qemu/target-xtensa/cpu.c
Peter Maydell 2472b6c07b gdbstub: Allow target CPUs to specify watchpoint STOP_BEFORE_ACCESS flag
GDB assumes that watchpoint set via the gdbstub remote protocol will
behave in the same way as hardware watchpoints for the target. In
particular, whether the CPU stops with the PC before or after the insn
which triggers the watchpoint is target dependent. Allow guest CPU
code to specify which behaviour to use. This fixes a bug where with
guest CPUs which stop before the accessing insn GDB would manually
step forward over what it thought was the insn and end up one insn
further forward than it should be.

We set this flag for the CPU architectures which set
gdbarch_have_nonsteppable_watchpoint in gdb 7.7:
ARM, CRIS, LM32, MIPS and Xtensa.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Tested-by: Michael Walle <michael@walle.cc> (for lm32)
Message-id: 1410545057-14014-1-git-send-email-peter.maydell@linaro.org
2014-10-06 14:25:43 +01:00

175 lines
5.4 KiB
C

/*
* QEMU Xtensa CPU
*
* Copyright (c) 2011, Max Filippov, Open Source and Linux Lab.
* Copyright (c) 2012 SUSE LINUX Products GmbH
* 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 "cpu.h"
#include "qemu-common.h"
#include "migration/vmstate.h"
static void xtensa_cpu_set_pc(CPUState *cs, vaddr value)
{
XtensaCPU *cpu = XTENSA_CPU(cs);
cpu->env.pc = value;
}
static bool xtensa_cpu_has_work(CPUState *cs)
{
XtensaCPU *cpu = XTENSA_CPU(cs);
return cpu->env.pending_irq_level;
}
/* CPUClass::reset() */
static void xtensa_cpu_reset(CPUState *s)
{
XtensaCPU *cpu = XTENSA_CPU(s);
XtensaCPUClass *xcc = XTENSA_CPU_GET_CLASS(cpu);
CPUXtensaState *env = &cpu->env;
xcc->parent_reset(s);
env->exception_taken = 0;
env->pc = env->config->exception_vector[EXC_RESET];
env->sregs[LITBASE] &= ~1;
env->sregs[PS] = xtensa_option_enabled(env->config,
XTENSA_OPTION_INTERRUPT) ? 0x1f : 0x10;
env->sregs[VECBASE] = env->config->vecbase;
env->sregs[IBREAKENABLE] = 0;
env->sregs[CACHEATTR] = 0x22222222;
env->sregs[ATOMCTL] = xtensa_option_enabled(env->config,
XTENSA_OPTION_ATOMCTL) ? 0x28 : 0x15;
env->sregs[CONFIGID0] = env->config->configid[0];
env->sregs[CONFIGID1] = env->config->configid[1];
env->pending_irq_level = 0;
reset_mmu(env);
}
static ObjectClass *xtensa_cpu_class_by_name(const char *cpu_model)
{
ObjectClass *oc;
char *typename;
if (cpu_model == NULL) {
return NULL;
}
typename = g_strdup_printf("%s-" TYPE_XTENSA_CPU, cpu_model);
oc = object_class_by_name(typename);
g_free(typename);
if (oc == NULL || !object_class_dynamic_cast(oc, TYPE_XTENSA_CPU) ||
object_class_is_abstract(oc)) {
return NULL;
}
return oc;
}
static void xtensa_cpu_realizefn(DeviceState *dev, Error **errp)
{
CPUState *cs = CPU(dev);
XtensaCPUClass *xcc = XTENSA_CPU_GET_CLASS(dev);
cs->gdb_num_regs = xcc->config->gdb_regmap.num_regs;
qemu_init_vcpu(cs);
xcc->parent_realize(dev, errp);
}
static void xtensa_cpu_initfn(Object *obj)
{
CPUState *cs = CPU(obj);
XtensaCPU *cpu = XTENSA_CPU(obj);
XtensaCPUClass *xcc = XTENSA_CPU_GET_CLASS(obj);
CPUXtensaState *env = &cpu->env;
static bool tcg_inited;
cs->env_ptr = env;
env->config = xcc->config;
cpu_exec_init(env);
if (tcg_enabled() && !tcg_inited) {
tcg_inited = true;
xtensa_translate_init();
}
}
static const VMStateDescription vmstate_xtensa_cpu = {
.name = "cpu",
.unmigratable = 1,
};
static void xtensa_cpu_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
CPUClass *cc = CPU_CLASS(oc);
XtensaCPUClass *xcc = XTENSA_CPU_CLASS(cc);
xcc->parent_realize = dc->realize;
dc->realize = xtensa_cpu_realizefn;
xcc->parent_reset = cc->reset;
cc->reset = xtensa_cpu_reset;
cc->class_by_name = xtensa_cpu_class_by_name;
cc->has_work = xtensa_cpu_has_work;
cc->do_interrupt = xtensa_cpu_do_interrupt;
cc->cpu_exec_interrupt = xtensa_cpu_exec_interrupt;
cc->dump_state = xtensa_cpu_dump_state;
cc->set_pc = xtensa_cpu_set_pc;
cc->gdb_read_register = xtensa_cpu_gdb_read_register;
cc->gdb_write_register = xtensa_cpu_gdb_write_register;
cc->gdb_stop_before_watchpoint = true;
#ifndef CONFIG_USER_ONLY
cc->do_unaligned_access = xtensa_cpu_do_unaligned_access;
cc->get_phys_page_debug = xtensa_cpu_get_phys_page_debug;
#endif
cc->debug_excp_handler = xtensa_breakpoint_handler;
dc->vmsd = &vmstate_xtensa_cpu;
}
static const TypeInfo xtensa_cpu_type_info = {
.name = TYPE_XTENSA_CPU,
.parent = TYPE_CPU,
.instance_size = sizeof(XtensaCPU),
.instance_init = xtensa_cpu_initfn,
.abstract = true,
.class_size = sizeof(XtensaCPUClass),
.class_init = xtensa_cpu_class_init,
};
static void xtensa_cpu_register_types(void)
{
type_register_static(&xtensa_cpu_type_info);
}
type_init(xtensa_cpu_register_types)