xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision d58f75de)
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 	struct request *request;	/* The command we are
115 				   	   working on */
116 
117 	unsigned char *sense_buffer;
118 				/* obtained by REQUEST SENSE when
119 				 * CHECK CONDITION is received on original
120 				 * command (auto-sense). Length must be
121 				 * SCSI_SENSE_BUFFERSIZE bytes. */
122 
123 	/* Low-level done function - can be used by low-level driver to point
124 	 *        to completion function.  Not used by mid/upper level code. */
125 	void (*scsi_done) (struct scsi_cmnd *);
126 
127 	/*
128 	 * The following fields can be written to by the host specific code.
129 	 * Everything else should be left alone.
130 	 */
131 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
132 
133 	unsigned char *host_scribble;	/* The host adapter is allowed to
134 					 * call scsi_malloc and get some memory
135 					 * and hang it here.  The host adapter
136 					 * is also expected to call scsi_free
137 					 * to release this memory.  (The memory
138 					 * obtained by scsi_malloc is guaranteed
139 					 * to be at an address < 16Mb). */
140 
141 	int result;		/* Status code from lower level driver */
142 	int flags;		/* Command flags */
143 	unsigned long state;	/* Command completion state */
144 
145 	unsigned char tag;	/* SCSI-II queued command tag */
146 	unsigned int extra_len;	/* length of alignment and padding */
147 };
148 
149 /*
150  * Return the driver private allocation behind the command.
151  * Only works if cmd_size is set in the host template.
152  */
153 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
154 {
155 	return cmd + 1;
156 }
157 
158 /* make sure not to use it with passthrough commands */
159 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
160 {
161 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
162 }
163 
164 extern void scsi_finish_command(struct scsi_cmnd *cmd);
165 
166 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
167 				 size_t *offset, size_t *len);
168 extern void scsi_kunmap_atomic_sg(void *virt);
169 
170 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd);
171 void scsi_free_sgtables(struct scsi_cmnd *cmd);
172 
173 #ifdef CONFIG_SCSI_DMA
174 extern int scsi_dma_map(struct scsi_cmnd *cmd);
175 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
176 #else /* !CONFIG_SCSI_DMA */
177 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
178 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
179 #endif /* !CONFIG_SCSI_DMA */
180 
181 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
182 {
183 	return cmd->sdb.table.nents;
184 }
185 
186 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
187 {
188 	return cmd->sdb.table.sgl;
189 }
190 
191 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
192 {
193 	return cmd->sdb.length;
194 }
195 
196 static inline void scsi_set_resid(struct scsi_cmnd *cmd, unsigned int resid)
197 {
198 	cmd->req.resid_len = resid;
199 }
200 
201 static inline unsigned int scsi_get_resid(struct scsi_cmnd *cmd)
202 {
203 	return cmd->req.resid_len;
204 }
205 
206 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
207 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
208 
209 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
210 					   void *buf, int buflen)
211 {
212 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
213 				   buf, buflen);
214 }
215 
216 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
217 					 void *buf, int buflen)
218 {
219 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
220 				 buf, buflen);
221 }
222 
223 /*
224  * The operations below are hints that tell the controller driver how
225  * to handle I/Os with DIF or similar types of protection information.
226  */
227 enum scsi_prot_operations {
228 	/* Normal I/O */
229 	SCSI_PROT_NORMAL = 0,
230 
231 	/* OS-HBA: Protected, HBA-Target: Unprotected */
232 	SCSI_PROT_READ_INSERT,
233 	SCSI_PROT_WRITE_STRIP,
234 
235 	/* OS-HBA: Unprotected, HBA-Target: Protected */
236 	SCSI_PROT_READ_STRIP,
237 	SCSI_PROT_WRITE_INSERT,
238 
239 	/* OS-HBA: Protected, HBA-Target: Protected */
240 	SCSI_PROT_READ_PASS,
241 	SCSI_PROT_WRITE_PASS,
242 };
243 
244 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
245 {
246 	scmd->prot_op = op;
247 }
248 
249 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
250 {
251 	return scmd->prot_op;
252 }
253 
254 enum scsi_prot_flags {
255 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
256 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
257 	SCSI_PROT_REF_CHECK		= 1 << 2,
258 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
259 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
260 };
261 
262 /*
263  * The controller usually does not know anything about the target it
264  * is communicating with.  However, when DIX is enabled the controller
265  * must be know target type so it can verify the protection
266  * information passed along with the I/O.
267  */
268 enum scsi_prot_target_type {
269 	SCSI_PROT_DIF_TYPE0 = 0,
270 	SCSI_PROT_DIF_TYPE1,
271 	SCSI_PROT_DIF_TYPE2,
272 	SCSI_PROT_DIF_TYPE3,
273 };
274 
275 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
276 {
277 	scmd->prot_type = type;
278 }
279 
280 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
281 {
282 	return scmd->prot_type;
283 }
284 
285 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
286 {
287 	return blk_rq_pos(scmd->request);
288 }
289 
290 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
291 {
292 	return scmd->device->sector_size;
293 }
294 
295 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
296 {
297 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
298 }
299 
300 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
301 {
302 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
303 }
304 
305 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
306 {
307 	return cmd->prot_sdb;
308 }
309 
310 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
311 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
312 
313 static inline void set_status_byte(struct scsi_cmnd *cmd, char status)
314 {
315 	cmd->result = (cmd->result & 0xffffff00) | status;
316 }
317 
318 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
319 {
320 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
321 }
322 
323 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
324 {
325 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
326 }
327 
328 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
329 {
330 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
331 }
332 
333 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
334 {
335 	unsigned int xfer_len = scmd->sdb.length;
336 	unsigned int prot_interval = scsi_prot_interval(scmd);
337 
338 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
339 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
340 
341 	return xfer_len;
342 }
343 
344 #endif /* _SCSI_SCSI_CMND_H */
345