tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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 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
64static 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 */