Chris Metcalf | 867e359 | 2010-05-28 23:09:12 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation, version 2. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but |
| 9 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or |
| 11 | * NON INFRINGEMENT. See the GNU General Public License for |
| 12 | * more details. |
| 13 | * |
| 14 | * These routines make two important assumptions: |
| 15 | * |
| 16 | * 1. atomic_t is really an int and can be freely cast back and forth |
| 17 | * (validated in __init_atomic_per_cpu). |
| 18 | * |
| 19 | * 2. userspace uses sys_cmpxchg() for all atomic operations, thus using |
| 20 | * the same locking convention that all the kernel atomic routines use. |
| 21 | */ |
| 22 | |
| 23 | #ifndef _ASM_TILE_FUTEX_H |
| 24 | #define _ASM_TILE_FUTEX_H |
| 25 | |
| 26 | #ifndef __ASSEMBLY__ |
| 27 | |
| 28 | #include <linux/futex.h> |
| 29 | #include <linux/uaccess.h> |
| 30 | #include <linux/errno.h> |
| 31 | |
| 32 | extern struct __get_user futex_set(int *v, int i); |
| 33 | extern struct __get_user futex_add(int *v, int n); |
| 34 | extern struct __get_user futex_or(int *v, int n); |
| 35 | extern struct __get_user futex_andn(int *v, int n); |
| 36 | extern struct __get_user futex_cmpxchg(int *v, int o, int n); |
| 37 | |
| 38 | #ifndef __tilegx__ |
| 39 | extern struct __get_user futex_xor(int *v, int n); |
| 40 | #else |
| 41 | static inline struct __get_user futex_xor(int __user *uaddr, int n) |
| 42 | { |
| 43 | struct __get_user asm_ret = __get_user_4(uaddr); |
| 44 | if (!asm_ret.err) { |
| 45 | int oldval, newval; |
| 46 | do { |
| 47 | oldval = asm_ret.val; |
| 48 | newval = oldval ^ n; |
| 49 | asm_ret = futex_cmpxchg(uaddr, oldval, newval); |
| 50 | } while (asm_ret.err == 0 && oldval != asm_ret.val); |
| 51 | } |
| 52 | return asm_ret; |
| 53 | } |
| 54 | #endif |
| 55 | |
| 56 | static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) |
| 57 | { |
| 58 | int op = (encoded_op >> 28) & 7; |
| 59 | int cmp = (encoded_op >> 24) & 15; |
| 60 | int oparg = (encoded_op << 8) >> 20; |
| 61 | int cmparg = (encoded_op << 20) >> 20; |
| 62 | int ret; |
| 63 | struct __get_user asm_ret; |
| 64 | |
| 65 | if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) |
| 66 | oparg = 1 << oparg; |
| 67 | |
| 68 | if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) |
| 69 | return -EFAULT; |
| 70 | |
| 71 | pagefault_disable(); |
| 72 | switch (op) { |
| 73 | case FUTEX_OP_SET: |
| 74 | asm_ret = futex_set(uaddr, oparg); |
| 75 | break; |
| 76 | case FUTEX_OP_ADD: |
| 77 | asm_ret = futex_add(uaddr, oparg); |
| 78 | break; |
| 79 | case FUTEX_OP_OR: |
| 80 | asm_ret = futex_or(uaddr, oparg); |
| 81 | break; |
| 82 | case FUTEX_OP_ANDN: |
| 83 | asm_ret = futex_andn(uaddr, oparg); |
| 84 | break; |
| 85 | case FUTEX_OP_XOR: |
| 86 | asm_ret = futex_xor(uaddr, oparg); |
| 87 | break; |
| 88 | default: |
| 89 | asm_ret.err = -ENOSYS; |
| 90 | } |
| 91 | pagefault_enable(); |
| 92 | |
| 93 | ret = asm_ret.err; |
| 94 | |
| 95 | if (!ret) { |
| 96 | switch (cmp) { |
| 97 | case FUTEX_OP_CMP_EQ: |
| 98 | ret = (asm_ret.val == cmparg); |
| 99 | break; |
| 100 | case FUTEX_OP_CMP_NE: |
| 101 | ret = (asm_ret.val != cmparg); |
| 102 | break; |
| 103 | case FUTEX_OP_CMP_LT: |
| 104 | ret = (asm_ret.val < cmparg); |
| 105 | break; |
| 106 | case FUTEX_OP_CMP_GE: |
| 107 | ret = (asm_ret.val >= cmparg); |
| 108 | break; |
| 109 | case FUTEX_OP_CMP_LE: |
| 110 | ret = (asm_ret.val <= cmparg); |
| 111 | break; |
| 112 | case FUTEX_OP_CMP_GT: |
| 113 | ret = (asm_ret.val > cmparg); |
| 114 | break; |
| 115 | default: |
| 116 | ret = -ENOSYS; |
| 117 | } |
| 118 | } |
| 119 | return ret; |
| 120 | } |
| 121 | |
| 122 | static inline int futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, |
| 123 | int newval) |
| 124 | { |
| 125 | struct __get_user asm_ret; |
| 126 | |
| 127 | if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) |
| 128 | return -EFAULT; |
| 129 | |
| 130 | asm_ret = futex_cmpxchg(uaddr, oldval, newval); |
| 131 | return asm_ret.err ? asm_ret.err : asm_ret.val; |
| 132 | } |
| 133 | |
| 134 | #endif /* !__ASSEMBLY__ */ |
| 135 | |
| 136 | #endif /* _ASM_TILE_FUTEX_H */ |