Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) /* SPDX-License-Identifier: GPL-2.0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) #ifndef _XFS_CKSUM_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #define _XFS_CKSUM_H 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) #define XFS_CRC_SEED	(~(uint32_t)0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  * Calculate the intermediate checksum for a buffer that has the CRC field
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  * inside it.  The offset of the 32bit crc fields is passed as the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  * cksum_offset parameter. We do not modify the buffer during verification,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  * hence we have to split the CRC calculation across the cksum_offset.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) static inline uint32_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) xfs_start_cksum_safe(char *buffer, size_t length, unsigned long cksum_offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 	uint32_t zero = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 	uint32_t crc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 	/* Calculate CRC up to the checksum. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	crc = crc32c(XFS_CRC_SEED, buffer, cksum_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 	/* Skip checksum field */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 	crc = crc32c(crc, &zero, sizeof(__u32));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 	/* Calculate the rest of the CRC. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 	return crc32c(crc, &buffer[cksum_offset + sizeof(__be32)],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 		      length - (cksum_offset + sizeof(__be32)));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)  * Fast CRC method where the buffer is modified. Callers must have exclusive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)  * access to the buffer while the calculation takes place.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) static inline uint32_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) xfs_start_cksum_update(char *buffer, size_t length, unsigned long cksum_offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	/* zero the CRC field */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	*(__le32 *)(buffer + cksum_offset) = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	/* single pass CRC calculation for the entire buffer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	return crc32c(XFS_CRC_SEED, buffer, length);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)  * Convert the intermediate checksum to the final ondisk format.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)  * The CRC32c calculation uses LE format even on BE machines, but returns the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)  * result in host endian format. Hence we need to byte swap it back to LE format
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)  * so that it is consistent on disk.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) static inline __le32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) xfs_end_cksum(uint32_t crc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 	return ~cpu_to_le32(crc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)  * Helper to generate the checksum for a buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)  * This modifies the buffer temporarily - callers must have exclusive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)  * access to the buffer while the calculation takes place.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) static inline void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) xfs_update_cksum(char *buffer, size_t length, unsigned long cksum_offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 	uint32_t crc = xfs_start_cksum_update(buffer, length, cksum_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 	*(__le32 *)(buffer + cksum_offset) = xfs_end_cksum(crc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)  * Helper to verify the checksum for a buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) static inline int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) xfs_verify_cksum(char *buffer, size_t length, unsigned long cksum_offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) 	uint32_t crc = xfs_start_cksum_safe(buffer, length, cksum_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) 	return *(__le32 *)(buffer + cksum_offset) == xfs_end_cksum(crc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) #endif /* _XFS_CKSUM_H */