xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision 293d5b43)
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 #include <scsi/scsi_device.h>
11 
12 struct Scsi_Host;
13 struct scsi_driver;
14 
15 #include <scsi/scsi_device.h>
16 
17 /*
18  * MAX_COMMAND_SIZE is:
19  * The longest fixed-length SCSI CDB as per the SCSI standard.
20  * fixed-length means: commands that their size can be determined
21  * by their opcode and the CDB does not carry a length specifier, (unlike
22  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
23  * true and the SCSI standard also defines extended commands and
24  * vendor specific commands that can be bigger than 16 bytes. The kernel
25  * will support these using the same infrastructure used for VARLEN CDB's.
26  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
27  * supports without specifying a cmd_len by ULD's
28  */
29 #define MAX_COMMAND_SIZE 16
30 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
31 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
32 #endif
33 
34 struct scsi_data_buffer {
35 	struct sg_table table;
36 	unsigned length;
37 	int resid;
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 
59 struct scsi_cmnd {
60 	struct scsi_device *device;
61 	struct list_head list;  /* scsi_cmnd participates in queue lists */
62 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
63 	struct delayed_work abort_work;
64 	int eh_eflags;		/* Used by error handlr */
65 
66 	/*
67 	 * A SCSI Command is assigned a nonzero serial_number before passed
68 	 * to the driver's queue command function.  The serial_number is
69 	 * cleared when scsi_done is entered indicating that the command
70 	 * has been completed.  It is a bug for LLDDs to use this number
71 	 * for purposes other than printk (and even that is only useful
72 	 * for debugging).
73 	 */
74 	unsigned long serial_number;
75 
76 	/*
77 	 * This is set to jiffies as it was when the command was first
78 	 * allocated.  It is used to time how long the command has
79 	 * been outstanding
80 	 */
81 	unsigned long jiffies_at_alloc;
82 
83 	int retries;
84 	int allowed;
85 
86 	unsigned char prot_op;
87 	unsigned char prot_type;
88 	unsigned char prot_flags;
89 
90 	unsigned short cmd_len;
91 	enum dma_data_direction sc_data_direction;
92 
93 	/* These elements define the operation we are about to perform */
94 	unsigned char *cmnd;
95 
96 
97 	/* These elements define the operation we ultimately want to perform */
98 	struct scsi_data_buffer sdb;
99 	struct scsi_data_buffer *prot_sdb;
100 
101 	unsigned underflow;	/* Return error if less than
102 				   this amount is transferred */
103 
104 	unsigned transfersize;	/* How much we are guaranteed to
105 				   transfer with each SCSI transfer
106 				   (ie, between disconnect /
107 				   reconnects.   Probably == sector
108 				   size */
109 
110 	struct request *request;	/* The command we are
111 				   	   working on */
112 
113 #define SCSI_SENSE_BUFFERSIZE 	96
114 	unsigned char *sense_buffer;
115 				/* obtained by REQUEST SENSE when
116 				 * CHECK CONDITION is received on original
117 				 * command (auto-sense) */
118 
119 	/* Low-level done function - can be used by low-level driver to point
120 	 *        to completion function.  Not used by mid/upper level code. */
121 	void (*scsi_done) (struct scsi_cmnd *);
122 
123 	/*
124 	 * The following fields can be written to by the host specific code.
125 	 * Everything else should be left alone.
126 	 */
127 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
128 
129 	unsigned char *host_scribble;	/* The host adapter is allowed to
130 					 * call scsi_malloc and get some memory
131 					 * and hang it here.  The host adapter
132 					 * is also expected to call scsi_free
133 					 * to release this memory.  (The memory
134 					 * obtained by scsi_malloc is guaranteed
135 					 * to be at an address < 16Mb). */
136 
137 	int result;		/* Status code from lower level driver */
138 	int flags;		/* Command flags */
139 
140 	unsigned char tag;	/* SCSI-II queued command tag */
141 };
142 
143 /*
144  * Return the driver private allocation behind the command.
145  * Only works if cmd_size is set in the host template.
146  */
147 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
148 {
149 	return cmd + 1;
150 }
151 
152 /* make sure not to use it with REQ_TYPE_BLOCK_PC commands */
153 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
154 {
155 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
156 }
157 
158 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
159 extern void scsi_put_command(struct scsi_cmnd *);
160 extern void scsi_finish_command(struct scsi_cmnd *cmd);
161 
162 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
163 				 size_t *offset, size_t *len);
164 extern void scsi_kunmap_atomic_sg(void *virt);
165 
166 extern int scsi_init_io(struct scsi_cmnd *cmd);
167 
168 extern int scsi_dma_map(struct scsi_cmnd *cmd);
169 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
170 
171 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
172 {
173 	return cmd->sdb.table.nents;
174 }
175 
176 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
177 {
178 	return cmd->sdb.table.sgl;
179 }
180 
181 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
182 {
183 	return cmd->sdb.length;
184 }
185 
186 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
187 {
188 	cmd->sdb.resid = resid;
189 }
190 
191 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
192 {
193 	return cmd->sdb.resid;
194 }
195 
196 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
197 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
198 
199 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
200 {
201 	return blk_bidi_rq(cmd->request) &&
202 		(cmd->request->next_rq->special != NULL);
203 }
204 
205 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
206 {
207 	return scsi_bidi_cmnd(cmd) ?
208 		cmd->request->next_rq->special : &cmd->sdb;
209 }
210 
211 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
212 {
213 	return &cmd->sdb;
214 }
215 
216 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
217 					   void *buf, int buflen)
218 {
219 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
220 				   buf, buflen);
221 }
222 
223 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
224 					 void *buf, int buflen)
225 {
226 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
227 				 buf, buflen);
228 }
229 
230 /*
231  * The operations below are hints that tell the controller driver how
232  * to handle I/Os with DIF or similar types of protection information.
233  */
234 enum scsi_prot_operations {
235 	/* Normal I/O */
236 	SCSI_PROT_NORMAL = 0,
237 
238 	/* OS-HBA: Protected, HBA-Target: Unprotected */
239 	SCSI_PROT_READ_INSERT,
240 	SCSI_PROT_WRITE_STRIP,
241 
242 	/* OS-HBA: Unprotected, HBA-Target: Protected */
243 	SCSI_PROT_READ_STRIP,
244 	SCSI_PROT_WRITE_INSERT,
245 
246 	/* OS-HBA: Protected, HBA-Target: Protected */
247 	SCSI_PROT_READ_PASS,
248 	SCSI_PROT_WRITE_PASS,
249 };
250 
251 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
252 {
253 	scmd->prot_op = op;
254 }
255 
256 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
257 {
258 	return scmd->prot_op;
259 }
260 
261 enum scsi_prot_flags {
262 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
263 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
264 	SCSI_PROT_REF_CHECK		= 1 << 2,
265 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
266 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
267 };
268 
269 /*
270  * The controller usually does not know anything about the target it
271  * is communicating with.  However, when DIX is enabled the controller
272  * must be know target type so it can verify the protection
273  * information passed along with the I/O.
274  */
275 enum scsi_prot_target_type {
276 	SCSI_PROT_DIF_TYPE0 = 0,
277 	SCSI_PROT_DIF_TYPE1,
278 	SCSI_PROT_DIF_TYPE2,
279 	SCSI_PROT_DIF_TYPE3,
280 };
281 
282 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
283 {
284 	scmd->prot_type = type;
285 }
286 
287 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
288 {
289 	return scmd->prot_type;
290 }
291 
292 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
293 {
294 	return blk_rq_pos(scmd->request);
295 }
296 
297 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
298 {
299 	return scmd->device->sector_size;
300 }
301 
302 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
303 {
304 	return blk_rq_pos(scmd->request) >>
305 		(ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
306 }
307 
308 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
309 {
310 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
311 }
312 
313 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
314 {
315 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
316 }
317 
318 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
319 {
320 	return cmd->prot_sdb;
321 }
322 
323 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
324 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
325 
326 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
327 {
328 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
329 }
330 
331 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
332 {
333 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
334 }
335 
336 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
337 {
338 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
339 }
340 
341 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
342 {
343 	unsigned int xfer_len = scsi_out(scmd)->length;
344 	unsigned int prot_interval = scsi_prot_interval(scmd);
345 
346 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
347 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
348 
349 	return xfer_len;
350 }
351 
352 #endif /* _SCSI_SCSI_CMND_H */
353