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qemu/target/openrisc/mmu.c

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/*
* OpenRISC MMU.
*
* Copyright (c) 2011-2012 Jia Liu <proljc@gmail.com>
* Zhizhou Zhang <etouzh@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 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/>.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "qemu-common.h"
#include "exec/gdbstub.h"
#include "qemu/host-utils.h"
#ifndef CONFIG_USER_ONLY
#include "hw/loader.h"
#endif
#ifndef CONFIG_USER_ONLY
int cpu_openrisc_get_phys_nommu(OpenRISCCPU *cpu,
hwaddr *physical,
int *prot, target_ulong address, int rw)
{
*physical = address;
*prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
return TLBRET_MATCH;
}
int cpu_openrisc_get_phys_code(OpenRISCCPU *cpu,
hwaddr *physical,
int *prot, target_ulong address, int rw)
{
int vpn = address >> TARGET_PAGE_BITS;
int idx = vpn & ITLB_MASK;
int right = 0;
if ((cpu->env.tlb->itlb[0][idx].mr >> TARGET_PAGE_BITS) != vpn) {
return TLBRET_NOMATCH;
}
if (!(cpu->env.tlb->itlb[0][idx].mr & 1)) {
return TLBRET_INVALID;
}
if (cpu->env.sr & SR_SM) { /* supervisor mode */
if (cpu->env.tlb->itlb[0][idx].tr & SXE) {
right |= PAGE_EXEC;
}
} else {
if (cpu->env.tlb->itlb[0][idx].tr & UXE) {
right |= PAGE_EXEC;
}
}
if ((rw & 2) && ((right & PAGE_EXEC) == 0)) {
return TLBRET_BADADDR;
}
*physical = (cpu->env.tlb->itlb[0][idx].tr & TARGET_PAGE_MASK) |
(address & (TARGET_PAGE_SIZE-1));
*prot = right;
return TLBRET_MATCH;
}
int cpu_openrisc_get_phys_data(OpenRISCCPU *cpu,
hwaddr *physical,
int *prot, target_ulong address, int rw)
{
int vpn = address >> TARGET_PAGE_BITS;
int idx = vpn & DTLB_MASK;
int right = 0;
if ((cpu->env.tlb->dtlb[0][idx].mr >> TARGET_PAGE_BITS) != vpn) {
return TLBRET_NOMATCH;
}
if (!(cpu->env.tlb->dtlb[0][idx].mr & 1)) {
return TLBRET_INVALID;
}
if (cpu->env.sr & SR_SM) { /* supervisor mode */
if (cpu->env.tlb->dtlb[0][idx].tr & SRE) {
right |= PAGE_READ;
}
if (cpu->env.tlb->dtlb[0][idx].tr & SWE) {
right |= PAGE_WRITE;
}
} else {
if (cpu->env.tlb->dtlb[0][idx].tr & URE) {
right |= PAGE_READ;
}
if (cpu->env.tlb->dtlb[0][idx].tr & UWE) {
right |= PAGE_WRITE;
}
}
if (!(rw & 1) && ((right & PAGE_READ) == 0)) {
return TLBRET_BADADDR;
}
if ((rw & 1) && ((right & PAGE_WRITE) == 0)) {
return TLBRET_BADADDR;
}
*physical = (cpu->env.tlb->dtlb[0][idx].tr & TARGET_PAGE_MASK) |
(address & (TARGET_PAGE_SIZE-1));
*prot = right;
return TLBRET_MATCH;
}
static int cpu_openrisc_get_phys_addr(OpenRISCCPU *cpu,
hwaddr *physical,
int *prot, target_ulong address,
int rw)
{
int ret = TLBRET_MATCH;
if (rw == MMU_INST_FETCH) { /* ITLB */
*physical = 0;
ret = cpu->env.tlb->cpu_openrisc_map_address_code(cpu, physical,
prot, address, rw);
} else { /* DTLB */
ret = cpu->env.tlb->cpu_openrisc_map_address_data(cpu, physical,
prot, address, rw);
}
return ret;
}
#endif
static void cpu_openrisc_raise_mmu_exception(OpenRISCCPU *cpu,
target_ulong address,
int rw, int tlb_error)
{
CPUState *cs = CPU(cpu);
int exception = 0;
switch (tlb_error) {
default:
if (rw == 2) {
exception = EXCP_IPF;
} else {
exception = EXCP_DPF;
}
break;
#ifndef CONFIG_USER_ONLY
case TLBRET_BADADDR:
if (rw == 2) {
exception = EXCP_IPF;
} else {
exception = EXCP_DPF;
}
break;
case TLBRET_INVALID:
case TLBRET_NOMATCH:
/* No TLB match for a mapped address */
if (rw == 2) {
exception = EXCP_ITLBMISS;
} else {
exception = EXCP_DTLBMISS;
}
break;
#endif
}
cs->exception_index = exception;
cpu->env.eear = address;
cpu->env.lock_addr = -1;
}
#ifndef CONFIG_USER_ONLY
int openrisc_cpu_handle_mmu_fault(CPUState *cs,
vaddr address, int rw, int mmu_idx)
{
OpenRISCCPU *cpu = OPENRISC_CPU(cs);
int ret = 0;
hwaddr physical = 0;
int prot = 0;
ret = cpu_openrisc_get_phys_addr(cpu, &physical, &prot,
address, rw);
if (ret == TLBRET_MATCH) {
tlb_set_page(cs, address & TARGET_PAGE_MASK,
physical & TARGET_PAGE_MASK, prot,
mmu_idx, TARGET_PAGE_SIZE);
ret = 0;
} else if (ret < 0) {
cpu_openrisc_raise_mmu_exception(cpu, address, rw, ret);
ret = 1;
}
return ret;
}
#else
int openrisc_cpu_handle_mmu_fault(CPUState *cs,
vaddr address, int rw, int mmu_idx)
{
OpenRISCCPU *cpu = OPENRISC_CPU(cs);
int ret = 0;
cpu_openrisc_raise_mmu_exception(cpu, address, rw, ret);
ret = 1;
return ret;
}
#endif
#ifndef CONFIG_USER_ONLY
hwaddr openrisc_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
{
OpenRISCCPU *cpu = OPENRISC_CPU(cs);
hwaddr phys_addr;
int prot;
int miss;
/* Check memory for any kind of address, since during debug the
gdb can ask for anything, check data tlb for address */
miss = cpu_openrisc_get_phys_addr(cpu, &phys_addr, &prot, addr, 0);
/* Check instruction tlb */
if (miss) {
miss = cpu_openrisc_get_phys_addr(cpu, &phys_addr, &prot, addr,
MMU_INST_FETCH);
}
/* Last, fall back to a plain address */
if (miss) {
miss = cpu_openrisc_get_phys_nommu(cpu, &phys_addr, &prot, addr, 0);
}
if (miss) {
return -1;
} else {
return phys_addr;
}
}
void cpu_openrisc_mmu_init(OpenRISCCPU *cpu)
{
cpu->env.tlb = g_malloc0(sizeof(CPUOpenRISCTLBContext));
cpu->env.tlb->cpu_openrisc_map_address_code = &cpu_openrisc_get_phys_nommu;
cpu->env.tlb->cpu_openrisc_map_address_data = &cpu_openrisc_get_phys_nommu;
}
#endif
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