xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision f519f0be)
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 /* flags preserved across unprep / reprep */
61 #define SCMD_PRESERVED_FLAGS	(SCMD_UNCHECKED_ISA_DMA | SCMD_INITIALIZED)
62 
63 /* for scmd->state */
64 #define SCMD_STATE_COMPLETE	0
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 
73 	struct rcu_head rcu;
74 
75 	int eh_eflags;		/* Used by error handlr */
76 
77 	/*
78 	 * This is set to jiffies as it was when the command was first
79 	 * allocated.  It is used to time how long the command has
80 	 * been outstanding
81 	 */
82 	unsigned long jiffies_at_alloc;
83 
84 	int retries;
85 	int allowed;
86 
87 	unsigned char prot_op;
88 	unsigned char prot_type;
89 	unsigned char prot_flags;
90 
91 	unsigned short cmd_len;
92 	enum dma_data_direction sc_data_direction;
93 
94 	/* These elements define the operation we are about to perform */
95 	unsigned char *cmnd;
96 
97 
98 	/* These elements define the operation we ultimately want to perform */
99 	struct scsi_data_buffer sdb;
100 	struct scsi_data_buffer *prot_sdb;
101 
102 	unsigned underflow;	/* Return error if less than
103 				   this amount is transferred */
104 
105 	unsigned transfersize;	/* How much we are guaranteed to
106 				   transfer with each SCSI transfer
107 				   (ie, between disconnect /
108 				   reconnects.   Probably == sector
109 				   size */
110 
111 	struct request *request;	/* The command we are
112 				   	   working on */
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 };
144 
145 /*
146  * Return the driver private allocation behind the command.
147  * Only works if cmd_size is set in the host template.
148  */
149 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
150 {
151 	return cmd + 1;
152 }
153 
154 /* make sure not to use it with passthrough commands */
155 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
156 {
157 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
158 }
159 
160 extern void scsi_put_command(struct scsi_cmnd *);
161 extern void scsi_finish_command(struct scsi_cmnd *cmd);
162 
163 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
164 				 size_t *offset, size_t *len);
165 extern void scsi_kunmap_atomic_sg(void *virt);
166 
167 extern blk_status_t scsi_init_io(struct scsi_cmnd *cmd);
168 
169 #ifdef CONFIG_SCSI_DMA
170 extern int scsi_dma_map(struct scsi_cmnd *cmd);
171 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
172 #else /* !CONFIG_SCSI_DMA */
173 static inline int scsi_dma_map(struct scsi_cmnd *cmd) { return -ENOSYS; }
174 static inline void scsi_dma_unmap(struct scsi_cmnd *cmd) { }
175 #endif /* !CONFIG_SCSI_DMA */
176 
177 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
178 {
179 	return cmd->sdb.table.nents;
180 }
181 
182 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
183 {
184 	return cmd->sdb.table.sgl;
185 }
186 
187 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
188 {
189 	return cmd->sdb.length;
190 }
191 
192 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
193 {
194 	cmd->req.resid_len = resid;
195 }
196 
197 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
198 {
199 	return cmd->req.resid_len;
200 }
201 
202 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
203 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
204 
205 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
206 					   void *buf, int buflen)
207 {
208 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
209 				   buf, buflen);
210 }
211 
212 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
213 					 void *buf, int buflen)
214 {
215 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
216 				 buf, buflen);
217 }
218 
219 /*
220  * The operations below are hints that tell the controller driver how
221  * to handle I/Os with DIF or similar types of protection information.
222  */
223 enum scsi_prot_operations {
224 	/* Normal I/O */
225 	SCSI_PROT_NORMAL = 0,
226 
227 	/* OS-HBA: Protected, HBA-Target: Unprotected */
228 	SCSI_PROT_READ_INSERT,
229 	SCSI_PROT_WRITE_STRIP,
230 
231 	/* OS-HBA: Unprotected, HBA-Target: Protected */
232 	SCSI_PROT_READ_STRIP,
233 	SCSI_PROT_WRITE_INSERT,
234 
235 	/* OS-HBA: Protected, HBA-Target: Protected */
236 	SCSI_PROT_READ_PASS,
237 	SCSI_PROT_WRITE_PASS,
238 };
239 
240 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
241 {
242 	scmd->prot_op = op;
243 }
244 
245 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
246 {
247 	return scmd->prot_op;
248 }
249 
250 enum scsi_prot_flags {
251 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
252 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
253 	SCSI_PROT_REF_CHECK		= 1 << 2,
254 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
255 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
256 };
257 
258 /*
259  * The controller usually does not know anything about the target it
260  * is communicating with.  However, when DIX is enabled the controller
261  * must be know target type so it can verify the protection
262  * information passed along with the I/O.
263  */
264 enum scsi_prot_target_type {
265 	SCSI_PROT_DIF_TYPE0 = 0,
266 	SCSI_PROT_DIF_TYPE1,
267 	SCSI_PROT_DIF_TYPE2,
268 	SCSI_PROT_DIF_TYPE3,
269 };
270 
271 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
272 {
273 	scmd->prot_type = type;
274 }
275 
276 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
277 {
278 	return scmd->prot_type;
279 }
280 
281 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
282 {
283 	return blk_rq_pos(scmd->request);
284 }
285 
286 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
287 {
288 	return scmd->device->sector_size;
289 }
290 
291 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
292 {
293 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
294 }
295 
296 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
297 {
298 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
299 }
300 
301 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
302 {
303 	return cmd->prot_sdb;
304 }
305 
306 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
307 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
308 
309 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
310 {
311 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
312 }
313 
314 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
315 {
316 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
317 }
318 
319 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
320 {
321 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
322 }
323 
324 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
325 {
326 	unsigned int xfer_len = scmd->sdb.length;
327 	unsigned int prot_interval = scsi_prot_interval(scmd);
328 
329 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
330 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
331 
332 	return xfer_len;
333 }
334 
335 #endif /* _SCSI_SCSI_CMND_H */
336