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ARC: Add llock/scond to futex backend

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Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2015-06-25 13:46:57 +05:30
parent 70d93d8941
commit 9138d4138d
1 changed files with 42 additions and 6 deletions
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48
arch/arc/include/asm/futex.h
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@ -16,12 +16,15 @@
#include <linux/uaccess.h>
#include <asm/errno.h>
#ifdef CONFIG_ARC_HAS_LLSC
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)\
\
__asm__ __volatile__( \
"1: ld %1, [%2] \n" \
"1: llock %1, [%2] \n" \
insn "\n" \
"2: st %0, [%2] \n" \
"2: scond %0, [%2] \n" \
" bnz 1b \n" \
" mov %0, 0 \n" \
"3: \n" \
" .section .fixup,\"ax\" \n" \
@ -39,6 +42,33 @@
: "r" (uaddr), "r" (oparg), "ir" (-EFAULT) \
: "cc", "memory")
#else /* !CONFIG_ARC_HAS_LLSC */
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)\
\
__asm__ __volatile__( \
"1: ld %1, [%2] \n" \
insn "\n" \
"2: st %0, [%2] \n" \
" mov %0, 0 \n" \
"3: \n" \
" .section .fixup,\"ax\" \n" \
" .align 4 \n" \
"4: mov %0, %4 \n" \
" b 3b \n" \
" .previous \n" \
" .section __ex_table,\"a\" \n" \
" .align 4 \n" \
" .word 1b, 4b \n" \
" .word 2b, 4b \n" \
" .previous \n" \
\
: "=&r" (ret), "=&r" (oldval) \
: "r" (uaddr), "r" (oparg), "ir" (-EFAULT) \
: "cc", "memory")
#endif
static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
{
int op = (encoded_op >> 28) & 7;
@ -123,11 +153,17 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 oldval,
pagefault_disable();
/* TBD : can use llock/scond */
__asm__ __volatile__(
"1: ld %0, [%3] \n"
" brne %0, %1, 3f \n"
"2: st %2, [%3] \n"
#ifdef CONFIG_ARC_HAS_LLSC
"1: llock %0, [%3] \n"
" brne %0, %1, 3f \n"
"2: scond %2, [%3] \n"
" bnz 1b \n"
#else
"1: ld %0, [%3] \n"
" brne %0, %1, 3f \n"
"2: st %2, [%3] \n"
#endif
"3: \n"
" .section .fixup,\"ax\" \n"
"4: mov %0, %4 \n"