xref: /linux/include/scsi/scsi_cmnd.h (revision 2624f124b3b5d550ab2fbef7ee3bc0e1fed09722)
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 	 * This is set to jiffies as it was when the command was first
56 	 * allocated.  It is used to time how long the command has
57 	 * been outstanding
58 	 */
59 	unsigned long jiffies_at_alloc;
60 
61 	int retries;
62 	int allowed;
63 	int timeout_per_command;
64 
65 	unsigned char cmd_len;
66 	unsigned char old_cmd_len;
67 	enum dma_data_direction sc_data_direction;
68 	enum dma_data_direction sc_old_data_direction;
69 
70 	/* These elements define the operation we are about to perform */
71 #define MAX_COMMAND_SIZE	16
72 	unsigned char cmnd[MAX_COMMAND_SIZE];
73 	unsigned request_bufflen;	/* Actual request size */
74 
75 	struct timer_list eh_timeout;	/* Used to time out the command. */
76 	void *request_buffer;		/* Actual requested buffer */
77 
78 	/* These elements define the operation we ultimately want to perform */
79 	unsigned char data_cmnd[MAX_COMMAND_SIZE];
80 	unsigned short old_use_sg;	/* We save  use_sg here when requesting
81 					 * sense info */
82 	unsigned short use_sg;	/* Number of pieces of scatter-gather */
83 	unsigned short sglist_len;	/* size of malloc'd scatter-gather list */
84 	unsigned bufflen;	/* Size of data buffer */
85 	void *buffer;		/* Data buffer */
86 
87 	unsigned underflow;	/* Return error if less than
88 				   this amount is transferred */
89 	unsigned old_underflow;	/* save underflow here when reusing the
90 				 * command for error handling */
91 
92 	unsigned transfersize;	/* How much we are guaranteed to
93 				   transfer with each SCSI transfer
94 				   (ie, between disconnect /
95 				   reconnects.   Probably == sector
96 				   size */
97 
98 	int resid;		/* Number of bytes requested to be
99 				   transferred less actual number
100 				   transferred (0 if not supported) */
101 
102 	struct request *request;	/* The command we are
103 				   	   working on */
104 
105 #define SCSI_SENSE_BUFFERSIZE 	96
106 	unsigned char sense_buffer[SCSI_SENSE_BUFFERSIZE];		/* obtained by REQUEST SENSE
107 						 * when CHECK CONDITION is
108 						 * received on original command
109 						 * (auto-sense) */
110 
111 	/* Low-level done function - can be used by low-level driver to point
112 	 *        to completion function.  Not used by mid/upper level code. */
113 	void (*scsi_done) (struct scsi_cmnd *);
114 
115 	/*
116 	 * The following fields can be written to by the host specific code.
117 	 * Everything else should be left alone.
118 	 */
119 	struct scsi_pointer SCp;	/* Scratchpad used by some host adapters */
120 
121 	unsigned char *host_scribble;	/* The host adapter is allowed to
122 					   * call scsi_malloc and get some memory
123 					   * and hang it here.     The host adapter
124 					   * is also expected to call scsi_free
125 					   * to release this memory.  (The memory
126 					   * obtained by scsi_malloc is guaranteed
127 					   * to be at an address < 16Mb). */
128 
129 	int result;		/* Status code from lower level driver */
130 
131 	unsigned char tag;	/* SCSI-II queued command tag */
132 	unsigned long pid;	/* Process ID, starts at 0. Unique per host. */
133 };
134 
135 /*
136  * These are the values that scsi_cmd->state can take.
137  */
138 #define SCSI_STATE_TIMEOUT         0x1000
139 #define SCSI_STATE_FINISHED        0x1001
140 #define SCSI_STATE_FAILED          0x1002
141 #define SCSI_STATE_QUEUED          0x1003
142 #define SCSI_STATE_UNUSED          0x1006
143 #define SCSI_STATE_DISCONNECTING   0x1008
144 #define SCSI_STATE_INITIALIZING    0x1009
145 #define SCSI_STATE_BHQUEUE         0x100a
146 #define SCSI_STATE_MLQUEUE         0x100b
147 
148 
149 extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, int);
150 extern void scsi_put_command(struct scsi_cmnd *);
151 extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
152 extern void scsi_finish_command(struct scsi_cmnd *cmd);
153 
154 #endif /* _SCSI_SCSI_CMND_H */
155