- 根目录:
- arch
- avr32
- mm
- tlb.c
/*
* AVR32 TLB operations
*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/mm.h>
#include <asm/mmu_context.h>
/* TODO: Get the correct number from the CONFIG1 system register */
#define NR_TLB_ENTRIES 32
static void show_dtlb_entry(unsigned int index)
{
u32 tlbehi, tlbehi_save, tlbelo, mmucr, mmucr_save;
unsigned long flags;
local_irq_save(flags);
mmucr_save = sysreg_read(MMUCR);
tlbehi_save = sysreg_read(TLBEHI);
mmucr = SYSREG_BFINS(DRP, index, mmucr_save);
sysreg_write(MMUCR, mmucr);
__builtin_tlbr();
cpu_sync_pipeline();
tlbehi = sysreg_read(TLBEHI);
tlbelo = sysreg_read(TLBELO);
printk("%2u: %c %c %02x %05x %05x %o %o %c %c %c %c\n",
index,
SYSREG_BFEXT(TLBEHI_V, tlbehi) ? '1' : '0',
SYSREG_BFEXT(G, tlbelo) ? '1' : '0',
SYSREG_BFEXT(ASID, tlbehi),
SYSREG_BFEXT(VPN, tlbehi) >> 2,
SYSREG_BFEXT(PFN, tlbelo) >> 2,
SYSREG_BFEXT(AP, tlbelo),
SYSREG_BFEXT(SZ, tlbelo),
SYSREG_BFEXT(TLBELO_C, tlbelo) ? 'C' : ' ',
SYSREG_BFEXT(B, tlbelo) ? 'B' : ' ',
SYSREG_BFEXT(W, tlbelo) ? 'W' : ' ',
SYSREG_BFEXT(TLBELO_D, tlbelo) ? 'D' : ' ');
sysreg_write(MMUCR, mmucr_save);
sysreg_write(TLBEHI, tlbehi_save);
cpu_sync_pipeline();
local_irq_restore(flags);
}
void dump_dtlb(void)
{
unsigned int i;
printk("ID V G ASID VPN PFN AP SZ C B W D\n");
for (i = 0; i < NR_TLB_ENTRIES; i++)
show_dtlb_entry(i);
}
static void update_dtlb(unsigned long address, pte_t pte)
{
u32 tlbehi;
u32 mmucr;
/*
* We're not changing the ASID here, so no need to flush the
* pipeline.
*/
tlbehi = sysreg_read(TLBEHI);
tlbehi = SYSREG_BF(ASID, SYSREG_BFEXT(ASID, tlbehi));
tlbehi |= address & MMU_VPN_MASK;
tlbehi |= SYSREG_BIT(TLBEHI_V);
sysreg_write(TLBEHI, tlbehi);
/* Does this mapping already exist? */
__builtin_tlbs();
mmucr = sysreg_read(MMUCR);
if (mmucr & SYSREG_BIT(MMUCR_N)) {
/* Not found -- pick a not-recently-accessed entry */
unsigned int rp;
u32 tlbar = sysreg_read(TLBARLO);
rp = 32 - fls(tlbar);
if (rp == 32) {
rp = 0;
sysreg_write(TLBARLO, -1L);
}
mmucr = SYSREG_BFINS(DRP, rp, mmucr);
sysreg_write(MMUCR, mmucr);
}
sysreg_write(TLBELO, pte_val(pte) & _PAGE_FLAGS_HARDWARE_MASK);
/* Let's go */
__builtin_tlbw();
}
void update_mmu_cache(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep)
{
unsigned long flags;
/* ptrace may call this routine */
if (vma && current->active_mm != vma->vm_mm)
return;
local_irq_save(flags);
update_dtlb(address, *ptep);
local_irq_restore(flags);
}
static void __flush_tlb_page(unsigned long asid, unsigned long page)
{
u32 mmucr, tlbehi;
/*
* Caller is responsible for masking out non-PFN bits in page
* and changing the current ASID if necessary. This means that
* we don't need to flush the pipeline after writing TLBEHI.
*/
tlbehi = page | asid;
sysreg_write(TLBEHI, tlbehi);
__builtin_tlbs();
mmucr = sysreg_read(MMUCR);
if (!(mmucr & SYSREG_BIT(MMUCR_N))) {
unsigned int entry;
u32 tlbarlo;
/* Clear the "valid" bit */
sysreg_write(TLBEHI, tlbehi);
/* mark the entry as "not accessed" */
entry = SYSREG_BFEXT(DRP, mmucr);
tlbarlo = sysreg_read(TLBARLO);
tlbarlo |= (0x80000000UL >> entry);
sysreg_write(TLBARLO, tlbarlo);
/* update the entry with valid bit clear */
__builtin_tlbw();
}
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
if (vma->vm_mm && vma->vm_mm->context != NO_CONTEXT) {
unsigned long flags, asid;
unsigned long saved_asid = MMU_NO_ASID;
asid = vma->vm_mm->context & MMU_CONTEXT_ASID_MASK;
page &= PAGE_MASK;
local_irq_save(flags);
if (vma->vm_mm != current->mm) {
saved_asid = get_asid();
set_asid(asid);
}
__flush_tlb_page(asid, page);
if (saved_asid != MMU_NO_ASID)
set_asid(saved_asid);
local_irq_restore(flags);
}
}
void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;
if (mm->context != NO_CONTEXT) {
unsigned long flags;
int size;
local_irq_save(flags);
size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
if (size > (MMU_DTLB_ENTRIES / 4)) { /* Too many entries to flush */
mm->context = NO_CONTEXT;
if (mm == current->mm)
activate_context(mm);
} else {
unsigned long asid;
unsigned long saved_asid;
asid = mm->context & MMU_CONTEXT_ASID_MASK;
saved_asid = MMU_NO_ASID;
start &= PAGE_MASK;
end += (PAGE_SIZE - 1);
end &= PAGE_MASK;
if (mm != current->mm) {
saved_asid = get_asid();
set_asid(asid);
}
while (start < end) {
__flush_tlb_page(asid, start);
start += PAGE_SIZE;
}
if (saved_asid != MMU_NO_ASID)
set_asid(saved_asid);
}
local_irq_restore(flags);
}
}
/*
* This function depends on the pages to be flushed having the G
* (global) bit set in their pte. This is true for all
* PAGE_KERNEL(_RO) pages.
*/
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
unsigned long flags;
int size;
size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
if (size > (MMU_DTLB_ENTRIES / 4)) { /* Too many entries to flush */
flush_tlb_all();
} else {
unsigned long asid;
local_irq_save(flags);
asid = get_asid();
start &= PAGE_MASK;
end += (PAGE_SIZE - 1);
end &= PAGE_MASK;
while (start < end) {
__flush_tlb_page(asid, start);
start += PAGE_SIZE;
}
local_irq_restore(flags);
}
}
void flush_tlb_mm(struct mm_struct *mm)
{
/* Invalidate all TLB entries of this process by getting a new ASID */
if (mm->context != NO_CONTEXT) {
unsigned long flags;
local_irq_save(flags);
mm->context = NO_CONTEXT;
if (mm == current->mm)
activate_context(mm);
local_irq_restore(flags);
}
}
void flush_tlb_all(void)
{
unsigned long flags;
local_irq_save(flags);
sysreg_write(MMUCR, sysreg_read(MMUCR) | SYSREG_BIT(MMUCR_I));
local_irq_restore(flags);
}
#ifdef CONFIG_PROC_FS
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
static void *tlb_start(struct seq_file *tlb, loff_t *pos)
{
static unsigned long tlb_index;
if (*pos >= NR_TLB_ENTRIES)
return NULL;
tlb_index = 0;
return &tlb_index;
}
static void *tlb_next(struct seq_file *tlb, void *v, loff_t *pos)
{
unsigned long *index = v;
if (*index >= NR_TLB_ENTRIES - 1)
return NULL;
++*pos;
++*index;
return index;
}
static void tlb_stop(struct seq_file *tlb, void *v)
{
}
static int tlb_show(struct seq_file *tlb, void *v)
{
unsigned int tlbehi, tlbehi_save, tlbelo, mmucr, mmucr_save;
unsigned long flags;
unsigned long *index = v;
if (*index == 0)
seq_puts(tlb, "ID V G ASID VPN PFN AP SZ C B W D\n");
BUG_ON(*index >= NR_TLB_ENTRIES);
local_irq_save(flags);
mmucr_save = sysreg_read(MMUCR);
tlbehi_save = sysreg_read(TLBEHI);
mmucr = SYSREG_BFINS(DRP, *index, mmucr_save);
sysreg_write(MMUCR, mmucr);
/* TLBR might change the ASID */
__builtin_tlbr();
cpu_sync_pipeline();
tlbehi = sysreg_read(TLBEHI);
tlbelo = sysreg_read(TLBELO);
sysreg_write(MMUCR, mmucr_save);
sysreg_write(TLBEHI, tlbehi_save);
cpu_sync_pipeline();
local_irq_restore(flags);
seq_printf(tlb, "%2lu: %c %c %02x %05x %05x %o %o %c %c %c %c\n",
*index,
SYSREG_BFEXT(TLBEHI_V, tlbehi) ? '1' : '0',
SYSREG_BFEXT(G, tlbelo) ? '1' : '0',
SYSREG_BFEXT(ASID, tlbehi),
SYSREG_BFEXT(VPN, tlbehi) >> 2,
SYSREG_BFEXT(PFN, tlbelo) >> 2,
SYSREG_BFEXT(AP, tlbelo),
SYSREG_BFEXT(SZ, tlbelo),
SYSREG_BFEXT(TLBELO_C, tlbelo) ? '1' : '0',
SYSREG_BFEXT(B, tlbelo) ? '1' : '0',
SYSREG_BFEXT(W, tlbelo) ? '1' : '0',
SYSREG_BFEXT(TLBELO_D, tlbelo) ? '1' : '0');
return 0;
}
static const struct seq_operations tlb_ops = {
.start = tlb_start,
.next = tlb_next,
.stop = tlb_stop,
.show = tlb_show,
};
static int tlb_open(struct inode *inode, struct file *file)
{
return seq_open(file, &tlb_ops);
}
static const struct file_operations proc_tlb_operations = {
.open = tlb_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int __init proctlb_init(void)
{
proc_create("tlb", 0, NULL, &proc_tlb_operations);
return 0;
}
late_initcall(proctlb_init);
#endif /* CONFIG_PROC_FS */