summaryrefslogtreecommitdiff
path: root/include/scsi/scsi_cmnd.h
blob: 9d9871c28abdc2a3e8932a9819001aadf41cb0cd (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
#ifndef _SCSI_SCSI_CMND_H
#define _SCSI_SCSI_CMND_H

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

struct request;
struct scatterlist;
struct scsi_device;
struct scsi_request;


/* 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 {
	int     sc_magic;

	struct scsi_device *device;
	unsigned short state;
	unsigned short owner;
	struct scsi_request *sc_request;

	struct list_head list;  /* scsi_cmnd participates in queue lists */

	struct list_head eh_entry; /* entry for the host eh_cmd_q */
	int eh_state;		/* Used for state tracking in error handlr */
	int eh_eflags;		/* Used by error handlr */
	void (*done) (struct scsi_cmnd *);	/* Mid-level done function */

	/*
	 * A SCSI Command is assigned a nonzero serial_number when internal_cmnd
	 * passes it to the driver's queue command function.  The serial_number
	 * is cleared when scsi_done is entered indicating that the command has
	 * been completed.  If a timeout occurs, the serial number at the moment
	 * of timeout is copied into serial_number_at_timeout.  By subsequently
	 * comparing the serial_number and serial_number_at_timeout fields
	 * during abort or reset processing, we can detect whether the command
	 * has already completed.  This also detects cases where the command has
	 * completed and the SCSI Command structure has already being reused
	 * for another command, so that we can avoid incorrectly aborting or
	 * resetting the new command.
	 * The serial number is only unique per host.
	 */
	unsigned long serial_number;
	unsigned long serial_number_at_timeout;

	int retries;
	int allowed;
	int timeout_per_command;
	int timeout_total;
	int timeout;

	/*
	 * We handle the timeout differently if it happens when a reset, 
	 * abort, etc are in process. 
	 */
	unsigned volatile char internal_timeout;

	unsigned char cmd_len;
	unsigned char old_cmd_len;
	enum dma_data_direction sc_data_direction;
	enum dma_data_direction sc_old_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 char data_cmnd[MAX_COMMAND_SIZE];
	unsigned short old_use_sg;	/* We save  use_sg here when requesting
					 * sense info */
	unsigned short use_sg;	/* Number of pieces of scatter-gather */
	unsigned short sglist_len;	/* size of malloc'd scatter-gather list */
	unsigned short abort_reason;	/* If the mid-level code requests an
					 * abort, this is the reason. */
	unsigned bufflen;	/* Size of data buffer */
	void *buffer;		/* Data buffer */

	unsigned underflow;	/* Return error if less than
				   this amount is transferred */
	unsigned old_underflow;	/* save underflow here when reusing the
				 * command for error handling */

	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 */
	unsigned long pid;	/* Process ID, starts at 0. Unique per host. */
};

/*
 * These are the values that scsi_cmd->state can take.
 */
#define SCSI_STATE_TIMEOUT         0x1000
#define SCSI_STATE_FINISHED        0x1001
#define SCSI_STATE_FAILED          0x1002
#define SCSI_STATE_QUEUED          0x1003
#define SCSI_STATE_UNUSED          0x1006
#define SCSI_STATE_DISCONNECTING   0x1008
#define SCSI_STATE_INITIALIZING    0x1009
#define SCSI_STATE_BHQUEUE         0x100a
#define SCSI_STATE_MLQUEUE         0x100b


extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, int);
extern void scsi_put_command(struct scsi_cmnd *);
extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
extern void scsi_finish_command(struct scsi_cmnd *cmd);

#endif /* _SCSI_SCSI_CMND_H */