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parisc: Do not hardcode registers in checksum functions

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[ Upstream commit 52b2d91752a82d9350981eb3b3ffc4b325c84ba9 ]

Do not hardcode processor registers r19 to r22 as scratch registers.
Instead let the compiler decide, which may give better optimization
results when the functions get inlined.

Signed-off-by: Helge Deller <deller@gmx.de>
Stable-dep-of: a2abae8f0b63 ("parisc: Fix ip_fast_csum")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Helge Deller 2019-09-29 21:00:42 +02:00 committed by Greg Kroah-Hartman
parent 64a1ccfa9a
commit 331b43d79a
1 changed files with 52 additions and 49 deletions
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101
arch/parisc/include/asm/checksum.h
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@ -42,31 +42,32 @@ extern __wsum csum_partial_copy_from_user(const void __user *src,
static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
unsigned int sum;
unsigned long t0, t1, t2;
__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"
" ldws 4(%1), %4\n"
" ldws 8(%1), %5\n"
" add %0, %4, %0\n"
" ldws,ma 12(%1), %3\n"
" addc %0, %5, %0\n"
" addc %0, %3, %0\n"
"1: ldws,ma 4(%1), %3\n"
" addib,< 0, %2, 1b\n"
" addc %0, %%r19, %0\n"
" addc %0, %3, %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"
" extru %0, 31, 16, %4\n"
" extru %0, 15, 16, %5\n"
" addc %4, %5, %0\n"
" extru %0, 15, 16, %5\n"
" add %0, %5, %0\n"
" subi -1, %0, %0\n"
"2:\n"
: "=r" (sum), "=r" (iph), "=r" (ihl)
: "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (t0), "=r" (t1), "=r" (t2)
: "1" (iph), "2" (ihl)
: "r19", "r20", "r21", "memory");
: "memory");
return (__force __sum16)sum;
}
@ -126,6 +127,10 @@ static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
__u32 len, __u8 proto,
__wsum sum)
{
unsigned long t0, t1, t2, t3;
len += proto; /* add 16-bit proto + len */
__asm__ __volatile__ (
#if BITS_PER_LONG > 32
@ -136,20 +141,19 @@ static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
** 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"
" ldd,ma 8(%1), %4\n" /* get 1st saddr word */
" ldd,ma 8(%2), %5\n" /* get 1st daddr word */
" add %4, %0, %0\n"
" ldd,ma 8(%1), %6\n" /* 2nd saddr */
" ldd,ma 8(%2), %7\n" /* 2nd daddr */
" add,dc %5, %0, %0\n"
" add,dc %6, %0, %0\n"
" add,dc %7, %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 */
" extrd,u %0, 31, 32, %4\n"/* copy upper half down */
" depdi 0, 31, 32, %0\n"/* clear upper half */
" add %4, %0, %0\n" /* fold into 32-bits */
" addc 0, %0, %0\n" /* add carry */
#else
@ -158,30 +162,29 @@ static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
** 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"
" ldw,ma 4(%1), %4\n" /* get 1st saddr word */
" ldw,ma 4(%2), %5\n" /* get 1st daddr word */
" add %4, %0, %0\n"
" ldw,ma 4(%1), %6\n" /* 2nd saddr */
" addc %5, %0, %0\n"
" ldw,ma 4(%2), %7\n" /* 2nd daddr */
" addc %6, %0, %0\n"
" ldw,ma 4(%1), %4\n" /* 3rd saddr */
" addc %7, %0, %0\n"
" ldw,ma 4(%2), %5\n" /* 3rd daddr */
" addc %4, %0, %0\n"
" ldw,ma 4(%1), %6\n" /* 4th saddr */
" addc %5, %0, %0\n"
" ldw,ma 4(%2), %7\n" /* 4th daddr */
" addc %6, %0, %0\n"
" addc %7, %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", "memory");
: "=r" (sum), "=r" (saddr), "=r" (daddr), "=r" (len),
"=r" (t0), "=r" (t1), "=r" (t2), "=r" (t3)
: "0" (sum), "1" (saddr), "2" (daddr), "3" (len)
: "memory");
return csum_fold(sum);
}