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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/mips/include/asm/checksum.h
Initial import
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diff --git a/arch/mips/include/asm/checksum.h b/arch/mips/include/asm/checksum.h
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+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle
+ * Copyright (C) 1999 Silicon Graphics, Inc.
+ * Copyright (C) 2001 Thiemo Seufer.
+ * Copyright (C) 2002 Maciej W. Rozycki
+ * Copyright (C) 2014 Imagination Technologies Ltd.
+ */
+#ifndef _ASM_CHECKSUM_H
+#define _ASM_CHECKSUM_H
+
+#ifdef CONFIG_GENERIC_CSUM
+#include <asm-generic/checksum.h>
+#else
+
+#include <linux/in6.h>
+
+#include <asm/uaccess.h>
+
+/*
+ * computes the checksum of a memory block at buff, length len,
+ * and adds in "sum" (32-bit)
+ *
+ * returns a 32-bit number suitable for feeding into itself
+ * or csum_tcpudp_magic
+ *
+ * this function must be called with even lengths, except
+ * for the last fragment, which may be odd
+ *
+ * it's best to have buff aligned on a 32-bit boundary
+ */
+__wsum csum_partial(const void *buff, int len, __wsum sum);
+
+__wsum __csum_partial_copy_kernel(const void *src, void *dst,
+ int len, __wsum sum, int *err_ptr);
+
+__wsum __csum_partial_copy_from_user(const void *src, void *dst,
+ int len, __wsum sum, int *err_ptr);
+__wsum __csum_partial_copy_to_user(const void *src, void *dst,
+ int len, __wsum sum, int *err_ptr);
+/*
+ * this is a new version of the above that records errors it finds in *errp,
+ * but continues and zeros the rest of the buffer.
+ */
+static inline
+__wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len,
+ __wsum sum, int *err_ptr)
+{
+ might_fault();
+ if (segment_eq(get_fs(), get_ds()))
+ return __csum_partial_copy_kernel((__force void *)src, dst,
+ len, sum, err_ptr);
+ else
+ return __csum_partial_copy_from_user((__force void *)src, dst,
+ len, sum, err_ptr);
+}
+
+#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
+static inline
+__wsum csum_and_copy_from_user(const void __user *src, void *dst,
+ int len, __wsum sum, int *err_ptr)
+{
+ if (access_ok(VERIFY_READ, src, len))
+ return csum_partial_copy_from_user(src, dst, len, sum,
+ err_ptr);
+ if (len)
+ *err_ptr = -EFAULT;
+
+ return sum;
+}
+
+/*
+ * Copy and checksum to user
+ */
+#define HAVE_CSUM_COPY_USER
+static inline
+__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
+ __wsum sum, int *err_ptr)
+{
+ might_fault();
+ if (access_ok(VERIFY_WRITE, dst, len)) {
+ if (segment_eq(get_fs(), get_ds()))
+ return __csum_partial_copy_kernel(src,
+ (__force void *)dst,
+ len, sum, err_ptr);
+ else
+ return __csum_partial_copy_to_user(src,
+ (__force void *)dst,
+ len, sum, err_ptr);
+ }
+ if (len)
+ *err_ptr = -EFAULT;
+
+ return (__force __wsum)-1; /* invalid checksum */
+}
+
+/*
+ * the same as csum_partial, but copies from user space (but on MIPS
+ * we have just one address space, so this is identical to the above)
+ */
+__wsum csum_partial_copy_nocheck(const void *src, void *dst,
+ int len, __wsum sum);
+#define csum_partial_copy_nocheck csum_partial_copy_nocheck
+
+/*
+ * Fold a partial checksum without adding pseudo headers
+ */
+static inline __sum16 csum_fold(__wsum csum)
+{
+ u32 sum = (__force u32)csum;;
+
+ sum += (sum << 16);
+ csum = (sum < csum);
+ sum >>= 16;
+ sum += csum;
+
+ return (__force __sum16)~sum;
+}
+#define csum_fold csum_fold
+
+/*
+ * This is a version of ip_compute_csum() optimized for IP headers,
+ * which always checksum on 4 octet boundaries.
+ *
+ * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
+ * Arnt Gulbrandsen.
+ */
+static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
+{
+ const unsigned int *word = iph;
+ const unsigned int *stop = word + ihl;
+ unsigned int csum;
+ int carry;
+
+ csum = word[0];
+ csum += word[1];
+ carry = (csum < word[1]);
+ csum += carry;
+
+ csum += word[2];
+ carry = (csum < word[2]);
+ csum += carry;
+
+ csum += word[3];
+ carry = (csum < word[3]);
+ csum += carry;
+
+ word += 4;
+ do {
+ csum += *word;
+ carry = (csum < *word);
+ csum += carry;
+ word++;
+ } while (word != stop);
+
+ return csum_fold(csum);
+}
+#define ip_fast_csum ip_fast_csum
+
+static inline __wsum csum_tcpudp_nofold(__be32 saddr,
+ __be32 daddr, unsigned short len, unsigned short proto,
+ __wsum sum)
+{
+ __asm__(
+ " .set push # csum_tcpudp_nofold\n"
+ " .set noat \n"
+#ifdef CONFIG_32BIT
+ " addu %0, %2 \n"
+ " sltu $1, %0, %2 \n"
+ " addu %0, $1 \n"
+
+ " addu %0, %3 \n"
+ " sltu $1, %0, %3 \n"
+ " addu %0, $1 \n"
+
+ " addu %0, %4 \n"
+ " sltu $1, %0, %4 \n"
+ " addu %0, $1 \n"
+#endif
+#ifdef CONFIG_64BIT
+ " daddu %0, %2 \n"
+ " daddu %0, %3 \n"
+ " daddu %0, %4 \n"
+ " dsll32 $1, %0, 0 \n"
+ " daddu %0, $1 \n"
+ " dsra32 %0, %0, 0 \n"
+#endif
+ " .set pop"
+ : "=r" (sum)
+ : "0" ((__force unsigned long)daddr),
+ "r" ((__force unsigned long)saddr),
+#ifdef __MIPSEL__
+ "r" ((proto + len) << 8),
+#else
+ "r" (proto + len),
+#endif
+ "r" ((__force unsigned long)sum));
+
+ return sum;
+}
+#define csum_tcpudp_nofold csum_tcpudp_nofold
+
+/*
+ * this routine is used for miscellaneous IP-like checksums, mainly
+ * in icmp.c
+ */
+static inline __sum16 ip_compute_csum(const void *buff, int len)
+{
+ return csum_fold(csum_partial(buff, len, 0));
+}
+
+#define _HAVE_ARCH_IPV6_CSUM
+static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
+ const struct in6_addr *daddr,
+ __u32 len, unsigned short proto,
+ __wsum sum)
+{
+ __wsum tmp;
+
+ __asm__(
+ " .set push # csum_ipv6_magic\n"
+ " .set noreorder \n"
+ " .set noat \n"
+ " addu %0, %5 # proto (long in network byte order)\n"
+ " sltu $1, %0, %5 \n"
+ " addu %0, $1 \n"
+
+ " addu %0, %6 # csum\n"
+ " sltu $1, %0, %6 \n"
+ " lw %1, 0(%2) # four words source address\n"
+ " addu %0, $1 \n"
+ " addu %0, %1 \n"
+ " sltu $1, %0, %1 \n"
+
+ " lw %1, 4(%2) \n"
+ " addu %0, $1 \n"
+ " addu %0, %1 \n"
+ " sltu $1, %0, %1 \n"
+
+ " lw %1, 8(%2) \n"
+ " addu %0, $1 \n"
+ " addu %0, %1 \n"
+ " sltu $1, %0, %1 \n"
+
+ " lw %1, 12(%2) \n"
+ " addu %0, $1 \n"
+ " addu %0, %1 \n"
+ " sltu $1, %0, %1 \n"
+
+ " lw %1, 0(%3) \n"
+ " addu %0, $1 \n"
+ " addu %0, %1 \n"
+ " sltu $1, %0, %1 \n"
+
+ " lw %1, 4(%3) \n"
+ " addu %0, $1 \n"
+ " addu %0, %1 \n"
+ " sltu $1, %0, %1 \n"
+
+ " lw %1, 8(%3) \n"
+ " addu %0, $1 \n"
+ " addu %0, %1 \n"
+ " sltu $1, %0, %1 \n"
+
+ " lw %1, 12(%3) \n"
+ " addu %0, $1 \n"
+ " addu %0, %1 \n"
+ " sltu $1, %0, %1 \n"
+
+ " addu %0, $1 # Add final carry\n"
+ " .set pop"
+ : "=&r" (sum), "=&r" (tmp)
+ : "r" (saddr), "r" (daddr),
+ "0" (htonl(len)), "r" (htonl(proto)), "r" (sum));
+
+ return csum_fold(sum);
+}
+
+#include <asm-generic/checksum.h>
+#endif /* CONFIG_GENERIC_CSUM */
+
+#endif /* _ASM_CHECKSUM_H */