Linux-2.6.12-rc2
[deliverable/linux.git] / include / scsi / scsi_cmnd.h
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1#ifndef _SCSI_SCSI_CMND_H
2#define _SCSI_SCSI_CMND_H
3
4#include <linux/dma-mapping.h>
5#include <linux/list.h>
6#include <linux/types.h>
7
8struct request;
9struct scatterlist;
10struct scsi_device;
11struct scsi_request;
12
13
14/* embedded in scsi_cmnd */
15struct scsi_pointer {
16 char *ptr; /* data pointer */
17 int this_residual; /* left in this buffer */
18 struct scatterlist *buffer; /* which buffer */
19 int buffers_residual; /* how many buffers left */
20
21 dma_addr_t dma_handle;
22
23 volatile int Status;
24 volatile int Message;
25 volatile int have_data_in;
26 volatile int sent_command;
27 volatile int phase;
28};
29
30struct scsi_cmnd {
31 int sc_magic;
32
33 struct scsi_device *device;
34 unsigned short state;
35 unsigned short owner;
36 struct scsi_request *sc_request;
37
38 struct list_head list; /* scsi_cmnd participates in queue lists */
39
40 struct list_head eh_entry; /* entry for the host eh_cmd_q */
41 int eh_state; /* Used for state tracking in error handlr */
42 int eh_eflags; /* Used by error handlr */
43 void (*done) (struct scsi_cmnd *); /* Mid-level done function */
44
45 /*
46 * A SCSI Command is assigned a nonzero serial_number when internal_cmnd
47 * passes it to the driver's queue command function. The serial_number
48 * is cleared when scsi_done is entered indicating that the command has
49 * been completed. If a timeout occurs, the serial number at the moment
50 * of timeout is copied into serial_number_at_timeout. By subsequently
51 * comparing the serial_number and serial_number_at_timeout fields
52 * during abort or reset processing, we can detect whether the command
53 * has already completed. This also detects cases where the command has
54 * completed and the SCSI Command structure has already being reused
55 * for another command, so that we can avoid incorrectly aborting or
56 * resetting the new command.
57 * The serial number is only unique per host.
58 */
59 unsigned long serial_number;
60 unsigned long serial_number_at_timeout;
61
62 int retries;
63 int allowed;
64 int timeout_per_command;
65 int timeout_total;
66 int timeout;
67
68 /*
69 * We handle the timeout differently if it happens when a reset,
70 * abort, etc are in process.
71 */
72 unsigned volatile char internal_timeout;
73
74 unsigned char cmd_len;
75 unsigned char old_cmd_len;
76 enum dma_data_direction sc_data_direction;
77 enum dma_data_direction sc_old_data_direction;
78
79 /* These elements define the operation we are about to perform */
80#define MAX_COMMAND_SIZE 16
81 unsigned char cmnd[MAX_COMMAND_SIZE];
82 unsigned request_bufflen; /* Actual request size */
83
84 struct timer_list eh_timeout; /* Used to time out the command. */
85 void *request_buffer; /* Actual requested buffer */
86
87 /* These elements define the operation we ultimately want to perform */
88 unsigned char data_cmnd[MAX_COMMAND_SIZE];
89 unsigned short old_use_sg; /* We save use_sg here when requesting
90 * sense info */
91 unsigned short use_sg; /* Number of pieces of scatter-gather */
92 unsigned short sglist_len; /* size of malloc'd scatter-gather list */
93 unsigned short abort_reason; /* If the mid-level code requests an
94 * abort, this is the reason. */
95 unsigned bufflen; /* Size of data buffer */
96 void *buffer; /* Data buffer */
97
98 unsigned underflow; /* Return error if less than
99 this amount is transferred */
100 unsigned old_underflow; /* save underflow here when reusing the
101 * command for error handling */
102
103 unsigned transfersize; /* How much we are guaranteed to
104 transfer with each SCSI transfer
105 (ie, between disconnect /
106 reconnects. Probably == sector
107 size */
108
109 int resid; /* Number of bytes requested to be
110 transferred less actual number
111 transferred (0 if not supported) */
112
113 struct request *request; /* The command we are
114 working on */
115
116#define SCSI_SENSE_BUFFERSIZE 96
117 unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE]; /* obtained by REQUEST SENSE
118 * when CHECK CONDITION is
119 * received on original command
120 * (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
142 unsigned char tag; /* SCSI-II queued command tag */
143 unsigned long pid; /* Process ID, starts at 0. Unique per host. */
144};
145
146/*
147 * These are the values that scsi_cmd->state can take.
148 */
149#define SCSI_STATE_TIMEOUT 0x1000
150#define SCSI_STATE_FINISHED 0x1001
151#define SCSI_STATE_FAILED 0x1002
152#define SCSI_STATE_QUEUED 0x1003
153#define SCSI_STATE_UNUSED 0x1006
154#define SCSI_STATE_DISCONNECTING 0x1008
155#define SCSI_STATE_INITIALIZING 0x1009
156#define SCSI_STATE_BHQUEUE 0x100a
157#define SCSI_STATE_MLQUEUE 0x100b
158
159
160extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, int);
161extern void scsi_put_command(struct scsi_cmnd *);
162extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
163extern void scsi_finish_command(struct scsi_cmnd *cmd);
164
165#endif /* _SCSI_SCSI_CMND_H */
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