xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision 260ea95c)
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 #include <scsi/scsi_request.h>
12 
13 struct Scsi_Host;
14 struct scsi_driver;
15 
16 #include <scsi/scsi_device.h>
17 
18 /*
19  * MAX_COMMAND_SIZE is:
20  * The longest fixed-length SCSI CDB as per the SCSI standard.
21  * fixed-length means: commands that their size can be determined
22  * by their opcode and the CDB does not carry a length specifier, (unlike
23  * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
24  * true and the SCSI standard also defines extended commands and
25  * vendor specific commands that can be bigger than 16 bytes. The kernel
26  * will support these using the same infrastructure used for VARLEN CDB's.
27  * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
28  * supports without specifying a cmd_len by ULD's
29  */
30 #define MAX_COMMAND_SIZE 16
31 #if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
32 # error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
33 #endif
34 
35 struct scsi_data_buffer {
36 	struct sg_table table;
37 	unsigned length;
38 	int resid;
39 };
40 
41 /* embedded in scsi_cmnd */
42 struct scsi_pointer {
43 	char *ptr;		/* data pointer */
44 	int this_residual;	/* left in this buffer */
45 	struct scatterlist *buffer;	/* which buffer */
46 	int buffers_residual;	/* how many buffers left */
47 
48         dma_addr_t dma_handle;
49 
50 	volatile int Status;
51 	volatile int Message;
52 	volatile int have_data_in;
53 	volatile int sent_command;
54 	volatile int phase;
55 };
56 
57 /* for scmd->flags */
58 #define SCMD_TAGGED		(1 << 0)
59 #define SCMD_UNCHECKED_ISA_DMA	(1 << 1)
60 
61 struct scsi_cmnd {
62 	struct scsi_request req;
63 	struct scsi_device *device;
64 	struct list_head list;  /* scsi_cmnd participates in queue lists */
65 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
66 	struct delayed_work abort_work;
67 	int eh_eflags;		/* Used by error handlr */
68 
69 	/*
70 	 * A SCSI Command is assigned a nonzero serial_number before passed
71 	 * to the driver's queue command function.  The serial_number is
72 	 * cleared when scsi_done is entered indicating that the command
73 	 * has been completed.  It is a bug for LLDDs to use this number
74 	 * for purposes other than printk (and even that is only useful
75 	 * for debugging).
76 	 */
77 	unsigned long serial_number;
78 
79 	/*
80 	 * This is set to jiffies as it was when the command was first
81 	 * allocated.  It is used to time how long the command has
82 	 * been outstanding
83 	 */
84 	unsigned long jiffies_at_alloc;
85 
86 	int retries;
87 	int allowed;
88 
89 	unsigned char prot_op;
90 	unsigned char prot_type;
91 	unsigned char prot_flags;
92 
93 	unsigned short cmd_len;
94 	enum dma_data_direction sc_data_direction;
95 
96 	/* These elements define the operation we are about to perform */
97 	unsigned char *cmnd;
98 
99 
100 	/* These elements define the operation we ultimately want to perform */
101 	struct scsi_data_buffer sdb;
102 	struct scsi_data_buffer *prot_sdb;
103 
104 	unsigned underflow;	/* Return error if less than
105 				   this amount is transferred */
106 
107 	unsigned transfersize;	/* How much we are guaranteed to
108 				   transfer with each SCSI transfer
109 				   (ie, between disconnect /
110 				   reconnects.   Probably == sector
111 				   size */
112 
113 	struct request *request;	/* The command we are
114 				   	   working on */
115 
116 #define SCSI_SENSE_BUFFERSIZE 	96
117 	unsigned char *sense_buffer;
118 				/* obtained by REQUEST SENSE when
119 				 * CHECK CONDITION is received on original
120 				 * command (auto-sense) */
121 
122 	/* Low-level done function - can be used by low-level driver to point
123 	 *        to completion function.  Not used by mid/upper level code. */
124 	void (*scsi_done) (struct scsi_cmnd *);
125 
126 	/*
127 	 * The following fields can be written to by the host specific code.
128 	 * Everything else should be left alone.
129 	 */
130 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
131 
132 	unsigned char *host_scribble;	/* The host adapter is allowed to
133 					 * call scsi_malloc and get some memory
134 					 * and hang it here.  The host adapter
135 					 * is also expected to call scsi_free
136 					 * to release this memory.  (The memory
137 					 * obtained by scsi_malloc is guaranteed
138 					 * to be at an address < 16Mb). */
139 
140 	int result;		/* Status code from lower level driver */
141 	int flags;		/* Command flags */
142 
143 	unsigned char tag;	/* SCSI-II queued command tag */
144 };
145 
146 /*
147  * Return the driver private allocation behind the command.
148  * Only works if cmd_size is set in the host template.
149  */
150 static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
151 {
152 	return cmd + 1;
153 }
154 
155 /* make sure not to use it with passthrough commands */
156 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
157 {
158 	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
159 }
160 
161 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
162 extern void scsi_put_command(struct scsi_cmnd *);
163 extern void scsi_finish_command(struct scsi_cmnd *cmd);
164 
165 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
166 				 size_t *offset, size_t *len);
167 extern void scsi_kunmap_atomic_sg(void *virt);
168 
169 extern int scsi_init_io(struct scsi_cmnd *cmd);
170 extern void scsi_initialize_rq(struct request *rq);
171 
172 extern int scsi_dma_map(struct scsi_cmnd *cmd);
173 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
174 
175 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
176 {
177 	return cmd->sdb.table.nents;
178 }
179 
180 static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
181 {
182 	return cmd->sdb.table.sgl;
183 }
184 
185 static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
186 {
187 	return cmd->sdb.length;
188 }
189 
190 static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
191 {
192 	cmd->sdb.resid = resid;
193 }
194 
195 static inline int scsi_get_resid(struct scsi_cmnd *cmd)
196 {
197 	return cmd->sdb.resid;
198 }
199 
200 #define scsi_for_each_sg(cmd, sg, nseg, __i)			\
201 	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)
202 
203 static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
204 {
205 	return blk_bidi_rq(cmd->request) &&
206 		(cmd->request->next_rq->special != NULL);
207 }
208 
209 static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
210 {
211 	return scsi_bidi_cmnd(cmd) ?
212 		cmd->request->next_rq->special : &cmd->sdb;
213 }
214 
215 static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
216 {
217 	return &cmd->sdb;
218 }
219 
220 static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
221 					   void *buf, int buflen)
222 {
223 	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
224 				   buf, buflen);
225 }
226 
227 static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
228 					 void *buf, int buflen)
229 {
230 	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
231 				 buf, buflen);
232 }
233 
234 /*
235  * The operations below are hints that tell the controller driver how
236  * to handle I/Os with DIF or similar types of protection information.
237  */
238 enum scsi_prot_operations {
239 	/* Normal I/O */
240 	SCSI_PROT_NORMAL = 0,
241 
242 	/* OS-HBA: Protected, HBA-Target: Unprotected */
243 	SCSI_PROT_READ_INSERT,
244 	SCSI_PROT_WRITE_STRIP,
245 
246 	/* OS-HBA: Unprotected, HBA-Target: Protected */
247 	SCSI_PROT_READ_STRIP,
248 	SCSI_PROT_WRITE_INSERT,
249 
250 	/* OS-HBA: Protected, HBA-Target: Protected */
251 	SCSI_PROT_READ_PASS,
252 	SCSI_PROT_WRITE_PASS,
253 };
254 
255 static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
256 {
257 	scmd->prot_op = op;
258 }
259 
260 static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
261 {
262 	return scmd->prot_op;
263 }
264 
265 enum scsi_prot_flags {
266 	SCSI_PROT_TRANSFER_PI		= 1 << 0,
267 	SCSI_PROT_GUARD_CHECK		= 1 << 1,
268 	SCSI_PROT_REF_CHECK		= 1 << 2,
269 	SCSI_PROT_REF_INCREMENT		= 1 << 3,
270 	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
271 };
272 
273 /*
274  * The controller usually does not know anything about the target it
275  * is communicating with.  However, when DIX is enabled the controller
276  * must be know target type so it can verify the protection
277  * information passed along with the I/O.
278  */
279 enum scsi_prot_target_type {
280 	SCSI_PROT_DIF_TYPE0 = 0,
281 	SCSI_PROT_DIF_TYPE1,
282 	SCSI_PROT_DIF_TYPE2,
283 	SCSI_PROT_DIF_TYPE3,
284 };
285 
286 static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
287 {
288 	scmd->prot_type = type;
289 }
290 
291 static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
292 {
293 	return scmd->prot_type;
294 }
295 
296 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
297 {
298 	return blk_rq_pos(scmd->request);
299 }
300 
301 static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
302 {
303 	return scmd->device->sector_size;
304 }
305 
306 static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
307 {
308 	return blk_rq_pos(scmd->request) >>
309 		(ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
310 }
311 
312 static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
313 {
314 	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
315 }
316 
317 static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
318 {
319 	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
320 }
321 
322 static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
323 {
324 	return cmd->prot_sdb;
325 }
326 
327 #define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
328 	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
329 
330 static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
331 {
332 	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
333 }
334 
335 static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
336 {
337 	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
338 }
339 
340 static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
341 {
342 	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
343 }
344 
345 static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
346 {
347 	unsigned int xfer_len = scsi_out(scmd)->length;
348 	unsigned int prot_interval = scsi_prot_interval(scmd);
349 
350 	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
351 		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;
352 
353 	return xfer_len;
354 }
355 
356 #endif /* _SCSI_SCSI_CMND_H */
357