xref: /openbmc/linux/arch/s390/include/asm/futex.h (revision 8cb5d748)
1 #ifndef _ASM_S390_FUTEX_H
2 #define _ASM_S390_FUTEX_H
3 
4 #include <linux/uaccess.h>
5 #include <linux/futex.h>
6 #include <asm/mmu_context.h>
7 #include <asm/errno.h>
8 
9 #define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg)	\
10 	asm volatile(							\
11 		"   sacf  256\n"					\
12 		"0: l     %1,0(%6)\n"					\
13 		"1:"insn						\
14 		"2: cs    %1,%2,0(%6)\n"				\
15 		"3: jl    1b\n"						\
16 		"   lhi   %0,0\n"					\
17 		"4: sacf  768\n"					\
18 		EX_TABLE(0b,4b) EX_TABLE(2b,4b) EX_TABLE(3b,4b)		\
19 		: "=d" (ret), "=&d" (oldval), "=&d" (newval),		\
20 		  "=m" (*uaddr)						\
21 		: "0" (-EFAULT), "d" (oparg), "a" (uaddr),		\
22 		  "m" (*uaddr) : "cc");
23 
24 static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
25 		u32 __user *uaddr)
26 {
27 	int oldval = 0, newval, ret;
28 
29 	load_kernel_asce();
30 
31 	pagefault_disable();
32 	switch (op) {
33 	case FUTEX_OP_SET:
34 		__futex_atomic_op("lr %2,%5\n",
35 				  ret, oldval, newval, uaddr, oparg);
36 		break;
37 	case FUTEX_OP_ADD:
38 		__futex_atomic_op("lr %2,%1\nar %2,%5\n",
39 				  ret, oldval, newval, uaddr, oparg);
40 		break;
41 	case FUTEX_OP_OR:
42 		__futex_atomic_op("lr %2,%1\nor %2,%5\n",
43 				  ret, oldval, newval, uaddr, oparg);
44 		break;
45 	case FUTEX_OP_ANDN:
46 		__futex_atomic_op("lr %2,%1\nnr %2,%5\n",
47 				  ret, oldval, newval, uaddr, oparg);
48 		break;
49 	case FUTEX_OP_XOR:
50 		__futex_atomic_op("lr %2,%1\nxr %2,%5\n",
51 				  ret, oldval, newval, uaddr, oparg);
52 		break;
53 	default:
54 		ret = -ENOSYS;
55 	}
56 	pagefault_enable();
57 
58 	if (!ret)
59 		*oval = oldval;
60 
61 	return ret;
62 }
63 
64 static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
65 						u32 oldval, u32 newval)
66 {
67 	int ret;
68 
69 	load_kernel_asce();
70 	asm volatile(
71 		"   sacf 256\n"
72 		"0: cs   %1,%4,0(%5)\n"
73 		"1: la   %0,0\n"
74 		"2: sacf 768\n"
75 		EX_TABLE(0b,2b) EX_TABLE(1b,2b)
76 		: "=d" (ret), "+d" (oldval), "=m" (*uaddr)
77 		: "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
78 		: "cc", "memory");
79 	*uval = oldval;
80 	return ret;
81 }
82 
83 #endif /* _ASM_S390_FUTEX_H */
84