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#ifndef _ASM_X86_FUTEX_H
#define _ASM_X86_FUTEX_H
#ifdef __KERNEL__
#include <linux/futex.h>
#include <asm/asm.h>
#include <asm/errno.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
__asm__ __volatile( \
"1: " insn "\n" \
"2: .section .fixup,\"ax\"\n \
3: mov %3, %1\n \
jmp 2b\n \
.previous\n \
.section __ex_table,\"a\"\n \
.align 8\n" \
_ASM_PTR "1b,3b\n \
.previous" \
: "=r" (oldval), "=r" (ret), "+m" (*uaddr) \
: "i" (-EFAULT), "0" (oparg), "1" (0))
#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
__asm__ __volatile( \
"1: movl %2, %0\n \
movl %0, %3\n" \
insn "\n" \
"2: lock; cmpxchgl %3, %2\n \
jnz 1b\n \
3: .section .fixup,\"ax\"\n \
4: mov %5, %1\n \
jmp 3b\n \
.previous\n \
.section __ex_table,\"a\"\n \
.align 8\n" \
_ASM_PTR "1b,4b,2b,4b\n \
.previous" \
: "=&a" (oldval), "=&r" (ret), "+m" (*uaddr), \
"=&r" (tem) \
: "r" (oparg), "i" (-EFAULT), "1" (0))
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, tem;
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
oparg = 1 << oparg;
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP)
/* Real i386 machines can only support FUTEX_OP_SET */
if (op != FUTEX_OP_SET && boot_cpu_data.x86 == 3)
return -ENOSYS;
#endif
pagefault_disable();
switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ADD:
__futex_atomic_op1("lock; xaddl %0, %2", ret, oldval,
uaddr, oparg);
break;
case FUTEX_OP_OR:
__futex_atomic_op2("orl %4, %3", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ANDN:
__futex_atomic_op2("andl %4, %3", ret, oldval, uaddr, ~oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op2("xorl %4, %3", 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)
{
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
__asm__ __volatile__(
"1: lock; cmpxchgl %3, %1 \n"
"2: .section .fixup, \"ax\" \n"
"3: mov %2, %0 \n"
" jmp 2b \n"
" .previous \n"
" .section __ex_table, \"a\" \n"
" .align 8 \n"
_ASM_PTR " 1b,3b \n"
" .previous \n"
: "=a" (oldval), "+m" (*uaddr)
: "i" (-EFAULT), "r" (newval), "0" (oldval)
: "memory"
);
return oldval;
}
#endif
#endif
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