xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision ce932d0c5589e9766e089c22c66890dfc48fbd94)
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 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
136 {
137 	if (!cmd->request->rq_disk)
138 		return NULL;
139 
140 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
141 }
142 
143 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
144 extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
145 extern void scsi_put_command(struct scsi_cmnd *);
146 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
147 			       struct device *);
148 extern void scsi_finish_command(struct scsi_cmnd *cmd);
149 
150 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
151 				 size_t *offset, size_t *len);
152 extern void scsi_kunmap_atomic_sg(void *virt);
153 
154 extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);
155 extern void scsi_release_buffers(struct scsi_cmnd *cmd);
156 
157 extern int scsi_dma_map(struct scsi_cmnd *cmd);
158 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
159 
160 struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
161 void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
162 
163 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
164 {
165 	return cmd->sdb.table.nents;
166 }
167 
168 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
169 {
170 	return cmd->sdb.table.sgl;
171 }
172 
173 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
174 {
175 	return cmd->sdb.length;
176 }
177 
178 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
179 {
180 	cmd->sdb.resid = resid;
181 }
182 
183 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
184 {
185 	return cmd->sdb.resid;
186 }
187 
188 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
189 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
190 
191 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
192 {
193 	return blk_bidi_rq(cmd->request) &&
194 		(cmd->request->next_rq->special != NULL);
195 }
196 
197 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
198 {
199 	return scsi_bidi_cmnd(cmd) ?
200 		cmd->request->next_rq->special : &cmd->sdb;
201 }
202 
203 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
204 {
205 	return &cmd->sdb;
206 }
207 
208 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
209 					   void *buf, int buflen)
210 {
211 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
212 				   buf, buflen);
213 }
214 
215 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
216 					 void *buf, int buflen)
217 {
218 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
219 				 buf, buflen);
220 }
221 
222 /*
223  * The operations below are hints that tell the controller driver how
224  * to handle I/Os with DIF or similar types of protection information.
225  */
226 enum scsi_prot_operations {
227 	/* Normal I/O */
228 	SCSI_PROT_NORMAL = 0,
229 
230 	/* OS-HBA: Protected, HBA-Target: Unprotected */
231 	SCSI_PROT_READ_INSERT,
232 	SCSI_PROT_WRITE_STRIP,
233 
234 	/* OS-HBA: Unprotected, HBA-Target: Protected */
235 	SCSI_PROT_READ_STRIP,
236 	SCSI_PROT_WRITE_INSERT,
237 
238 	/* OS-HBA: Protected, HBA-Target: Protected */
239 	SCSI_PROT_READ_PASS,
240 	SCSI_PROT_WRITE_PASS,
241 };
242 
243 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
244 {
245 	scmd->prot_op = op;
246 }
247 
248 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
249 {
250 	return scmd->prot_op;
251 }
252 
253 /*
254  * The controller usually does not know anything about the target it
255  * is communicating with.  However, when DIX is enabled the controller
256  * must be know target type so it can verify the protection
257  * information passed along with the I/O.
258  */
259 enum scsi_prot_target_type {
260 	SCSI_PROT_DIF_TYPE0 = 0,
261 	SCSI_PROT_DIF_TYPE1,
262 	SCSI_PROT_DIF_TYPE2,
263 	SCSI_PROT_DIF_TYPE3,
264 };
265 
266 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
267 {
268 	scmd->prot_type = type;
269 }
270 
271 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
272 {
273 	return scmd->prot_type;
274 }
275 
276 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
277 {
278 	return blk_rq_pos(scmd->request);
279 }
280 
281 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
282 {
283 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
284 }
285 
286 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
287 {
288 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
289 }
290 
291 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
292 {
293 	return cmd->prot_sdb;
294 }
295 
296 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
297 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
298 
299 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
300 {
301 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
302 }
303 
304 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
305 {
306 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
307 }
308 
309 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
310 {
311 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
312 }
313 
314 #endif /* _SCSI_SCSI_CMND_H */
315