| Akira Takeuchi | 368dd5a | 2010-10-27 17:28:55 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Helpers used by both rw spinlocks and rw semaphores. |
| 3 | * |
| 4 | * Based in part on code from semaphore.h and |
| 5 | * spinlock.h Copyright 1996 Linus Torvalds. |
| 6 | * |
| 7 | * Copyright 1999 Red Hat, Inc. |
| 8 | * |
| 9 | * Written by Benjamin LaHaise. |
| 10 | * |
| 11 | * Modified by Matsushita Electric Industrial Co., Ltd. |
| 12 | * Modifications: |
| 13 | * 13-Nov-2006 MEI Temporarily delete lock functions for SMP support. |
| 14 | * |
| 15 | * This program is free software; you can redistribute it and/or modify it |
| 16 | * under the terms of the GNU General Public License as published by the Free |
| 17 | * Software Foundation; either version 2 of the License, or (at your option) |
| 18 | * any later version. |
| 19 | */ |
| 20 | #ifndef _ASM_RWLOCK_H |
| 21 | #define _ASM_RWLOCK_H |
| 22 | |
| 23 | #define RW_LOCK_BIAS 0x01000000 |
| 24 | |
| 25 | #ifndef CONFIG_SMP |
| 26 | |
| 27 | typedef struct { unsigned long a[100]; } __dummy_lock_t; |
| 28 | #define __dummy_lock(lock) (*(__dummy_lock_t *)(lock)) |
| 29 | |
| 30 | #define RW_LOCK_BIAS_STR "0x01000000" |
| 31 | |
| 32 | #define __build_read_lock_ptr(rw, helper) \ |
| 33 | do { \ |
| 34 | asm volatile( \ |
| 35 | " mov (%0),d3 \n" \ |
| 36 | " sub 1,d3 \n" \ |
| 37 | " mov d3,(%0) \n" \ |
| 38 | " blt 1f \n" \ |
| 39 | " bra 2f \n" \ |
| 40 | "1: jmp 3f \n" \ |
| 41 | "2: \n" \ |
| 42 | " .section .text.lock,\"ax\" \n" \ |
| 43 | "3: call "helper"[],0 \n" \ |
| 44 | " jmp 2b \n" \ |
| 45 | " .previous" \ |
| 46 | : \ |
| 47 | : "d" (rw) \ |
| 48 | : "memory", "d3", "cc"); \ |
| 49 | } while (0) |
| 50 | |
| 51 | #define __build_read_lock_const(rw, helper) \ |
| 52 | do { \ |
| 53 | asm volatile( \ |
| 54 | " mov (%0),d3 \n" \ |
| 55 | " sub 1,d3 \n" \ |
| 56 | " mov d3,(%0) \n" \ |
| 57 | " blt 1f \n" \ |
| 58 | " bra 2f \n" \ |
| 59 | "1: jmp 3f \n" \ |
| 60 | "2: \n" \ |
| 61 | " .section .text.lock,\"ax\" \n" \ |
| 62 | "3: call "helper"[],0 \n" \ |
| 63 | " jmp 2b \n" \ |
| 64 | " .previous" \ |
| 65 | : \ |
| 66 | : "d" (rw) \ |
| 67 | : "memory", "d3", "cc"); \ |
| 68 | } while (0) |
| 69 | |
| 70 | #define __build_read_lock(rw, helper) \ |
| 71 | do { \ |
| 72 | if (__builtin_constant_p(rw)) \ |
| 73 | __build_read_lock_const(rw, helper); \ |
| 74 | else \ |
| 75 | __build_read_lock_ptr(rw, helper); \ |
| 76 | } while (0) |
| 77 | |
| 78 | #define __build_write_lock_ptr(rw, helper) \ |
| 79 | do { \ |
| 80 | asm volatile( \ |
| 81 | " mov (%0),d3 \n" \ |
| 82 | " sub 1,d3 \n" \ |
| 83 | " mov d3,(%0) \n" \ |
| 84 | " blt 1f \n" \ |
| 85 | " bra 2f \n" \ |
| 86 | "1: jmp 3f \n" \ |
| 87 | "2: \n" \ |
| 88 | " .section .text.lock,\"ax\" \n" \ |
| 89 | "3: call "helper"[],0 \n" \ |
| 90 | " jmp 2b \n" \ |
| 91 | " .previous" \ |
| 92 | : \ |
| 93 | : "d" (rw) \ |
| 94 | : "memory", "d3", "cc"); \ |
| 95 | } while (0) |
| 96 | |
| 97 | #define __build_write_lock_const(rw, helper) \ |
| 98 | do { \ |
| 99 | asm volatile( \ |
| 100 | " mov (%0),d3 \n" \ |
| 101 | " sub 1,d3 \n" \ |
| 102 | " mov d3,(%0) \n" \ |
| 103 | " blt 1f \n" \ |
| 104 | " bra 2f \n" \ |
| 105 | "1: jmp 3f \n" \ |
| 106 | "2: \n" \ |
| 107 | " .section .text.lock,\"ax\" \n" \ |
| 108 | "3: call "helper"[],0 \n" \ |
| 109 | " jmp 2b \n" \ |
| 110 | " .previous" \ |
| 111 | : \ |
| 112 | : "d" (rw) \ |
| 113 | : "memory", "d3", "cc"); \ |
| 114 | } while (0) |
| 115 | |
| 116 | #define __build_write_lock(rw, helper) \ |
| 117 | do { \ |
| 118 | if (__builtin_constant_p(rw)) \ |
| 119 | __build_write_lock_const(rw, helper); \ |
| 120 | else \ |
| 121 | __build_write_lock_ptr(rw, helper); \ |
| 122 | } while (0) |
| 123 | |
| 124 | #endif /* CONFIG_SMP */ |
| 125 | #endif /* _ASM_RWLOCK_H */ |