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/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _ASM_POWERPC_CHECKSUM_H
#define _ASM_POWERPC_CHECKSUM_H
#ifdef __KERNEL__
/*
*/
#include <linux/bitops.h>
#include <linux/in6.h>
/*
* Computes the checksum of a memory block at src, length len,
* and adds in "sum" (32-bit), while copying the block to dst.
* If an access exception occurs on src or dst, it stores -EFAULT
* to *src_err or *dst_err respectively (if that pointer is not
* NULL), and, for an error on src, zeroes the rest of dst.
*
* Like csum_partial, this must be called with even lengths,
* except for the last fragment.
*/
extern __wsum csum_partial_copy_generic(const void *src, void *dst,
int len, __wsum sum,
int *src_err, int *dst_err);
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
extern __wsum csum_and_copy_from_user(const void __user *src, void *dst,
int len, __wsum sum, int *err_ptr);
#define HAVE_CSUM_COPY_USER
extern __wsum csum_and_copy_to_user(const void *src, void __user *dst,
int len, __wsum sum, int *err_ptr);
#define _HAVE_ARCH_CSUM_AND_COPY
#define csum_partial_copy_nocheck(src, dst, len, sum) \
csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL)
/*
* turns a 32-bit partial checksum (e.g. from csum_partial) into a
* 1's complement 16-bit checksum.
*/
static inline __sum16 csum_fold(__wsum sum)
{
unsigned int tmp;
/* swap the two 16-bit halves of sum */
__asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum));
/* if there is a carry from adding the two 16-bit halves,
it will carry from the lower half into the upper half,
giving us the correct sum in the upper half. */
return (__force __sum16)(~((__force u32)sum + tmp) >> 16);
}
static inline u32 from64to32(u64 x)
{
return (x + ror64(x, 32)) >> 32;
}
static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
__u8 proto, __wsum sum)
{
#ifdef __powerpc64__
u64 s = (__force u32)sum;
s += (__force u32)saddr;
s += (__force u32)daddr;
#ifdef __BIG_ENDIAN__
s += proto + len;
#else
s += (proto + len) << 8;
#endif
return (__force __wsum) from64to32(s);
#else
__asm__("\n\
addc %0,%0,%1 \n\
adde %0,%0,%2 \n\
adde %0,%0,%3 \n\
addze %0,%0 \n\
"
: "=r" (sum)
: "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum));
return sum;
#endif
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
__u8 proto, __wsum sum)
{
return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
}
#define HAVE_ARCH_CSUM_ADD
static inline __wsum csum_add(__wsum csum, __wsum addend)
{
#ifdef __powerpc64__
u64 res = (__force u64)csum;
#endif
if (__builtin_constant_p(csum) && csum == 0)
return addend;
if (__builtin_constant_p(addend) && addend == 0)
return csum;
#ifdef __powerpc64__
res += (__force u64)addend;
return (__force __wsum)((u32)res + (res >> 32));
#else
asm("addc %0,%0,%1;"
"addze %0,%0;"
: "+r" (csum) : "r" (addend) : "xer");
return csum;
#endif
}
/*
* This is a version of ip_compute_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries. ihl is the number
* of 32-bit words and is always >= 5.
*/
static inline __wsum ip_fast_csum_nofold(const void *iph, unsigned int ihl)
{
const u32 *ptr = (const u32 *)iph + 1;
#ifdef __powerpc64__
unsigned int i;
u64 s = *(const u32 *)iph;
for (i = 0; i < ihl - 1; i++, ptr++)
s += *ptr;
return (__force __wsum)from64to32(s);
#else
__wsum sum, tmp;
asm("mtctr %3;"
"addc %0,%4,%5;"
"1: lwzu %1, 4(%2);"
"adde %0,%0,%1;"
"bdnz 1b;"
"addze %0,%0;"
: "=r" (sum), "=r" (tmp), "+b" (ptr)
: "r" (ihl - 2), "r" (*(const u32 *)iph), "r" (*ptr)
: "ctr", "xer", "memory");
return sum;
#endif
}
static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
return csum_fold(ip_fast_csum_nofold(iph, ihl));
}
/*
* 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);
static inline __wsum csum_partial(const void *buff, int len, __wsum sum)
{
if (__builtin_constant_p(len) && len <= 16 && (len & 1) == 0) {
if (len == 2)
sum = csum_add(sum, (__force __wsum)*(const u16 *)buff);
if (len >= 4)
sum = csum_add(sum, (__force __wsum)*(const u32 *)buff);
if (len == 6)
sum = csum_add(sum, (__force __wsum)
*(const u16 *)(buff + 4));
if (len >= 8)
sum = csum_add(sum, (__force __wsum)
*(const u32 *)(buff + 4));
if (len == 10)
sum = csum_add(sum, (__force __wsum)
*(const u16 *)(buff + 8));
if (len >= 12)
sum = csum_add(sum, (__force __wsum)
*(const u32 *)(buff + 8));
if (len == 14)
sum = csum_add(sum, (__force __wsum)
*(const u16 *)(buff + 12));
if (len >= 16)
sum = csum_add(sum, (__force __wsum)
*(const u32 *)(buff + 12));
} else if (__builtin_constant_p(len) && (len & 3) == 0) {
sum = csum_add(sum, ip_fast_csum_nofold(buff, len >> 2));
} else {
sum = __csum_partial(buff, len, sum);
}
return sum;
}
/*
* 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
__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
const struct in6_addr *daddr,
__u32 len, __u8 proto, __wsum sum);
#endif /* __KERNEL__ */
#endif
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