1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_T10_PI_H 3 #define _LINUX_T10_PI_H 4 5 #include <linux/types.h> 6 #include <linux/blk-mq.h> 7 #include <linux/wordpart.h> 8 9 /* 10 * A T10 PI-capable target device can be formatted with different 11 * protection schemes. Currently 0 through 3 are defined: 12 * 13 * Type 0 is regular (unprotected) I/O 14 * 15 * Type 1 defines the contents of the guard and reference tags 16 * 17 * Type 2 defines the contents of the guard and reference tags and 18 * uses 32-byte commands to seed the latter 19 * 20 * Type 3 defines the contents of the guard tag only 21 */ 22 enum t10_dif_type { 23 T10_PI_TYPE0_PROTECTION = 0x0, 24 T10_PI_TYPE1_PROTECTION = 0x1, 25 T10_PI_TYPE2_PROTECTION = 0x2, 26 T10_PI_TYPE3_PROTECTION = 0x3, 27 }; 28 full_pi_ref_tag(const struct request * rq)29static inline u64 full_pi_ref_tag(const struct request *rq) 30 { 31 unsigned int shift = ilog2(queue_logical_block_size(rq->q)); 32 33 if (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) && 34 rq->q->limits.integrity.interval_exp) 35 shift = rq->q->limits.integrity.interval_exp; 36 return blk_rq_pos(rq) >> (shift - SECTOR_SHIFT); 37 } 38 39 /* 40 * T10 Protection Information tuple. 41 */ 42 struct t10_pi_tuple { 43 __be16 guard_tag; /* Checksum */ 44 __be16 app_tag; /* Opaque storage */ 45 __be32 ref_tag; /* Target LBA or indirect LBA */ 46 }; 47 48 #define T10_PI_APP_ESCAPE cpu_to_be16(0xffff) 49 #define T10_PI_REF_ESCAPE cpu_to_be32(0xffffffff) 50 t10_pi_ref_tag(struct request * rq)51static inline u32 t10_pi_ref_tag(struct request *rq) 52 { 53 return lower_32_bits(full_pi_ref_tag(rq)); 54 } 55 56 struct crc64_pi_tuple { 57 __be64 guard_tag; 58 __be16 app_tag; 59 __u8 ref_tag[6]; 60 }; 61 62 /** 63 * lower_48_bits() - return bits 0-47 of a number 64 * @n: the number we're accessing 65 */ lower_48_bits(u64 n)66static inline u64 lower_48_bits(u64 n) 67 { 68 return n & ((1ull << 48) - 1); 69 } 70 ext_pi_ref_tag(struct request * rq)71static inline u64 ext_pi_ref_tag(struct request *rq) 72 { 73 return lower_48_bits(full_pi_ref_tag(rq)); 74 } 75 76 #endif 77