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#ifndef ASM_X86__FUTEX_H
#define ASM_X86__FUTEX_H
#ifdef __KERNEL__
#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/asm.h>
#include <asm/errno.h>
#include <asm/processor.h>
#include <asm/system.h>
#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
asm volatile("1:\t" insn "\n" \
"2:\t.section .fixup,\"ax\"\n" \
"3:\tmov\t%3, %1\n" \
"\tjmp\t2b\n" \
"\t.previous\n" \
_ASM_EXTABLE(1b, 3b) \
: "=r" (oldval), "=r" (ret), "+m" (*uaddr) \
: "i" (-EFAULT), "0" (oparg), "1" (0))
#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
asm volatile("1:\tmovl %2, %0\n" \
"\tmovl\t%0, %3\n" \
"\t" insn "\n" \
"2:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" \
"\tjnz\t1b\n" \
"3:\t.section .fixup,\"ax\"\n" \
"4:\tmov\t%5, %1\n" \
"\tjmp\t3b\n" \
"\t.previous\n" \
_ASM_EXTABLE(1b, 4b) \
_ASM_EXTABLE(2b, 4b) \
: "=&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_PREFIX "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 defined(CONFIG_X86_32) && !defined(CONFIG_X86_BSWAP)
/* Real i386 machines have no cmpxchg instruction */
if (boot_cpu_data.x86 == 3)
return -ENOSYS;
#endif
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
asm volatile("1:\t" LOCK_PREFIX "cmpxchgl %3, %1\n"
"2:\t.section .fixup, \"ax\"\n"
"3:\tmov %2, %0\n"
"\tjmp 2b\n"
"\t.previous\n"
_ASM_EXTABLE(1b, 3b)
: "=a" (oldval), "+m" (*uaddr)
: "i" (-EFAULT), "r" (newval), "0" (oldval)
: "memory"
);
return oldval;
}
#endif
#endif /* ASM_X86__FUTEX_H */
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