xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision e23feb16)
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 struct scsi_driver;
14 
15 /*
16  * MAX_COMMAND_SIZE is:
17  * The longest fixed-length SCSI CDB as per the SCSI standard.
18  * fixed-length means: commands that their size can be determined
19  * by their opcode and the CDB does not carry a length specifier, (unlike
20  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
21  * true and the SCSI standard also defines extended commands and
22  * vendor specific commands that can be bigger than 16 bytes. The kernel
23  * will support these using the same infrastructure used for VARLEN CDB's.
24  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
25  * supports without specifying a cmd_len by ULD's
26  */
27 #define MAX_COMMAND_SIZE 16
28 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
29 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
30 #endif
31 
32 struct scsi_data_buffer {
33 	struct sg_table table;
34 	unsigned length;
35 	int resid;
36 };
37 
38 /* embedded in scsi_cmnd */
39 struct scsi_pointer {
40 	char *ptr;		/* data pointer */
41 	int this_residual;	/* left in this buffer */
42 	struct scatterlist *buffer;	/* which buffer */
43 	int buffers_residual;	/* how many buffers left */
44 
45         dma_addr_t dma_handle;
46 
47 	volatile int Status;
48 	volatile int Message;
49 	volatile int have_data_in;
50 	volatile int sent_command;
51 	volatile int phase;
52 };
53 
54 struct scsi_cmnd {
55 	struct scsi_device *device;
56 	struct list_head list;  /* scsi_cmnd participates in queue lists */
57 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
58 	int eh_eflags;		/* Used by error handlr */
59 
60 	/*
61 	 * A SCSI Command is assigned a nonzero serial_number before passed
62 	 * to the driver's queue command function.  The serial_number is
63 	 * cleared when scsi_done is entered indicating that the command
64 	 * has been completed.  It is a bug for LLDDs to use this number
65 	 * for purposes other than printk (and even that is only useful
66 	 * for debugging).
67 	 */
68 	unsigned long serial_number;
69 
70 	/*
71 	 * This is set to jiffies as it was when the command was first
72 	 * allocated.  It is used to time how long the command has
73 	 * been outstanding
74 	 */
75 	unsigned long jiffies_at_alloc;
76 
77 	int retries;
78 	int allowed;
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 
90 	/* These elements define the operation we ultimately want to perform */
91 	struct scsi_data_buffer sdb;
92 	struct scsi_data_buffer *prot_sdb;
93 
94 	unsigned underflow;	/* Return error if less than
95 				   this amount is transferred */
96 
97 	unsigned transfersize;	/* How much we are guaranteed to
98 				   transfer with each SCSI transfer
99 				   (ie, between disconnect /
100 				   reconnects.   Probably == sector
101 				   size */
102 
103 	struct request *request;	/* The command we are
104 				   	   working on */
105 
106 #define SCSI_SENSE_BUFFERSIZE 	96
107 	unsigned char *sense_buffer;
108 				/* obtained by REQUEST SENSE when
109 				 * CHECK CONDITION is received on original
110 				 * command (auto-sense) */
111 
112 	/* Low-level done function - can be used by low-level driver to point
113 	 *        to completion function.  Not used by mid/upper level code. */
114 	void (*scsi_done) (struct scsi_cmnd *);
115 
116 	/*
117 	 * The following fields can be written to by the host specific code.
118 	 * Everything else should be left alone.
119 	 */
120 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
121 
122 	unsigned char *host_scribble;	/* The host adapter is allowed to
123 					 * call scsi_malloc and get some memory
124 					 * and hang it here.  The host adapter
125 					 * is also expected to call scsi_free
126 					 * to release this memory.  (The memory
127 					 * obtained by scsi_malloc is guaranteed
128 					 * to be at an address < 16Mb). */
129 
130 	int result;		/* Status code from lower level driver */
131 
132 	unsigned char tag;	/* SCSI-II queued command tag */
133 };
134 
135 /* make sure not to use it with REQ_TYPE_BLOCK_PC commands */
136 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
137 {
138 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
139 }
140 
141 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
142 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
143 extern void scsi_put_command(struct scsi_cmnd *);
144 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
145 			       struct device *);
146 extern void scsi_finish_command(struct scsi_cmnd *cmd);
147 
148 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
149 				 size_t *offset, size_t *len);
150 extern void scsi_kunmap_atomic_sg(void *virt);
151 
152 extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
153 extern void scsi_release_buffers(struct scsi_cmnd *cmd);
154 
155 extern int scsi_dma_map(struct scsi_cmnd *cmd);
156 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
157 
158 struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
159 void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
160 
161 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
162 {
163 	return cmd->sdb.table.nents;
164 }
165 
166 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
167 {
168 	return cmd->sdb.table.sgl;
169 }
170 
171 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
172 {
173 	return cmd->sdb.length;
174 }
175 
176 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
177 {
178 	cmd->sdb.resid = resid;
179 }
180 
181 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
182 {
183 	return cmd->sdb.resid;
184 }
185 
186 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
187 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
188 
189 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
190 {
191 	return blk_bidi_rq(cmd->request) &&
192 		(cmd->request->next_rq->special != NULL);
193 }
194 
195 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
196 {
197 	return scsi_bidi_cmnd(cmd) ?
198 		cmd->request->next_rq->special : &cmd->sdb;
199 }
200 
201 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
202 {
203 	return &cmd->sdb;
204 }
205 
206 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
207 					   void *buf, int buflen)
208 {
209 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
210 				   buf, buflen);
211 }
212 
213 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
214 					 void *buf, int buflen)
215 {
216 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
217 				 buf, buflen);
218 }
219 
220 /*
221  * The operations below are hints that tell the controller driver how
222  * to handle I/Os with DIF or similar types of protection information.
223  */
224 enum scsi_prot_operations {
225 	/* Normal I/O */
226 	SCSI_PROT_NORMAL = 0,
227 
228 	/* OS-HBA: Protected, HBA-Target: Unprotected */
229 	SCSI_PROT_READ_INSERT,
230 	SCSI_PROT_WRITE_STRIP,
231 
232 	/* OS-HBA: Unprotected, HBA-Target: Protected */
233 	SCSI_PROT_READ_STRIP,
234 	SCSI_PROT_WRITE_INSERT,
235 
236 	/* OS-HBA: Protected, HBA-Target: Protected */
237 	SCSI_PROT_READ_PASS,
238 	SCSI_PROT_WRITE_PASS,
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 blk_rq_pos(scmd->request);
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 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
298 {
299 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
300 }
301 
302 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
303 {
304 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
305 }
306 
307 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
308 {
309 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
310 }
311 
312 #endif /* _SCSI_SCSI_CMND_H */
313