xref: /linux/arch/s390/include/asm/futex.h (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
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 futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
25 {
26 	int op = (encoded_op >> 28) & 7;
27 	int cmp = (encoded_op >> 24) & 15;
28 	int oparg = (encoded_op << 8) >> 20;
29 	int cmparg = (encoded_op << 20) >> 20;
30 	int oldval = 0, newval, ret;
31 
32 	load_kernel_asce();
33 	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
34 		oparg = 1 << oparg;
35 
36 	pagefault_disable();
37 	switch (op) {
38 	case FUTEX_OP_SET:
39 		__futex_atomic_op("lr %2,%5\n",
40 				  ret, oldval, newval, uaddr, oparg);
41 		break;
42 	case FUTEX_OP_ADD:
43 		__futex_atomic_op("lr %2,%1\nar %2,%5\n",
44 				  ret, oldval, newval, uaddr, oparg);
45 		break;
46 	case FUTEX_OP_OR:
47 		__futex_atomic_op("lr %2,%1\nor %2,%5\n",
48 				  ret, oldval, newval, uaddr, oparg);
49 		break;
50 	case FUTEX_OP_ANDN:
51 		__futex_atomic_op("lr %2,%1\nnr %2,%5\n",
52 				  ret, oldval, newval, uaddr, oparg);
53 		break;
54 	case FUTEX_OP_XOR:
55 		__futex_atomic_op("lr %2,%1\nxr %2,%5\n",
56 				  ret, oldval, newval, uaddr, oparg);
57 		break;
58 	default:
59 		ret = -ENOSYS;
60 	}
61 	pagefault_enable();
62 
63 	if (!ret) {
64 		switch (cmp) {
65 		case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
66 		case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
67 		case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
68 		case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
69 		case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
70 		case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
71 		default: ret = -ENOSYS;
72 		}
73 	}
74 	return ret;
75 }
76 
77 static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
78 						u32 oldval, u32 newval)
79 {
80 	int ret;
81 
82 	load_kernel_asce();
83 	asm volatile(
84 		"   sacf 256\n"
85 		"0: cs   %1,%4,0(%5)\n"
86 		"1: la   %0,0\n"
87 		"2: sacf 768\n"
88 		EX_TABLE(0b,2b) EX_TABLE(1b,2b)
89 		: "=d" (ret), "+d" (oldval), "=m" (*uaddr)
90 		: "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
91 		: "cc", "memory");
92 	*uval = oldval;
93 	return ret;
94 }
95 
96 #endif /* _ASM_S390_FUTEX_H */
97