xref: /linux/include/scsi/scsi_cmnd.h (revision de6e0b198239857943db395377dc1d2ddd6c05df)
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_request.h>
14 
15 struct Scsi_Host;
16 struct scsi_driver;
17 
18 /*
19  * MAX_COMMAND_SIZE is:
20  * The longest fixed-length SCSI CDB as per the SCSI standard.
21  * fixed-length means: commands that their size can be determined
22  * by their opcode and the CDB does not carry a length specifier, (unlike
23  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
24  * true and the SCSI standard also defines extended commands and
25  * vendor specific commands that can be bigger than 16 bytes. The kernel
26  * will support these using the same infrastructure used for VARLEN CDB's.
27  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
28  * supports without specifying a cmd_len by ULD's
29  */
30 #define MAX_COMMAND_SIZE 16
31 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
32 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
33 #endif
34 
35 struct scsi_data_buffer {
36 	struct sg_table table;
37 	unsigned length;
38 };
39 
40 /* embedded in scsi_cmnd */
41 struct scsi_pointer {
42 	char *ptr;		/* data pointer */
43 	int this_residual;	/* left in this buffer */
44 	struct scatterlist *buffer;	/* which buffer */
45 	int buffers_residual;	/* how many buffers left */
46 
47         dma_addr_t dma_handle;
48 
49 	volatile int Status;
50 	volatile int Message;
51 	volatile int have_data_in;
52 	volatile int sent_command;
53 	volatile int phase;
54 };
55 
56 /* for scmd->flags */
57 #define SCMD_TAGGED		(1 << 0)
58 #define SCMD_UNCHECKED_ISA_DMA	(1 << 1)
59 #define SCMD_INITIALIZED	(1 << 2)
60 #define SCMD_LAST		(1 << 3)
61 /* flags preserved across unprep / reprep */
62 #define SCMD_PRESERVED_FLAGS	(SCMD_UNCHECKED_ISA_DMA | 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 	/*
79 	 * This is set to jiffies as it was when the command was first
80 	 * allocated.  It is used to time how long the command has
81 	 * been outstanding
82 	 */
83 	unsigned long jiffies_at_alloc;
84 
85 	int retries;
86 	int allowed;
87 
88 	unsigned char prot_op;
89 	unsigned char prot_type;
90 	unsigned char prot_flags;
91 
92 	unsigned short cmd_len;
93 	enum dma_data_direction sc_data_direction;
94 
95 	/* These elements define the operation we are about to perform */
96 	unsigned char *cmnd;
97 
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 
112 	struct request *request;	/* The command we are
113 				   	   working on */
114 
115 	unsigned char *sense_buffer;
116 				/* obtained by REQUEST SENSE when
117 				 * CHECK CONDITION is received on original
118 				 * command (auto-sense). Length must be
119 				 * SCSI_SENSE_BUFFERSIZE bytes. */
120 
121 	/* Low-level done function - can be used by low-level driver to point
122 	 *        to completion function.  Not used by mid/upper level code. */
123 	void (*scsi_done) (struct scsi_cmnd *);
124 
125 	/*
126 	 * The following fields can be written to by the host specific code.
127 	 * Everything else should be left alone.
128 	 */
129 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
130 
131 	unsigned char *host_scribble;	/* The host adapter is allowed to
132 					 * call scsi_malloc and get some memory
133 					 * and hang it here.  The host adapter
134 					 * is also expected to call scsi_free
135 					 * to release this memory.  (The memory
136 					 * obtained by scsi_malloc is guaranteed
137 					 * to be at an address < 16Mb). */
138 
139 	int result;		/* Status code from lower level driver */
140 	int flags;		/* Command flags */
141 	unsigned long state;	/* Command completion state */
142 
143 	unsigned char tag;	/* SCSI-II queued command tag */
144 	unsigned int extra_len;	/* length of alignment and padding */
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 /* make sure not to use it with passthrough commands */
157 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
158 {
159 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
160 }
161 
162 extern void scsi_finish_command(struct scsi_cmnd *cmd);
163 
164 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
165 				 size_t *offset, size_t *len);
166 extern void scsi_kunmap_atomic_sg(void *virt);
167 
168 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
169 void scsi_free_sgtables(struct scsi_cmnd *cmd);
170 
171 #ifdef CONFIG_SCSI_DMA
172 extern int scsi_dma_map(struct scsi_cmnd *cmd);
173 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
174 #else /* !CONFIG_SCSI_DMA */
175 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
176 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
177 #endif /* !CONFIG_SCSI_DMA */
178 
179 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
180 {
181 	return cmd->sdb.table.nents;
182 }
183 
184 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
185 {
186 	return cmd->sdb.table.sgl;
187 }
188 
189 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
190 {
191 	return cmd->sdb.length;
192 }
193 
194 static inline void scsi_set_resid(struct scsi_cmnd *cmd, unsigned int resid)
195 {
196 	cmd->req.resid_len = resid;
197 }
198 
199 static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
200 {
201 	return cmd->req.resid_len;
202 }
203 
204 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
205 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
206 
207 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
208 					   void *buf, int buflen)
209 {
210 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
211 				   buf, buflen);
212 }
213 
214 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
215 					 void *buf, int buflen)
216 {
217 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
218 				 buf, buflen);
219 }
220 
221 /*
222  * The operations below are hints that tell the controller driver how
223  * to handle I/Os with DIF or similar types of protection information.
224  */
225 enum scsi_prot_operations {
226 	/* Normal I/O */
227 	SCSI_PROT_NORMAL = 0,
228 
229 	/* OS-HBA: Protected, HBA-Target: Unprotected */
230 	SCSI_PROT_READ_INSERT,
231 	SCSI_PROT_WRITE_STRIP,
232 
233 	/* OS-HBA: Unprotected, HBA-Target: Protected */
234 	SCSI_PROT_READ_STRIP,
235 	SCSI_PROT_WRITE_INSERT,
236 
237 	/* OS-HBA: Protected, HBA-Target: Protected */
238 	SCSI_PROT_READ_PASS,
239 	SCSI_PROT_WRITE_PASS,
240 };
241 
242 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
243 {
244 	scmd->prot_op = op;
245 }
246 
247 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
248 {
249 	return scmd->prot_op;
250 }
251 
252 enum scsi_prot_flags {
253 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
254 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
255 	SCSI_PROT_REF_CHECK		= 1 << 2,
256 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
257 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
258 };
259 
260 /*
261  * The controller usually does not know anything about the target it
262  * is communicating with.  However, when DIX is enabled the controller
263  * must be know target type so it can verify the protection
264  * information passed along with the I/O.
265  */
266 enum scsi_prot_target_type {
267 	SCSI_PROT_DIF_TYPE0 = 0,
268 	SCSI_PROT_DIF_TYPE1,
269 	SCSI_PROT_DIF_TYPE2,
270 	SCSI_PROT_DIF_TYPE3,
271 };
272 
273 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
274 {
275 	scmd->prot_type = type;
276 }
277 
278 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
279 {
280 	return scmd->prot_type;
281 }
282 
283 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
284 {
285 	return blk_rq_pos(scmd->request);
286 }
287 
288 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
289 {
290 	return scmd->device->sector_size;
291 }
292 
293 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
294 {
295 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
296 }
297 
298 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
299 {
300 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
301 }
302 
303 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
304 {
305 	return cmd->prot_sdb;
306 }
307 
308 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
309 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
310 
311 static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
312 {
313 	cmd->result = (cmd->result & 0xffffff00) | status;
314 }
315 
316 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
317 {
318 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
319 }
320 
321 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
322 {
323 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
324 }
325 
326 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
327 {
328 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
329 }
330 
331 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
332 {
333 	unsigned int xfer_len = scmd->sdb.length;
334 	unsigned int prot_interval = scsi_prot_interval(scmd);
335 
336 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
337 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
338 
339 	return xfer_len;
340 }
341 
342 #endif /* _SCSI_SCSI_CMND_H */
343