b13d618b44
This and the following patches aim to optimize the code dealing with
page tables and TLB operations. Each patch reduces the time it takes
to gzip a 16 MB file slightly, but I expect things like fork() and
mmap() will improve somewhat more.
This patch deals with the low-level TLB operations:
* Remove unused _TLBEHI_I define
* Use gcc builtins instead of inline assembly
* Remove a few unnecessary pipeline flushes and nops
* Introduce NR_TLB_ENTRIES define and use it instead of hardcoding it
to 32 a few places throughout the code.
* Use sysreg bitops instead of hardcoded shifts and masks
* Make a few needlessly global functions static
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
376 lines
8.3 KiB
C
376 lines
8.3 KiB
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 pte)
|
|
{
|
|
unsigned long flags;
|
|
|
|
/* ptrace may call this routine */
|
|
if (vma && current->active_mm != vma->vm_mm)
|
|
return;
|
|
|
|
local_irq_save(flags);
|
|
update_dtlb(address, pte);
|
|
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 */
|