// SPDX-License-Identifier: GPL-2.0-or-later/* * Crypto library utility functions * * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au> */ #include <linux/unaligned.h>#include <crypto/utils.h>#include <linux/module.h> /* * XOR @len bytes from @src1 and @src2 together, writing the result to @dst * (which may alias one of the sources).  Don't call this directly; call * crypto_xor() or crypto_xor_cpy() instead. */void __crypto_xor(u8 *dst, const u8 *src1, const u8 *src2, unsigned int len){	int relalign = 0; 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {		int size = sizeof(unsigned long);		int d = (((unsigned long)dst ^ (unsigned long)src1) |			 ((unsigned long)dst ^ (unsigned long)src2)) &			(size - 1); 		relalign = d ? 1 << __ffs(d) : size; 		/*		 * If we care about alignment, process as many bytes as		 * needed to advance dst and src to values whose alignments		 * equal their relative alignment. This will allow us to		 * process the remainder of the input using optimal strides.		 */		while (((unsigned long)dst & (relalign - 1)) && len > 0) {			*dst++ = *src1++ ^ *src2++;			len--;		}	} 	while (IS_ENABLED(CONFIG_64BIT) && len >= 8 && !(relalign & 7)) {		if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {			u64 l = get_unaligned((u64 *)src1) ^				get_unaligned((u64 *)src2);			put_unaligned(l, (u64 *)dst);		} else {			*(u64 *)dst = *(u64 *)src1 ^ *(u64 *)src2;		}		dst += 8;		src1 += 8;		src2 += 8;		len -= 8;	} 	while (len >= 4 && !(relalign & 3)) {		if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {			u32 l = get_unaligned((u32 *)src1) ^				get_unaligned((u32 *)src2);			put_unaligned(l, (u32 *)dst);		} else {			*(u32 *)dst = *(u32 *)src1 ^ *(u32 *)src2;		}		dst += 4;		src1 += 4;		src2 += 4;		len -= 4;	} 	while (len >= 2 && !(relalign & 1)) {		if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) {			u16 l = get_unaligned((u16 *)src1) ^				get_unaligned((u16 *)src2);			put_unaligned(l, (u16 *)dst);		} else {			*(u16 *)dst = *(u16 *)src1 ^ *(u16 *)src2;		}		dst += 2;		src1 += 2;		src2 += 2;		len -= 2;	} 	while (len--)		*dst++ = *src1++ ^ *src2++;}EXPORT_SYMBOL_GPL(__crypto_xor); MODULE_DESCRIPTION("Crypto library utility functions");MODULE_LICENSE("GPL");