xref: /linux/include/scsi/scsi_cmnd.h (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
1 #ifndef _SCSI_SCSI_CMND_H
2 #define _SCSI_SCSI_CMND_H
3 
4 #include <linux/dma-mapping.h>
5 #include <linux/blkdev.h>
6 #include <linux/list.h>
7 #include <linux/types.h>
8 #include <linux/timer.h>
9 #include <linux/scatterlist.h>
10 
11 struct Scsi_Host;
12 struct scsi_device;
13 
14 /*
15  * MAX_COMMAND_SIZE is:
16  * The longest fixed-length SCSI CDB as per the SCSI standard.
17  * fixed-length means: commands that their size can be determined
18  * by their opcode and the CDB does not carry a length specifier, (unlike
19  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
20  * true and the SCSI standard also defines extended commands and
21  * vendor specific commands that can be bigger than 16 bytes. The kernel
22  * will support these using the same infrastructure used for VARLEN CDB's.
23  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
24  * supports without specifying a cmd_len by ULD's
25  */
26 #define MAX_COMMAND_SIZE 16
27 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
28 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
29 #endif
30 
31 struct scsi_data_buffer {
32 	struct sg_table table;
33 	unsigned length;
34 	int resid;
35 };
36 
37 /* embedded in scsi_cmnd */
38 struct scsi_pointer {
39 	char *ptr;		/* data pointer */
40 	int this_residual;	/* left in this buffer */
41 	struct scatterlist *buffer;	/* which buffer */
42 	int buffers_residual;	/* how many buffers left */
43 
44         dma_addr_t dma_handle;
45 
46 	volatile int Status;
47 	volatile int Message;
48 	volatile int have_data_in;
49 	volatile int sent_command;
50 	volatile int phase;
51 };
52 
53 struct scsi_cmnd {
54 	struct scsi_device *device;
55 	struct list_head list;  /* scsi_cmnd participates in queue lists */
56 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
57 	int eh_eflags;		/* Used by error handlr */
58 
59 	/*
60 	 * A SCSI Command is assigned a nonzero serial_number before passed
61 	 * to the driver's queue command function.  The serial_number is
62 	 * cleared when scsi_done is entered indicating that the command
63 	 * has been completed.  It is a bug for LLDDs to use this number
64 	 * for purposes other than printk (and even that is only useful
65 	 * for debugging).
66 	 */
67 	unsigned long serial_number;
68 
69 	/*
70 	 * This is set to jiffies as it was when the command was first
71 	 * allocated.  It is used to time how long the command has
72 	 * been outstanding
73 	 */
74 	unsigned long jiffies_at_alloc;
75 
76 	int retries;
77 	int allowed;
78 
79 	unsigned char prot_op;
80 	unsigned char prot_type;
81 
82 	unsigned short cmd_len;
83 	enum dma_data_direction sc_data_direction;
84 
85 	/* These elements define the operation we are about to perform */
86 	unsigned char *cmnd;
87 
88 
89 	/* These elements define the operation we ultimately want to perform */
90 	struct scsi_data_buffer sdb;
91 	struct scsi_data_buffer *prot_sdb;
92 
93 	unsigned underflow;	/* Return error if less than
94 				   this amount is transferred */
95 
96 	unsigned transfersize;	/* How much we are guaranteed to
97 				   transfer with each SCSI transfer
98 				   (ie, between disconnect /
99 				   reconnects.   Probably == sector
100 				   size */
101 
102 	struct request *request;	/* The command we are
103 				   	   working on */
104 
105 #define SCSI_SENSE_BUFFERSIZE 	96
106 	unsigned char *sense_buffer;
107 				/* obtained by REQUEST SENSE when
108 				 * CHECK CONDITION is received on original
109 				 * command (auto-sense) */
110 
111 	/* Low-level done function - can be used by low-level driver to point
112 	 *        to completion function.  Not used by mid/upper level code. */
113 	void (*scsi_done) (struct scsi_cmnd *);
114 
115 	/*
116 	 * The following fields can be written to by the host specific code.
117 	 * Everything else should be left alone.
118 	 */
119 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
120 
121 	unsigned char *host_scribble;	/* The host adapter is allowed to
122 					 * call scsi_malloc and get some memory
123 					 * and hang it here.  The host adapter
124 					 * is also expected to call scsi_free
125 					 * to release this memory.  (The memory
126 					 * obtained by scsi_malloc is guaranteed
127 					 * to be at an address < 16Mb). */
128 
129 	int result;		/* Status code from lower level driver */
130 
131 	unsigned char tag;	/* SCSI-II queued command tag */
132 };
133 
134 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
135 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
136 extern void scsi_put_command(struct scsi_cmnd *);
137 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
138 			       struct device *);
139 extern void scsi_finish_command(struct scsi_cmnd *cmd);
140 
141 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
142 				 size_t *offset, size_t *len);
143 extern void scsi_kunmap_atomic_sg(void *virt);
144 
145 extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
146 extern void scsi_release_buffers(struct scsi_cmnd *cmd);
147 
148 extern int scsi_dma_map(struct scsi_cmnd *cmd);
149 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
150 
151 struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
152 void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
153 
154 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
155 {
156 	return cmd->sdb.table.nents;
157 }
158 
159 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
160 {
161 	return cmd->sdb.table.sgl;
162 }
163 
164 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
165 {
166 	return cmd->sdb.length;
167 }
168 
169 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
170 {
171 	cmd->sdb.resid = resid;
172 }
173 
174 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
175 {
176 	return cmd->sdb.resid;
177 }
178 
179 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
180 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
181 
182 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
183 {
184 	return blk_bidi_rq(cmd->request) &&
185 		(cmd->request->next_rq->special != NULL);
186 }
187 
188 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
189 {
190 	return scsi_bidi_cmnd(cmd) ?
191 		cmd->request->next_rq->special : &cmd->sdb;
192 }
193 
194 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
195 {
196 	return &cmd->sdb;
197 }
198 
199 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
200 					   void *buf, int buflen)
201 {
202 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
203 				   buf, buflen);
204 }
205 
206 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
207 					 void *buf, int buflen)
208 {
209 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
210 				 buf, buflen);
211 }
212 
213 /*
214  * The operations below are hints that tell the controller driver how
215  * to handle I/Os with DIF or similar types of protection information.
216  */
217 enum scsi_prot_operations {
218 	/* Normal I/O */
219 	SCSI_PROT_NORMAL = 0,
220 
221 	/* OS-HBA: Protected, HBA-Target: Unprotected */
222 	SCSI_PROT_READ_INSERT,
223 	SCSI_PROT_WRITE_STRIP,
224 
225 	/* OS-HBA: Unprotected, HBA-Target: Protected */
226 	SCSI_PROT_READ_STRIP,
227 	SCSI_PROT_WRITE_INSERT,
228 
229 	/* OS-HBA: Protected, HBA-Target: Protected */
230 	SCSI_PROT_READ_PASS,
231 	SCSI_PROT_WRITE_PASS,
232 
233 	/* OS-HBA: Protected, HBA-Target: Protected, checksum conversion */
234 	SCSI_PROT_READ_CONVERT,
235 	SCSI_PROT_WRITE_CONVERT,
236 };
237 
238 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
239 {
240 	scmd->prot_op = op;
241 }
242 
243 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
244 {
245 	return scmd->prot_op;
246 }
247 
248 /*
249  * The controller usually does not know anything about the target it
250  * is communicating with.  However, when DIX is enabled the controller
251  * must be know target type so it can verify the protection
252  * information passed along with the I/O.
253  */
254 enum scsi_prot_target_type {
255 	SCSI_PROT_DIF_TYPE0 = 0,
256 	SCSI_PROT_DIF_TYPE1,
257 	SCSI_PROT_DIF_TYPE2,
258 	SCSI_PROT_DIF_TYPE3,
259 };
260 
261 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
262 {
263 	scmd->prot_type = type;
264 }
265 
266 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
267 {
268 	return scmd->prot_type;
269 }
270 
271 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
272 {
273 	return scmd->request->sector;
274 }
275 
276 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
277 {
278 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
279 }
280 
281 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
282 {
283 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
284 }
285 
286 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
287 {
288 	return cmd->prot_sdb;
289 }
290 
291 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
292 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
293 
294 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
295 {
296 	cmd->result |= status << 8;
297 }
298 
299 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
300 {
301 	cmd->result |= status << 16;
302 }
303 
304 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
305 {
306 	cmd->result |= status << 24;
307 }
308 
309 #endif /* _SCSI_SCSI_CMND_H */
310