xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
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 	int timeout_per_command;
79 
80 	unsigned char prot_op;
81 	unsigned char prot_type;
82 
83 	unsigned short cmd_len;
84 	enum dma_data_direction sc_data_direction;
85 
86 	/* These elements define the operation we are about to perform */
87 	unsigned char *cmnd;
88 
89 	struct timer_list eh_timeout;	/* Used to time out the command. */
90 
91 	/* These elements define the operation we ultimately want to perform */
92 	struct scsi_data_buffer sdb;
93 	struct scsi_data_buffer *prot_sdb;
94 
95 	unsigned underflow;	/* Return error if less than
96 				   this amount is transferred */
97 
98 	unsigned transfersize;	/* How much we are guaranteed to
99 				   transfer with each SCSI transfer
100 				   (ie, between disconnect /
101 				   reconnects.   Probably == sector
102 				   size */
103 
104 	struct request *request;	/* The command we are
105 				   	   working on */
106 
107 #define SCSI_SENSE_BUFFERSIZE 	96
108 	unsigned char *sense_buffer;
109 				/* obtained by REQUEST SENSE when
110 				 * CHECK CONDITION is received on original
111 				 * command (auto-sense) */
112 
113 	/* Low-level done function - can be used by low-level driver to point
114 	 *        to completion function.  Not used by mid/upper level code. */
115 	void (*scsi_done) (struct scsi_cmnd *);
116 
117 	/*
118 	 * The following fields can be written to by the host specific code.
119 	 * Everything else should be left alone.
120 	 */
121 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
122 
123 	unsigned char *host_scribble;	/* The host adapter is allowed to
124 					 * call scsi_malloc and get some memory
125 					 * and hang it here.  The host adapter
126 					 * is also expected to call scsi_free
127 					 * to release this memory.  (The memory
128 					 * obtained by scsi_malloc is guaranteed
129 					 * to be at an address < 16Mb). */
130 
131 	int result;		/* Status code from lower level driver */
132 
133 	unsigned char tag;	/* SCSI-II queued command tag */
134 };
135 
136 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
137 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
138 extern void scsi_put_command(struct scsi_cmnd *);
139 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
140 			       struct device *);
141 extern void scsi_finish_command(struct scsi_cmnd *cmd);
142 extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
143 
144 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
145 				 size_t *offset, size_t *len);
146 extern void scsi_kunmap_atomic_sg(void *virt);
147 
148 extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
149 extern void scsi_release_buffers(struct scsi_cmnd *cmd);
150 
151 extern int scsi_dma_map(struct scsi_cmnd *cmd);
152 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
153 
154 struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
155 void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
156 
157 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
158 {
159 	return cmd->sdb.table.nents;
160 }
161 
162 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
163 {
164 	return cmd->sdb.table.sgl;
165 }
166 
167 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
168 {
169 	return cmd->sdb.length;
170 }
171 
172 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
173 {
174 	cmd->sdb.resid = resid;
175 }
176 
177 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
178 {
179 	return cmd->sdb.resid;
180 }
181 
182 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
183 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
184 
185 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
186 {
187 	return blk_bidi_rq(cmd->request) &&
188 		(cmd->request->next_rq->special != NULL);
189 }
190 
191 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
192 {
193 	return scsi_bidi_cmnd(cmd) ?
194 		cmd->request->next_rq->special : &cmd->sdb;
195 }
196 
197 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
198 {
199 	return &cmd->sdb;
200 }
201 
202 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
203 					   void *buf, int buflen)
204 {
205 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
206 				   buf, buflen);
207 }
208 
209 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
210 					 void *buf, int buflen)
211 {
212 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
213 				 buf, buflen);
214 }
215 
216 /*
217  * The operations below are hints that tell the controller driver how
218  * to handle I/Os with DIF or similar types of protection information.
219  */
220 enum scsi_prot_operations {
221 	/* Normal I/O */
222 	SCSI_PROT_NORMAL = 0,
223 
224 	/* OS-HBA: Protected, HBA-Target: Unprotected */
225 	SCSI_PROT_READ_INSERT,
226 	SCSI_PROT_WRITE_STRIP,
227 
228 	/* OS-HBA: Unprotected, HBA-Target: Protected */
229 	SCSI_PROT_READ_STRIP,
230 	SCSI_PROT_WRITE_INSERT,
231 
232 	/* OS-HBA: Protected, HBA-Target: Protected */
233 	SCSI_PROT_READ_PASS,
234 	SCSI_PROT_WRITE_PASS,
235 
236 	/* OS-HBA: Protected, HBA-Target: Protected, checksum conversion */
237 	SCSI_PROT_READ_CONVERT,
238 	SCSI_PROT_WRITE_CONVERT,
239 };
240 
241 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
242 {
243 	scmd->prot_op = op;
244 }
245 
246 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
247 {
248 	return scmd->prot_op;
249 }
250 
251 /*
252  * The controller usually does not know anything about the target it
253  * is communicating with.  However, when DIX is enabled the controller
254  * must be know target type so it can verify the protection
255  * information passed along with the I/O.
256  */
257 enum scsi_prot_target_type {
258 	SCSI_PROT_DIF_TYPE0 = 0,
259 	SCSI_PROT_DIF_TYPE1,
260 	SCSI_PROT_DIF_TYPE2,
261 	SCSI_PROT_DIF_TYPE3,
262 };
263 
264 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
265 {
266 	scmd->prot_type = type;
267 }
268 
269 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
270 {
271 	return scmd->prot_type;
272 }
273 
274 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
275 {
276 	return scmd->request->sector;
277 }
278 
279 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
280 {
281 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
282 }
283 
284 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
285 {
286 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
287 }
288 
289 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
290 {
291 	return cmd->prot_sdb;
292 }
293 
294 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
295 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
296 
297 #endif /* _SCSI_SCSI_CMND_H */
298