qemu/target/xtensa/exc_helper.c
Max Filippov cb2d627a00 target/xtensa: don't generate extra EXCP_DEBUG on exception
target/xtensa used to generate an extra EXCP_DEBUG exception before the
first instruction executed after an interrupt or an exception is taken
to allow single-stepping that instruction in the debugger.
This is no longer needed after the following commits:
a7ba744f40 ("tcg/cpu-exec: precise single-stepping after an exception")
ba3c35d9c4 ("tcg/cpu-exec: precise single-stepping after an interrupt")
Drop exception state tracking/extra EXCP_DEBUG generation code.

Cc: qemu-stable@nongnu.org # v5.1, v5.2, v6.0
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2021-05-20 13:02:58 -07:00

273 lines
8.6 KiB
C

/*
* Copyright (c) 2011 - 2019, 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"
void HELPER(exception)(CPUXtensaState *env, uint32_t excp)
{
CPUState *cs = env_cpu(env);
cs->exception_index = excp;
if (excp == EXCP_YIELD) {
env->yield_needed = 0;
}
cpu_loop_exit(cs);
}
void HELPER(exception_cause)(CPUXtensaState *env, uint32_t pc, uint32_t cause)
{
uint32_t vector;
env->pc = pc;
if (env->sregs[PS] & PS_EXCM) {
if (env->config->ndepc) {
env->sregs[DEPC] = pc;
} else {
env->sregs[EPC1] = pc;
}
vector = EXC_DOUBLE;
} else {
env->sregs[EPC1] = pc;
vector = (env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;
}
env->sregs[EXCCAUSE] = cause;
env->sregs[PS] |= PS_EXCM;
HELPER(exception)(env, vector);
}
void HELPER(exception_cause_vaddr)(CPUXtensaState *env,
uint32_t pc, uint32_t cause, uint32_t vaddr)
{
env->sregs[EXCVADDR] = vaddr;
HELPER(exception_cause)(env, pc, cause);
}
void debug_exception_env(CPUXtensaState *env, uint32_t cause)
{
if (xtensa_get_cintlevel(env) < env->config->debug_level) {
HELPER(debug_exception)(env, env->pc, cause);
}
}
void HELPER(debug_exception)(CPUXtensaState *env, uint32_t pc, uint32_t cause)
{
unsigned level = env->config->debug_level;
env->pc = pc;
env->sregs[DEBUGCAUSE] = cause;
env->sregs[EPC1 + level - 1] = pc;
env->sregs[EPS2 + level - 2] = env->sregs[PS];
env->sregs[PS] = (env->sregs[PS] & ~PS_INTLEVEL) | PS_EXCM |
(level << PS_INTLEVEL_SHIFT);
HELPER(exception)(env, EXC_DEBUG);
}
#ifndef CONFIG_USER_ONLY
void HELPER(waiti)(CPUXtensaState *env, uint32_t pc, uint32_t intlevel)
{
CPUState *cpu = env_cpu(env);
env->pc = pc;
env->sregs[PS] = (env->sregs[PS] & ~PS_INTLEVEL) |
(intlevel << PS_INTLEVEL_SHIFT);
qemu_mutex_lock_iothread();
check_interrupts(env);
qemu_mutex_unlock_iothread();
if (env->pending_irq_level) {
cpu_loop_exit(cpu);
return;
}
cpu->halted = 1;
HELPER(exception)(env, EXCP_HLT);
}
void HELPER(check_interrupts)(CPUXtensaState *env)
{
qemu_mutex_lock_iothread();
check_interrupts(env);
qemu_mutex_unlock_iothread();
}
void HELPER(intset)(CPUXtensaState *env, uint32_t v)
{
qatomic_or(&env->sregs[INTSET],
v & env->config->inttype_mask[INTTYPE_SOFTWARE]);
}
static void intclear(CPUXtensaState *env, uint32_t v)
{
qatomic_and(&env->sregs[INTSET], ~v);
}
void HELPER(intclear)(CPUXtensaState *env, uint32_t v)
{
intclear(env, v & (env->config->inttype_mask[INTTYPE_SOFTWARE] |
env->config->inttype_mask[INTTYPE_EDGE]));
}
static uint32_t relocated_vector(CPUXtensaState *env, uint32_t vector)
{
if (xtensa_option_enabled(env->config,
XTENSA_OPTION_RELOCATABLE_VECTOR)) {
return vector - env->config->vecbase + env->sregs[VECBASE];
} else {
return vector;
}
}
/*!
* Handle penging IRQ.
* For the high priority interrupt jump to the corresponding interrupt vector.
* For the level-1 interrupt convert it to either user, kernel or double
* exception with the 'level-1 interrupt' exception cause.
*/
static void handle_interrupt(CPUXtensaState *env)
{
int level = env->pending_irq_level;
if ((level > xtensa_get_cintlevel(env) &&
level <= env->config->nlevel &&
(env->config->level_mask[level] &
env->sregs[INTSET] & env->sregs[INTENABLE])) ||
level == env->config->nmi_level) {
CPUState *cs = env_cpu(env);
if (level > 1) {
env->sregs[EPC1 + level - 1] = env->pc;
env->sregs[EPS2 + level - 2] = env->sregs[PS];
env->sregs[PS] =
(env->sregs[PS] & ~PS_INTLEVEL) | level | PS_EXCM;
env->pc = relocated_vector(env,
env->config->interrupt_vector[level]);
if (level == env->config->nmi_level) {
intclear(env, env->config->inttype_mask[INTTYPE_NMI]);
}
} else {
env->sregs[EXCCAUSE] = LEVEL1_INTERRUPT_CAUSE;
if (env->sregs[PS] & PS_EXCM) {
if (env->config->ndepc) {
env->sregs[DEPC] = env->pc;
} else {
env->sregs[EPC1] = env->pc;
}
cs->exception_index = EXC_DOUBLE;
} else {
env->sregs[EPC1] = env->pc;
cs->exception_index =
(env->sregs[PS] & PS_UM) ? EXC_USER : EXC_KERNEL;
}
env->sregs[PS] |= PS_EXCM;
}
}
}
/* Called from cpu_handle_interrupt with BQL held */
void xtensa_cpu_do_interrupt(CPUState *cs)
{
XtensaCPU *cpu = XTENSA_CPU(cs);
CPUXtensaState *env = &cpu->env;
if (cs->exception_index == EXC_IRQ) {
qemu_log_mask(CPU_LOG_INT,
"%s(EXC_IRQ) level = %d, cintlevel = %d, "
"pc = %08x, a0 = %08x, ps = %08x, "
"intset = %08x, intenable = %08x, "
"ccount = %08x\n",
__func__, env->pending_irq_level,
xtensa_get_cintlevel(env),
env->pc, env->regs[0], env->sregs[PS],
env->sregs[INTSET], env->sregs[INTENABLE],
env->sregs[CCOUNT]);
handle_interrupt(env);
}
switch (cs->exception_index) {
case EXC_WINDOW_OVERFLOW4:
case EXC_WINDOW_UNDERFLOW4:
case EXC_WINDOW_OVERFLOW8:
case EXC_WINDOW_UNDERFLOW8:
case EXC_WINDOW_OVERFLOW12:
case EXC_WINDOW_UNDERFLOW12:
case EXC_KERNEL:
case EXC_USER:
case EXC_DOUBLE:
case EXC_DEBUG:
qemu_log_mask(CPU_LOG_INT, "%s(%d) "
"pc = %08x, a0 = %08x, ps = %08x, ccount = %08x\n",
__func__, cs->exception_index,
env->pc, env->regs[0], env->sregs[PS],
env->sregs[CCOUNT]);
if (env->config->exception_vector[cs->exception_index]) {
uint32_t vector;
vector = env->config->exception_vector[cs->exception_index];
env->pc = relocated_vector(env, vector);
} else {
qemu_log_mask(CPU_LOG_INT,
"%s(pc = %08x) bad exception_index: %d\n",
__func__, env->pc, cs->exception_index);
}
break;
case EXC_IRQ:
break;
default:
qemu_log("%s(pc = %08x) unknown exception_index: %d\n",
__func__, env->pc, cs->exception_index);
break;
}
check_interrupts(env);
}
#else
void xtensa_cpu_do_interrupt(CPUState *cs)
{
}
#endif
bool xtensa_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
{
if (interrupt_request & CPU_INTERRUPT_HARD) {
cs->exception_index = EXC_IRQ;
xtensa_cpu_do_interrupt(cs);
return true;
}
return false;
}