100 lines
2.6 KiB
C
100 lines
2.6 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright 2002, 2003 Andi Kleen, SuSE Labs.
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*
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* Wrappers of assembly checksum functions for x86-64.
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*/
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#include <asm/checksum.h>
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#include <linux/export.h>
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#include <linux/uaccess.h>
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#include <asm/smap.h>
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/**
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* csum_and_copy_from_user - Copy and checksum from user space.
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* @src: source address (user space)
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* @dst: destination address
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* @len: number of bytes to be copied.
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* @isum: initial sum that is added into the result (32bit unfolded)
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* @errp: set to -EFAULT for an bad source address.
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*
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* Returns an 32bit unfolded checksum of the buffer.
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* src and dst are best aligned to 64bits.
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*/
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__wsum
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csum_and_copy_from_user(const void __user *src, void *dst, int len)
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{
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__wsum sum;
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might_sleep();
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if (!user_access_begin(src, len))
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return 0;
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sum = csum_partial_copy_generic((__force const void *)src, dst, len);
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user_access_end();
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return sum;
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}
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EXPORT_SYMBOL(csum_and_copy_from_user);
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/**
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* csum_and_copy_to_user - Copy and checksum to user space.
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* @src: source address
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* @dst: destination address (user space)
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* @len: number of bytes to be copied.
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* @isum: initial sum that is added into the result (32bit unfolded)
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* @errp: set to -EFAULT for an bad destination address.
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*
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* Returns an 32bit unfolded checksum of the buffer.
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* src and dst are best aligned to 64bits.
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*/
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__wsum
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csum_and_copy_to_user(const void *src, void __user *dst, int len)
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{
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__wsum sum;
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might_sleep();
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if (!user_access_begin(dst, len))
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return 0;
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sum = csum_partial_copy_generic(src, (void __force *)dst, len);
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user_access_end();
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return sum;
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}
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EXPORT_SYMBOL(csum_and_copy_to_user);
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/**
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* csum_partial_copy_nocheck - Copy and checksum.
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* @src: source address
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* @dst: destination address
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* @len: number of bytes to be copied.
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* @sum: initial sum that is added into the result (32bit unfolded)
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*
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* Returns an 32bit unfolded checksum of the buffer.
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*/
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__wsum
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csum_partial_copy_nocheck(const void *src, void *dst, int len)
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{
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return csum_partial_copy_generic(src, dst, len);
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}
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EXPORT_SYMBOL(csum_partial_copy_nocheck);
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__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
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const struct in6_addr *daddr,
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__u32 len, __u8 proto, __wsum sum)
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{
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__u64 rest, sum64;
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rest = (__force __u64)htonl(len) + (__force __u64)htons(proto) +
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(__force __u64)sum;
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asm(" addq (%[saddr]),%[sum]\n"
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" adcq 8(%[saddr]),%[sum]\n"
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" adcq (%[daddr]),%[sum]\n"
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" adcq 8(%[daddr]),%[sum]\n"
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" adcq $0,%[sum]\n"
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: [sum] "=r" (sum64)
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: "[sum]" (rest), [saddr] "r" (saddr), [daddr] "r" (daddr));
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return csum_fold(
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(__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32));
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}
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EXPORT_SYMBOL(csum_ipv6_magic);
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