/*
* 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>
#define _TLBEHI_I 0x100
void show_dtlb_entry(unsigned int index)
{
unsigned int 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 = mmucr_save & 0x13;
mmucr |= index << 14;
sysreg_write(MMUCR, mmucr);
asm volatile("tlbr" : : : "memory");
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,
(tlbehi & 0x200)?'1':'0',
(tlbelo & 0x100)?'1':'0',
(tlbehi & 0xff),
(tlbehi >> 12), (tlbelo >> 12),
(tlbelo >> 4) & 7, (tlbelo >> 2) & 3,
(tlbelo & 0x200)?'1':'0',
(tlbelo & 0x080)?'1':'0',
(tlbelo & 0x001)?'1':'0',
(tlbelo & 0x002)?'1':'0');
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 < 32; i++)
show_dtlb_entry(i);
}
static unsigned long last_mmucr;
static inline void set_replacement_pointer(unsigned shift)
{
unsigned long mmucr, mmucr_save;
mmucr = mmucr_save = sysreg_read(MMUCR);
/* Does this mapping already exist? */
__asm__ __volatile__(
" tlbs\n"
" mfsr %0, %1"
: "=r"(mmucr)
: "i"(SYSREG_MMUCR));
if (mmucr & SYSREG_BIT(MMUCR_N)) {
/* Not found -- pick a not-recently-accessed entry */
unsigned long rp;
unsigned long tlbar = sysreg_read(TLBARLO);
rp = 32 - fls(tlbar);
if (rp == 32) {
rp = 0;
sysreg_write(TLBARLO, -1L);
}
mmucr &= 0x13;
mmucr |= (rp << shift);
sysreg_write(MMUCR, mmucr);
}
last_mmucr = mmucr;
}
static void update_dtlb(unsigned long address, pte_t pte, unsigned long asid)
{
unsigned long vpn;
vpn = (address & MMU_VPN_MASK) | _TLBEHI_VALID | asid;
sysreg_write(TLBEHI, vpn);
cpu_sync_pipeline();
set_replacement_pointer(14);
sysreg_write(TLBELO, pte_val(pte) & _PAGE_FLAGS_HARDWARE_MASK);
/* Let's go */
asm volatile("nop\n\ttlbw" : : : "memory");
cpu_sync_pipeline();
}
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, get_asid());
local_irq_restore(flags);
}
void __flush_tlb_page(unsigned long asid, unsigned long page)
{
unsigned long mmucr, tlbehi;
page |= asid;
sysreg_write(TLBEHI, page);
cpu_sync_pipeline();
asm volatile("tlbs");
mmucr = sysreg_read(MMUCR);
if (!(mmucr & SYSREG_BIT(MMUCR_N))) {
unsigned long tlbarlo;
unsigned long entry;
/* Clear the "valid" bit */
tlbehi = sysreg_read(TLBEHI);
tlbehi &= ~_TLBEHI_VALID;
sysreg_write(TLBEHI, tlbehi);
cpu_sync_pipeline();
/* mark the entry as "not accessed" */
entry = (mmucr >> 14) & 0x3f;
tlbarlo = sysreg_read(TLBARLO);
tlbarlo |= (0x80000000 >> entry);
sysreg_write(TLBARLO, tlbarlo);
/* update the entry with valid bit clear */
asm volatile("tlbw");
cpu_sync_pipeline();
}
}
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 = mm->context & MMU_CONTEXT_ASID_MASK;
unsigned long 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);
}
}
/*
* TODO: If this is only called for addresses > TASK_SIZE, we can probably
* skip the ASID stuff and just use the Global bit...
*/
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
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 */
flush_tlb_all();
} else {
unsigned long asid = init_mm.context & MMU_CONTEXT_ASID_MASK;
unsigned long saved_asid = get_asid();
start &= PAGE_MASK;
end += (PAGE_SIZE - 1);
end &= PAGE_MASK;
set_asid(asid);
while (start < end) {
__flush_tlb_page(asid, start);
start += PAGE_SIZE;
}
set_asid(saved_asid);
}
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 >= 32)
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 >= 31)
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 >= 32);
local_irq_save(flags);
mmucr_save = sysreg_read(MMUCR);
tlbehi_save = sysreg_read(TLBEHI);
mmucr = mmucr_save & 0x13;
mmucr |= *index << 14;
sysreg_write(MMUCR, mmucr);
asm volatile("tlbr" : : : "memory");
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,
(tlbehi & 0x200)?'1':'0',
(tlbelo & 0x100)?'1':'0',
(tlbehi & 0xff),
(tlbehi >> 12), (tlbelo >> 12),
(tlbelo >> 4) & 7, (tlbelo >> 2) & 3,
(tlbelo & 0x200)?'1':'0',
(tlbelo & 0x080)?'1':'0',
(tlbelo & 0x001)?'1':'0',
(tlbelo & 0x002)?'1':'0');
return 0;
}
static 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)
{
struct proc_dir_entry *entry;
entry = create_proc_entry("tlb", 0, NULL);
if (entry)
entry->proc_fops = &proc_tlb_operations;
return 0;
}
late_initcall(proctlb_init);
#endif /* CONFIG_PROC_FS */
