aboutsummaryrefslogtreecommitdiffstats
path: root/include/scsi/scsi_cmnd.h
blob: e119142e565eb739abba6b07b1ec606de4f2dd80 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
#ifndef _SCSI_SCSI_CMND_H
#define _SCSI_SCSI_CMND_H

#include <linux/dma-mapping.h>
#include <linux/blkdev.h>
#include <linux/list.h>
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/scatterlist.h>
#include <scsi/scsi_device.h>

struct Scsi_Host;
struct scsi_driver;

#include <scsi/scsi_device.h>

/*
 * MAX_COMMAND_SIZE is:
 * The longest fixed-length SCSI CDB as per the SCSI standard.
 * fixed-length means: commands that their size can be determined
 * by their opcode and the CDB does not carry a length specifier, (unlike
 * the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
 * true and the SCSI standard also defines extended commands and
 * vendor specific commands that can be bigger than 16 bytes. The kernel
 * will support these using the same infrastructure used for VARLEN CDB's.
 * So in effect MAX_COMMAND_SIZE means the maximum size command scsi-ml
 * supports without specifying a cmd_len by ULD's
 */
#define MAX_COMMAND_SIZE 16
#if (MAX_COMMAND_SIZE > BLK_MAX_CDB)
# error MAX_COMMAND_SIZE can not be bigger than BLK_MAX_CDB
#endif

struct scsi_data_buffer {
	struct sg_table table;
	unsigned length;
	int resid;
};

/* embedded in scsi_cmnd */
struct scsi_pointer {
	char *ptr;		/* data pointer */
	int this_residual;	/* left in this buffer */
	struct scatterlist *buffer;	/* which buffer */
	int buffers_residual;	/* how many buffers left */

        dma_addr_t dma_handle;

	volatile int Status;
	volatile int Message;
	volatile int have_data_in;
	volatile int sent_command;
	volatile int phase;
};

/* for scmd->flags */
#define SCMD_TAGGED		(1 << 0)

struct scsi_cmnd {
	struct scsi_device *device;
	struct list_head list;  /* scsi_cmnd participates in queue lists */
	struct list_head eh_entry; /* entry for the host eh_cmd_q */
	struct delayed_work abort_work;
	int eh_eflags;		/* Used by error handlr */

	/*
	 * A SCSI Command is assigned a nonzero serial_number before passed
	 * to the driver's queue command function.  The serial_number is
	 * cleared when scsi_done is entered indicating that the command
	 * has been completed.  It is a bug for LLDDs to use this number
	 * for purposes other than printk (and even that is only useful
	 * for debugging).
	 */
	unsigned long serial_number;

	/*
	 * This is set to jiffies as it was when the command was first
	 * allocated.  It is used to time how long the command has
	 * been outstanding
	 */
	unsigned long jiffies_at_alloc;

	int retries;
	int allowed;

	unsigned char prot_op;
	unsigned char prot_type;
	unsigned char prot_flags;

	unsigned short cmd_len;
	enum dma_data_direction sc_data_direction;

	/* These elements define the operation we are about to perform */
	unsigned char *cmnd;


	/* These elements define the operation we ultimately want to perform */
	struct scsi_data_buffer sdb;
	struct scsi_data_buffer *prot_sdb;

	unsigned underflow;	/* Return error if less than
				   this amount is transferred */

	unsigned transfersize;	/* How much we are guaranteed to
				   transfer with each SCSI transfer
				   (ie, between disconnect / 
				   reconnects.   Probably == sector
				   size */

	struct request *request;	/* The command we are
				   	   working on */

#define SCSI_SENSE_BUFFERSIZE 	96
	unsigned char *sense_buffer;
				/* obtained by REQUEST SENSE when
				 * CHECK CONDITION is received on original
				 * command (auto-sense) */

	/* Low-level done function - can be used by low-level driver to point
	 *        to completion function.  Not used by mid/upper level code. */
	void (*scsi_done) (struct scsi_cmnd *);

	/*
	 * The following fields can be written to by the host specific code. 
	 * Everything else should be left alone. 
	 */
	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */

	unsigned char *host_scribble;	/* The host adapter is allowed to
					 * call scsi_malloc and get some memory
					 * and hang it here.  The host adapter
					 * is also expected to call scsi_free
					 * to release this memory.  (The memory
					 * obtained by scsi_malloc is guaranteed
					 * to be at an address < 16Mb). */

	int result;		/* Status code from lower level driver */
	int flags;		/* Command flags */

	unsigned char tag;	/* SCSI-II queued command tag */
};

/*
 * Return the driver private allocation behind the command.
 * Only works if cmd_size is set in the host template.
 */
static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
{
	return cmd + 1;
}

/* make sure not to use it with REQ_TYPE_BLOCK_PC commands */
static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
{
	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
}

extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
extern void scsi_put_command(struct scsi_cmnd *);
extern void scsi_finish_command(struct scsi_cmnd *cmd);

extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
				 size_t *offset, size_t *len);
extern void scsi_kunmap_atomic_sg(void *virt);

extern int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask);

extern int scsi_dma_map(struct scsi_cmnd *cmd);
extern void scsi_dma_unmap(struct scsi_cmnd *cmd);

static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
{
	return cmd->sdb.table.nents;
}

static inline struct scatterlist *scsi_sglist(struct scsi_cmnd *cmd)
{
	return cmd->sdb.table.sgl;
}

static inline unsigned scsi_bufflen(struct scsi_cmnd *cmd)
{
	return cmd->sdb.length;
}

static inline void scsi_set_resid(struct scsi_cmnd *cmd, int resid)
{
	cmd->sdb.resid = resid;
}

static inline int scsi_get_resid(struct scsi_cmnd *cmd)
{
	return cmd->sdb.resid;
}

#define scsi_for_each_sg(cmd, sg, nseg, __i)			\
	for_each_sg(scsi_sglist(cmd), sg, nseg, __i)

static inline int scsi_bidi_cmnd(struct scsi_cmnd *cmd)
{
	return blk_bidi_rq(cmd->request) &&
		(cmd->request->next_rq->special != NULL);
}

static inline struct scsi_data_buffer *scsi_in(struct scsi_cmnd *cmd)
{
	return scsi_bidi_cmnd(cmd) ?
		cmd->request->next_rq->special : &cmd->sdb;
}

static inline struct scsi_data_buffer *scsi_out(struct scsi_cmnd *cmd)
{
	return &cmd->sdb;
}

static inline int scsi_sg_copy_from_buffer(struct scsi_cmnd *cmd,
					   void *buf, int buflen)
{
	return sg_copy_from_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
				   buf, buflen);
}

static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
					 void *buf, int buflen)
{
	return sg_copy_to_buffer(scsi_sglist(cmd), scsi_sg_count(cmd),
				 buf, buflen);
}

/*
 * The operations below are hints that tell the controller driver how
 * to handle I/Os with DIF or similar types of protection information.
 */
enum scsi_prot_operations {
	/* Normal I/O */
	SCSI_PROT_NORMAL = 0,

	/* OS-HBA: Protected, HBA-Target: Unprotected */
	SCSI_PROT_READ_INSERT,
	SCSI_PROT_WRITE_STRIP,

	/* OS-HBA: Unprotected, HBA-Target: Protected */
	SCSI_PROT_READ_STRIP,
	SCSI_PROT_WRITE_INSERT,

	/* OS-HBA: Protected, HBA-Target: Protected */
	SCSI_PROT_READ_PASS,
	SCSI_PROT_WRITE_PASS,
};

static inline void scsi_set_prot_op(struct scsi_cmnd *scmd, unsigned char op)
{
	scmd->prot_op = op;
}

static inline unsigned char scsi_get_prot_op(struct scsi_cmnd *scmd)
{
	return scmd->prot_op;
}

enum scsi_prot_flags {
	SCSI_PROT_TRANSFER_PI		= 1 << 0,
	SCSI_PROT_GUARD_CHECK		= 1 << 1,
	SCSI_PROT_REF_CHECK		= 1 << 2,
	SCSI_PROT_REF_INCREMENT		= 1 << 3,
	SCSI_PROT_IP_CHECKSUM		= 1 << 4,
};

/*
 * The controller usually does not know anything about the target it
 * is communicating with.  However, when DIX is enabled the controller
 * must be know target type so it can verify the protection
 * information passed along with the I/O.
 */
enum scsi_prot_target_type {
	SCSI_PROT_DIF_TYPE0 = 0,
	SCSI_PROT_DIF_TYPE1,
	SCSI_PROT_DIF_TYPE2,
	SCSI_PROT_DIF_TYPE3,
};

static inline void scsi_set_prot_type(struct scsi_cmnd *scmd, unsigned char type)
{
	scmd->prot_type = type;
}

static inline unsigned char scsi_get_prot_type(struct scsi_cmnd *scmd)
{
	return scmd->prot_type;
}

static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
{
	return blk_rq_pos(scmd->request);
}

static inline unsigned int scsi_prot_interval(struct scsi_cmnd *scmd)
{
	return scmd->device->sector_size;
}

static inline u32 scsi_prot_ref_tag(struct scsi_cmnd *scmd)
{
	return blk_rq_pos(scmd->request) >>
		(ilog2(scsi_prot_interval(scmd)) - 9) & 0xffffffff;
}

static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
{
	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
}

static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
{
	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
}

static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
{
	return cmd->prot_sdb;
}

#define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\
	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)

static inline void set_msg_byte(struct scsi_cmnd *cmd, char status)
{
	cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
}

static inline void set_host_byte(struct scsi_cmnd *cmd, char status)
{
	cmd->result = (cmd->result & 0xff00ffff) | (status << 16);
}

static inline void set_driver_byte(struct scsi_cmnd *cmd, char status)
{
	cmd->result = (cmd->result & 0x00ffffff) | (status << 24);
}

static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
{
	unsigned int xfer_len = scsi_out(scmd)->length;
	unsigned int prot_interval = scsi_prot_interval(scmd);

	if (scmd->prot_flags & SCSI_PROT_TRANSFER_PI)
		xfer_len += (xfer_len >> ilog2(prot_interval)) * 8;

	return xfer_len;
}

#endif /* _SCSI_SCSI_CMND_H */

Privacy Policy