xref: /linux/include/scsi/sg.h (revision 0661cb2af0ba628e40a288d134b64c5a9e001a3f)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _SCSI_GENERIC_H
3 #define _SCSI_GENERIC_H
4 
5 #include <linux/compiler.h>
6 
7 /*
8  * History:
9  *  Started: Aug 9 by Lawrence Foard (entropy@world.std.com), to allow user
10  *   process control of SCSI devices.
11  *  Development Sponsored by Killy Corp. NY NY
12  *
13  * Original driver (sg.h):
14  *       Copyright (C) 1992 Lawrence Foard
15  * Version 2 and 3 extensions to driver:
16  *	Copyright (C) 1998 - 2014 Douglas Gilbert
17  *
18  *  Version: 3.5.36 (20140603)
19  *  This version is for 2.6 and 3 series kernels.
20  *
21  * Documentation
22  * =============
23  * A web site for the SG device driver can be found at:
24  *	http://sg.danny.cz/sg  [alternatively check the MAINTAINERS file]
25  * The documentation for the sg version 3 driver can be found at:
26  *	http://sg.danny.cz/sg/p/sg_v3_ho.html
27  * Also see: <kernel_source>/Documentation/scsi/scsi-generic.rst
28  *
29  * For utility and test programs see: http://sg.danny.cz/sg/sg3_utils.html
30  */
31 
32 #ifdef __KERNEL__
33 extern int sg_big_buff; /* for sysctl */
34 #endif
35 
36 
37 typedef struct sg_iovec /* same structure as used by readv() Linux system */
38 {                       /* call. It defines one scatter-gather element. */
39     void __user *iov_base;      /* Starting address  */
40     size_t iov_len;             /* Length in bytes  */
41 } sg_iovec_t;
42 
43 
44 typedef struct sg_io_hdr
45 {
46     int interface_id;           /* [i] 'S' for SCSI generic (required) */
47     int dxfer_direction;        /* [i] data transfer direction  */
48     unsigned char cmd_len;      /* [i] SCSI command length */
49     unsigned char mx_sb_len;    /* [i] max length to write to sbp */
50     unsigned short iovec_count; /* [i] 0 implies no scatter gather */
51     unsigned int dxfer_len;     /* [i] byte count of data transfer */
52     void __user *dxferp;	/* [i], [*io] points to data transfer memory
53 					      or scatter gather list */
54     unsigned char __user *cmdp; /* [i], [*i] points to command to perform */
55     void __user *sbp;		/* [i], [*o] points to sense_buffer memory */
56     unsigned int timeout;       /* [i] MAX_UINT->no timeout (unit: millisec) */
57     unsigned int flags;         /* [i] 0 -> default, see SG_FLAG... */
58     int pack_id;                /* [i->o] unused internally (normally) */
59     void __user * usr_ptr;      /* [i->o] unused internally */
60     unsigned char status;       /* [o] scsi status */
61     unsigned char masked_status;/* [o] shifted, masked scsi status */
62     unsigned char msg_status;   /* [o] messaging level data (optional) */
63     unsigned char sb_len_wr;    /* [o] byte count actually written to sbp */
64     unsigned short host_status; /* [o] errors from host adapter */
65     unsigned short driver_status;/* [o] errors from software driver */
66     int resid;                  /* [o] dxfer_len - actual_transferred */
67     unsigned int duration;      /* [o] time taken by cmd (unit: millisec) */
68     unsigned int info;          /* [o] auxiliary information */
69 } sg_io_hdr_t;  /* 64 bytes long (on i386) */
70 
71 #if defined(__KERNEL__)
72 #include <linux/compat.h>
73 
74 struct compat_sg_io_hdr {
75 	compat_int_t interface_id;	/* [i] 'S' for SCSI generic (required) */
76 	compat_int_t dxfer_direction;	/* [i] data transfer direction  */
77 	unsigned char cmd_len;		/* [i] SCSI command length ( <= 16 bytes) */
78 	unsigned char mx_sb_len;	/* [i] max length to write to sbp */
79 	unsigned short iovec_count;	/* [i] 0 implies no scatter gather */
80 	compat_uint_t dxfer_len;	/* [i] byte count of data transfer */
81 	compat_uint_t dxferp;		/* [i], [*io] points to data transfer memory
82 						or scatter gather list */
83 	compat_uptr_t cmdp;		/* [i], [*i] points to command to perform */
84 	compat_uptr_t sbp;		/* [i], [*o] points to sense_buffer memory */
85 	compat_uint_t timeout;		/* [i] MAX_UINT->no timeout (unit: millisec) */
86 	compat_uint_t flags;		/* [i] 0 -> default, see SG_FLAG... */
87 	compat_int_t pack_id;		/* [i->o] unused internally (normally) */
88 	compat_uptr_t usr_ptr;		/* [i->o] unused internally */
89 	unsigned char status;		/* [o] scsi status */
90 	unsigned char masked_status;	/* [o] shifted, masked scsi status */
91 	unsigned char msg_status;	/* [o] messaging level data (optional) */
92 	unsigned char sb_len_wr;	/* [o] byte count actually written to sbp */
93 	unsigned short host_status;	/* [o] errors from host adapter */
94 	unsigned short driver_status;	/* [o] errors from software driver */
95 	compat_int_t resid;		/* [o] dxfer_len - actual_transferred */
96 	compat_uint_t duration;		/* [o] time taken by cmd (unit: millisec) */
97 	compat_uint_t info;		/* [o] auxiliary information */
98 };
99 #endif
100 
101 #define SG_INTERFACE_ID_ORIG 'S'
102 
103 /* Use negative values to flag difference from original sg_header structure */
104 #define SG_DXFER_NONE (-1)      /* e.g. a SCSI Test Unit Ready command */
105 #define SG_DXFER_TO_DEV (-2)    /* e.g. a SCSI WRITE command */
106 #define SG_DXFER_FROM_DEV (-3)  /* e.g. a SCSI READ command */
107 #define SG_DXFER_TO_FROM_DEV (-4) /* treated like SG_DXFER_FROM_DEV with the
108 				   additional property than during indirect
109 				   IO the user buffer is copied into the
110 				   kernel buffers before the transfer */
111 #define SG_DXFER_UNKNOWN (-5)   /* Unknown data direction */
112 
113 /* following flag values can be "or"-ed together */
114 #define SG_FLAG_DIRECT_IO 1     /* default is indirect IO */
115 #define SG_FLAG_UNUSED_LUN_INHIBIT 2   /* default is overwrite lun in SCSI */
116 				/* command block (when <= SCSI_2) */
117 #define SG_FLAG_MMAP_IO 4       /* request memory mapped IO */
118 #define SG_FLAG_NO_DXFER 0x10000 /* no transfer of kernel buffers to/from */
119 				/* user space (debug indirect IO) */
120 /* defaults:: for sg driver: Q_AT_HEAD; for block layer: Q_AT_TAIL */
121 #define SG_FLAG_Q_AT_TAIL 0x10
122 #define SG_FLAG_Q_AT_HEAD 0x20
123 
124 /* following 'info' values are "or"-ed together */
125 #define SG_INFO_OK_MASK 0x1
126 #define SG_INFO_OK 0x0          /* no sense, host nor driver "noise" */
127 #define SG_INFO_CHECK 0x1       /* something abnormal happened */
128 
129 #define SG_INFO_DIRECT_IO_MASK 0x6
130 #define SG_INFO_INDIRECT_IO 0x0 /* data xfer via kernel buffers (or no xfer) */
131 #define SG_INFO_DIRECT_IO 0x2   /* direct IO requested and performed */
132 #define SG_INFO_MIXED_IO 0x4    /* part direct, part indirect IO */
133 
134 /*
135  * Obsolete DRIVER_SENSE driver byte
136  *
137  * Originally the SCSI midlayer would set the DRIVER_SENSE driver byte when
138  * a sense code was generated and a sense buffer was allocated.
139  * However, as nowadays every scsi command has a sense code allocated this
140  * distinction became moot as one could check the sense buffer directly.
141  * Consequently this byte is not set anymore from the midlayer, but SG will
142  * keep setting this byte to be compatible with previous releases.
143  */
144 #define DRIVER_SENSE 0x08
145 /* Obsolete driver_byte() declaration */
146 #define driver_byte(result) (((result) >> 24) & 0xff)
147 
148 /*
149  *  Original linux SCSI Status codes. They are shifted 1 bit right
150  *  from those found in the SCSI standards.
151  */
152 
153 #define GOOD                 0x00
154 #define CHECK_CONDITION      0x01
155 #define CONDITION_GOOD       0x02
156 #define BUSY                 0x04
157 #define INTERMEDIATE_GOOD    0x08
158 #define INTERMEDIATE_C_GOOD  0x0a
159 #define RESERVATION_CONFLICT 0x0c
160 #define COMMAND_TERMINATED   0x11
161 #define QUEUE_FULL           0x14
162 #define ACA_ACTIVE           0x18
163 #define TASK_ABORTED         0x20
164 
165 /* Obsolete status_byte() declaration */
166 #define status_byte(result) (((result) >> 1) & 0x7f)
167 
168 typedef struct sg_scsi_id { /* used by SG_GET_SCSI_ID ioctl() */
169     int host_no;        /* as in "scsi<n>" where 'n' is one of 0, 1, 2 etc */
170     int channel;
171     int scsi_id;        /* scsi id of target device */
172     int lun;
173     int scsi_type;      /* TYPE_... defined in scsi/scsi.h */
174     short h_cmd_per_lun;/* host (adapter) maximum commands per lun */
175     short d_queue_depth;/* device (or adapter) maximum queue length */
176     int unused[2];      /* probably find a good use, set 0 for now */
177 } sg_scsi_id_t; /* 32 bytes long on i386 */
178 
179 typedef struct sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
180     char req_state;     /* 0 -> not used, 1 -> written, 2 -> ready to read */
181     char orphan;        /* 0 -> normal request, 1 -> from interrupted SG_IO */
182     char sg_io_owned;   /* 0 -> complete with read(), 1 -> owned by SG_IO */
183     char problem;       /* 0 -> no problem detected, 1 -> error to report */
184     int pack_id;        /* pack_id associated with request */
185     void __user *usr_ptr;     /* user provided pointer (in new interface) */
186     unsigned int duration; /* millisecs elapsed since written (req_state==1)
187 			      or request duration (req_state==2) */
188     int unused;
189 } sg_req_info_t; /* 20 bytes long on i386 */
190 
191 
192 /* IOCTLs: Those ioctls that are relevant to the SG 3.x drivers follow.
193  [Those that only apply to the SG 2.x drivers are at the end of the file.]
194  (_GET_s yield result via 'int *' 3rd argument unless otherwise indicated) */
195 
196 #define SG_EMULATED_HOST 0x2203 /* true for emulated host adapter (ATAPI) */
197 
198 /* Used to configure SCSI command transformation layer for ATAPI devices */
199 /* Only supported by the ide-scsi driver */
200 #define SG_SET_TRANSFORM 0x2204 /* N.B. 3rd arg is not pointer but value: */
201 		      /* 3rd arg = 0 to disable transform, 1 to enable it */
202 #define SG_GET_TRANSFORM 0x2205
203 
204 #define SG_SET_RESERVED_SIZE 0x2275  /* request a new reserved buffer size */
205 #define SG_GET_RESERVED_SIZE 0x2272  /* actual size of reserved buffer */
206 
207 /* The following ioctl has a 'sg_scsi_id_t *' object as its 3rd argument. */
208 #define SG_GET_SCSI_ID 0x2276   /* Yields fd's bus, chan, dev, lun + type */
209 /* SCSI id information can also be obtained from SCSI_IOCTL_GET_IDLUN */
210 
211 /* Override host setting and always DMA using low memory ( <16MB on i386) */
212 #define SG_SET_FORCE_LOW_DMA 0x2279  /* 0-> use adapter setting, 1-> force */
213 #define SG_GET_LOW_DMA 0x227a   /* 0-> use all ram for dma; 1-> low dma ram */
214 
215 /* When SG_SET_FORCE_PACK_ID set to 1, pack_id is input to read() which
216    tries to fetch a packet with a matching pack_id, waits, or returns EAGAIN.
217    If pack_id is -1 then read oldest waiting. When ...FORCE_PACK_ID set to 0
218    then pack_id ignored by read() and oldest readable fetched. */
219 #define SG_SET_FORCE_PACK_ID 0x227b
220 #define SG_GET_PACK_ID 0x227c /* Yields oldest readable pack_id (or -1) */
221 
222 #define SG_GET_NUM_WAITING 0x227d /* Number of commands awaiting read() */
223 
224 /* Yields max scatter gather tablesize allowed by current host adapter */
225 #define SG_GET_SG_TABLESIZE 0x227F  /* 0 implies can't do scatter gather */
226 
227 #define SG_GET_VERSION_NUM 0x2282 /* Example: version 2.1.34 yields 20134 */
228 
229 /* Returns -EBUSY if occupied. 3rd argument pointer to int (see next) */
230 #define SG_SCSI_RESET 0x2284
231 /* Associated values that can be given to SG_SCSI_RESET follow.
232  * SG_SCSI_RESET_NO_ESCALATE may be OR-ed to the _DEVICE, _TARGET, _BUS
233  * or _HOST reset value so only that action is attempted. */
234 #define		SG_SCSI_RESET_NOTHING	0
235 #define		SG_SCSI_RESET_DEVICE	1
236 #define		SG_SCSI_RESET_BUS	2
237 #define		SG_SCSI_RESET_HOST	3
238 #define		SG_SCSI_RESET_TARGET	4
239 #define		SG_SCSI_RESET_NO_ESCALATE	0x100
240 
241 /* synchronous SCSI command ioctl, (only in version 3 interface) */
242 #define SG_IO 0x2285   /* similar effect as write() followed by read() */
243 
244 #define SG_GET_REQUEST_TABLE 0x2286   /* yields table of active requests */
245 
246 /* How to treat EINTR during SG_IO ioctl(), only in SG 3.x series */
247 #define SG_SET_KEEP_ORPHAN 0x2287 /* 1 -> hold for read(), 0 -> drop (def) */
248 #define SG_GET_KEEP_ORPHAN 0x2288
249 
250 /* yields scsi midlevel's access_count for this SCSI device */
251 #define SG_GET_ACCESS_COUNT 0x2289
252 
253 
254 #define SG_SCATTER_SZ (8 * 4096)
255 /* Largest size (in bytes) a single scatter-gather list element can have.
256    The value used by the driver is 'max(SG_SCATTER_SZ, PAGE_SIZE)'.
257    This value should be a power of 2 (and may be rounded up internally).
258    If scatter-gather is not supported by adapter then this value is the
259    largest data block that can be read/written by a single scsi command. */
260 
261 #define SG_DEFAULT_RETRIES 0
262 
263 /* Defaults, commented if they differ from original sg driver */
264 #define SG_DEF_FORCE_PACK_ID 0
265 #define SG_DEF_KEEP_ORPHAN 0
266 #define SG_DEF_RESERVED_SIZE SG_SCATTER_SZ /* load time option */
267 
268 /* maximum outstanding requests, write() yields EDOM if exceeded */
269 #define SG_MAX_QUEUE 16
270 
271 #define SG_BIG_BUFF SG_DEF_RESERVED_SIZE    /* for backward compatibility */
272 
273 /* Alternate style type names, "..._t" variants preferred */
274 typedef struct sg_io_hdr Sg_io_hdr;
275 typedef struct sg_io_vec Sg_io_vec;
276 typedef struct sg_scsi_id Sg_scsi_id;
277 typedef struct sg_req_info Sg_req_info;
278 
279 
280 /* vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv */
281 /*   The older SG interface based on the 'sg_header' structure follows.   */
282 /* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
283 
284 #define SG_MAX_SENSE 16   /* this only applies to the sg_header interface */
285 
286 struct sg_header
287 {
288     int pack_len;    /* [o] reply_len (ie useless), ignored as input */
289     int reply_len;   /* [i] max length of expected reply (inc. sg_header) */
290     int pack_id;     /* [io] id number of packet (use ints >= 0) */
291     int result;      /* [o] 0==ok, else (+ve) Unix errno (best ignored) */
292     unsigned int twelve_byte:1;
293 	/* [i] Force 12 byte command length for group 6 & 7 commands  */
294     unsigned int target_status:5;   /* [o] scsi status from target */
295     unsigned int host_status:8;     /* [o] host status (see "DID" codes) */
296     unsigned int driver_status:8;   /* [o] driver status+suggestion */
297     unsigned int other_flags:10;    /* unused */
298     unsigned char sense_buffer[SG_MAX_SENSE]; /* [o] Output in 3 cases:
299 	   when target_status is CHECK_CONDITION or
300 	   when target_status is COMMAND_TERMINATED or
301 	   when (driver_status & DRIVER_SENSE) is true. */
302 };      /* This structure is 36 bytes long on i386 */
303 
304 
305 /* IOCTLs: The following are not required (or ignored) when the sg_io_hdr_t
306 	   interface is used. They are kept for backward compatibility with
307 	   the original and version 2 drivers. */
308 
309 #define SG_SET_TIMEOUT 0x2201  /* unit: jiffies (10ms on i386) */
310 #define SG_GET_TIMEOUT 0x2202  /* yield timeout as _return_ value */
311 
312 /* Get/set command queuing state per fd (default is SG_DEF_COMMAND_Q.
313    Each time a sg_io_hdr_t object is seen on this file descriptor, this
314    command queuing flag is set on (overriding the previous setting). */
315 #define SG_GET_COMMAND_Q 0x2270   /* Yields 0 (queuing off) or 1 (on) */
316 #define SG_SET_COMMAND_Q 0x2271   /* Change queuing state with 0 or 1 */
317 
318 /* Turn on/off error sense trace (1 and 0 respectively, default is off).
319    Try using: "# cat /proc/scsi/sg/debug" instead in the v3 driver */
320 #define SG_SET_DEBUG 0x227e    /* 0 -> turn off debug */
321 
322 #define SG_NEXT_CMD_LEN 0x2283  /* override SCSI command length with given
323 		   number on the next write() on this file descriptor */
324 
325 
326 /* Defaults, commented if they differ from original sg driver */
327 #ifdef __KERNEL__
328 #define SG_DEFAULT_TIMEOUT_USER	(60*USER_HZ) /* HZ == 'jiffies in 1 second' */
329 #else
330 #define SG_DEFAULT_TIMEOUT	(60*HZ)	     /* HZ == 'jiffies in 1 second' */
331 #endif
332 
333 #define SG_DEF_COMMAND_Q 0     /* command queuing is always on when
334 				  the new interface is used */
335 #define SG_DEF_UNDERRUN_FLAG 0
336 
337 #endif
338