xref: /linux/include/scsi/scsi_cmnd.h (revision 13abf8130139c2ccd4962a7e5a8902be5e6cb5a7)
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 
8 struct request;
9 struct scatterlist;
10 struct scsi_device;
11 struct scsi_request;
12 
13 
14 /* embedded in scsi_cmnd */
15 struct 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 
30 struct scsi_cmnd {
31 	int     sc_magic;
32 
33 	struct scsi_device *device;
34 	struct scsi_request *sc_request;
35 
36 	struct list_head list;  /* scsi_cmnd participates in queue lists */
37 
38 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
39 	int eh_eflags;		/* Used by error handlr */
40 	void (*done) (struct scsi_cmnd *);	/* Mid-level done function */
41 
42 	/*
43 	 * A SCSI Command is assigned a nonzero serial_number before passed
44 	 * to the driver's queue command function.  The serial_number is
45 	 * cleared when scsi_done is entered indicating that the command
46 	 * has been completed.  It currently doesn't have much use other
47 	 * than printk's.  Some lldd's use this number for other purposes.
48 	 * It's almost certain that such usages are either incorrect or
49 	 * meaningless.  Please kill all usages other than printk's.  Also,
50 	 * as this number is always identical to ->pid, please convert
51 	 * printk's to use ->pid, so that we can kill this field.
52 	 */
53 	unsigned long serial_number;
54 
55 	int retries;
56 	int allowed;
57 	int timeout_per_command;
58 	int timeout_total;
59 	int timeout;
60 
61 	unsigned char cmd_len;
62 	unsigned char old_cmd_len;
63 	enum dma_data_direction sc_data_direction;
64 	enum dma_data_direction sc_old_data_direction;
65 
66 	/* These elements define the operation we are about to perform */
67 #define MAX_COMMAND_SIZE	16
68 	unsigned char cmnd[MAX_COMMAND_SIZE];
69 	unsigned request_bufflen;	/* Actual request size */
70 
71 	struct timer_list eh_timeout;	/* Used to time out the command. */
72 	void *request_buffer;		/* Actual requested buffer */
73 
74 	/* These elements define the operation we ultimately want to perform */
75 	unsigned char data_cmnd[MAX_COMMAND_SIZE];
76 	unsigned short old_use_sg;	/* We save  use_sg here when requesting
77 					 * sense info */
78 	unsigned short use_sg;	/* Number of pieces of scatter-gather */
79 	unsigned short sglist_len;	/* size of malloc'd scatter-gather list */
80 	unsigned bufflen;	/* Size of data buffer */
81 	void *buffer;		/* Data buffer */
82 
83 	unsigned underflow;	/* Return error if less than
84 				   this amount is transferred */
85 	unsigned old_underflow;	/* save underflow here when reusing the
86 				 * command for error handling */
87 
88 	unsigned transfersize;	/* How much we are guaranteed to
89 				   transfer with each SCSI transfer
90 				   (ie, between disconnect /
91 				   reconnects.   Probably == sector
92 				   size */
93 
94 	int resid;		/* Number of bytes requested to be
95 				   transferred less actual number
96 				   transferred (0 if not supported) */
97 
98 	struct request *request;	/* The command we are
99 				   	   working on */
100 
101 #define SCSI_SENSE_BUFFERSIZE 	96
102 	unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];		/* obtained by REQUEST SENSE
103 						 * when CHECK CONDITION is
104 						 * received on original command
105 						 * (auto-sense) */
106 
107 	/* Low-level done function - can be used by low-level driver to point
108 	 *        to completion function.  Not used by mid/upper level code. */
109 	void (*scsi_done) (struct scsi_cmnd *);
110 
111 	/*
112 	 * The following fields can be written to by the host specific code.
113 	 * Everything else should be left alone.
114 	 */
115 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
116 
117 	unsigned char *host_scribble;	/* The host adapter is allowed to
118 					   * call scsi_malloc and get some memory
119 					   * and hang it here.     The host adapter
120 					   * is also expected to call scsi_free
121 					   * to release this memory.  (The memory
122 					   * obtained by scsi_malloc is guaranteed
123 					   * to be at an address < 16Mb). */
124 
125 	int result;		/* Status code from lower level driver */
126 
127 	unsigned char tag;	/* SCSI-II queued command tag */
128 	unsigned long pid;	/* Process ID, starts at 0. Unique per host. */
129 };
130 
131 /*
132  * These are the values that scsi_cmd->state can take.
133  */
134 #define SCSI_STATE_TIMEOUT         0x1000
135 #define SCSI_STATE_FINISHED        0x1001
136 #define SCSI_STATE_FAILED          0x1002
137 #define SCSI_STATE_QUEUED          0x1003
138 #define SCSI_STATE_UNUSED          0x1006
139 #define SCSI_STATE_DISCONNECTING   0x1008
140 #define SCSI_STATE_INITIALIZING    0x1009
141 #define SCSI_STATE_BHQUEUE         0x100a
142 #define SCSI_STATE_MLQUEUE         0x100b
143 
144 
145 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, int);
146 extern void scsi_put_command(struct scsi_cmnd *);
147 extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
148 extern void scsi_finish_command(struct scsi_cmnd *cmd);
149 
150 #endif /* _SCSI_SCSI_CMND_H */
151