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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2006 Ralf Baechle (ralf@linux-mips.org)
*/
#ifndef _ASM_FUTEX_H
#define _ASM_FUTEX_H
#ifdef __KERNEL__
#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/barrier.h>
#include <asm/errno.h>
#ifdef CONFIG_CPU_HAS_LLSC
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
{ \
__asm__ __volatile__( \
" .set push \n" \
" .set noat \n" \
"1: ll %1, %4 # __futex_atomic_op \n" \
#if defined(CONFIG_CPU_RLX4181) || defined(CONFIG_CPU_RLX5181) || defined(CONFIG_CPU_RLX5281)
" nop \n" \
#endif
" " insn " \n" \
"2: sc $1, %2 \n" \
" beqz $1, 1b \n" \
__WEAK_LLSC_MB \
"3: \n" \
" .set pop \n" \
" .section .fixup,\"ax\" \n" \
"4: li %0, %6 \n" \
" j 3b \n" \
" .previous \n" \
" .section __ex_table,\"a\" \n" \
" "__UA_ADDR "\t1b, 4b \n" \
" "__UA_ADDR "\t2b, 4b \n" \
" .previous \n" \
: "=r" (ret), "=&r" (oldval), "=R" (*uaddr) \
: "0" (0), "R" (*uaddr), "Jr" (oparg), "i" (-EFAULT) \
: "memory"); \
}
#else
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
{ \
ret = -ENOSYS; \
}
#endif
static inline int
futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
{
int op = (encoded_op >> 28) & 7;
int cmp = (encoded_op >> 24) & 15;
int oparg = (encoded_op << 8) >> 20;
int cmparg = (encoded_op << 20) >> 20;
int oldval = 0, ret;
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
oparg = 1 << oparg;
if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
pagefault_disable();
switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op("move $1, %z5", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ADD:
__futex_atomic_op("addu $1, %1, %z5",
ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_OR:
__futex_atomic_op("or $1, %1, %z5",
ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ANDN:
__futex_atomic_op("and $1, %1, %z5",
ret, oldval, uaddr, ~oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op("xor $1, %1, %z5",
ret, oldval, uaddr, oparg);
break;
default:
ret = -ENOSYS;
}
pagefault_enable();
if (!ret) {
switch (cmp) {
case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
default: ret = -ENOSYS;
}
}
return ret;
}
static inline int
futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
{
int retval;
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
#ifdef CONFIG_CPU_HAS_LLSC
__asm__ __volatile__(
"# futex_atomic_cmpxchg_inatomic \n"
" .set push \n"
" .set noat \n"
"1: ll %0, %2 \n"
#if defined(CONFIG_CPU_RLX4181) || defined(CONFIG_CPU_RLX5181) || defined(CONFIG_CPU_RLX5281)
" nop \n"
#endif
" bne %0, %z3, 3f \n"
" move $1, %z4 \n"
"2: sc $1, %1 \n"
" beqz $1, 1b \n"
__WEAK_LLSC_MB
"3: \n"
" .set pop \n"
" .section .fixup,\"ax\" \n"
"4: li %0, %5 \n"
" j 3b \n"
" .previous \n"
" .section __ex_table,\"a\" \n"
" "__UA_ADDR "\t1b, 4b \n"
" "__UA_ADDR "\t2b, 4b \n"
" .previous \n"
: "=&r" (retval), "=R" (*uaddr)
: "R" (*uaddr), "Jr" (oldval), "Jr" (newval), "i" (-EFAULT)
: "memory");
#else
return -ENOSYS;
#endif
return retval;
}
#endif
#endif /* _ASM_FUTEX_H */
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