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
24static 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
77static 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