Thomas Gleixner | d2912cb | 2019-06-04 10:11:33 +0200 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) |
| 4 | * |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 5 | * Vineetg: August 2010: From Android kernel work |
| 6 | */ |
| 7 | |
| 8 | #ifndef _ASM_FUTEX_H |
| 9 | #define _ASM_FUTEX_H |
| 10 | |
| 11 | #include <linux/futex.h> |
| 12 | #include <linux/preempt.h> |
| 13 | #include <linux/uaccess.h> |
| 14 | #include <asm/errno.h> |
| 15 | |
Vineet Gupta | 9138d41 | 2015-06-25 13:46:57 +0530 | [diff] [blame] | 16 | #ifdef CONFIG_ARC_HAS_LLSC |
| 17 | |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 18 | #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)\ |
| 19 | \ |
Vineet Gupta | 31d30c8 | 2015-08-05 19:10:02 +0530 | [diff] [blame] | 20 | smp_mb(); \ |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 21 | __asm__ __volatile__( \ |
Vineet Gupta | 9138d41 | 2015-06-25 13:46:57 +0530 | [diff] [blame] | 22 | "1: llock %1, [%2] \n" \ |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 23 | insn "\n" \ |
Vineet Gupta | 9138d41 | 2015-06-25 13:46:57 +0530 | [diff] [blame] | 24 | "2: scond %0, [%2] \n" \ |
| 25 | " bnz 1b \n" \ |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 26 | " mov %0, 0 \n" \ |
| 27 | "3: \n" \ |
| 28 | " .section .fixup,\"ax\" \n" \ |
| 29 | " .align 4 \n" \ |
| 30 | "4: mov %0, %4 \n" \ |
Yuriy Kolerov | 6de6066 | 2015-08-12 17:23:32 +0300 | [diff] [blame] | 31 | " j 3b \n" \ |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 32 | " .previous \n" \ |
| 33 | " .section __ex_table,\"a\" \n" \ |
| 34 | " .align 4 \n" \ |
| 35 | " .word 1b, 4b \n" \ |
| 36 | " .word 2b, 4b \n" \ |
| 37 | " .previous \n" \ |
| 38 | \ |
| 39 | : "=&r" (ret), "=&r" (oldval) \ |
| 40 | : "r" (uaddr), "r" (oparg), "ir" (-EFAULT) \ |
Vineet Gupta | 31d30c8 | 2015-08-05 19:10:02 +0530 | [diff] [blame] | 41 | : "cc", "memory"); \ |
| 42 | smp_mb() \ |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 43 | |
Vineet Gupta | 9138d41 | 2015-06-25 13:46:57 +0530 | [diff] [blame] | 44 | #else /* !CONFIG_ARC_HAS_LLSC */ |
| 45 | |
| 46 | #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg)\ |
| 47 | \ |
Vineet Gupta | 31d30c8 | 2015-08-05 19:10:02 +0530 | [diff] [blame] | 48 | smp_mb(); \ |
Vineet Gupta | 9138d41 | 2015-06-25 13:46:57 +0530 | [diff] [blame] | 49 | __asm__ __volatile__( \ |
| 50 | "1: ld %1, [%2] \n" \ |
| 51 | insn "\n" \ |
| 52 | "2: st %0, [%2] \n" \ |
| 53 | " mov %0, 0 \n" \ |
| 54 | "3: \n" \ |
| 55 | " .section .fixup,\"ax\" \n" \ |
| 56 | " .align 4 \n" \ |
| 57 | "4: mov %0, %4 \n" \ |
Yuriy Kolerov | 6de6066 | 2015-08-12 17:23:32 +0300 | [diff] [blame] | 58 | " j 3b \n" \ |
Vineet Gupta | 9138d41 | 2015-06-25 13:46:57 +0530 | [diff] [blame] | 59 | " .previous \n" \ |
| 60 | " .section __ex_table,\"a\" \n" \ |
| 61 | " .align 4 \n" \ |
| 62 | " .word 1b, 4b \n" \ |
| 63 | " .word 2b, 4b \n" \ |
| 64 | " .previous \n" \ |
| 65 | \ |
| 66 | : "=&r" (ret), "=&r" (oldval) \ |
| 67 | : "r" (uaddr), "r" (oparg), "ir" (-EFAULT) \ |
Vineet Gupta | 31d30c8 | 2015-08-05 19:10:02 +0530 | [diff] [blame] | 68 | : "cc", "memory"); \ |
| 69 | smp_mb() \ |
Vineet Gupta | 9138d41 | 2015-06-25 13:46:57 +0530 | [diff] [blame] | 70 | |
| 71 | #endif |
| 72 | |
Jiri Slaby | 30d6e0a | 2017-08-24 09:31:05 +0200 | [diff] [blame] | 73 | static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval, |
| 74 | u32 __user *uaddr) |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 75 | { |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 76 | int oldval = 0, ret; |
| 77 | |
Vineet Gupta | eb2cd8b | 2015-08-06 19:11:06 +0530 | [diff] [blame] | 78 | #ifndef CONFIG_ARC_HAS_LLSC |
| 79 | preempt_disable(); /* to guarantee atomic r-m-w of futex op */ |
| 80 | #endif |
David Hildenbrand | 2f09b22 | 2015-05-11 17:52:17 +0200 | [diff] [blame] | 81 | pagefault_disable(); |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 82 | |
| 83 | switch (op) { |
| 84 | case FUTEX_OP_SET: |
| 85 | __futex_atomic_op("mov %0, %3", ret, oldval, uaddr, oparg); |
| 86 | break; |
| 87 | case FUTEX_OP_ADD: |
Vineet Gupta | ed574e2 | 2015-08-05 19:23:34 +0530 | [diff] [blame] | 88 | /* oldval = *uaddr; *uaddr += oparg ; ret = *uaddr */ |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 89 | __futex_atomic_op("add %0, %1, %3", ret, oldval, uaddr, oparg); |
| 90 | break; |
| 91 | case FUTEX_OP_OR: |
| 92 | __futex_atomic_op("or %0, %1, %3", ret, oldval, uaddr, oparg); |
| 93 | break; |
| 94 | case FUTEX_OP_ANDN: |
| 95 | __futex_atomic_op("bic %0, %1, %3", ret, oldval, uaddr, oparg); |
| 96 | break; |
| 97 | case FUTEX_OP_XOR: |
| 98 | __futex_atomic_op("xor %0, %1, %3", ret, oldval, uaddr, oparg); |
| 99 | break; |
| 100 | default: |
| 101 | ret = -ENOSYS; |
| 102 | } |
| 103 | |
David Hildenbrand | 2f09b22 | 2015-05-11 17:52:17 +0200 | [diff] [blame] | 104 | pagefault_enable(); |
Vineet Gupta | eb2cd8b | 2015-08-06 19:11:06 +0530 | [diff] [blame] | 105 | #ifndef CONFIG_ARC_HAS_LLSC |
| 106 | preempt_enable(); |
| 107 | #endif |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 108 | |
Jiri Slaby | 30d6e0a | 2017-08-24 09:31:05 +0200 | [diff] [blame] | 109 | if (!ret) |
| 110 | *oval = oldval; |
| 111 | |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 112 | return ret; |
| 113 | } |
| 114 | |
Vineet Gupta | 31d30c8 | 2015-08-05 19:10:02 +0530 | [diff] [blame] | 115 | /* |
| 116 | * cmpxchg of futex (pagefaults disabled by caller) |
Vineet Gupta | 882a95a | 2015-08-06 17:03:17 +0530 | [diff] [blame] | 117 | * Return 0 for success, -EFAULT otherwise |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 118 | */ |
| 119 | static inline int |
Vineet Gupta | ed574e2 | 2015-08-05 19:23:34 +0530 | [diff] [blame] | 120 | futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, u32 expval, |
| 121 | u32 newval) |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 122 | { |
Vineet Gupta | 882a95a | 2015-08-06 17:03:17 +0530 | [diff] [blame] | 123 | int ret = 0; |
Vineet Gupta | ed574e2 | 2015-08-05 19:23:34 +0530 | [diff] [blame] | 124 | u32 existval; |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 125 | |
Linus Torvalds | 96d4f26 | 2019-01-03 18:57:57 -0800 | [diff] [blame] | 126 | if (!access_ok(uaddr, sizeof(u32))) |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 127 | return -EFAULT; |
| 128 | |
Vineet Gupta | eb2cd8b | 2015-08-06 19:11:06 +0530 | [diff] [blame] | 129 | #ifndef CONFIG_ARC_HAS_LLSC |
| 130 | preempt_disable(); /* to guarantee atomic r-m-w of futex op */ |
| 131 | #endif |
Vineet Gupta | 31d30c8 | 2015-08-05 19:10:02 +0530 | [diff] [blame] | 132 | smp_mb(); |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 133 | |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 134 | __asm__ __volatile__( |
Vineet Gupta | 9138d41 | 2015-06-25 13:46:57 +0530 | [diff] [blame] | 135 | #ifdef CONFIG_ARC_HAS_LLSC |
Vineet Gupta | 882a95a | 2015-08-06 17:03:17 +0530 | [diff] [blame] | 136 | "1: llock %1, [%4] \n" |
| 137 | " brne %1, %2, 3f \n" |
| 138 | "2: scond %3, [%4] \n" |
Vineet Gupta | 9138d41 | 2015-06-25 13:46:57 +0530 | [diff] [blame] | 139 | " bnz 1b \n" |
| 140 | #else |
Vineet Gupta | 882a95a | 2015-08-06 17:03:17 +0530 | [diff] [blame] | 141 | "1: ld %1, [%4] \n" |
| 142 | " brne %1, %2, 3f \n" |
| 143 | "2: st %3, [%4] \n" |
Vineet Gupta | 9138d41 | 2015-06-25 13:46:57 +0530 | [diff] [blame] | 144 | #endif |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 145 | "3: \n" |
| 146 | " .section .fixup,\"ax\" \n" |
Vineet Gupta | 882a95a | 2015-08-06 17:03:17 +0530 | [diff] [blame] | 147 | "4: mov %0, %5 \n" |
Yuriy Kolerov | 6de6066 | 2015-08-12 17:23:32 +0300 | [diff] [blame] | 148 | " j 3b \n" |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 149 | " .previous \n" |
| 150 | " .section __ex_table,\"a\" \n" |
| 151 | " .align 4 \n" |
| 152 | " .word 1b, 4b \n" |
| 153 | " .word 2b, 4b \n" |
| 154 | " .previous\n" |
Vineet Gupta | 882a95a | 2015-08-06 17:03:17 +0530 | [diff] [blame] | 155 | : "+&r"(ret), "=&r"(existval) |
Vineet Gupta | ed574e2 | 2015-08-05 19:23:34 +0530 | [diff] [blame] | 156 | : "r"(expval), "r"(newval), "r"(uaddr), "ir"(-EFAULT) |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 157 | : "cc", "memory"); |
| 158 | |
Vineet Gupta | 31d30c8 | 2015-08-05 19:10:02 +0530 | [diff] [blame] | 159 | smp_mb(); |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 160 | |
Vineet Gupta | eb2cd8b | 2015-08-06 19:11:06 +0530 | [diff] [blame] | 161 | #ifndef CONFIG_ARC_HAS_LLSC |
| 162 | preempt_enable(); |
| 163 | #endif |
Vineet Gupta | ed574e2 | 2015-08-05 19:23:34 +0530 | [diff] [blame] | 164 | *uval = existval; |
Vineet Gupta | 882a95a | 2015-08-06 17:03:17 +0530 | [diff] [blame] | 165 | return ret; |
Vineet Gupta | 01b812b | 2013-01-18 15:12:22 +0530 | [diff] [blame] | 166 | } |
| 167 | |
| 168 | #endif |