include/scsi/sg.h

   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.txt
  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 #define SG_INTERFACE_ID_ORIG 'S'
  72
  73 /* Use negative values to flag difference from original sg_header structure */
  74 #define SG_DXFER_NONE (-1)      /* e.g. a SCSI Test Unit Ready command */
  75 #define SG_DXFER_TO_DEV (-2)    /* e.g. a SCSI WRITE command */
  76 #define SG_DXFER_FROM_DEV (-3)  /* e.g. a SCSI READ command */
  77 #define SG_DXFER_TO_FROM_DEV (-4) /* treated like SG_DXFER_FROM_DEV with the
  78                                    additional property than during indirect
  79                                    IO the user buffer is copied into the
  80                                    kernel buffers before the transfer */
  81 #define SG_DXFER_UNKNOWN (-5)   /* Unknown data direction */
  82
  83 /* following flag values can be "or"-ed together */
  84 #define SG_FLAG_DIRECT_IO 1     /* default is indirect IO */
  85 #define SG_FLAG_UNUSED_LUN_INHIBIT 2   /* default is overwrite lun in SCSI */
  86                                 /* command block (when <= SCSI_2) */
  87 #define SG_FLAG_MMAP_IO 4       /* request memory mapped IO */
  88 #define SG_FLAG_NO_DXFER 0x10000 /* no transfer of kernel buffers to/from */
  89                                 /* user space (debug indirect IO) */
  90 /* defaults:: for sg driver: Q_AT_HEAD; for block layer: Q_AT_TAIL */
  91 #define SG_FLAG_Q_AT_TAIL 0x10
  92 #define SG_FLAG_Q_AT_HEAD 0x20
  93
  94 /* following 'info' values are "or"-ed together */
  95 #define SG_INFO_OK_MASK 0x1
  96 #define SG_INFO_OK 0x0          /* no sense, host nor driver "noise" */
  97 #define SG_INFO_CHECK 0x1       /* something abnormal happened */
  98
  99 #define SG_INFO_DIRECT_IO_MASK 0x6
 100 #define SG_INFO_INDIRECT_IO 0x0 /* data xfer via kernel buffers (or no xfer) */
 101 #define SG_INFO_DIRECT_IO 0x2   /* direct IO requested and performed */
 102 #define SG_INFO_MIXED_IO 0x4    /* part direct, part indirect IO */
 103
 104
 105 typedef struct sg_scsi_id { /* used by SG_GET_SCSI_ID ioctl() */
 106     int host_no;        /* as in "scsi<n>" where 'n' is one of 0, 1, 2 etc */
 107     int channel;
 108     int scsi_id;        /* scsi id of target device */
 109     int lun;
 110     int scsi_type;      /* TYPE_... defined in scsi/scsi.h */
 111     short h_cmd_per_lun;/* host (adapter) maximum commands per lun */
 112     short d_queue_depth;/* device (or adapter) maximum queue length */
 113     int unused[2];      /* probably find a good use, set 0 for now */
 114 } sg_scsi_id_t; /* 32 bytes long on i386 */
 115
 116 typedef struct sg_req_info { /* used by SG_GET_REQUEST_TABLE ioctl() */
 117     char req_state;     /* 0 -> not used, 1 -> written, 2 -> ready to read */
 118     char orphan;        /* 0 -> normal request, 1 -> from interruped SG_IO */
 119     char sg_io_owned;   /* 0 -> complete with read(), 1 -> owned by SG_IO */
 120     char problem;       /* 0 -> no problem detected, 1 -> error to report */
 121     int pack_id;        /* pack_id associated with request */
 122     void __user *usr_ptr;     /* user provided pointer (in new interface) */
 123     unsigned int duration; /* millisecs elapsed since written (req_state==1)
 124                               or request duration (req_state==2) */
 125     int unused;
 126 } sg_req_info_t; /* 20 bytes long on i386 */
 127
 128
 129 /* IOCTLs: Those ioctls that are relevant to the SG 3.x drivers follow.
 130  [Those that only apply to the SG 2.x drivers are at the end of the file.]
 131  (_GET_s yield result via 'int *' 3rd argument unless otherwise indicated) */
 132
 133 #define SG_EMULATED_HOST 0x2203 /* true for emulated host adapter (ATAPI) */
 134
 135 /* Used to configure SCSI command transformation layer for ATAPI devices */
 136 /* Only supported by the ide-scsi driver */
 137 #define SG_SET_TRANSFORM 0x2204 /* N.B. 3rd arg is not pointer but value: */
 138                       /* 3rd arg = 0 to disable transform, 1 to enable it */
 139 #define SG_GET_TRANSFORM 0x2205
 140
 141 #define SG_SET_RESERVED_SIZE 0x2275  /* request a new reserved buffer size */
 142 #define SG_GET_RESERVED_SIZE 0x2272  /* actual size of reserved buffer */
 143
 144 /* The following ioctl has a 'sg_scsi_id_t *' object as its 3rd argument. */
 145 #define SG_GET_SCSI_ID 0x2276   /* Yields fd's bus, chan, dev, lun + type */
 146 /* SCSI id information can also be obtained from SCSI_IOCTL_GET_IDLUN */
 147
 148 /* Override host setting and always DMA using low memory ( <16MB on i386) */
 149 #define SG_SET_FORCE_LOW_DMA 0x2279  /* 0-> use adapter setting, 1-> force */
 150 #define SG_GET_LOW_DMA 0x227a   /* 0-> use all ram for dma; 1-> low dma ram */
 151
 152 /* When SG_SET_FORCE_PACK_ID set to 1, pack_id is input to read() which
 153    tries to fetch a packet with a matching pack_id, waits, or returns EAGAIN.
 154    If pack_id is -1 then read oldest waiting. When ...FORCE_PACK_ID set to 0
 155    then pack_id ignored by read() and oldest readable fetched. */
 156 #define SG_SET_FORCE_PACK_ID 0x227b
 157 #define SG_GET_PACK_ID 0x227c /* Yields oldest readable pack_id (or -1) */
 158
 159 #define SG_GET_NUM_WAITING 0x227d /* Number of commands awaiting read() */
 160
 161 /* Yields max scatter gather tablesize allowed by current host adapter */
 162 #define SG_GET_SG_TABLESIZE 0x227F  /* 0 implies can't do scatter gather */
 163
 164 #define SG_GET_VERSION_NUM 0x2282 /* Example: version 2.1.34 yields 20134 */
 165
 166 /* Returns -EBUSY if occupied. 3rd argument pointer to int (see next) */
 167 #define SG_SCSI_RESET 0x2284
 168 /* Associated values that can be given to SG_SCSI_RESET follow.
 169  * SG_SCSI_RESET_NO_ESCALATE may be OR-ed to the _DEVICE, _TARGET, _BUS
 170  * or _HOST reset value so only that action is attempted. */
 171 #define         SG_SCSI_RESET_NOTHING   0
 172 #define         SG_SCSI_RESET_DEVICE    1
 173 #define         SG_SCSI_RESET_BUS       2
 174 #define         SG_SCSI_RESET_HOST      3
 175 #define         SG_SCSI_RESET_TARGET    4
 176 #define         SG_SCSI_RESET_NO_ESCALATE       0x100
 177
 178 /* synchronous SCSI command ioctl, (only in version 3 interface) */
 179 #define SG_IO 0x2285   /* similar effect as write() followed by read() */
 180
 181 #define SG_GET_REQUEST_TABLE 0x2286   /* yields table of active requests */
 182
 183 /* How to treat EINTR during SG_IO ioctl(), only in SG 3.x series */
 184 #define SG_SET_KEEP_ORPHAN 0x2287 /* 1 -> hold for read(), 0 -> drop (def) */
 185 #define SG_GET_KEEP_ORPHAN 0x2288
 186
 187 /* yields scsi midlevel's access_count for this SCSI device */
 188 #define SG_GET_ACCESS_COUNT 0x2289
 189
 190
 191 #define SG_SCATTER_SZ (8 * 4096)
 192 /* Largest size (in bytes) a single scatter-gather list element can have.
 193    The value used by the driver is 'max(SG_SCATTER_SZ, PAGE_SIZE)'.
 194    This value should be a power of 2 (and may be rounded up internally).
 195    If scatter-gather is not supported by adapter then this value is the
 196    largest data block that can be read/written by a single scsi command. */
 197
 198 #define SG_DEFAULT_RETRIES 0
 199
 200 /* Defaults, commented if they differ from original sg driver */
 201 #define SG_DEF_FORCE_PACK_ID 0
 202 #define SG_DEF_KEEP_ORPHAN 0
 203 #define SG_DEF_RESERVED_SIZE SG_SCATTER_SZ /* load time option */
 204
 205 /* maximum outstanding requests, write() yields EDOM if exceeded */
 206 #define SG_MAX_QUEUE 16
 207
 208 #define SG_BIG_BUFF SG_DEF_RESERVED_SIZE    /* for backward compatibility */
 209
 210 /* Alternate style type names, "..._t" variants preferred */
 211 typedef struct sg_io_hdr Sg_io_hdr;
 212 typedef struct sg_io_vec Sg_io_vec;
 213 typedef struct sg_scsi_id Sg_scsi_id;
 214 typedef struct sg_req_info Sg_req_info;
 215
 216
 217 /* vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv */
 218 /*   The older SG interface based on the 'sg_header' structure follows.   */
 219 /* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */
 220
 221 #define SG_MAX_SENSE 16   /* this only applies to the sg_header interface */
 222
 223 struct sg_header
 224 {
 225     int pack_len;    /* [o] reply_len (ie useless), ignored as input */
 226     int reply_len;   /* [i] max length of expected reply (inc. sg_header) */
 227     int pack_id;     /* [io] id number of packet (use ints >= 0) */
 228     int result;      /* [o] 0==ok, else (+ve) Unix errno (best ignored) */
 229     unsigned int twelve_byte:1;
 230         /* [i] Force 12 byte command length for group 6 & 7 commands  */
 231     unsigned int target_status:5;   /* [o] scsi status from target */
 232     unsigned int host_status:8;     /* [o] host status (see "DID" codes) */
 233     unsigned int driver_status:8;   /* [o] driver status+suggestion */
 234     unsigned int other_flags:10;    /* unused */
 235     unsigned char sense_buffer[SG_MAX_SENSE]; /* [o] Output in 3 cases:
 236            when target_status is CHECK_CONDITION or
 237            when target_status is COMMAND_TERMINATED or
 238            when (driver_status & DRIVER_SENSE) is true. */
 239 };      /* This structure is 36 bytes long on i386 */
 240
 241
 242 /* IOCTLs: The following are not required (or ignored) when the sg_io_hdr_t
 243            interface is used. They are kept for backward compatibility with
 244            the original and version 2 drivers. */
 245
 246 #define SG_SET_TIMEOUT 0x2201  /* unit: jiffies (10ms on i386) */
 247 #define SG_GET_TIMEOUT 0x2202  /* yield timeout as _return_ value */
 248
 249 /* Get/set command queuing state per fd (default is SG_DEF_COMMAND_Q.
 250    Each time a sg_io_hdr_t object is seen on this file descriptor, this
 251    command queuing flag is set on (overriding the previous setting). */
 252 #define SG_GET_COMMAND_Q 0x2270   /* Yields 0 (queuing off) or 1 (on) */
 253 #define SG_SET_COMMAND_Q 0x2271   /* Change queuing state with 0 or 1 */
 254
 255 /* Turn on/off error sense trace (1 and 0 respectively, default is off).
 256    Try using: "# cat /proc/scsi/sg/debug" instead in the v3 driver */
 257 #define SG_SET_DEBUG 0x227e    /* 0 -> turn off debug */
 258
 259 #define SG_NEXT_CMD_LEN 0x2283  /* override SCSI command length with given
 260                    number on the next write() on this file descriptor */
 261
 262
 263 /* Defaults, commented if they differ from original sg driver */
 264 #ifdef __KERNEL__
 265 #define SG_DEFAULT_TIMEOUT_USER (60*USER_HZ) /* HZ == 'jiffies in 1 second' */
 266 #else
 267 #define SG_DEFAULT_TIMEOUT      (60*HZ)      /* HZ == 'jiffies in 1 second' */
 268 #endif
 269
 270 #define SG_DEF_COMMAND_Q 0     /* command queuing is always on when
 271                                   the new interface is used */
 272 #define SG_DEF_UNDERRUN_FLAG 0
 273
 274 #endif