1/* 2 * Copyright 2013, winocm. <winocm@icloud.com> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without modification, 6 * are permitted provided that the following conditions are met: 7 * 8 * Redistributions of source code must retain the above copyright notice, this 9 * list of conditions and the following disclaimer. 10 * 11 * Redistributions in binary form must reproduce the above copyright notice, this 12 * list of conditions and the following disclaimer in the documentation and/or 13 * other materials provided with the distribution. 14 * 15 * If you are going to use this software in any form that does not involve 16 * releasing the source to this project or improving it, let me know beforehand. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 21 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR 22 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 25 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 27 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29/* 30 * ARM atomic hardware functions. 31 */ 32 33#include <arm/arch.h> 34#include <arm/asm_help.h> 35 36#if defined(BOARD_CONFIG_OMAP3530) || defined(BOARD_CONFIG_OMAP335X) 37//#define ldrex ldr 38#endif 39 40/** 41 * hw_compare_and_store 42 * 43 * Take the value in the destination, compare it to the old value, if equal 44 * atomically write the new value to the address. 45 */ 46EnterARM(hw_compare_and_store) 47EnterARM(OSCompareAndSwap) 48 mov r12, r0 49loop: 50 ldrex r3, [r2] 51 mov r0, #0 52 cmp r3, r12 53 bxne lr 54 strex r0, r1, [r2] 55 eors r0, r0, #1 56 bxne lr 57 b loop 58 59/* 60 * Atomic functions 61 */ 62 AtomicMachine(sub, sub) 63 AtomicMachine(add, add) 64 AtomicMachine(and_noret, and) 65 AtomicMachine(or_noret, orr) 66