kernel-ark/drivers/scsi/sd.h
Martin K. Petersen c98a0eb0e9 [SCSI] sd: Logical Block Provisioning update
SBC3r26 contains many changes to the Logical Block Provisioning
interfaces (formerly known as Thin Provisioning ditto). This patch
implements support for both the old and new schemes using the same
heuristic as before (whether the LBP VPD page is present).

The new code also allows the provisioning mode (i.e. choice of command)
to be overridden on a per-device basis via sysfs. Two additional modes
are supported in this version:

 - WRITE SAME(10) with the UNMAP bit set

 - WRITE SAME(10) without the UNMAP bit set. This allows us to support
   devices that predate the TP/LBP enhancements in SBC3 and which work
   by way zero-detection

Switching between modes has been consolidated in a helper function that
also updates the block layer topology according to the limitations of
the chosen command.

I experimented with trying WRITE SAME(16) if UNMAP fails, WRITE SAME(10)
if WRITE SAME(16) fails, etc. but found several devices that got
cranky. So for now we'll disable discard if one of the commands
fail. The user still has the option of selecting a different mode in
sysfs.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
2011-03-14 18:37:34 -05:00

149 lines
3.9 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
/*
* This is limited by the naming scheme enforced in sd_probe,
* add another character to it if you really need more disks.
*/
#define SD_MAX_DISKS (((26 * 26) + 26 + 1) * 26)
/*
* 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)
/*
* Number of allowed retries
*/
#define SD_MAX_RETRIES 5
#define SD_PASSTHROUGH_RETRIES 1
/*
* 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_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;
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;
};
#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)
/*
* 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 int 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 */