x86: clean up csum-wrappers_64.c some more (d76c1ae4) · Commits · 戴 / test

arch/x86/lib/csum-wrappers_64.c

+51 −36

Original line number	Diff line number	Diff line
		/* Copyright 2002,2003 Andi Kleen, SuSE Labs.
		/*
		* Copyright 2002, 2003 Andi Kleen, SuSE Labs.
		* Subject to the GNU Public License v.2
		*
		* Wrappers of assembly checksum functions for x86-64.
		*/

		#include <asm/checksum.h>
		#include <linux/module.h>

		@@ -24,19 +24,26 @@ csum_partial_copy_from_user(const void __user src, void dst,
		{
		might_sleep();
		*errp = 0;
		if (likely(access_ok(VERIFY_READ, src, len))) {
		/* Why 6, not 7? To handle odd addresses aligned we
		would need to do considerable complications to fix the
		checksum which is defined as an 16bit accumulator. The
		fix alignment code is primarily for performance
		compatibility with 32bit and that will handle odd
		addresses slowly too. */

		if (!likely(access_ok(VERIFY_READ, src, len)))
		goto out_err;

		/*
		* Why 6, not 7? To handle odd addresses aligned we
		* would need to do considerable complications to fix the
		* checksum which is defined as an 16bit accumulator. The
		* fix alignment code is primarily for performance
		* compatibility with 32bit and that will handle odd
		* addresses slowly too.
		*/
		if (unlikely((unsigned long)src & 6)) {
		while (((unsigned long)src & 6) && len >= 2) {
		__u16 val16;

		errp = __get_user(val16, (const __u16 __user )src);
		if (*errp)
		return isum;

		(__u16 )dst = val16;
		isum = (__force __wsum)add32_with_carry(
		(__force unsigned)isum, val16);
		@@ -47,14 +54,17 @@ csum_partial_copy_from_user(const void __user src, void dst,
		}
		isum = csum_partial_copy_generic((__force const void *)src,
		dst, len, isum, errp, NULL);
		if (likely(*errp == 0))
		if (unlikely(*errp))
		goto out_err;

		return isum;
		}

		out_err:
		*errp = -EFAULT;
		memset(dst, 0, len);

		return isum;
		}

		EXPORT_SYMBOL(csum_partial_copy_from_user);

		/**
		@@ -73,6 +83,7 @@ csum_partial_copy_to_user(const void src, void __user dst,
		int len, __wsum isum, int *errp)
		{
		might_sleep();

		if (unlikely(!access_ok(VERIFY_WRITE, dst, len))) {
		*errp = -EFAULT;
		return 0;
		@@ -81,6 +92,7 @@ csum_partial_copy_to_user(const void src, void __user dst,
		if (unlikely((unsigned long)dst & 6)) {
		while (((unsigned long)dst & 6) && len >= 2) {
		__u16 val16 = (__u16 )src;

		isum = (__force __wsum)add32_with_carry(
		(__force unsigned)isum, val16);
		errp = __put_user(val16, (__u16 __user )dst);
		@@ -93,9 +105,9 @@ csum_partial_copy_to_user(const void src, void __user dst,
		}

		*errp = 0;
		return csum_partial_copy_generic(src, (void __force *)dst, len, isum, NULL, errp);
		return csum_partial_copy_generic(src, (void __force *)dst,
		len, isum, NULL, errp);
		}

		EXPORT_SYMBOL(csum_partial_copy_to_user);

		/**
		@@ -122,14 +134,17 @@ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,

		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));
		}

		return csum_fold(
		(__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32));
		}
		EXPORT_SYMBOL(csum_ipv6_magic);

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