Projet_SETI_RISC-V/riscv-gnu-toolchain/qemu/target/nios2/cpu.c
2023-03-06 14:48:14 +01:00

389 lines
10 KiB
C

/*
* QEMU Nios II CPU
*
* Copyright (c) 2012 Chris Wulff <crwulff@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see
* <http://www.gnu.org/licenses/lgpl-2.1.html>
*/
#include "qemu/osdep.h"
#include "qemu/module.h"
#include "qapi/error.h"
#include "cpu.h"
#include "exec/log.h"
#include "exec/gdbstub.h"
#include "hw/qdev-properties.h"
static void nios2_cpu_set_pc(CPUState *cs, vaddr value)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
CPUNios2State *env = &cpu->env;
env->pc = value;
}
static bool nios2_cpu_has_work(CPUState *cs)
{
return cs->interrupt_request & CPU_INTERRUPT_HARD;
}
static void nios2_cpu_reset(DeviceState *dev)
{
CPUState *cs = CPU(dev);
Nios2CPU *cpu = NIOS2_CPU(cs);
Nios2CPUClass *ncc = NIOS2_CPU_GET_CLASS(cpu);
CPUNios2State *env = &cpu->env;
ncc->parent_reset(dev);
memset(env->ctrl, 0, sizeof(env->ctrl));
env->pc = cpu->reset_addr;
#if defined(CONFIG_USER_ONLY)
/* Start in user mode with interrupts enabled. */
env->ctrl[CR_STATUS] = CR_STATUS_RSIE | CR_STATUS_U | CR_STATUS_PIE;
memset(env->regs, 0, sizeof(env->regs));
#else
env->ctrl[CR_STATUS] = CR_STATUS_RSIE;
nios2_update_crs(env);
memset(env->shadow_regs, 0, sizeof(env->shadow_regs));
#endif
}
#ifndef CONFIG_USER_ONLY
static void eic_set_irq(void *opaque, int irq, int level)
{
Nios2CPU *cpu = opaque;
CPUState *cs = CPU(cpu);
if (level) {
cpu_interrupt(cs, CPU_INTERRUPT_HARD);
} else {
cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
}
}
static void iic_set_irq(void *opaque, int irq, int level)
{
Nios2CPU *cpu = opaque;
CPUNios2State *env = &cpu->env;
CPUState *cs = CPU(cpu);
env->ctrl[CR_IPENDING] = deposit32(env->ctrl[CR_IPENDING], irq, 1, !!level);
if (env->ctrl[CR_IPENDING]) {
cpu_interrupt(cs, CPU_INTERRUPT_HARD);
} else {
cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
}
}
#endif
static void nios2_cpu_initfn(Object *obj)
{
Nios2CPU *cpu = NIOS2_CPU(obj);
cpu_set_cpustate_pointers(cpu);
#if !defined(CONFIG_USER_ONLY)
mmu_init(&cpu->env);
#endif
}
static ObjectClass *nios2_cpu_class_by_name(const char *cpu_model)
{
return object_class_by_name(TYPE_NIOS2_CPU);
}
static void realize_cr_status(CPUState *cs)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
/* Begin with all fields of all registers are reserved. */
memset(cpu->cr_state, 0, sizeof(cpu->cr_state));
/*
* The combination of writable and readonly is the set of all
* non-reserved fields. We apply writable as a mask to bits,
* and merge in existing readonly bits, before storing.
*/
#define WR_REG(C) cpu->cr_state[C].writable = -1
#define RO_REG(C) cpu->cr_state[C].readonly = -1
#define WR_FIELD(C, F) cpu->cr_state[C].writable |= R_##C##_##F##_MASK
#define RO_FIELD(C, F) cpu->cr_state[C].readonly |= R_##C##_##F##_MASK
WR_FIELD(CR_STATUS, PIE);
WR_REG(CR_ESTATUS);
WR_REG(CR_BSTATUS);
RO_REG(CR_CPUID);
RO_REG(CR_EXCEPTION);
WR_REG(CR_BADADDR);
if (cpu->eic_present) {
WR_FIELD(CR_STATUS, RSIE);
RO_FIELD(CR_STATUS, NMI);
WR_FIELD(CR_STATUS, PRS);
RO_FIELD(CR_STATUS, CRS);
WR_FIELD(CR_STATUS, IL);
WR_FIELD(CR_STATUS, IH);
} else {
RO_FIELD(CR_STATUS, RSIE);
WR_REG(CR_IENABLE);
RO_REG(CR_IPENDING);
}
if (cpu->mmu_present) {
WR_FIELD(CR_STATUS, U);
WR_FIELD(CR_STATUS, EH);
WR_FIELD(CR_PTEADDR, VPN);
WR_FIELD(CR_PTEADDR, PTBASE);
RO_FIELD(CR_TLBMISC, D);
RO_FIELD(CR_TLBMISC, PERM);
RO_FIELD(CR_TLBMISC, BAD);
RO_FIELD(CR_TLBMISC, DBL);
WR_FIELD(CR_TLBMISC, PID);
WR_FIELD(CR_TLBMISC, WE);
WR_FIELD(CR_TLBMISC, RD);
WR_FIELD(CR_TLBMISC, WAY);
WR_REG(CR_TLBACC);
}
/*
* TODO: ECC (config, eccinj) and MPU (config, mpubase, mpuacc) are
* unimplemented, so their corresponding control regs remain reserved.
*/
#undef WR_REG
#undef RO_REG
#undef WR_FIELD
#undef RO_FIELD
}
static void nios2_cpu_realizefn(DeviceState *dev, Error **errp)
{
CPUState *cs = CPU(dev);
Nios2CPU *cpu = NIOS2_CPU(cs);
Nios2CPUClass *ncc = NIOS2_CPU_GET_CLASS(dev);
Error *local_err = NULL;
#ifndef CONFIG_USER_ONLY
if (cpu->eic_present) {
qdev_init_gpio_in_named(DEVICE(cpu), eic_set_irq, "EIC", 1);
} else {
qdev_init_gpio_in_named(DEVICE(cpu), iic_set_irq, "IRQ", 32);
}
#endif
cpu_exec_realizefn(cs, &local_err);
if (local_err != NULL) {
error_propagate(errp, local_err);
return;
}
realize_cr_status(cs);
qemu_init_vcpu(cs);
cpu_reset(cs);
/* We have reserved storage for cpuid; might as well use it. */
cpu->env.ctrl[CR_CPUID] = cs->cpu_index;
ncc->parent_realize(dev, errp);
}
#ifndef CONFIG_USER_ONLY
static bool eic_take_interrupt(Nios2CPU *cpu)
{
CPUNios2State *env = &cpu->env;
const uint32_t status = env->ctrl[CR_STATUS];
if (cpu->rnmi) {
return !(status & CR_STATUS_NMI);
}
if (!(status & CR_STATUS_PIE)) {
return false;
}
if (cpu->ril <= FIELD_EX32(status, CR_STATUS, IL)) {
return false;
}
if (cpu->rrs != FIELD_EX32(status, CR_STATUS, CRS)) {
return true;
}
return status & CR_STATUS_RSIE;
}
static bool iic_take_interrupt(Nios2CPU *cpu)
{
CPUNios2State *env = &cpu->env;
if (!(env->ctrl[CR_STATUS] & CR_STATUS_PIE)) {
return false;
}
return env->ctrl[CR_IPENDING] & env->ctrl[CR_IENABLE];
}
static bool nios2_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
if (interrupt_request & CPU_INTERRUPT_HARD) {
if (cpu->eic_present
? eic_take_interrupt(cpu)
: iic_take_interrupt(cpu)) {
cs->exception_index = EXCP_IRQ;
nios2_cpu_do_interrupt(cs);
return true;
}
}
return false;
}
#endif /* !CONFIG_USER_ONLY */
static void nios2_cpu_disas_set_info(CPUState *cpu, disassemble_info *info)
{
/* NOTE: NiosII R2 is not supported yet. */
info->mach = bfd_arch_nios2;
info->print_insn = print_insn_nios2;
}
static int nios2_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
CPUNios2State *env = &cpu->env;
uint32_t val;
if (n < 32) { /* GP regs */
val = env->regs[n];
} else if (n == 32) { /* PC */
val = env->pc;
} else if (n < 49) { /* Status regs */
unsigned cr = n - 33;
if (nios2_cr_reserved(&cpu->cr_state[cr])) {
val = 0;
} else {
val = env->ctrl[n - 33];
}
} else {
/* Invalid regs */
return 0;
}
return gdb_get_reg32(mem_buf, val);
}
static int nios2_cpu_gdb_write_register(CPUState *cs, uint8_t *mem_buf, int n)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
CPUClass *cc = CPU_GET_CLASS(cs);
CPUNios2State *env = &cpu->env;
uint32_t val;
if (n > cc->gdb_num_core_regs) {
return 0;
}
val = ldl_p(mem_buf);
if (n < 32) { /* GP regs */
env->regs[n] = val;
} else if (n == 32) { /* PC */
env->pc = val;
} else if (n < 49) { /* Status regs */
unsigned cr = n - 33;
/* ??? Maybe allow the debugger to write to readonly fields. */
val &= cpu->cr_state[cr].writable;
val |= cpu->cr_state[cr].readonly & env->ctrl[cr];
env->ctrl[cr] = val;
} else {
g_assert_not_reached();
}
return 4;
}
static Property nios2_properties[] = {
DEFINE_PROP_BOOL("diverr_present", Nios2CPU, diverr_present, true),
DEFINE_PROP_BOOL("mmu_present", Nios2CPU, mmu_present, true),
/* ALTR,pid-num-bits */
DEFINE_PROP_UINT32("mmu_pid_num_bits", Nios2CPU, pid_num_bits, 8),
/* ALTR,tlb-num-ways */
DEFINE_PROP_UINT32("mmu_tlb_num_ways", Nios2CPU, tlb_num_ways, 16),
/* ALTR,tlb-num-entries */
DEFINE_PROP_UINT32("mmu_pid_num_entries", Nios2CPU, tlb_num_entries, 256),
DEFINE_PROP_END_OF_LIST(),
};
#ifndef CONFIG_USER_ONLY
#include "hw/core/sysemu-cpu-ops.h"
static const struct SysemuCPUOps nios2_sysemu_ops = {
.get_phys_page_debug = nios2_cpu_get_phys_page_debug,
};
#endif
#include "hw/core/tcg-cpu-ops.h"
static const struct TCGCPUOps nios2_tcg_ops = {
.initialize = nios2_tcg_init,
#ifndef CONFIG_USER_ONLY
.tlb_fill = nios2_cpu_tlb_fill,
.cpu_exec_interrupt = nios2_cpu_exec_interrupt,
.do_interrupt = nios2_cpu_do_interrupt,
.do_unaligned_access = nios2_cpu_do_unaligned_access,
#endif /* !CONFIG_USER_ONLY */
};
static void nios2_cpu_class_init(ObjectClass *oc, void *data)
{
DeviceClass *dc = DEVICE_CLASS(oc);
CPUClass *cc = CPU_CLASS(oc);
Nios2CPUClass *ncc = NIOS2_CPU_CLASS(oc);
device_class_set_parent_realize(dc, nios2_cpu_realizefn,
&ncc->parent_realize);
device_class_set_props(dc, nios2_properties);
device_class_set_parent_reset(dc, nios2_cpu_reset, &ncc->parent_reset);
cc->class_by_name = nios2_cpu_class_by_name;
cc->has_work = nios2_cpu_has_work;
cc->dump_state = nios2_cpu_dump_state;
cc->set_pc = nios2_cpu_set_pc;
cc->disas_set_info = nios2_cpu_disas_set_info;
#ifndef CONFIG_USER_ONLY
cc->sysemu_ops = &nios2_sysemu_ops;
#endif
cc->gdb_read_register = nios2_cpu_gdb_read_register;
cc->gdb_write_register = nios2_cpu_gdb_write_register;
cc->gdb_num_core_regs = 49;
cc->tcg_ops = &nios2_tcg_ops;
}
static const TypeInfo nios2_cpu_type_info = {
.name = TYPE_NIOS2_CPU,
.parent = TYPE_CPU,
.instance_size = sizeof(Nios2CPU),
.instance_init = nios2_cpu_initfn,
.class_size = sizeof(Nios2CPUClass),
.class_init = nios2_cpu_class_init,
};
static void nios2_cpu_register_types(void)
{
type_register_static(&nios2_cpu_type_info);
}
type_init(nios2_cpu_register_types)