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/*
* arch/sh/mm/tlb-sh5.c
*
* Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org>
* Copyright (C) 2003 Richard Curnow <richard.curnow@superh.com>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/mm.h>
#include <linux/init.h>
#include <asm/page.h>
#include <asm/tlb.h>
#include <asm/mmu_context.h>
/**
* sh64_tlb_init - Perform initial setup for the DTLB and ITLB.
*/
int __init sh64_tlb_init(void)
{
/* Assign some sane DTLB defaults */
cpu_data->dtlb.entries = 64;
cpu_data->dtlb.step = 0x10;
cpu_data->dtlb.first = DTLB_FIXED | cpu_data->dtlb.step;
cpu_data->dtlb.next = cpu_data->dtlb.first;
cpu_data->dtlb.last = DTLB_FIXED |
((cpu_data->dtlb.entries - 1) *
cpu_data->dtlb.step);
/* And again for the ITLB */
cpu_data->itlb.entries = 64;
cpu_data->itlb.step = 0x10;
cpu_data->itlb.first = ITLB_FIXED | cpu_data->itlb.step;
cpu_data->itlb.next = cpu_data->itlb.first;
cpu_data->itlb.last = ITLB_FIXED |
((cpu_data->itlb.entries - 1) *
cpu_data->itlb.step);
return 0;
}
/**
* sh64_next_free_dtlb_entry - Find the next available DTLB entry
*/
unsigned long long sh64_next_free_dtlb_entry(void)
{
return cpu_data->dtlb.next;
}
/**
* sh64_get_wired_dtlb_entry - Allocate a wired (locked-in) entry in the DTLB
*/
unsigned long long sh64_get_wired_dtlb_entry(void)
{
unsigned long long entry = sh64_next_free_dtlb_entry();
cpu_data->dtlb.first += cpu_data->dtlb.step;
cpu_data->dtlb.next += cpu_data->dtlb.step;
return entry;
}
/**
* sh64_put_wired_dtlb_entry - Free a wired (locked-in) entry in the DTLB.
*
* @entry: Address of TLB slot.
*
* Works like a stack, last one to allocate must be first one to free.
*/
int sh64_put_wired_dtlb_entry(unsigned long long entry)
{
__flush_tlb_slot(entry);
/*
* We don't do any particularly useful tracking of wired entries,
* so this approach works like a stack .. last one to be allocated
* has to be the first one to be freed.
*
* We could potentially load wired entries into a list and work on
* rebalancing the list periodically (which also entails moving the
* contents of a TLB entry) .. though I have a feeling that this is
* more trouble than it's worth.
*/
/*
* Entry must be valid .. we don't want any ITLB addresses!
*/
if (entry <= DTLB_FIXED)
return -EINVAL;
/*
* Next, check if we're within range to be freed. (ie, must be the
* entry beneath the first 'free' entry!
*/
if (entry < (cpu_data->dtlb.first - cpu_data->dtlb.step))
return -EINVAL;
/* If we are, then bring this entry back into the list */
cpu_data->dtlb.first -= cpu_data->dtlb.step;
cpu_data->dtlb.next = entry;
return 0;
}
/**
* sh64_setup_tlb_slot - Load up a translation in a wired slot.
*
* @config_addr: Address of TLB slot.
* @eaddr: Virtual address.
* @asid: Address Space Identifier.
* @paddr: Physical address.
*
* Load up a virtual<->physical translation for @eaddr<->@paddr in the
* pre-allocated TLB slot @config_addr (see sh64_get_wired_dtlb_entry).
*/
void sh64_setup_tlb_slot(unsigned long long config_addr, unsigned long eaddr,
unsigned long asid, unsigned long paddr)
{
unsigned long long pteh, ptel;
pteh = neff_sign_extend(eaddr);
pteh &= PAGE_MASK;
pteh |= (asid << PTEH_ASID_SHIFT) | PTEH_VALID;
ptel = neff_sign_extend(paddr);
ptel &= PAGE_MASK;
ptel |= (_PAGE_CACHABLE | _PAGE_READ | _PAGE_WRITE);
asm volatile("putcfg %0, 1, %1\n\t"
"putcfg %0, 0, %2\n"
: : "r" (config_addr), "r" (ptel), "r" (pteh));
}
/**
* sh64_teardown_tlb_slot - Teardown a translation.
*
* @config_addr: Address of TLB slot.
*
* Teardown any existing mapping in the TLB slot @config_addr.
*/
void sh64_teardown_tlb_slot(unsigned long long config_addr)
__attribute__ ((alias("__flush_tlb_slot")));
static int dtlb_entry;
static unsigned long long dtlb_entries[64];
void tlb_wire_entry(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
{
unsigned long long entry;
unsigned long paddr, flags;
BUG_ON(dtlb_entry == ARRAY_SIZE(dtlb_entries));
local_irq_save(flags);
entry = sh64_get_wired_dtlb_entry();
dtlb_entries[dtlb_entry++] = entry;
paddr = pte_val(pte) & _PAGE_FLAGS_HARDWARE_MASK;
paddr &= ~PAGE_MASK;
sh64_setup_tlb_slot(entry, addr, get_asid(), paddr);
local_irq_restore(flags);
}
void tlb_unwire_entry(void)
{
unsigned long long entry;
unsigned long flags;
BUG_ON(!dtlb_entry);
local_irq_save(flags);
entry = dtlb_entries[dtlb_entry--];
sh64_teardown_tlb_slot(entry);
sh64_put_wired_dtlb_entry(entry);
local_irq_restore(flags);
}
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