xref: /linux/include/scsi/scsi_cmnd.h (revision 776cfebb430c7b22c208b1b17add97f354d97cab)
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 	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 before passed
47 	 * to the driver's queue command function.  The serial_number is
48 	 * cleared when scsi_done is entered indicating that the command
49 	 * has been completed.  It currently doesn't have much use other
50 	 * than printk's.  Some lldd's use this number for other purposes.
51 	 * It's almost certain that such usages are either incorrect or
52 	 * meaningless.  Please kill all usages other than printk's.  Also,
53 	 * as this number is always identical to ->pid, please convert
54 	 * printk's to use ->pid, so that we can kill this field.
55 	 */
56 	unsigned long serial_number;
57 
58 	int retries;
59 	int allowed;
60 	int timeout_per_command;
61 	int timeout_total;
62 	int timeout;
63 
64 	unsigned char cmd_len;
65 	unsigned char old_cmd_len;
66 	enum dma_data_direction sc_data_direction;
67 	enum dma_data_direction sc_old_data_direction;
68 
69 	/* These elements define the operation we are about to perform */
70 #define MAX_COMMAND_SIZE	16
71 	unsigned char cmnd[MAX_COMMAND_SIZE];
72 	unsigned request_bufflen;	/* Actual request size */
73 
74 	struct timer_list eh_timeout;	/* Used to time out the command. */
75 	void *request_buffer;		/* Actual requested buffer */
76 
77 	/* These elements define the operation we ultimately want to perform */
78 	unsigned char data_cmnd[MAX_COMMAND_SIZE];
79 	unsigned short old_use_sg;	/* We save  use_sg here when requesting
80 					 * sense info */
81 	unsigned short use_sg;	/* Number of pieces of scatter-gather */
82 	unsigned short sglist_len;	/* size of malloc'd scatter-gather list */
83 	unsigned short abort_reason;	/* If the mid-level code requests an
84 					 * abort, this is the reason. */
85 	unsigned bufflen;	/* Size of data buffer */
86 	void *buffer;		/* Data buffer */
87 
88 	unsigned underflow;	/* Return error if less than
89 				   this amount is transferred */
90 	unsigned old_underflow;	/* save underflow here when reusing the
91 				 * command for error handling */
92 
93 	unsigned transfersize;	/* How much we are guaranteed to
94 				   transfer with each SCSI transfer
95 				   (ie, between disconnect /
96 				   reconnects.   Probably == sector
97 				   size */
98 
99 	int resid;		/* Number of bytes requested to be
100 				   transferred less actual number
101 				   transferred (0 if not supported) */
102 
103 	struct request *request;	/* The command we are
104 				   	   working on */
105 
106 #define SCSI_SENSE_BUFFERSIZE 	96
107 	unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];		/* obtained by REQUEST SENSE
108 						 * when CHECK CONDITION is
109 						 * received on original command
110 						 * (auto-sense) */
111 
112 	/* Low-level done function - can be used by low-level driver to point
113 	 *        to completion function.  Not used by mid/upper level code. */
114 	void (*scsi_done) (struct scsi_cmnd *);
115 
116 	/*
117 	 * The following fields can be written to by the host specific code.
118 	 * Everything else should be left alone.
119 	 */
120 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
121 
122 	unsigned char *host_scribble;	/* The host adapter is allowed to
123 					   * call scsi_malloc and get some memory
124 					   * and hang it here.     The host adapter
125 					   * is also expected to call scsi_free
126 					   * to release this memory.  (The memory
127 					   * obtained by scsi_malloc is guaranteed
128 					   * to be at an address < 16Mb). */
129 
130 	int result;		/* Status code from lower level driver */
131 
132 	unsigned char tag;	/* SCSI-II queued command tag */
133 	unsigned long pid;	/* Process ID, starts at 0. Unique per host. */
134 };
135 
136 /*
137  * These are the values that scsi_cmd->state can take.
138  */
139 #define SCSI_STATE_TIMEOUT         0x1000
140 #define SCSI_STATE_FINISHED        0x1001
141 #define SCSI_STATE_FAILED          0x1002
142 #define SCSI_STATE_QUEUED          0x1003
143 #define SCSI_STATE_UNUSED          0x1006
144 #define SCSI_STATE_DISCONNECTING   0x1008
145 #define SCSI_STATE_INITIALIZING    0x1009
146 #define SCSI_STATE_BHQUEUE         0x100a
147 #define SCSI_STATE_MLQUEUE         0x100b
148 
149 
150 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, int);
151 extern void scsi_put_command(struct scsi_cmnd *);
152 extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
153 extern void scsi_finish_command(struct scsi_cmnd *cmd);
154 
155 #endif /* _SCSI_SCSI_CMND_H */
156