xref: /openbmc/linux/include/scsi/scsi_cmnd.h (revision 87c2ce3b)
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 #include <linux/timer.h>
8 
9 struct request;
10 struct scatterlist;
11 struct scsi_device;
12 struct scsi_request;
13 
14 
15 /* embedded in scsi_cmnd */
16 struct scsi_pointer {
17 	char *ptr;		/* data pointer */
18 	int this_residual;	/* left in this buffer */
19 	struct scatterlist *buffer;	/* which buffer */
20 	int buffers_residual;	/* how many buffers left */
21 
22         dma_addr_t dma_handle;
23 
24 	volatile int Status;
25 	volatile int Message;
26 	volatile int have_data_in;
27 	volatile int sent_command;
28 	volatile int phase;
29 };
30 
31 struct scsi_cmnd {
32 	int     sc_magic;
33 
34 	struct scsi_device *device;
35 	struct scsi_request *sc_request;
36 
37 	struct list_head list;  /* scsi_cmnd participates in queue lists */
38 
39 	struct list_head eh_entry; /* entry for the host eh_cmd_q */
40 	int eh_eflags;		/* Used by error handlr */
41 	void (*done) (struct scsi_cmnd *);	/* Mid-level done function */
42 
43 	/*
44 	 * A SCSI Command is assigned a nonzero serial_number before passed
45 	 * to the driver's queue command function.  The serial_number is
46 	 * cleared when scsi_done is entered indicating that the command
47 	 * has been completed.  It currently doesn't have much use other
48 	 * than printk's.  Some lldd's use this number for other purposes.
49 	 * It's almost certain that such usages are either incorrect or
50 	 * meaningless.  Please kill all usages other than printk's.  Also,
51 	 * as this number is always identical to ->pid, please convert
52 	 * printk's to use ->pid, so that we can kill this field.
53 	 */
54 	unsigned long serial_number;
55 	/*
56 	 * This is set to jiffies as it was when the command was first
57 	 * allocated.  It is used to time how long the command has
58 	 * been outstanding
59 	 */
60 	unsigned long jiffies_at_alloc;
61 
62 	int retries;
63 	int allowed;
64 	int timeout_per_command;
65 
66 	unsigned char cmd_len;
67 	unsigned char old_cmd_len;
68 	enum dma_data_direction sc_data_direction;
69 	enum dma_data_direction sc_old_data_direction;
70 
71 	/* These elements define the operation we are about to perform */
72 #define MAX_COMMAND_SIZE	16
73 	unsigned char cmnd[MAX_COMMAND_SIZE];
74 	unsigned request_bufflen;	/* Actual request size */
75 
76 	struct timer_list eh_timeout;	/* Used to time out the command. */
77 	void *request_buffer;		/* Actual requested buffer */
78 
79 	/* These elements define the operation we ultimately want to perform */
80 	unsigned char data_cmnd[MAX_COMMAND_SIZE];
81 	unsigned short old_use_sg;	/* We save  use_sg here when requesting
82 					 * sense info */
83 	unsigned short use_sg;	/* Number of pieces of scatter-gather */
84 	unsigned short sglist_len;	/* size of malloc'd scatter-gather list */
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 *, gfp_t);
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 extern void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd);
155 
156 #endif /* _SCSI_SCSI_CMND_H */
157