mirror of
https://github.com/torvalds/linux.git
synced 2024-12-21 02:21:36 +00:00
0ee3b6f87d
futex_atomic_cmpxchg_inatomic() is simply the 32-bit implementation of user_atomic_cmpxchg_inatomic(), which in turn is simply a generalization of the original code in futex_atomic_cmpxchg_inatomic(). Use the newly generalized user_atomic_cmpxchg_inatomic() as the futex implementation, too. [ hpa: retain the inline in futex.h rather than changing it to a macro ] Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com> Link: http://lkml.kernel.org/r/1387002303-6620-2-git-send-email-qiaowei.ren@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
118 lines
2.8 KiB
C
118 lines
2.8 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/smap.h>
|
|
|
|
#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
|
|
asm volatile("\t" ASM_STAC "\n" \
|
|
"1:\t" insn "\n" \
|
|
"2:\t" ASM_CLAC "\n" \
|
|
"\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("\t" ASM_STAC "\n" \
|
|
"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" ASM_CLAC "\n" \
|
|
"\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, u32 __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(u32)))
|
|
return -EFAULT;
|
|
|
|
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(u32 *uval, u32 __user *uaddr,
|
|
u32 oldval, u32 newval)
|
|
{
|
|
return user_atomic_cmpxchg_inatomic(uval, uaddr, oldval, newval);
|
|
}
|
|
|
|
#endif
|
|
#endif /* _ASM_X86_FUTEX_H */
|