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Subject[PATCH v2 11/20] sh: propage the calling conventions change down to csum_partial_copy_generic()
Date
From: Al Viro <viro@zeniv.linux.org.uk>

... and get rid of zeroing destination on error there.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
arch/sh/include/asm/checksum_32.h | 20 ++-----
arch/sh/lib/checksum.S | 119 +++++++++++---------------------------
2 files changed, 39 insertions(+), 100 deletions(-)

diff --git a/arch/sh/include/asm/checksum_32.h b/arch/sh/include/asm/checksum_32.h
index a08e8eb924ed..1a391e3a7659 100644
--- a/arch/sh/include/asm/checksum_32.h
+++ b/arch/sh/include/asm/checksum_32.h
@@ -30,9 +30,7 @@ asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum);
* better 64-bit) boundary
*/

-asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst,
- int len, __wsum sum,
- int *src_err_ptr, int *dst_err_ptr);
+asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, int len);

#define _HAVE_ARCH_CSUM_AND_COPY
/*
@@ -45,21 +43,16 @@ asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst,
static inline
__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len)
{
- return csum_partial_copy_generic(src, dst, len, 0, NULL, NULL);
+ return csum_partial_copy_generic(src, dst, len);
}

#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
static inline
__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len)
{
- int err = 0;
- __wsum sum = ~0U;
-
if (!access_ok(src, len))
return 0;
- sum = csum_partial_copy_generic((__force const void *)src, dst,
- len, sum, &err, NULL);
- return err ? 0 : sum;
+ return csum_partial_copy_generic((__force const void *)src, dst, len);
}

/*
@@ -202,13 +195,8 @@ static inline __wsum csum_and_copy_to_user(const void *src,
void __user *dst,
int len)
{
- int err = 0;
- __wsum sum = ~0U;
-
if (!access_ok(dst, len))
return 0;
- sum = csum_partial_copy_generic((__force const void *)src,
- dst, len, sum, NULL, &err);
- return err ? 0 : sum;
+ return csum_partial_copy_generic((__force const void *)src, dst, len);
}
#endif /* __ASM_SH_CHECKSUM_H */
diff --git a/arch/sh/lib/checksum.S b/arch/sh/lib/checksum.S
index 97b5c2d9fec4..3e07074e0098 100644
--- a/arch/sh/lib/checksum.S
+++ b/arch/sh/lib/checksum.S
@@ -173,47 +173,27 @@ ENTRY(csum_partial)
mov r6, r0

/*
-unsigned int csum_partial_copy_generic (const char *src, char *dst, int len,
- int sum, int *src_err_ptr, int *dst_err_ptr)
+unsigned int csum_partial_copy_generic (const char *src, char *dst, int len)
*/

/*
- * Copy from ds while checksumming, otherwise like csum_partial
- *
- * The macros SRC and DST specify the type of access for the instruction.
- * thus we can call a custom exception handler for all access types.
- *
- * FIXME: could someone double-check whether I haven't mixed up some SRC and
- * DST definitions? It's damn hard to trigger all cases. I hope I got
- * them all but there's no guarantee.
+ * Copy from ds while checksumming, otherwise like csum_partial with initial
+ * sum being ~0U
*/

-#define SRC(...) \
+#define EXC(...) \
9999: __VA_ARGS__ ; \
.section __ex_table, "a"; \
.long 9999b, 6001f ; \
.previous

-#define DST(...) \
- 9999: __VA_ARGS__ ; \
- .section __ex_table, "a"; \
- .long 9999b, 6002f ; \
- .previous
-
!
! r4: const char *SRC
! r5: char *DST
! r6: int LEN
-! r7: int SUM
-!
-! on stack:
-! int *SRC_ERR_PTR
-! int *DST_ERR_PTR
!
ENTRY(csum_partial_copy_generic)
- mov.l r5,@-r15
- mov.l r6,@-r15
-
+ mov #-1,r7
mov #3,r0 ! Check src and dest are equally aligned
mov r4,r1
and r0,r1
@@ -243,11 +223,11 @@ ENTRY(csum_partial_copy_generic)
clrt
.align 2
5:
-SRC( mov.b @r4+,r1 )
-SRC( mov.b @r4+,r0 )
+EXC( mov.b @r4+,r1 )
+EXC( mov.b @r4+,r0 )
extu.b r1,r1
-DST( mov.b r1,@r5 )
-DST( mov.b r0,@(1,r5) )
+EXC( mov.b r1,@r5 )
+EXC( mov.b r0,@(1,r5) )
extu.b r0,r0
add #2,r5

@@ -276,8 +256,8 @@ DST( mov.b r0,@(1,r5) )
! Handle first two bytes as a special case
.align 2
1:
-SRC( mov.w @r4+,r0 )
-DST( mov.w r0,@r5 )
+EXC( mov.w @r4+,r0 )
+EXC( mov.w r0,@r5 )
add #2,r5
extu.w r0,r0
addc r0,r7
@@ -292,32 +272,32 @@ DST( mov.w r0,@r5 )
clrt
.align 2
1:
-SRC( mov.l @r4+,r0 )
-SRC( mov.l @r4+,r1 )
+EXC( mov.l @r4+,r0 )
+EXC( mov.l @r4+,r1 )
addc r0,r7
-DST( mov.l r0,@r5 )
-DST( mov.l r1,@(4,r5) )
+EXC( mov.l r0,@r5 )
+EXC( mov.l r1,@(4,r5) )
addc r1,r7

-SRC( mov.l @r4+,r0 )
-SRC( mov.l @r4+,r1 )
+EXC( mov.l @r4+,r0 )
+EXC( mov.l @r4+,r1 )
addc r0,r7
-DST( mov.l r0,@(8,r5) )
-DST( mov.l r1,@(12,r5) )
+EXC( mov.l r0,@(8,r5) )
+EXC( mov.l r1,@(12,r5) )
addc r1,r7

-SRC( mov.l @r4+,r0 )
-SRC( mov.l @r4+,r1 )
+EXC( mov.l @r4+,r0 )
+EXC( mov.l @r4+,r1 )
addc r0,r7
-DST( mov.l r0,@(16,r5) )
-DST( mov.l r1,@(20,r5) )
+EXC( mov.l r0,@(16,r5) )
+EXC( mov.l r1,@(20,r5) )
addc r1,r7

-SRC( mov.l @r4+,r0 )
-SRC( mov.l @r4+,r1 )
+EXC( mov.l @r4+,r0 )
+EXC( mov.l @r4+,r1 )
addc r0,r7
-DST( mov.l r0,@(24,r5) )
-DST( mov.l r1,@(28,r5) )
+EXC( mov.l r0,@(24,r5) )
+EXC( mov.l r1,@(28,r5) )
addc r1,r7
add #32,r5
movt r0
@@ -335,9 +315,9 @@ DST( mov.l r1,@(28,r5) )
clrt
shlr2 r6
3:
-SRC( mov.l @r4+,r0 )
+EXC( mov.l @r4+,r0 )
addc r0,r7
-DST( mov.l r0,@r5 )
+EXC( mov.l r0,@r5 )
add #4,r5
movt r0
dt r6
@@ -353,8 +333,8 @@ DST( mov.l r0,@r5 )
mov #2,r1
cmp/hs r1,r6
bf 5f
-SRC( mov.w @r4+,r0 )
-DST( mov.w r0,@r5 )
+EXC( mov.w @r4+,r0 )
+EXC( mov.w r0,@r5 )
extu.w r0,r0
add #2,r5
cmp/eq r1,r6
@@ -363,8 +343,8 @@ DST( mov.w r0,@r5 )
shll16 r0
addc r0,r7
5:
-SRC( mov.b @r4+,r0 )
-DST( mov.b r0,@r5 )
+EXC( mov.b @r4+,r0 )
+EXC( mov.b r0,@r5 )
extu.b r0,r0
#ifndef __LITTLE_ENDIAN__
shll8 r0
@@ -373,42 +353,13 @@ DST( mov.b r0,@r5 )
mov #0,r0
addc r0,r7
7:
-5000:

# Exception handler:
.section .fixup, "ax"

6001:
- mov.l @(8,r15),r0 ! src_err_ptr
- mov #-EFAULT,r1
- mov.l r1,@r0
-
- ! zero the complete destination - computing the rest
- ! is too much work
- mov.l @(4,r15),r5 ! dst
- mov.l @r15,r6 ! len
- mov #0,r7
-1: mov.b r7,@r5
- dt r6
- bf/s 1b
- add #1,r5
- mov.l 8000f,r0
- jmp @r0
- nop
- .align 2
-8000: .long 5000b
-
-6002:
- mov.l @(12,r15),r0 ! dst_err_ptr
- mov #-EFAULT,r1
- mov.l r1,@r0
- mov.l 8001f,r0
- jmp @r0
- nop
- .align 2
-8001: .long 5000b
-
+ rts
+ mov #0,r0
.previous
- add #8,r15
rts
mov r7,r0
--
2.11.0
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