linux-stable/drivers/scsi/sd.h
Martin K. Petersen 5db44863b6 [SCSI] sd: Implement support for WRITE SAME
Implement support for WRITE SAME(10) and WRITE SAME(16) in the SCSI disk
driver.

 - We set the default maximum to 0xFFFF because there are several
   devices out there that only support two-byte block counts even with
   WRITE SAME(16). We only enable transfers bigger than 0xFFFF if the
   device explicitly reports MAXIMUM WRITE SAME LENGTH in the BLOCK
   LIMITS VPD.

 - max_write_same_blocks can be overriden per-device basis in sysfs.

 - The UNMAP discovery heuristics remain unchanged but the discard
   limits are tweaked to match the "real" WRITE SAME commands.

 - In the error handling logic we now distinguish between WRITE SAME
   with and without UNMAP set.

The discovery process heuristics are:

 - If the device reports a SCSI level of SPC-3 or greater we'll issue
   READ SUPPORTED OPERATION CODES to find out whether WRITE SAME(16) is
   supported. If that's the case we will use it.

 - If the device supports the block limits VPD and reports a MAXIMUM
   WRITE SAME LENGTH bigger than 0xFFFF we will use WRITE SAME(16).

 - Otherwise we will use WRITE SAME(10) unless the target LBA is beyond
   0xFFFFFFFF or the block count exceeds 0xFFFF.

 - no_write_same is set for ATA, FireWire and USB.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-11-13 22:45:42 -08:00

184 lines
4.4 KiB
C

#ifndef _SCSI_DISK_H
#define _SCSI_DISK_H
/*
* More than enough for everybody ;) The huge number of majors
* is a leftover from 16bit dev_t days, we don't really need that
* much numberspace.
*/
#define SD_MAJORS 16
/*
* Time out in seconds for disks and Magneto-opticals (which are slower).
*/
#define SD_TIMEOUT (30 * HZ)
#define SD_MOD_TIMEOUT (75 * HZ)
#define SD_FLUSH_TIMEOUT (60 * HZ)
#define SD_WRITE_SAME_TIMEOUT (120 * HZ)
/*
* Number of allowed retries
*/
#define SD_MAX_RETRIES 5
#define SD_PASSTHROUGH_RETRIES 1
#define SD_MAX_MEDIUM_TIMEOUTS 2
/*
* Size of the initial data buffer for mode and read capacity data
*/
#define SD_BUF_SIZE 512
/*
* Number of sectors at the end of the device to avoid multi-sector
* accesses to in the case of last_sector_bug
*/
#define SD_LAST_BUGGY_SECTORS 8
enum {
SD_EXT_CDB_SIZE = 32, /* Extended CDB size */
SD_MEMPOOL_SIZE = 2, /* CDB pool size */
};
enum {
SD_MAX_WS10_BLOCKS = 0xffff,
SD_MAX_WS16_BLOCKS = 0x7fffff,
};
enum {
SD_LBP_FULL = 0, /* Full logical block provisioning */
SD_LBP_UNMAP, /* Use UNMAP command */
SD_LBP_WS16, /* Use WRITE SAME(16) with UNMAP bit */
SD_LBP_WS10, /* Use WRITE SAME(10) with UNMAP bit */
SD_LBP_ZERO, /* Use WRITE SAME(10) with zero payload */
SD_LBP_DISABLE, /* Discard disabled due to failed cmd */
};
struct scsi_disk {
struct scsi_driver *driver; /* always &sd_template */
struct scsi_device *device;
struct device dev;
struct gendisk *disk;
atomic_t openers;
sector_t capacity; /* size in 512-byte sectors */
u32 max_ws_blocks;
u32 max_unmap_blocks;
u32 unmap_granularity;
u32 unmap_alignment;
u32 index;
unsigned int physical_block_size;
unsigned int max_medium_access_timeouts;
unsigned int medium_access_timed_out;
u8 media_present;
u8 write_prot;
u8 protection_type;/* Data Integrity Field */
u8 provisioning_mode;
unsigned ATO : 1; /* state of disk ATO bit */
unsigned WCE : 1; /* state of disk WCE bit */
unsigned RCD : 1; /* state of disk RCD bit, unused */
unsigned DPOFUA : 1; /* state of disk DPOFUA bit */
unsigned first_scan : 1;
unsigned lbpme : 1;
unsigned lbprz : 1;
unsigned lbpu : 1;
unsigned lbpws : 1;
unsigned lbpws10 : 1;
unsigned lbpvpd : 1;
unsigned ws16 : 1;
};
#define to_scsi_disk(obj) container_of(obj,struct scsi_disk,dev)
static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
{
return container_of(disk->private_data, struct scsi_disk, driver);
}
#define sd_printk(prefix, sdsk, fmt, a...) \
(sdsk)->disk ? \
sdev_printk(prefix, (sdsk)->device, "[%s] " fmt, \
(sdsk)->disk->disk_name, ##a) : \
sdev_printk(prefix, (sdsk)->device, fmt, ##a)
static inline int scsi_medium_access_command(struct scsi_cmnd *scmd)
{
switch (scmd->cmnd[0]) {
case READ_6:
case READ_10:
case READ_12:
case READ_16:
case SYNCHRONIZE_CACHE:
case VERIFY:
case VERIFY_12:
case VERIFY_16:
case WRITE_6:
case WRITE_10:
case WRITE_12:
case WRITE_16:
case WRITE_SAME:
case WRITE_SAME_16:
case UNMAP:
return 1;
case VARIABLE_LENGTH_CMD:
switch (scmd->cmnd[9]) {
case READ_32:
case VERIFY_32:
case WRITE_32:
case WRITE_SAME_32:
return 1;
}
}
return 0;
}
/*
* A DIF-capable target device can be formatted with different
* protection schemes. Currently 0 through 3 are defined:
*
* Type 0 is regular (unprotected) I/O
*
* Type 1 defines the contents of the guard and reference tags
*
* Type 2 defines the contents of the guard and reference tags and
* uses 32-byte commands to seed the latter
*
* Type 3 defines the contents of the guard tag only
*/
enum sd_dif_target_protection_types {
SD_DIF_TYPE0_PROTECTION = 0x0,
SD_DIF_TYPE1_PROTECTION = 0x1,
SD_DIF_TYPE2_PROTECTION = 0x2,
SD_DIF_TYPE3_PROTECTION = 0x3,
};
/*
* Data Integrity Field tuple.
*/
struct sd_dif_tuple {
__be16 guard_tag; /* Checksum */
__be16 app_tag; /* Opaque storage */
__be32 ref_tag; /* Target LBA or indirect LBA */
};
#ifdef CONFIG_BLK_DEV_INTEGRITY
extern void sd_dif_config_host(struct scsi_disk *);
extern void sd_dif_prepare(struct request *rq, sector_t, unsigned int);
extern void sd_dif_complete(struct scsi_cmnd *, unsigned int);
#else /* CONFIG_BLK_DEV_INTEGRITY */
static inline void sd_dif_config_host(struct scsi_disk *disk)
{
}
static inline int sd_dif_prepare(struct request *rq, sector_t s, unsigned int a)
{
return 0;
}
static inline void sd_dif_complete(struct scsi_cmnd *cmd, unsigned int a)
{
}
#endif /* CONFIG_BLK_DEV_INTEGRITY */
#endif /* _SCSI_DISK_H */