forked from mirrors/linux
		
	 868e6139c5
			
		
	
	
		868e6139c5
		
	
	
	
	
		
			
			The function is not generally applicable enough to be included in the core kernel header. Move it to block since it's the only subsystem using it. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/20220327173316.315-1-kbusch@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
		
			
				
	
	
		
			85 lines
		
	
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			85 lines
		
	
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
 | |
| #ifndef _LINUX_T10_PI_H
 | |
| #define _LINUX_T10_PI_H
 | |
| 
 | |
| #include <linux/types.h>
 | |
| #include <linux/blk-mq.h>
 | |
| 
 | |
| /*
 | |
|  * A T10 PI-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 t10_dif_type {
 | |
| 	T10_PI_TYPE0_PROTECTION = 0x0,
 | |
| 	T10_PI_TYPE1_PROTECTION = 0x1,
 | |
| 	T10_PI_TYPE2_PROTECTION = 0x2,
 | |
| 	T10_PI_TYPE3_PROTECTION = 0x3,
 | |
| };
 | |
| 
 | |
| /*
 | |
|  * T10 Protection Information tuple.
 | |
|  */
 | |
| struct t10_pi_tuple {
 | |
| 	__be16 guard_tag;	/* Checksum */
 | |
| 	__be16 app_tag;		/* Opaque storage */
 | |
| 	__be32 ref_tag;		/* Target LBA or indirect LBA */
 | |
| };
 | |
| 
 | |
| #define T10_PI_APP_ESCAPE cpu_to_be16(0xffff)
 | |
| #define T10_PI_REF_ESCAPE cpu_to_be32(0xffffffff)
 | |
| 
 | |
| static inline u32 t10_pi_ref_tag(struct request *rq)
 | |
| {
 | |
| 	unsigned int shift = ilog2(queue_logical_block_size(rq->q));
 | |
| 
 | |
| #ifdef CONFIG_BLK_DEV_INTEGRITY
 | |
| 	if (rq->q->integrity.interval_exp)
 | |
| 		shift = rq->q->integrity.interval_exp;
 | |
| #endif
 | |
| 	return blk_rq_pos(rq) >> (shift - SECTOR_SHIFT) & 0xffffffff;
 | |
| }
 | |
| 
 | |
| extern const struct blk_integrity_profile t10_pi_type1_crc;
 | |
| extern const struct blk_integrity_profile t10_pi_type1_ip;
 | |
| extern const struct blk_integrity_profile t10_pi_type3_crc;
 | |
| extern const struct blk_integrity_profile t10_pi_type3_ip;
 | |
| 
 | |
| struct crc64_pi_tuple {
 | |
| 	__be64 guard_tag;
 | |
| 	__be16 app_tag;
 | |
| 	__u8   ref_tag[6];
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * lower_48_bits() - return bits 0-47 of a number
 | |
|  * @n: the number we're accessing
 | |
|  */
 | |
| static inline u64 lower_48_bits(u64 n)
 | |
| {
 | |
| 	return n & ((1ull << 48) - 1);
 | |
| }
 | |
| 
 | |
| static inline u64 ext_pi_ref_tag(struct request *rq)
 | |
| {
 | |
| 	unsigned int shift = ilog2(queue_logical_block_size(rq->q));
 | |
| 
 | |
| #ifdef CONFIG_BLK_DEV_INTEGRITY
 | |
| 	if (rq->q->integrity.interval_exp)
 | |
| 		shift = rq->q->integrity.interval_exp;
 | |
| #endif
 | |
| 	return lower_48_bits(blk_rq_pos(rq) >> (shift - SECTOR_SHIFT));
 | |
| }
 | |
| 
 | |
| extern const struct blk_integrity_profile ext_pi_type1_crc64;
 | |
| extern const struct blk_integrity_profile ext_pi_type3_crc64;
 | |
| 
 | |
| #endif
 |