xref: /linux/include/scsi/scsi_cmnd.h (revision a2b0fe7435faee6f6fbb27409878013bc4727e98)
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/list.h>
8 #include <linux/types.h>
9 #include <linux/timer.h>
10 #include <linux/scatterlist.h>
11 #include <scsi/scsi_device.h>
12 #include <scsi/scsi_request.h>
13 
14 struct Scsi_Host;
15 struct scsi_driver;
16 
17 #include <scsi/scsi_device.h>
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 	int resid;
40 };
41 
42 /* embedded in scsi_cmnd */
43 struct scsi_pointer {
44 	char *ptr;		/* data pointer */
45 	int this_residual;	/* left in this buffer */
46 	struct scatterlist *buffer;	/* which buffer */
47 	int buffers_residual;	/* how many buffers left */
48 
49         dma_addr_t dma_handle;
50 
51 	volatile int Status;
52 	volatile int Message;
53 	volatile int have_data_in;
54 	volatile int sent_command;
55 	volatile int phase;
56 };
57 
58 /* for scmd->flags */
59 #define SCMD_TAGGED		(1 << 0)
60 #define SCMD_UNCHECKED_ISA_DMA	(1 << 1)
61 #define SCMD_ZONE_WRITE_LOCK	(1 << 2)
62 #define SCMD_INITIALIZED	(1 << 3)
63 /* flags preserved across unprep / reprep */
64 #define SCMD_PRESERVED_FLAGS	(SCMD_UNCHECKED_ISA_DMA | SCMD_INITIALIZED)
65 
66 struct scsi_cmnd {
67 	struct scsi_request req;
68 	struct scsi_device *device;
69 	struct list_head list;  /* scsi_cmnd participates in queue lists */
70 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
71 	struct delayed_work abort_work;
72 	int eh_eflags;		/* Used by error handlr */
73 
74 	/*
75 	 * A SCSI Command is assigned a nonzero serial_number before passed
76 	 * to the driver's queue command function.  The serial_number is
77 	 * cleared when scsi_done is entered indicating that the command
78 	 * has been completed.  It is a bug for LLDDs to use this number
79 	 * for purposes other than printk (and even that is only useful
80 	 * for debugging).
81 	 */
82 	unsigned long serial_number;
83 
84 	/*
85 	 * This is set to jiffies as it was when the command was first
86 	 * allocated.  It is used to time how long the command has
87 	 * been outstanding
88 	 */
89 	unsigned long jiffies_at_alloc;
90 
91 	int retries;
92 	int allowed;
93 
94 	unsigned char prot_op;
95 	unsigned char prot_type;
96 	unsigned char prot_flags;
97 
98 	unsigned short cmd_len;
99 	enum dma_data_direction sc_data_direction;
100 
101 	/* These elements define the operation we are about to perform */
102 	unsigned char *cmnd;
103 
104 
105 	/* These elements define the operation we ultimately want to perform */
106 	struct scsi_data_buffer sdb;
107 	struct scsi_data_buffer *prot_sdb;
108 
109 	unsigned underflow;	/* Return error if less than
110 				   this amount is transferred */
111 
112 	unsigned transfersize;	/* How much we are guaranteed to
113 				   transfer with each SCSI transfer
114 				   (ie, between disconnect /
115 				   reconnects.   Probably == sector
116 				   size */
117 
118 	struct request *request;	/* The command we are
119 				   	   working on */
120 
121 #define SCSI_SENSE_BUFFERSIZE 	96
122 	unsigned char *sense_buffer;
123 				/* obtained by REQUEST SENSE when
124 				 * CHECK CONDITION is received on original
125 				 * command (auto-sense) */
126 
127 	/* Low-level done function - can be used by low-level driver to point
128 	 *        to completion function.  Not used by mid/upper level code. */
129 	void (*scsi_done) (struct scsi_cmnd *);
130 
131 	/*
132 	 * The following fields can be written to by the host specific code.
133 	 * Everything else should be left alone.
134 	 */
135 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
136 
137 	unsigned char *host_scribble;	/* The host adapter is allowed to
138 					 * call scsi_malloc and get some memory
139 					 * and hang it here.  The host adapter
140 					 * is also expected to call scsi_free
141 					 * to release this memory.  (The memory
142 					 * obtained by scsi_malloc is guaranteed
143 					 * to be at an address < 16Mb). */
144 
145 	int result;		/* Status code from lower level driver */
146 	int flags;		/* Command flags */
147 
148 	unsigned char tag;	/* SCSI-II queued command tag */
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 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
164 }
165 
166 extern void scsi_put_command(struct scsi_cmnd *);
167 extern void scsi_finish_command(struct scsi_cmnd *cmd);
168 
169 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
170 				 size_t *offset, size_t *len);
171 extern void scsi_kunmap_atomic_sg(void *virt);
172 
173 extern int scsi_init_io(struct scsi_cmnd *cmd);
174 
175 extern int scsi_dma_map(struct scsi_cmnd *cmd);
176 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
177 
178 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
179 {
180 	return cmd->sdb.table.nents;
181 }
182 
183 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
184 {
185 	return cmd->sdb.table.sgl;
186 }
187 
188 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
189 {
190 	return cmd->sdb.length;
191 }
192 
193 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
194 {
195 	cmd->sdb.resid = resid;
196 }
197 
198 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
199 {
200 	return cmd->sdb.resid;
201 }
202 
203 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
204 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
205 
206 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
207 {
208 	return blk_bidi_rq(cmd->request) &&
209 		(cmd->request->next_rq->special != NULL);
210 }
211 
212 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
213 {
214 	return scsi_bidi_cmnd(cmd) ?
215 		cmd->request->next_rq->special : &cmd->sdb;
216 }
217 
218 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
219 {
220 	return &cmd->sdb;
221 }
222 
223 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
224 					   void *buf, int buflen)
225 {
226 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
227 				   buf, buflen);
228 }
229 
230 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
231 					 void *buf, int buflen)
232 {
233 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
234 				 buf, buflen);
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 sector_t scsi_get_lba(struct scsi_cmnd *scmd)
300 {
301 	return blk_rq_pos(scmd->request);
302 }
303 
304 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
305 {
306 	return scmd->device->sector_size;
307 }
308 
309 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
310 {
311 	return blk_rq_pos(scmd->request) >>
312 		(ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
313 }
314 
315 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
316 {
317 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
318 }
319 
320 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
321 {
322 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
323 }
324 
325 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
326 {
327 	return cmd->prot_sdb;
328 }
329 
330 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
331 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
332 
333 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
334 {
335 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
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 void set_driver_byte(struct scsi_cmnd *cmd, char status)
344 {
345 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
346 }
347 
348 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
349 {
350 	unsigned int xfer_len = scsi_out(scmd)->length;
351 	unsigned int prot_interval = scsi_prot_interval(scmd);
352 
353 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
354 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
355 
356 	return xfer_len;
357 }
358 
359 #endif /* _SCSI_SCSI_CMND_H */
360