/*
* Common CPU TLB handling
*
* Copyright (c) 2003 Fabrice Bellard
*
* 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 "config.h"
#include "cpu.h"
#include "exec/exec-all.h"
#include "exec/memory.h"
#include "exec/address-spaces.h"
#include "exec/cputlb.h"
#include "exec/memory-internal.h"
//#define DEBUG_TLB
//#define DEBUG_TLB_CHECK
/* statistics */
int tlb_flush_count;
static const CPUTLBEntry s_cputlb_empty_entry = {
.addr_read = -1,
.addr_write = -1,
.addr_code = -1,
.addend = -1,
};
/* NOTE:
* If flush_global is true (the usual case), flush all tlb entries.
* If flush_global is false, flush (at least) all tlb entries not
* marked global.
*
* Since QEMU doesn't currently implement a global/not-global flag
* for tlb entries, at the moment tlb_flush() will also flush all
* tlb entries in the flush_global == false case. This is OK because
* CPU architectures generally permit an implementation to drop
* entries from the TLB at any time, so flushing more entries than
* required is only an efficiency issue, not a correctness issue.
*/
void tlb_flush(CPUArchState *env, int flush_global)
{
int i;
#if defined(DEBUG_TLB)
printf("tlb_flush:\n");
#endif
/* must reset current TB so that interrupts cannot modify the
links while we are modifying them */
env->current_tb = NULL;
for (i = 0; i < CPU_TLB_SIZE; i++) {
int mmu_idx;
for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
env->tlb_table[mmu_idx][i] = s_cputlb_empty_entry;
}
}
memset(env->tb_jmp_cache, 0, TB_JMP_CACHE_SIZE * sizeof (void *));
env->tlb_flush_addr = -1;
env->tlb_flush_mask = 0;
tlb_flush_count++;
}
static inline void tlb_flush_entry(CPUTLBEntry *tlb_entry, target_ulong addr)
{
if (addr == (tlb_entry->addr_read &
(TARGET_PAGE_MASK | TLB_INVALID_MASK)) ||
addr == (tlb_entry->addr_write &
(TARGET_PAGE_MASK | TLB_INVALID_MASK)) ||
addr == (tlb_entry->addr_code &
(TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
*tlb_entry = s_cputlb_empty_entry;
}
}
void tlb_flush_page(CPUArchState *env, target_ulong addr)
{
int i;
int mmu_idx;
#if defined(DEBUG_TLB)
printf("tlb_flush_page: " TARGET_FMT_lx "\n", addr);
#endif
/* Check if we need to flush due to large pages. */
if ((addr & env->tlb_flush_mask) == env->tlb_flush_addr) {
#if defined(DEBUG_TLB)
printf("tlb_flush_page: forced full flush ("
TARGET_FMT_lx "/" TARGET_FMT_lx ")\n",
env->tlb_flush_addr, env->tlb_flush_mask);
#endif
tlb_flush(env, 1);
return;
}
/* must reset current TB so that interrupts cannot modify the
links while we are modifying them */
env->current_tb = NULL;
addr &= TARGET_PAGE_MASK;
i = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
tlb_flush_entry(&env->tlb_table[mmu_idx][i], addr);
}
tb_flush_jmp_cache(env, addr);
}
/* update the TLBs so that writes to code in the virtual page 'addr'
can be detected */
void tlb_protect_code(ram_addr_t ram_addr)
{
cpu_physical_memory_reset_dirty(ram_addr,
ram_addr + TARGET_PAGE_SIZE,
CODE_DIRTY_FLAG);
}
/* update the TLB so that writes in physical page 'phys_addr' are no longer
tested for self modifying code */
void tlb_unprotect_code_phys(CPUArchState *env, ram_addr_t ram_addr,
target_ulong vaddr)
{
cpu_physical_memory_set_dirty_flags(ram_addr, CODE_DIRTY_FLAG);
}
static bool tlb_is_dirty_ram(CPUTLBEntry *tlbe)
{
return (tlbe->addr_write & (TLB_INVALID_MASK|TLB_MMIO|TLB_NOTDIRTY)) == 0;
}
void tlb_reset_dirty_range(CPUTLBEntry *tlb_entry, uintptr_t start,
uintptr_t length)
{
uintptr_t addr;
if (tlb_is_dirty_ram(tlb_entry)) {
addr = (tlb_entry->addr_write & TARGET_PAGE_MASK) + tlb_entry->addend;
if ((addr - start) < length) {
tlb_entry->addr_write |= TLB_NOTDIRTY;
}
}
}
static inline void tlb_update_dirty(CPUTLBEntry *tlb_entry)
{
ram_addr_t ram_addr;
void *p;
if (tlb_is_dirty_ram(tlb_entry)) {
p = (void *)(uintptr_t)((tlb_entry->addr_write & TARGET_PAGE_MASK)
+ tlb_entry->addend);
ram_addr = qemu_ram_addr_from_host_nofail(p);
if (!cpu_physical_memory_is_dirty(ram_addr)) {
tlb_entry->addr_write |= TLB_NOTDIRTY;
}
}
}
void cpu_tlb_reset_dirty_all(ram_addr_t start1, ram_addr_t length)
{
CPUArchState *env;
for (env = first_cpu; env != NULL; env = env->next_cpu) {
int mmu_idx;
for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
unsigned int i;
for (i = 0; i < CPU_TLB_SIZE; i++) {
tlb_reset_dirty_range(&env->tlb_table[mmu_idx][i],
start1, length);
}
}
}
}
static inline void tlb_set_dirty1(CPUTLBEntry *tlb_entry, target_ulong vaddr)
{
if (tlb_entry->addr_write == (vaddr | TLB_NOTDIRTY)) {
tlb_entry->addr_write = vaddr;
}
}
/* update the TLB corresponding to virtual page vaddr
so that it is no longer dirty */
void tlb_set_dirty(CPUArchState *env, target_ulong vaddr)
{
int i;
int mmu_idx;
vaddr &= TARGET_PAGE_MASK;
i = (vaddr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
tlb_set_dirty1(&env->tlb_table[mmu_idx][i], vaddr);
}
}
/* Our TLB does not support large pages, so remember the area covered by
large pages and trigger a full TLB flush if these are invalidated. */
static void tlb_add_large_page(CPUArchState *env, target_ulong vaddr,
target_ulong size)
{
target_ulong mask = ~(size - 1);
if (env->tlb_flush_addr == (target_ulong)-1) {
env->tlb_flush_addr = vaddr & mask;
env->tlb_flush_mask = mask;
return;
}
/* Extend the existing region to include the new page.
This is a compromise between unnecessary flushes and the cost
of maintaining a full variable size TLB. */
mask &= env->tlb_flush_mask;
while (((env->tlb_flush_addr ^ vaddr) & mask) != 0) {
mask <<= 1;
}
env->tlb_flush_addr &= mask;
env->tlb_flush_mask = mask;
}
/* Add a new TLB entry. At most one entry for a given virtual address
is permitted. Only a single TARGET_PAGE_SIZE region is mapped, the
supplied size is only used by tlb_flush_page. */
void tlb_set_page(CPUArchState *env, target_ulong vaddr,
hwaddr paddr, int prot,
int mmu_idx, target_ulong size)
{
MemoryRegionSection *section;
unsigned int index;
target_ulong address;
target_ulong code_address;
uintptr_t addend;
CPUTLBEntry *te;
hwaddr iotlb;
assert(size >= TARGET_PAGE_SIZE);
if (size != TARGET_PAGE_SIZE) {
tlb_add_large_page(env, vaddr, size);
}
section = phys_page_find(address_space_memory.dispatch, paddr >> TARGET_PAGE_BITS);
#if defined(DEBUG_TLB)
printf("tlb_set_page: vaddr=" TARGET_FMT_lx " paddr=0x" TARGET_FMT_plx
" prot=%x idx=%d pd=0x%08lx\n",
vaddr, paddr, prot, mmu_idx, pd);
#endif
address = vaddr;
if (!(memory_region_is_ram(section->mr) ||
memory_region_is_romd(section->mr))) {
/* IO memory case (romd handled later) */
address |= TLB_MMIO;
}
if (memory_region_is_ram(section->mr) ||
memory_region_is_romd(section->mr)) {
addend = (uintptr_t)memory_region_get_ram_ptr(section->mr)
+ memory_region_section_addr(section, paddr);
} else {
addend = 0;
}
code_address = address;
iotlb = memory_region_section_get_iotlb(env, section, vaddr, paddr, prot,
&address);
index = (vaddr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
env->iotlb[mmu_idx][index] = iotlb - vaddr;
te = &env->tlb_table[mmu_idx][index];
te->addend = addend - vaddr;
if (prot & PAGE_READ) {
te->addr_read = address;
} else {
te->addr_read = -1;
}
if (prot & PAGE_EXEC) {
te->addr_code = code_address;
} else {
te->addr_code = -1;
}
if (prot & PAGE_WRITE) {
if ((memory_region_is_ram(section->mr) && section->readonly)
|| memory_region_is_romd(section->mr)) {
/* Write access calls the I/O callback. */
te->addr_write = address | TLB_MMIO;
} else if (memory_region_is_ram(section->mr)
&& !cpu_physical_memory_is_dirty(
section->mr->ram_addr
+ memory_region_section_addr(section, paddr))) {
te->addr_write = address | TLB_NOTDIRTY;
} else {
te->addr_write = address;
}
} else {
te->addr_write = -1;
}
}
/* NOTE: this function can trigger an exception */
/* NOTE2: the returned address is not exactly the physical address: it
* is actually a ram_addr_t (in system mode; the user mode emulation
* version of this function returns a guest virtual address).
*/
tb_page_addr_t get_page_addr_code(CPUArchState *env1, target_ulong addr)
{
int mmu_idx, page_index, pd;
void *p;
MemoryRegion *mr;
page_index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
mmu_idx = cpu_mmu_index(env1);
if (unlikely(env1->tlb_table[mmu_idx][page_index].addr_code !=
(addr & TARGET_PAGE_MASK))) {
cpu_ldub_code(env1, addr);
}
pd = env1->iotlb[mmu_idx][page_index] & ~TARGET_PAGE_MASK;
mr = iotlb_to_region(pd);
if (memory_region_is_unassigned(mr)) {
#if defined(TARGET_ALPHA) || defined(TARGET_MIPS) || defined(TARGET_SPARC)
cpu_unassigned_access(env1, addr, 0, 1, 0, 4);
#else
cpu_abort(env1, "Trying to execute code outside RAM or ROM at 0x"
TARGET_FMT_lx "\n", addr);
#endif
}
p = (void *)((uintptr_t)addr + env1->tlb_table[mmu_idx][page_index].addend);
return qemu_ram_addr_from_host_nofail(p);
}
#define MMUSUFFIX _cmmu
#undef GETPC
#define GETPC() ((uintptr_t)0)
#define SOFTMMU_CODE_ACCESS
#define SHIFT 0
#include "exec/softmmu_template.h"
#define SHIFT 1
#include "exec/softmmu_template.h"
#define SHIFT 2
#include "exec/softmmu_template.h"
#define SHIFT 3
#include "exec/softmmu_template.h"
#undef env
