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m32r: get rid of zeroing 

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2017-03-19 16:11:13 -04:00
parent 35f8acd5c6
commit 8cd920f267
2 changed files with 6 additions and 69 deletions
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66
arch/m32r/include/asm/uaccess.h
View File

@ -460,77 +460,13 @@ do { \
: "r14", "memory"); \
} while (0)
#define __copy_user_zeroing(to, from, size) \
do { \
unsigned long __dst, __src, __c; \
__asm__ __volatile__ ( \
" mv r14, %0\n" \
" or r14, %1\n" \
" beq %0, %1, 9f\n" \
" beqz %2, 9f\n" \
" and3 r14, r14, #3\n" \
" bnez r14, 2f\n" \
" and3 %2, %2, #3\n" \
" beqz %3, 2f\n" \
" addi %0, #-4 ; word_copy \n" \
" .fillinsn\n" \
"0: ld r14, @%1+\n" \
" addi %3, #-1\n" \
" .fillinsn\n" \
"1: st r14, @+%0\n" \
" bnez %3, 0b\n" \
" beqz %2, 9f\n" \
" addi %0, #4\n" \
" .fillinsn\n" \
"2: ldb r14, @%1 ; byte_copy \n" \
" .fillinsn\n" \
"3: stb r14, @%0\n" \
" addi %1, #1\n" \
" addi %2, #-1\n" \
" addi %0, #1\n" \
" bnez %2, 2b\n" \
" .fillinsn\n" \
"9:\n" \
".section .fixup,\"ax\"\n" \
" .balign 4\n" \
"5: addi %3, #1\n" \
" addi %1, #-4\n" \
" .fillinsn\n" \
"6: slli %3, #2\n" \
" add %2, %3\n" \
" addi %0, #4\n" \
" .fillinsn\n" \
"7: ldi r14, #0 ; store zero \n" \
" .fillinsn\n" \
"8: addi %2, #-1\n" \
" stb r14, @%0 ; ACE? \n" \
" addi %0, #1\n" \
" bnez %2, 8b\n" \
" seth r14, #high(9b)\n" \
" or3 r14, r14, #low(9b)\n" \
" jmp r14\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 0b,6b\n" \
" .long 1b,5b\n" \
" .long 2b,7b\n" \
" .long 3b,7b\n" \
".previous\n" \
: "=&r" (__dst), "=&r" (__src), "=&r" (size), \
"=&r" (__c) \
: "0" (to), "1" (from), "2" (size), "3" (size / 4) \
: "r14", "memory"); \
} while (0)
/* We let the __ versions of copy_from/to_user inline, because they're often
* used in fast paths and have only a small space overhead.
*/
static inline unsigned long __generic_copy_from_user_nocheck(void *to,
const void __user *from, unsigned long n)
{
__copy_user_zeroing(to, from, n);
__copy_user(to, from, n);
return n;
}

9
arch/m32r/lib/usercopy.c
View File

@ -23,12 +23,13 @@ __generic_copy_to_user(void __user *to, const void *from, unsigned long n)
unsigned long
__generic_copy_from_user(void *to, const void __user *from, unsigned long n)
{
unsigned long ret = n;
prefetchw(to);
if (access_ok(VERIFY_READ, from, n))
__copy_user_zeroing(to,from,n);
else
memset(to, 0, n);
return n;
ret = __copy_user(to,from,n);
if (unlikely(ret))
memset(to + n - ret, 0, ret);
return ret;
}