xref: /openbmc/linux/arch/alpha/include/asm/futex.h (revision 711aab1d)
1 #ifndef _ASM_ALPHA_FUTEX_H
2 #define _ASM_ALPHA_FUTEX_H
3 
4 #ifdef __KERNEL__
5 
6 #include <linux/futex.h>
7 #include <linux/uaccess.h>
8 #include <asm/errno.h>
9 #include <asm/barrier.h>
10 
11 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)	\
12 	__asm__ __volatile__(					\
13 		__ASM_SMP_MB					\
14 	"1:	ldl_l	%0,0(%2)\n"				\
15 		insn						\
16 	"2:	stl_c	%1,0(%2)\n"				\
17 	"	beq	%1,4f\n"				\
18 	"	mov	$31,%1\n"				\
19 	"3:	.subsection 2\n"				\
20 	"4:	br	1b\n"					\
21 	"	.previous\n"					\
22 	EXC(1b,3b,%1,$31)					\
23 	EXC(2b,3b,%1,$31)					\
24 	:	"=&r" (oldval), "=&r"(ret)			\
25 	:	"r" (uaddr), "r"(oparg)				\
26 	:	"memory")
27 
28 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
29 		u32 __user *uaddr)
30 {
31 	int oldval = 0, ret;
32 
33 	pagefault_disable();
34 
35 	switch (op) {
36 	case FUTEX_OP_SET:
37 		__futex_atomic_op("mov %3,%1\n", ret, oldval, uaddr, oparg);
38 		break;
39 	case FUTEX_OP_ADD:
40 		__futex_atomic_op("addl %0,%3,%1\n", ret, oldval, uaddr, oparg);
41 		break;
42 	case FUTEX_OP_OR:
43 		__futex_atomic_op("or %0,%3,%1\n", ret, oldval, uaddr, oparg);
44 		break;
45 	case FUTEX_OP_ANDN:
46 		__futex_atomic_op("andnot %0,%3,%1\n", ret, oldval, uaddr, oparg);
47 		break;
48 	case FUTEX_OP_XOR:
49 		__futex_atomic_op("xor %0,%3,%1\n", ret, oldval, uaddr, oparg);
50 		break;
51 	default:
52 		ret = -ENOSYS;
53 	}
54 
55 	pagefault_enable();
56 
57 	if (!ret)
58 		*oval = oldval;
59 
60 	return ret;
61 }
62 
63 static inline int
64 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
65 			      u32 oldval, u32 newval)
66 {
67 	int ret = 0, cmp;
68 	u32 prev;
69 
70 	if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
71 		return -EFAULT;
72 
73 	__asm__ __volatile__ (
74 		__ASM_SMP_MB
75 	"1:	ldl_l	%1,0(%3)\n"
76 	"	cmpeq	%1,%4,%2\n"
77 	"	beq	%2,3f\n"
78 	"	mov	%5,%2\n"
79 	"2:	stl_c	%2,0(%3)\n"
80 	"	beq	%2,4f\n"
81 	"3:	.subsection 2\n"
82 	"4:	br	1b\n"
83 	"	.previous\n"
84 	EXC(1b,3b,%0,$31)
85 	EXC(2b,3b,%0,$31)
86 	:	"+r"(ret), "=&r"(prev), "=&r"(cmp)
87 	:	"r"(uaddr), "r"((long)(int)oldval), "r"(newval)
88 	:	"memory");
89 
90 	*uval = prev;
91 	return ret;
92 }
93 
94 #endif /* __KERNEL__ */
95 #endif /* _ASM_ALPHA_FUTEX_H */
96