summaryrefslogtreecommitdiff
path: root/include/scsi/scsi_cmnd.h
blob: 3f47e522a1ec3bedf6c85b9d30145c7208a626b5 (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
#ifndef _SCSI_SCSI_CMND_H
#define _SCSI_SCSI_CMND_H

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

struct request;
struct scatterlist;
struct Scsi_Host;
struct scsi_device;


/* 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;
};

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 */
	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;
	int timeout_per_command;

	unsigned char cmd_len;
	enum dma_data_direction sc_data_direction;

	/* These elements define the operation we are about to perform */
#define MAX_COMMAND_SIZE	16
	unsigned char cmnd[MAX_COMMAND_SIZE];
	unsigned request_bufflen;	/* Actual request size */

	struct timer_list eh_timeout;	/* Used to time out the command. */
	void *request_buffer;		/* Actual requested buffer */

	/* These elements define the operation we ultimately want to perform */
	unsigned short use_sg;	/* Number of pieces of scatter-gather */
	unsigned short __use_sg;

	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 */

	int resid;		/* Number of bytes requested to be
				   transferred less actual number
				   transferred (0 if not supported) */

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

#define SCSI_SENSE_BUFFERSIZE 	96
	unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];
				/* 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 */

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

extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
extern void scsi_put_command(struct scsi_cmnd *);
extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
			       struct device *);
extern void scsi_finish_command(struct scsi_cmnd *cmd);
extern void scsi_req_abort_cmd(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 struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *, gfp_t);
extern void scsi_free_sgtable(struct scsi_cmnd *);

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

#define scsi_sg_count(cmd) ((cmd)->use_sg)
#define scsi_sglist(cmd) ((struct scatterlist *)(cmd)->request_buffer)
#define scsi_bufflen(cmd) ((cmd)->request_bufflen)

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

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

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

#endif /* _SCSI_SCSI_CMND_H */