141 lines
3.4 KiB
C
141 lines
3.4 KiB
C
#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 */
|