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caab277b | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
6170a974 CM |
2 | /* |
3 | * Copyright (C) 2012 ARM Ltd. | |
6170a974 CM |
4 | */ |
5 | #ifndef __ASM_FUTEX_H | |
6 | #define __ASM_FUTEX_H | |
7 | ||
6170a974 CM |
8 | #include <linux/futex.h> |
9 | #include <linux/uaccess.h> | |
338d4f49 | 10 | |
6170a974 CM |
11 | #include <asm/errno.h> |
12 | ||
03110a5c WD |
13 | #define FUTEX_MAX_LOOPS 128 /* What's the largest number you can think of? */ |
14 | ||
6170a974 | 15 | #define __futex_atomic_op(insn, ret, oldval, uaddr, tmp, oparg) \ |
bd38967d | 16 | do { \ |
03110a5c WD |
17 | unsigned int loops = FUTEX_MAX_LOOPS; \ |
18 | \ | |
923e1e7d | 19 | uaccess_enable_privileged(); \ |
6170a974 | 20 | asm volatile( \ |
0ea366f5 | 21 | " prfm pstl1strm, %2\n" \ |
8e86f0b4 | 22 | "1: ldxr %w1, %2\n" \ |
6170a974 | 23 | insn "\n" \ |
045afc24 | 24 | "2: stlxr %w0, %w3, %2\n" \ |
03110a5c WD |
25 | " cbz %w0, 3f\n" \ |
26 | " sub %w4, %w4, %w0\n" \ | |
27 | " cbnz %w4, 1b\n" \ | |
2e77a62c | 28 | " mov %w0, %w6\n" \ |
6170a974 | 29 | "3:\n" \ |
03110a5c | 30 | " dmb ish\n" \ |
2e77a62c MR |
31 | _ASM_EXTABLE_UACCESS_ERR(1b, 3b, %w0) \ |
32 | _ASM_EXTABLE_UACCESS_ERR(2b, 3b, %w0) \ | |
03110a5c WD |
33 | : "=&r" (ret), "=&r" (oldval), "+Q" (*uaddr), "=&r" (tmp), \ |
34 | "+r" (loops) \ | |
2e77a62c | 35 | : "r" (oparg), "Ir" (-EAGAIN) \ |
bd38967d | 36 | : "memory"); \ |
923e1e7d | 37 | uaccess_disable_privileged(); \ |
bd38967d | 38 | } while (0) |
6170a974 CM |
39 | |
40 | static inline int | |
91b2d344 | 41 | arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *_uaddr) |
6170a974 | 42 | { |
ff8acf92 | 43 | int oldval = 0, ret, tmp; |
91b2d344 | 44 | u32 __user *uaddr = __uaccess_mask_ptr(_uaddr); |
6170a974 | 45 | |
a08971e9 AV |
46 | if (!access_ok(_uaddr, sizeof(u32))) |
47 | return -EFAULT; | |
6170a974 CM |
48 | |
49 | switch (op) { | |
50 | case FUTEX_OP_SET: | |
03110a5c | 51 | __futex_atomic_op("mov %w3, %w5", |
6170a974 CM |
52 | ret, oldval, uaddr, tmp, oparg); |
53 | break; | |
54 | case FUTEX_OP_ADD: | |
03110a5c | 55 | __futex_atomic_op("add %w3, %w1, %w5", |
6170a974 CM |
56 | ret, oldval, uaddr, tmp, oparg); |
57 | break; | |
58 | case FUTEX_OP_OR: | |
03110a5c | 59 | __futex_atomic_op("orr %w3, %w1, %w5", |
6170a974 CM |
60 | ret, oldval, uaddr, tmp, oparg); |
61 | break; | |
62 | case FUTEX_OP_ANDN: | |
03110a5c | 63 | __futex_atomic_op("and %w3, %w1, %w5", |
6170a974 CM |
64 | ret, oldval, uaddr, tmp, ~oparg); |
65 | break; | |
66 | case FUTEX_OP_XOR: | |
03110a5c | 67 | __futex_atomic_op("eor %w3, %w1, %w5", |
6170a974 CM |
68 | ret, oldval, uaddr, tmp, oparg); |
69 | break; | |
70 | default: | |
71 | ret = -ENOSYS; | |
72 | } | |
73 | ||
30d6e0a4 JS |
74 | if (!ret) |
75 | *oval = oldval; | |
76 | ||
6170a974 CM |
77 | return ret; |
78 | } | |
79 | ||
80 | static inline int | |
91b2d344 | 81 | futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *_uaddr, |
6170a974 CM |
82 | u32 oldval, u32 newval) |
83 | { | |
84 | int ret = 0; | |
03110a5c | 85 | unsigned int loops = FUTEX_MAX_LOOPS; |
6170a974 | 86 | u32 val, tmp; |
91b2d344 | 87 | u32 __user *uaddr; |
6170a974 | 88 | |
96d4f267 | 89 | if (!access_ok(_uaddr, sizeof(u32))) |
6170a974 CM |
90 | return -EFAULT; |
91 | ||
91b2d344 | 92 | uaddr = __uaccess_mask_ptr(_uaddr); |
923e1e7d | 93 | uaccess_enable_privileged(); |
6170a974 | 94 | asm volatile("// futex_atomic_cmpxchg_inatomic\n" |
0ea366f5 | 95 | " prfm pstl1strm, %2\n" |
8e86f0b4 | 96 | "1: ldxr %w1, %2\n" |
03110a5c WD |
97 | " sub %w3, %w1, %w5\n" |
98 | " cbnz %w3, 4f\n" | |
99 | "2: stlxr %w3, %w6, %2\n" | |
100 | " cbz %w3, 3f\n" | |
101 | " sub %w4, %w4, %w3\n" | |
102 | " cbnz %w4, 1b\n" | |
2e77a62c | 103 | " mov %w0, %w7\n" |
6170a974 | 104 | "3:\n" |
03110a5c WD |
105 | " dmb ish\n" |
106 | "4:\n" | |
2e77a62c MR |
107 | _ASM_EXTABLE_UACCESS_ERR(1b, 4b, %w0) |
108 | _ASM_EXTABLE_UACCESS_ERR(2b, 4b, %w0) | |
03110a5c | 109 | : "+r" (ret), "=&r" (val), "+Q" (*uaddr), "=&r" (tmp), "+r" (loops) |
2e77a62c | 110 | : "r" (oldval), "r" (newval), "Ir" (-EAGAIN) |
95c41896 | 111 | : "memory"); |
923e1e7d | 112 | uaccess_disable_privileged(); |
6170a974 | 113 | |
8e4e0ac0 WD |
114 | if (!ret) |
115 | *uval = val; | |
116 | ||
6170a974 CM |
117 | return ret; |
118 | } | |
119 | ||
6170a974 | 120 | #endif /* __ASM_FUTEX_H */ |