neorv32/sw/lib/source/neorv32_cpu_amo.c

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// #################################################################################################
// # << NEORV32: neorv32_amo.c - CPU Core - Atomic Memory Access Emulation Functions >> #
// # ********************************************************************************************* #
// # BSD 3-Clause License #
// # #
// # Copyright (c) 2023, Stephan Nolting. All rights reserved. #
// # #
// # Redistribution and use in source and binary forms, with or without modification, are #
// # permitted provided that the following conditions are met: #
// # #
// # 1. Redistributions of source code must retain the above copyright notice, this list of #
// # conditions and the following disclaimer. #
// # #
// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #
// # conditions and the following disclaimer in the documentation and/or other materials #
// # provided with the distribution. #
// # #
// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #
// # endorse or promote products derived from this software without specific prior written #
// # permission. #
// # #
// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS #
// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF #
// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE #
// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #
// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED #
// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING #
// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #
// # OF THE POSSIBILITY OF SUCH DAMAGE. #
// # ********************************************************************************************* #
// # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #
// #################################################################################################
/**********************************************************************//**
* @file neorv32_cpu_amo.c
* @brief Atomic memory access (read-modify-write) emulation functions using LR/SC pairs - source file.
**************************************************************************/
#include "neorv32.h"
#include "neorv32_cpu_amo.h"
/**********************************************************************//**
* MIN/MAX helpers.
**************************************************************************/
/**@{*/
static inline int32_t MAX(int32_t a, int32_t b) { return((a) > (b) ? a : b); }
static inline int32_t MIN(int32_t a, int32_t b) { return((a) < (b) ? a : b); }
static inline int32_t MAXU(uint32_t a, uint32_t b) { return((a) > (b) ? a : b); }
static inline int32_t MINU(uint32_t a, uint32_t b) { return((a) < (b) ? a : b); }
/**@}*/
/**********************************************************************//**
* Atomic SWAP (AMOSWAP.W).
* return <= MEM[addr]; MEM[addr] <= wdata
*
* @note This function requires the CPU A ISA extension.
*
* @param[in] addr 32-bit memory address, word-aligned.
* @param[in] wdata Data word to be atomically stored to address (32-bit).
* @return Pre-operation data loaded from address (32-bit)
**************************************************************************/
uint32_t neorv32_cpu_amoswapw(uint32_t addr, uint32_t wdata) {
uint32_t rdata;
uint32_t status;
while(1) {
rdata = neorv32_cpu_load_reservate_word(addr);
status = neorv32_cpu_store_conditional_word(addr, wdata);
if (status == 0) {
break;
}
}
return rdata;
}
/**********************************************************************//**
* Atomic ADD (AMOADD.W).
* return <= MEM[addr]; MEM[addr] <= MEM[addr] + wdata
*
* @note This function requires the CPU A ISA extension.
*
* @param[in] addr 32-bit memory address, word-aligned.
* @param[in] wdata Data word to be atomically added to original data at address (32-bit).
* @return Pre-operation data loaded from address (32-bit)
**************************************************************************/
uint32_t neorv32_cpu_amoaddw(uint32_t addr, uint32_t wdata) {
uint32_t rdata;
uint32_t tmp;
uint32_t status;
while(1) {
rdata = neorv32_cpu_load_reservate_word(addr);
tmp = rdata + wdata;
status = neorv32_cpu_store_conditional_word(addr, tmp);
if (status == 0) {
break;
}
}
return rdata;
}
/**********************************************************************//**
* Atomic AND (AMOAND.W).
* return <= MEM[addr]; MEM[addr] <= MEM[addr] and wdata
*
* @note This function requires the CPU A ISA extension.
*
* @param[in] addr 32-bit memory address, word-aligned.
* @param[in] wdata Data word to be atomically AND-ed with original data at address (32-bit).
* @return Pre-operation data loaded from address (32-bit)
**************************************************************************/
uint32_t neorv32_cpu_amoandw(uint32_t addr, uint32_t wdata) {
uint32_t rdata;
uint32_t tmp;
uint32_t status;
while(1) {
rdata = neorv32_cpu_load_reservate_word(addr);
tmp = rdata & wdata;
status = neorv32_cpu_store_conditional_word(addr, tmp);
if (status == 0) {
break;
}
}
return rdata;
}
/**********************************************************************//**
* Atomic OR (AMOOR.W).
* return <= MEM[addr]; MEM[addr] <= MEM[addr] or wdata
*
* @note This function requires the CPU A ISA extension.
*
* @param[in] addr 32-bit memory address, word-aligned.
* @param[in] wdata Data word to be atomically OR-ed with original data at address (32-bit).
* @return Pre-operation data loaded from address (32-bit)
**************************************************************************/
uint32_t neorv32_cpu_amoorw(uint32_t addr, uint32_t wdata) {
uint32_t rdata;
uint32_t tmp;
uint32_t status;
while(1) {
rdata = neorv32_cpu_load_reservate_word(addr);
tmp = rdata | wdata;
status = neorv32_cpu_store_conditional_word(addr, tmp);
if (status == 0) {
break;
}
}
return rdata;
}
/**********************************************************************//**
* Atomic XOR (AMOXOR.W).
* return <= MEM[addr]; MEM[addr] <= MEM[addr] xor wdata
*
* @note This function requires the CPU A ISA extension.
*
* @param[in] addr 32-bit memory address, word-aligned.
* @param[in] wdata Data word to be atomically XOR-ed with original data at address (32-bit).
* @return Pre-operation data loaded from address (32-bit)
**************************************************************************/
uint32_t neorv32_cpu_amoxorw(uint32_t addr, uint32_t wdata) {
uint32_t rdata;
uint32_t tmp;
uint32_t status;
while(1) {
rdata = neorv32_cpu_load_reservate_word(addr);
tmp = rdata ^ wdata;
status = neorv32_cpu_store_conditional_word(addr, tmp);
if (status == 0) {
break;
}
}
return rdata;
}
/**********************************************************************//**
* Atomic signed MAX (AMOMAX.W).
* return <= MEM[addr]; MEM[addr] <= maximum_signed(MEM[addr], wdata)
*
* @note This function requires the CPU A ISA extension.
*
* @param[in] addr 32-bit memory address, word-aligned.
* @param[in] wdata Data word to be atomically MAX-ed with original data at address (signed 32-bit).
* @return Pre-operation data loaded from address (signed 32-bit)
**************************************************************************/
int32_t neorv32_cpu_amomaxw(uint32_t addr, int32_t wdata) {
int32_t rdata;
int32_t tmp;
uint32_t status;
while(1) {
rdata = (int32_t)neorv32_cpu_load_reservate_word(addr);
tmp = MAX(rdata, wdata);
status = neorv32_cpu_store_conditional_word(addr, tmp);
if (status == 0) {
break;
}
}
return rdata;
}
/**********************************************************************//**
* Atomic unsigned MAX (AMOMAXU.W).
* return <= MEM[addr]; MEM[addr] <= maximum_unsigned(MEM[addr], wdata)
*
* @note This function requires the CPU A ISA extension.
*
* @param[in] addr 32-bit memory address, word-aligned.
* @param[in] wdata Data word to be atomically MAX-ed with original data at address (unsigned 32-bit).
* @return Pre-operation data loaded from address (unsigned 32-bit)
**************************************************************************/
uint32_t neorv32_cpu_amomaxuw(uint32_t addr, uint32_t wdata) {
uint32_t rdata;
uint32_t tmp;
uint32_t status;
while(1) {
rdata = (uint32_t)neorv32_cpu_load_reservate_word(addr);
tmp = MAXU(rdata, wdata);
status = neorv32_cpu_store_conditional_word(addr, tmp);
if (status == 0) {
break;
}
}
return rdata;
}
/**********************************************************************//**
* Atomic signed MIN (AMOMIN.W).
* return <= MEM[addr]; MEM[addr] <= minimum_signed(MEM[addr], wdata)
*
* @note This function requires the CPU A ISA extension.
*
* @param[in] addr 32-bit memory address, word-aligned.
* @param[in] wdata Data word to be atomically MIN-ed with original data at address (signed 32-bit).
* @return Pre-operation data loaded from address (signed 32-bit)
**************************************************************************/
int32_t neorv32_cpu_amominw(uint32_t addr, int32_t wdata) {
int32_t rdata;
int32_t tmp;
uint32_t status;
while(1) {
rdata = (int32_t)neorv32_cpu_load_reservate_word(addr);
tmp = MIN(rdata, wdata);
status = neorv32_cpu_store_conditional_word(addr, tmp);
if (status == 0) {
break;
}
}
return rdata;
}
/**********************************************************************//**
* Atomic unsigned MIN (AMOMINU.W).
* return <= MEM[addr]; MEM[addr] <= minimum_unsigned(MEM[addr], wdata)
*
* @note This function requires the CPU A ISA extension.
*
* @param[in] addr 32-bit memory address, word-aligned.
* @param[in] wdata Data word to be atomically MIN-ed with original data at address (unsigned 32-bit).
* @return Pre-operation data loaded from address (unsigned 32-bit)
**************************************************************************/
uint32_t neorv32_cpu_amominuw(uint32_t addr, uint32_t wdata) {
uint32_t rdata;
uint32_t tmp;
uint32_t status;
while(1) {
rdata = (uint32_t)neorv32_cpu_load_reservate_word(addr);
tmp = MINU(rdata, wdata);
status = neorv32_cpu_store_conditional_word(addr, tmp);
if (status == 0) {
break;
}
}
return rdata;
}