diff options
Diffstat (limited to 'arch/x86/lib/csum-wrappers_64.c')
-rw-r--r-- | arch/x86/lib/csum-wrappers_64.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/arch/x86/lib/csum-wrappers_64.c b/arch/x86/lib/csum-wrappers_64.c new file mode 100644 index 000000000..145f9a0bd --- /dev/null +++ b/arch/x86/lib/csum-wrappers_64.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2002, 2003 Andi Kleen, SuSE Labs. + * + * Wrappers of assembly checksum functions for x86-64. + */ +#include <asm/checksum.h> +#include <linux/export.h> +#include <linux/uaccess.h> +#include <asm/smap.h> + +/** + * csum_and_copy_from_user - Copy and checksum from user space. + * @src: source address (user space) + * @dst: destination address + * @len: number of bytes to be copied. + * @isum: initial sum that is added into the result (32bit unfolded) + * @errp: set to -EFAULT for an bad source address. + * + * Returns an 32bit unfolded checksum of the buffer. + * src and dst are best aligned to 64bits. + */ +__wsum +csum_and_copy_from_user(const void __user *src, void *dst, int len) +{ + __wsum sum; + + might_sleep(); + if (!user_access_begin(src, len)) + return 0; + sum = csum_partial_copy_generic((__force const void *)src, dst, len); + user_access_end(); + return sum; +} + +/** + * csum_and_copy_to_user - Copy and checksum to user space. + * @src: source address + * @dst: destination address (user space) + * @len: number of bytes to be copied. + * @isum: initial sum that is added into the result (32bit unfolded) + * @errp: set to -EFAULT for an bad destination address. + * + * Returns an 32bit unfolded checksum of the buffer. + * src and dst are best aligned to 64bits. + */ +__wsum +csum_and_copy_to_user(const void *src, void __user *dst, int len) +{ + __wsum sum; + + might_sleep(); + if (!user_access_begin(dst, len)) + return 0; + sum = csum_partial_copy_generic(src, (void __force *)dst, len); + user_access_end(); + return sum; +} + +/** + * csum_partial_copy_nocheck - Copy and checksum. + * @src: source address + * @dst: destination address + * @len: number of bytes to be copied. + * @sum: initial sum that is added into the result (32bit unfolded) + * + * Returns an 32bit unfolded checksum of the buffer. + */ +__wsum +csum_partial_copy_nocheck(const void *src, void *dst, int len) +{ + return csum_partial_copy_generic(src, dst, len); +} +EXPORT_SYMBOL(csum_partial_copy_nocheck); + +__sum16 csum_ipv6_magic(const struct in6_addr *saddr, + const struct in6_addr *daddr, + __u32 len, __u8 proto, __wsum sum) +{ + __u64 rest, sum64; + + rest = (__force __u64)htonl(len) + (__force __u64)htons(proto) + + (__force __u64)sum; + + asm(" addq (%[saddr]),%[sum]\n" + " adcq 8(%[saddr]),%[sum]\n" + " adcq (%[daddr]),%[sum]\n" + " adcq 8(%[daddr]),%[sum]\n" + " adcq $0,%[sum]\n" + + : [sum] "=r" (sum64) + : "[sum]" (rest), [saddr] "r" (saddr), [daddr] "r" (daddr)); + + return csum_fold( + (__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32)); +} +EXPORT_SYMBOL(csum_ipv6_magic); |