drivers/scsi/sd.h

   1 #ifndef _SCSI_DISK_H
   2 #define _SCSI_DISK_H
   3
   4 /*
   5  * More than enough for everybody ;)  The huge number of majors
   6  * is a leftover from 16bit dev_t days, we don't really need that
   7  * much numberspace.
   8  */
   9 #define SD_MAJORS       16
  10
  11 /*
  12  * This is limited by the naming scheme enforced in sd_probe,
  13  * add another character to it if you really need more disks.
  14  */
  15 #define SD_MAX_DISKS    (((26 * 26) + 26 + 1) * 26)
  16
  17 /*
  18  * Time out in seconds for disks and Magneto-opticals (which are slower).
  19  */
  20 #define SD_TIMEOUT              (30 * HZ)
  21 #define SD_MOD_TIMEOUT          (75 * HZ)
  22
  23 /*
  24  * Number of allowed retries
  25  */
  26 #define SD_MAX_RETRIES          5
  27 #define SD_PASSTHROUGH_RETRIES  1
  28
  29 /*
  30  * Size of the initial data buffer for mode and read capacity data
  31  */
  32 #define SD_BUF_SIZE             512
  33
  34 /*
  35  * Number of sectors at the end of the device to avoid multi-sector
  36  * accesses to in the case of last_sector_bug
  37  */
  38 #define SD_LAST_BUGGY_SECTORS   8
  39
  40 struct scsi_disk {
  41         struct scsi_driver *driver;     /* always &sd_template */
  42         struct scsi_device *device;
  43         struct device   dev;
  44         struct gendisk  *disk;
  45         unsigned int    openers;        /* protected by BKL for now, yuck */
  46         sector_t        capacity;       /* size in 512-byte sectors */
  47         u32             index;
  48         u8              media_present;
  49         u8              write_prot;
  50         u8              protection_type;/* Data Integrity Field */
  51         unsigned        previous_state : 1;
  52         unsigned        ATO : 1;        /* state of disk ATO bit */
  53         unsigned        WCE : 1;        /* state of disk WCE bit */
  54         unsigned        RCD : 1;        /* state of disk RCD bit, unused */
  55         unsigned        DPOFUA : 1;     /* state of disk DPOFUA bit */
  56 };
  57 #define to_scsi_disk(obj) container_of(obj,struct scsi_disk,dev)
  58
  59 static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
  60 {
  61         return container_of(disk->private_data, struct scsi_disk, driver);
  62 }
  63
  64 #define sd_printk(prefix, sdsk, fmt, a...)                              \
  65         (sdsk)->disk ?                                                  \
  66         sdev_printk(prefix, (sdsk)->device, "[%s] " fmt,                \
  67                     (sdsk)->disk->disk_name, ##a) :                     \
  68         sdev_printk(prefix, (sdsk)->device, fmt, ##a)
  69
  70 /*
  71  * A DIF-capable target device can be formatted with different
  72  * protection schemes.  Currently 0 through 3 are defined:
  73  *
  74  * Type 0 is regular (unprotected) I/O
  75  *
  76  * Type 1 defines the contents of the guard and reference tags
  77  *
  78  * Type 2 defines the contents of the guard and reference tags and
  79  * uses 32-byte commands to seed the latter
  80  *
  81  * Type 3 defines the contents of the guard tag only
  82  */
  83
  84 enum sd_dif_target_protection_types {
  85         SD_DIF_TYPE0_PROTECTION = 0x0,
  86         SD_DIF_TYPE1_PROTECTION = 0x1,
  87         SD_DIF_TYPE2_PROTECTION = 0x2,
  88         SD_DIF_TYPE3_PROTECTION = 0x3,
  89 };
  90
  91 /*
  92  * Data Integrity Field tuple.
  93  */
  94 struct sd_dif_tuple {
  95        __be16 guard_tag;        /* Checksum */
  96        __be16 app_tag;          /* Opaque storage */
  97        __be32 ref_tag;          /* Target LBA or indirect LBA */
  98 };
  99
 100 #ifdef CONFIG_BLK_DEV_INTEGRITY
 101
 102 extern void sd_dif_op(struct scsi_cmnd *, unsigned int, unsigned int, unsigned int);
 103 extern void sd_dif_config_host(struct scsi_disk *);
 104 extern int sd_dif_prepare(struct request *rq, sector_t, unsigned int);
 105 extern void sd_dif_complete(struct scsi_cmnd *, unsigned int);
 106
 107 #else /* CONFIG_BLK_DEV_INTEGRITY */
 108
 109 static inline void sd_dif_op(struct scsi_cmnd *cmd, unsigned int a, unsigned int b, unsigned int c)
 110 {
 111 }
 112 static inline void sd_dif_config_host(struct scsi_disk *disk)
 113 {
 114 }
 115 static inline int sd_dif_prepare(struct request *rq, sector_t s, unsigned int a)
 116 {
 117         return 0;
 118 }
 119 static inline void sd_dif_complete(struct scsi_cmnd *cmd, unsigned int a)
 120 {
 121 }
 122
 123 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 124
 125 #endif /* _SCSI_DISK_H */