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DEFINITIONS
This source file includes following definitions.
- ip_fast_csum
- csum_fold
- csum_tcpudp_nofold
- csum_tcpudp_magic
- ip_compute_csum
- csum_ipv6_magic
- csum_and_copy_to_user
#ifndef _PARISC_CHECKSUM_H
#define _PARISC_CHECKSUM_H
#include <linux/in6.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
*/
extern __wsum csum_partial(const void *, int, __wsum);
/*
* The same as csum_partial, but copies from src while it checksums.
*
* Here even more important to align src and dst on a 32-bit (or even
* better 64-bit) boundary
*/
extern __wsum csum_partial_copy_nocheck(const void *, void *, int, __wsum);
/*
* this is a new version of the above that records errors it finds in *errp,
* but continues and zeros the rest of the buffer.
*/
extern __wsum csum_partial_copy_from_user(const void __user *src,
void *dst, int len, __wsum sum, int *errp);
/*
* Optimized for IP headers, which always checksum on 4 octet boundaries.
*
* Written by Randolph Chung <tausq@debian.org>, and then mucked with by
* LaMont Jones <lamont@debian.org>
*/
static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
unsigned int sum;
__asm__ __volatile__ (
" ldws,ma 4(%1), %0\n"
" addib,<= -4, %2, 2f\n"
"\n"
" ldws 4(%1), %%r20\n"
" ldws 8(%1), %%r21\n"
" add %0, %%r20, %0\n"
" ldws,ma 12(%1), %%r19\n"
" addc %0, %%r21, %0\n"
" addc %0, %%r19, %0\n"
"1: ldws,ma 4(%1), %%r19\n"
" addib,< 0, %2, 1b\n"
" addc %0, %%r19, %0\n"
"\n"
" extru %0, 31, 16, %%r20\n"
" extru %0, 15, 16, %%r21\n"
" addc %%r20, %%r21, %0\n"
" extru %0, 15, 16, %%r21\n"
" add %0, %%r21, %0\n"
" subi -1, %0, %0\n"
"2:\n"
: "=r" (sum), "=r" (iph), "=r" (ihl)
: "1" (iph), "2" (ihl)
: "r19", "r20", "r21", "memory");
return (__force __sum16)sum;
}
/*
* Fold a partial checksum
*/
static inline __sum16 csum_fold(__wsum csum)
{
u32 sum = (__force u32)csum;
/* add the swapped two 16-bit halves of sum,
a possible carry from adding the two 16-bit halves,
will carry from the lower half into the upper half,
giving us the correct sum in the upper half. */
sum += (sum << 16) + (sum >> 16);
return (__force __sum16)(~sum >> 16);
}
static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
unsigned short len,
unsigned short proto,
__wsum sum)
{
__asm__(
" add %1, %0, %0\n"
" addc %2, %0, %0\n"
" addc %3, %0, %0\n"
" addc %%r0, %0, %0\n"
: "=r" (sum)
: "r" (daddr), "r"(saddr), "r"(proto+len), "0"(sum));
return sum;
}
/*
* 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,
unsigned short len,
unsigned short proto,
__wsum sum)
{
return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
}
/*
* this routine is used for miscellaneous IP-like checksums, mainly
* in icmp.c
*/
static inline __sum16 ip_compute_csum(const void *buf, int len)
{
return csum_fold (csum_partial(buf, 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)
{
__asm__ __volatile__ (
#if BITS_PER_LONG > 32
/*
** We can execute two loads and two adds per cycle on PA 8000.
** But add insn's get serialized waiting for the carry bit.
** Try to keep 4 registers with "live" values ahead of the ALU.
*/
" ldd,ma 8(%1), %%r19\n" /* get 1st saddr word */
" ldd,ma 8(%2), %%r20\n" /* get 1st daddr word */
" add %8, %3, %3\n"/* add 16-bit proto + len */
" add %%r19, %0, %0\n"
" ldd,ma 8(%1), %%r21\n" /* 2cd saddr */
" ldd,ma 8(%2), %%r22\n" /* 2cd daddr */
" add,dc %%r20, %0, %0\n"
" add,dc %%r21, %0, %0\n"
" add,dc %%r22, %0, %0\n"
" add,dc %3, %0, %0\n" /* fold in proto+len | carry bit */
" extrd,u %0, 31, 32, %%r19\n" /* copy upper half down */
" depdi 0, 31, 32, %0\n" /* clear upper half */
" add %%r19, %0, %0\n" /* fold into 32-bits */
" addc 0, %0, %0\n" /* add carry */
#else
/*
** For PA 1.x, the insn order doesn't matter as much.
** Insn stream is serialized on the carry bit here too.
** result from the previous operation (eg r0 + x)
*/
" ldw,ma 4(%1), %%r19\n" /* get 1st saddr word */
" ldw,ma 4(%2), %%r20\n" /* get 1st daddr word */
" add %8, %3, %3\n" /* add 16-bit proto + len */
" add %%r19, %0, %0\n"
" ldw,ma 4(%1), %%r21\n" /* 2cd saddr */
" addc %%r20, %0, %0\n"
" ldw,ma 4(%2), %%r22\n" /* 2cd daddr */
" addc %%r21, %0, %0\n"
" ldw,ma 4(%1), %%r19\n" /* 3rd saddr */
" addc %%r22, %0, %0\n"
" ldw,ma 4(%2), %%r20\n" /* 3rd daddr */
" addc %%r19, %0, %0\n"
" ldw,ma 4(%1), %%r21\n" /* 4th saddr */
" addc %%r20, %0, %0\n"
" ldw,ma 4(%2), %%r22\n" /* 4th daddr */
" addc %%r21, %0, %0\n"
" addc %%r22, %0, %0\n"
" addc %3, %0, %0\n" /* fold in proto+len, catch carry */
#endif
: "=r" (sum), "=r" (saddr), "=r" (daddr), "=r" (len)
: "0" (sum), "1" (saddr), "2" (daddr), "3" (len), "r" (proto)
: "r19", "r20", "r21", "r22");
return csum_fold(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)
{
/* code stolen from include/asm-mips64 */
sum = csum_partial(src, len, sum);
if (copy_to_user(dst, src, len)) {
*err_ptr = -EFAULT;
return (__force __wsum)-1;
}
return sum;
}
#endif