#ifndef _XFS_CKSUM_H #define _XFS_CKSUM_H 1 #define XFS_CRC_SEED (~(__uint32_t)0) /* * Calculate the intermediate checksum for a buffer that has the CRC field * inside it. The offset of the 32bit crc fields is passed as the * cksum_offset parameter. We do not modify the buffer during verification, * hence we have to split the CRC calculation across the cksum_offset. */ static inline __uint32_t xfs_start_cksum_safe(char *buffer, size_t length, unsigned long cksum_offset) { __uint32_t zero = 0; __uint32_t crc; /* Calculate CRC up to the checksum. */ crc = crc32c(XFS_CRC_SEED, buffer, cksum_offset); /* Skip checksum field */ crc = crc32c(crc, &zero, sizeof(__u32)); /* Calculate the rest of the CRC. */ return crc32c(crc, &buffer[cksum_offset + sizeof(__be32)], length - (cksum_offset + sizeof(__be32))); } /* * Fast CRC method where the buffer is modified. Callers must have exclusive * access to the buffer while the calculation takes place. */ static inline __uint32_t xfs_start_cksum_update(char *buffer, size_t length, unsigned long cksum_offset) { /* zero the CRC field */ *(__le32 *)(buffer + cksum_offset) = 0; /* single pass CRC calculation for the entire buffer */ return crc32c(XFS_CRC_SEED, buffer, length); } /* * Convert the intermediate checksum to the final ondisk format. * * The CRC32c calculation uses LE format even on BE machines, but returns the * result in host endian format. Hence we need to byte swap it back to LE format * so that it is consistent on disk. */ static inline __le32 xfs_end_cksum(__uint32_t crc) { return ~cpu_to_le32(crc); } /* * Helper to generate the checksum for a buffer. * * This modifies the buffer temporarily - callers must have exclusive * access to the buffer while the calculation takes place. */ static inline void xfs_update_cksum(char *buffer, size_t length, unsigned long cksum_offset) { __uint32_t crc = xfs_start_cksum_update(buffer, length, cksum_offset); *(__le32 *)(buffer + cksum_offset) = xfs_end_cksum(crc); } /* * Helper to verify the checksum for a buffer. */ static inline int xfs_verify_cksum(char *buffer, size_t length, unsigned long cksum_offset) { __uint32_t crc = xfs_start_cksum_safe(buffer, length, cksum_offset); return *(__le32 *)(buffer + cksum_offset) == xfs_end_cksum(crc); } #endif /* _XFS_CKSUM_H */ 31'/>
path: root/include/dt-bindings/mfd/st-lpc.h
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