| /**************************************************************************** |
| * arch/arm/src/common/gnu/arm_fetchadd.S |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. The |
| * ASF licenses this file to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance with the |
| * License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations |
| * under the License. |
| * |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Included Files |
| ****************************************************************************/ |
| |
| #include <nuttx/config.h> |
| |
| .syntax unified |
| .file "arm_fetchadd.S" |
| |
| /**************************************************************************** |
| * Public Functions |
| ****************************************************************************/ |
| |
| .text |
| |
| /**************************************************************************** |
| * Name: up_fetchadd32 |
| * |
| * Description: |
| * Perform an atomic fetch add operation on the provided 32-bit value. |
| * |
| * This function must be provided via the architecture-specific logic. |
| * |
| * Input Parameters: |
| * addr - The address of 32-bit value to be incremented. |
| * value - The 32-bit addend |
| * |
| * Returned Value: |
| * The incremented value (volatile!) |
| * |
| ****************************************************************************/ |
| |
| .globl up_fetchadd32 |
| .type up_fetchadd32, %function |
| |
| up_fetchadd32: |
| |
| 1: |
| ldrex r2, [r0] /* Fetch the value to be incremented */ |
| add r2, r2, r1 /* Add the addend */ |
| |
| strex r3, r2, [r0] /* Attempt to save the result */ |
| teq r3, #0 /* r3 will be 1 if strex failed */ |
| bne 1b /* Failed to lock... try again */ |
| |
| mov r0, r2 /* Return the incremented value */ |
| bx lr /* Successful! */ |
| .size up_fetchadd32, . - up_fetchadd32 |
| |
| /**************************************************************************** |
| * Name: up_fetchsub32 |
| * |
| * Description: |
| * Perform an atomic fetch subtract operation on the provided 32-bit value. |
| * |
| * This function must be provided via the architecture-specific logic. |
| * |
| * Input Parameters: |
| * addr - The address of 32-bit value to be decremented. |
| * value - The 32-bit subtrahend |
| * |
| * Returned Value: |
| * The decremented value (volatile!) |
| * |
| ****************************************************************************/ |
| |
| .globl up_fetchsub32 |
| .type up_fetchsub32, %function |
| |
| up_fetchsub32: |
| |
| 1: |
| ldrex r2, [r0] /* Fetch the value to be decremented */ |
| sub r2, r2, r1 /* Subtract the subtrahend */ |
| |
| strex r3, r2, [r0] /* Attempt to save the result */ |
| teq r3, #0 /* r3 will be 1 if strex failed */ |
| bne 1b /* Failed to lock... try again */ |
| |
| mov r0, r2 /* Return the decremented value */ |
| bx lr /* Successful! */ |
| .size up_fetchsub32, . - up_fetchsub32 |
| |
| /**************************************************************************** |
| * Name: up_fetchadd16 |
| * |
| * Description: |
| * Perform an atomic fetch add operation on the provided 16-bit value. |
| * |
| * This function must be provided via the architecture-specific logic. |
| * |
| * Input Parameters: |
| * addr - The address of 16-bit value to be incremented. |
| * value - The 16-bit addend |
| * |
| * Returned Value: |
| * The incremented value (volatile!) |
| * |
| ****************************************************************************/ |
| |
| .globl up_fetchadd16 |
| .type up_fetchadd16, %function |
| |
| up_fetchadd16: |
| |
| 1: |
| ldrexh r2, [r0] /* Fetch the value to be incremented */ |
| add r2, r2, r1 /* Add the addend */ |
| |
| strexh r3, r2, [r0] /* Attempt to save the result */ |
| teq r3, #0 /* r3 will be 1 if strexh failed */ |
| bne 1b /* Failed to lock... try again */ |
| |
| mov r0, r2 /* Return the incremented value */ |
| bx lr /* Successful! */ |
| .size up_fetchadd16, . - up_fetchadd16 |
| |
| /**************************************************************************** |
| * Name: up_fetchsub16 |
| * |
| * Description: |
| * Perform an atomic fetch subtract operation on the provided 16-bit value. |
| * |
| * This function must be provided via the architecture-specific logic. |
| * |
| * Input Parameters: |
| * addr - The address of 16-bit value to be decremented. |
| * value - The 16-bit subtrahend |
| * |
| * Returned Value: |
| * The decremented value (volatile!) |
| * |
| ****************************************************************************/ |
| |
| .globl up_fetchsub16 |
| .type up_fetchsub16, %function |
| |
| up_fetchsub16: |
| |
| 1: |
| ldrexh r2, [r0] /* Fetch the value to be decremented */ |
| sub r2, r2, r1 /* Subtract the subtrahend */ |
| |
| /* Attempt to save the decremented value */ |
| |
| strexh r3, r2, [r0] /* Attempt to save the result */ |
| teq r3, #0 /* r3 will be 1 if strexh failed */ |
| bne 1b /* Failed to lock... try again */ |
| |
| mov r0, r2 /* Return the decremented value */ |
| bx lr /* Successful! */ |
| .size up_fetchsub16, . - up_fetchsub16 |
| |
| /**************************************************************************** |
| * Name: up_fetchadd8 |
| * |
| * Description: |
| * Perform an atomic fetch add operation on the provided 8-bit value. |
| * |
| * This function must be provided via the architecture-specific logic. |
| * |
| * Input Parameters: |
| * addr - The address of 8-bit value to be incremented. |
| * value - The 8-bit addend |
| * |
| * Returned Value: |
| * The incremented value (volatile!) |
| * |
| ****************************************************************************/ |
| |
| .globl up_fetchadd8 |
| .type up_fetchadd8, %function |
| |
| up_fetchadd8: |
| |
| 1: |
| ldrexb r2, [r0] /* Fetch the value to be incremented */ |
| add r2, r2, r1 /* Add the addend */ |
| |
| strexb r3, r2, [r0] /* Attempt to save the result */ |
| teq r3, #0 /* r3 will be 1 if strexb failed */ |
| bne 1b /* Failed to lock... try again */ |
| |
| mov r0, r2 /* Return the incremented value */ |
| bx lr /* Successful! */ |
| .size up_fetchadd8, . - up_fetchadd8 |
| |
| /**************************************************************************** |
| * Name: up_fetchsub8 |
| * |
| * Description: |
| * Perform an atomic fetch subtract operation on the provided 8-bit value. |
| * |
| * This function must be provided via the architecture-specific logic. |
| * |
| * Input Parameters: |
| * addr - The address of 8-bit value to be decremented. |
| * value - The 8-bit subtrahend |
| * |
| * Returned Value: |
| * The decremented value (volatile!) |
| * |
| ****************************************************************************/ |
| |
| .globl up_fetchsub8 |
| .type up_fetchsub8, %function |
| |
| up_fetchsub8: |
| |
| 1: |
| ldrexb r2, [r0] /* Fetch the value to be decremented */ |
| sub r2, r2, r1 /* Subtract the subtrahend */ |
| |
| strexb r3, r2, [r0] /* Attempt to save the result */ |
| teq r3, #0 /* r3 will be 1 if strexb failed */ |
| bne 1b /* Failed to lock... try again */ |
| |
| mov r0, r2 /* Return the decremented value */ |
| bx lr /* Successful! */ |
| .size up_fetchsub8, . - up_fetchsub8 |
| .end |
