations below are hints that tell the controller driver how
249  * to handle I/Os with DIF or similar types of protection information.
250  */
251 enum scsi_prot_operations {
252 	/* Normal I/O */
253 	SCSI_PROT_NORMAL = 0,
254 
255 	/* OS-HBA: Protected, HBA-Target: Unprotected */
256 	SCSI_PROT_READ_INSERT,
257 	SCSI_PROT_WRITE_STRIP,
258 
259 	/* OS-HBA: Unprotected, HBA-Target: Protected */
260 	SCSI_PROT_READ_STRIP,
261 	SCSI_PROT_WRITE_INSERT,
262 
263 	/* OS-HBA: Protected, HBA-Target: Protected */
264 	SCSI_PROT_READ_PASS,
265 	SCSI_PROT_WRITE_PASS,
266 };
267 
268 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
269 {
270 	scmd->prot_op = op;
271 }
272 
273 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
274 {
275 	return scmd->prot_op;
276 }
277 
278 enum scsi_prot_flags {
279 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
280 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
281 	SCSI_PROT_REF_CHECK		= 1 << 2,
282 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
283 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
284 };
285 
286 /*
287  * The controller usually does not know anything about the target it
288  * is communicating with.  However, when DIX is enabled the controller
289  * must be know target type so it can verify the protection
290  * information passed along with the I/O.
291  */
292 enum scsi_prot_target_type {
293 	SCSI_PROT_DIF_TYPE0 = 0,
294 	SCSI_PROT_DIF_TYPE1,
295 	SCSI_PROT_DIF_TYPE2,
296 	SCSI_PROT_DIF_TYPE3,
297 };
298 
299 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
300 {
301 	scmd->prot_type = type;
302 }
303 
304 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
305 {
306 	return scmd->prot_type;
307 }
308 
309 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
310 {
311 	struct request *rq = blk_mq_rq_from_pdu(scmd);
312 
313 	return t10_pi_ref_tag(rq);
314 }
315 
316 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
317 {
318 	return scmd->device->sector_size;
319 }
320 
321 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
322 {
323 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
324 }
325 
326 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
327 {
328 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
329 }
330 
331 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
332 {
333 	return cmd->prot_sdb;
334 }
335 
336 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
337 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
338 
339 static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
340 {
341 	cmd->result = (cmd->result & 0xffffff00) | status;
342 }
343 
344 static inline u8 get_status_byte(struct scsi_cmnd *cmd)
345 {
346 	return cmd->result & 0xff;
347 }
348 
349 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
350 {
351 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
352 }
353 
354 static inline u8 get_host_byte(struct scsi_cmnd *cmd)
355 {
356 	return (cmd->result >> 16) & 0xff;
357 }
358 
359 /**
360  * scsi_msg_to_host_byte() - translate message byte
361  *
362  * Translate the SCSI parallel message byte to a matching
363  * host byte setting. A message of COMMAND_COMPLETE indicates
364  * a successful command execution, any other message indicate
365  * an error. As the messages themselves only have a meaning
366  * for the SCSI parallel protocol this function translates
367  * them into a matching host byte value for SCSI EH.
368  */
369 static inline void scsi_msg_to_host_byte(struct scsi_cmnd *cmd, u8 msg)
370 {
371 	switch (msg) {
372 	case COMMAND_COMPLETE:
373 		break;
374 	case ABORT_TASK_SET:
375 		set_host_byte(cmd, DID_ABORT);
376 		break;
377 	case TARGET_RESET:
378 		set_host_byte(cmd, DID_RESET);
379 		break;
380 	default:
381 		set_host_byte(cmd, DID_ERROR);
382 		break;
383 	}
384 }
385 
386 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
387 {
388 	unsigned int xfer_len = scmd->sdb.length;
389 	unsigned int prot_interval = scsi_prot_interval(scmd);
390 
391 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
392 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
393 
394 	return xfer_len;
395 }
396 
397 extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
398 			     u8 key, u8 asc, u8 ascq);
399 
400 #endif /* _SCSI_SCSI_CMND_H */
401