qemu/target/xtensa/op_helper.c
Max Filippov b345e14053 target/xtensa: implement exclusive access option
The Exclusive Instructions provide a general-purpose mechanism for
atomic updates of memory-based synchronization variables that can be
used for exclusion algorithms.

Use cmpxchg-based implementation that is sufficient for the typical use
of exclusive access in atomic operations.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2019-05-15 10:31:52 -07:00

218 lines
7.0 KiB
C

/*
* Copyright (c) 2011, Max Filippov, Open Source and Linux Lab.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of the Open Source and Linux Lab 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 AUTHOR 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.
*/
#include "qemu/osdep.h"
#include "qemu/main-loop.h"
#include "cpu.h"
#include "exec/helper-proto.h"
#include "qemu/host-utils.h"
#include "exec/exec-all.h"
#include "exec/cpu_ldst.h"
#include "exec/address-spaces.h"
#include "qemu/timer.h"
#ifndef CONFIG_USER_ONLY
void HELPER(update_ccount)(CPUXtensaState *env)
{
uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
env->ccount_time = now;
env->sregs[CCOUNT] = env->ccount_base +
(uint32_t)((now - env->time_base) *
env->config->clock_freq_khz / 1000000);
}
void HELPER(wsr_ccount)(CPUXtensaState *env, uint32_t v)
{
int i;
HELPER(update_ccount)(env);
env->ccount_base += v - env->sregs[CCOUNT];
for (i = 0; i < env->config->nccompare; ++i) {
HELPER(update_ccompare)(env, i);
}
}
void HELPER(update_ccompare)(CPUXtensaState *env, uint32_t i)
{
uint64_t dcc;
atomic_and(&env->sregs[INTSET],
~(1u << env->config->timerint[i]));
HELPER(update_ccount)(env);
dcc = (uint64_t)(env->sregs[CCOMPARE + i] - env->sregs[CCOUNT] - 1) + 1;
timer_mod(env->ccompare[i].timer,
env->ccount_time + (dcc * 1000000) / env->config->clock_freq_khz);
env->yield_needed = 1;
}
/*!
* Check vaddr accessibility/cache attributes and raise an exception if
* specified by the ATOMCTL SR.
*
* Note: local memory exclusion is not implemented
*/
void HELPER(check_atomctl)(CPUXtensaState *env, uint32_t pc, uint32_t vaddr)
{
uint32_t paddr, page_size, access;
uint32_t atomctl = env->sregs[ATOMCTL];
int rc = xtensa_get_physical_addr(env, true, vaddr, 1,
xtensa_get_cring(env), &paddr, &page_size, &access);
/*
* s32c1i never causes LOAD_PROHIBITED_CAUSE exceptions,
* see opcode description in the ISA
*/
if (rc == 0 &&
(access & (PAGE_READ | PAGE_WRITE)) != (PAGE_READ | PAGE_WRITE)) {
rc = STORE_PROHIBITED_CAUSE;
}
if (rc) {
HELPER(exception_cause_vaddr)(env, pc, rc, vaddr);
}
/*
* When data cache is not configured use ATOMCTL bypass field.
* See ISA, 4.3.12.4 The Atomic Operation Control Register (ATOMCTL)
* under the Conditional Store Option.
*/
if (!xtensa_option_enabled(env->config, XTENSA_OPTION_DCACHE)) {
access = PAGE_CACHE_BYPASS;
}
switch (access & PAGE_CACHE_MASK) {
case PAGE_CACHE_WB:
atomctl >>= 2;
/* fall through */
case PAGE_CACHE_WT:
atomctl >>= 2;
/* fall through */
case PAGE_CACHE_BYPASS:
if ((atomctl & 0x3) == 0) {
HELPER(exception_cause_vaddr)(env, pc,
LOAD_STORE_ERROR_CAUSE, vaddr);
}
break;
case PAGE_CACHE_ISOLATE:
HELPER(exception_cause_vaddr)(env, pc,
LOAD_STORE_ERROR_CAUSE, vaddr);
break;
default:
break;
}
}
void HELPER(check_exclusive)(CPUXtensaState *env, uint32_t pc, uint32_t vaddr,
uint32_t is_write)
{
uint32_t paddr, page_size, access;
uint32_t atomctl = env->sregs[ATOMCTL];
int rc = xtensa_get_physical_addr(env, true, vaddr, is_write,
xtensa_get_cring(env), &paddr,
&page_size, &access);
if (rc) {
HELPER(exception_cause_vaddr)(env, pc, rc, vaddr);
}
/* When data cache is not configured use ATOMCTL bypass field. */
if (!xtensa_option_enabled(env->config, XTENSA_OPTION_DCACHE)) {
access = PAGE_CACHE_BYPASS;
}
switch (access & PAGE_CACHE_MASK) {
case PAGE_CACHE_WB:
atomctl >>= 2;
/* fall through */
case PAGE_CACHE_WT:
atomctl >>= 2;
/* fall through */
case PAGE_CACHE_BYPASS:
if ((atomctl & 0x3) == 0) {
HELPER(exception_cause_vaddr)(env, pc,
EXCLUSIVE_ERROR_CAUSE, vaddr);
}
break;
case PAGE_CACHE_ISOLATE:
HELPER(exception_cause_vaddr)(env, pc,
LOAD_STORE_ERROR_CAUSE, vaddr);
break;
default:
break;
}
}
void HELPER(wsr_memctl)(CPUXtensaState *env, uint32_t v)
{
if (xtensa_option_enabled(env->config, XTENSA_OPTION_ICACHE)) {
if (extract32(v, MEMCTL_IUSEWAYS_SHIFT, MEMCTL_IUSEWAYS_LEN) >
env->config->icache_ways) {
deposit32(v, MEMCTL_IUSEWAYS_SHIFT, MEMCTL_IUSEWAYS_LEN,
env->config->icache_ways);
}
}
if (xtensa_option_enabled(env->config, XTENSA_OPTION_DCACHE)) {
if (extract32(v, MEMCTL_DUSEWAYS_SHIFT, MEMCTL_DUSEWAYS_LEN) >
env->config->dcache_ways) {
deposit32(v, MEMCTL_DUSEWAYS_SHIFT, MEMCTL_DUSEWAYS_LEN,
env->config->dcache_ways);
}
if (extract32(v, MEMCTL_DALLOCWAYS_SHIFT, MEMCTL_DALLOCWAYS_LEN) >
env->config->dcache_ways) {
deposit32(v, MEMCTL_DALLOCWAYS_SHIFT, MEMCTL_DALLOCWAYS_LEN,
env->config->dcache_ways);
}
}
env->sregs[MEMCTL] = v & env->config->memctl_mask;
}
#endif
uint32_t HELPER(rer)(CPUXtensaState *env, uint32_t addr)
{
#ifndef CONFIG_USER_ONLY
return address_space_ldl(env->address_space_er, addr,
MEMTXATTRS_UNSPECIFIED, NULL);
#else
return 0;
#endif
}
void HELPER(wer)(CPUXtensaState *env, uint32_t data, uint32_t addr)
{
#ifndef CONFIG_USER_ONLY
address_space_stl(env->address_space_er, addr, data,
MEMTXATTRS_UNSPECIFIED, NULL);
#endif
}