/*
* 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.
*
* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
* Copyright (C) 1997, 1998, 1999, 2000 Ralf Baechle ralf@gnu.org
* Carsten Langgaard, carstenl@mips.com
* Copyright (C) 2002 MIPS Technologies, Inc. All rights reserved.
*/
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/module.h>
#include <asm/cpu.h>
#include <asm/bootinfo.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/tlbmisc.h>
extern void build_tlb_refill_handler(void);
/*
* Make sure all entries differ. If they're not different
* MIPS32 will take revenge ...
*/
#define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
/* Atomicity and interruptability */
#ifdef CONFIG_MIPS_MT_SMTC
#include <asm/smtc.h>
#include <asm/mipsmtregs.h>
#define ENTER_CRITICAL(flags) \
{ \
unsigned int mvpflags; \
local_irq_save(flags);\
mvpflags = dvpe()
#define EXIT_CRITICAL(flags) \
evpe(mvpflags); \
local_irq_restore(flags); \
}
#else
#define ENTER_CRITICAL(flags) local_irq_save(flags)
#define EXIT_CRITICAL(flags) local_irq_restore(flags)
#endif /* CONFIG_MIPS_MT_SMTC */
#if defined(CONFIG_CPU_LOONGSON2)
/*
* LOONGSON2 has a 4 entry itlb which is a subset of dtlb,
* unfortrunately, itlb is not totally transparent to software.
*/
#define FLUSH_ITLB write_c0_diag(4);
#define FLUSH_ITLB_VM(vma) { if ((vma)->vm_flags & VM_EXEC) write_c0_diag(4); }
#else
#define FLUSH_ITLB
#define FLUSH_ITLB_VM(vma)
#endif
void local_flush_tlb_all(void)
{
unsigned long flags;
unsigned long old_ctx;
int entry;
ENTER_CRITICAL(flags);
/* Save old context and create impossible VPN2 value */
old_ctx = read_c0_entryhi();
write_c0_entrylo0(0);
write_c0_entrylo1(0);
entry = read_c0_wired();
/* Blast 'em all away. */
while (entry < current_cpu_data.tlbsize) {
/* Make sure all entries differ. */
write_c0_entryhi(UNIQUE_ENTRYHI(entry));
write_c0_index(entry);
mtc0_tlbw_hazard();
tlb_write_indexed();
entry++;
}
tlbw_use_hazard();
write_c0_entryhi(old_ctx);
FLUSH_ITLB;
EXIT_CRITICAL(flags);
}
EXPORT_SYMBOL(local_flush_tlb_all);
/* All entries common to a mm share an asid. To effectively flush
these entries, we just bump the asid. */
void local_flush_tlb_mm(struct mm_struct *mm)
{
int cpu;
preempt_disable();
cpu = smp_processor_id();
if (cpu_context(cpu, mm) != 0) {
drop_mmu_context(mm, cpu);
}
preempt_enable();
}
void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;
int cpu = smp_processor_id();
if (cpu_context(cpu, mm) != 0) {
unsigned long size, flags;
ENTER_CRITICAL(flags);
start = round_down(start, PAGE_SIZE << 1);
end = round_up(end, PAGE_SIZE << 1);
size = (end - start) >> (PAGE_SHIFT + 1);
if (size <= current_cpu_data.tlbsize/2) {
int oldpid = read_c0_entryhi();
int newpid = cpu_asid(cpu, mm);
while (start < end) {
int idx;
write_c0_entryhi(start | newpid);
start += (PAGE_SIZE << 1);
mtc0_tlbw_hazard();
tlb_probe();
tlb_probe_hazard();
idx = read_c0_index();
write_c0_entrylo0(0);
write_c0_entrylo1(0);
if (idx < 0)
continue;
/* Make sure all entries differ. */
write_c0_entryhi(UNIQUE_ENTRYHI(idx));
mtc0_tlbw_hazard();
tlb_write_indexed();
}
tlbw_use_hazard();
write_c0_entryhi(oldpid);
} else {
drop_mmu_context(mm, cpu);
}
FLUSH_ITLB;
EXIT_CRITICAL(flags);
}
}
void local_flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
unsigned long size, flags;
ENTER_CRITICAL(flags);
size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
size = (size + 1) >> 1;
if (size <= current_cpu_data.tlbsize / 2) {
int pid = read_c0_entryhi();
start &= (PAGE_MASK << 1);
end += ((PAGE_SIZE << 1) - 1);
end &= (PAGE_MASK << 1);
while (start < end) {
int idx;
write_c0_entryhi(start);
start += (PAGE_SIZE << 1);
mtc0_tlbw_hazard();
tlb_probe();
tlb_probe_hazard();
idx = read_c0_index();
write_c0_entrylo0(0);
write_c0_entrylo1(0);
if (idx < 0)
continue;
/* Make sure all entries differ. */
write_c0_entryhi(UNIQUE_ENTRYHI(idx));
mtc0_tlbw_hazard();
tlb_write_indexed();
}
tlbw_use_hazard();
write_c0_entryhi(pid);
} else {
local_flush_tlb_all();
}
FLUSH_ITLB;
EXIT_CRITICAL(flags);
}
void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
{
int cpu = smp_processor_id();
if (cpu_context(cpu, vma->vm_mm) != 0) {
unsigned long flags;
int oldpid, newpid, idx;
newpid = cpu_asid(cpu, vma->vm_mm);
page &= (PAGE_MASK << 1);
ENTER_CRITICAL(flags);
oldpid = read_c0_entryhi();
write_c0_entryhi(page | newpid);
mtc0_tlbw_hazard();
tlb_probe();
tlb_probe_hazard();
idx = read_c0_index();
write_c0_entrylo0(0);
write_c0_entrylo1(0);
if (idx < 0)
goto finish;
/* Make sure all entries differ. */
write_c0_entryhi(UNIQUE_ENTRYHI(idx));
mtc0_tlbw_hazard();
tlb_write_indexed();
tlbw_use_hazard();
finish:
write_c0_entryhi(oldpid);
FLUSH_ITLB_VM(vma);
EXIT_CRITICAL(flags);
}
}
/*
* This one is only used for pages with the global bit set so we don't care
* much about the ASID.
*/
void local_flush_tlb_one(unsigned long page)
{
unsigned long flags;
int oldpid, idx;
ENTER_CRITICAL(flags);
oldpid = read_c0_entryhi();
page &= (PAGE_MASK << 1);
write_c0_entryhi(page);
mtc0_tlbw_hazard();
tlb_probe();
tlb_probe_hazard();
idx = read_c0_index();
write_c0_entrylo0(0);
write_c0_entrylo1(0);
if (idx >= 0) {
/* Make sure all entries differ. */
write_c0_entryhi(UNIQUE_ENTRYHI(idx));
mtc0_tlbw_hazard();
tlb_write_indexed();
tlbw_use_hazard();
}
write_c0_entryhi(oldpid);
FLUSH_ITLB;
EXIT_CRITICAL(flags);
}
/*
* We will need multiple versions of update_mmu_cache(), one that just
* updates the TLB with the new pte(s), and another which also checks
* for the R4k "end of page" hardware bug and does the needy.
*/
void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
{
unsigned long flags;
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
int idx, pid;
/*
* Handle debugger faulting in for debugee.
*/
if (current->active_mm != vma->vm_mm)
return;
ENTER_CRITICAL(flags);
pid = read_c0_entryhi() & ASID_MASK;
address &= (PAGE_MASK << 1);
write_c0_entryhi(address | pid);
pgdp = pgd_offset(vma->vm_mm, address);
mtc0_tlbw_hazard();
tlb_probe();
tlb_probe_hazard();
pudp = pud_offset(pgdp, address);
pmdp = pmd_offset(pudp, address);
idx = read_c0_index();
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
/* this could be a huge page */
if (pmd_huge(*pmdp)) {
unsigned long lo;
write_c0_pagemask(PM_HUGE_MASK);
ptep = (pte_t *)pmdp;
lo = pte_to_entrylo(pte_val(*ptep));
write_c0_entrylo0(lo);
write_c0_entrylo1(lo + (HPAGE_SIZE >> 7));
mtc0_tlbw_hazard();
if (idx < 0)
tlb_write_random();
else
tlb_write_indexed();
tlbw_use_hazard();
write_c0_pagemask(PM_DEFAULT_MASK);
} else
#endif
{
ptep = pte_offset_map(pmdp, address);
#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
write_c0_entrylo0(ptep->pte_high);
ptep++;
write_c0_entrylo1(ptep->pte_high);
#else
write_c0_entrylo0(pte_to_entrylo(pte_val(*ptep++)));
write_c0_entrylo1(pte_to_entrylo(pte_val(*ptep)));
#endif
mtc0_tlbw_hazard();
if (idx < 0)
tlb_write_random();
else
tlb_write_indexed();
}
tlbw_use_hazard();
FLUSH_ITLB_VM(vma);
EXIT_CRITICAL(flags);
}
void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
unsigned long entryhi, unsigned long pagemask)
{
unsigned long flags;
unsigned long wired;
unsigned long old_pagemask;
unsigned long old_ctx;
ENTER_CRITICAL(flags);
/* Save old context and create impossible VPN2 value */
old_ctx = read_c0_entryhi();
old_pagemask = read_c0_pagemask();
wired = read_c0_wired();
write_c0_wired(wired + 1);
write_c0_index(wired);
tlbw_use_hazard(); /* What is the hazard here? */
write_c0_pagemask(pagemask);
write_c0_entryhi(entryhi);
write_c0_entrylo0(entrylo0);
write_c0_entrylo1(entrylo1);
mtc0_tlbw_hazard();
tlb_write_indexed();
tlbw_use_hazard();
write_c0_entryhi(old_ctx);
tlbw_use_hazard(); /* What is the hazard here? */
write_c0_pagemask(old_pagemask);
local_flush_tlb_all();
EXIT_CRITICAL(flags);
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
int __init has_transparent_hugepage(void)
{
unsigned int mask;
unsigned long flags;
ENTER_CRITICAL(flags);
write_c0_pagemask(PM_HUGE_MASK);
back_to_back_c0_hazard();
mask = read_c0_pagemask();
write_c0_pagemask(PM_DEFAULT_MASK);
EXIT_CRITICAL(flags);
return mask == PM_HUGE_MASK;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
static int __cpuinitdata ntlb;
static int __init set_ntlb(char *str)
{
get_option(&str, &ntlb);
return 1;
}
__setup("ntlb=", set_ntlb);
void __cpuinit tlb_init(void)
{
/*
* You should never change this register:
* - On R4600 1.7 the tlbp never hits for pages smaller than
* the value in the c0_pagemask register.
* - The entire mm handling assumes the c0_pagemask register to
* be set to fixed-size pages.
*/
write_c0_pagemask(PM_DEFAULT_MASK);
write_c0_wired(0);
if (current_cpu_type() == CPU_R10000 ||
current_cpu_type() == CPU_R12000 ||
current_cpu_type() == CPU_R14000)
write_c0_framemask(0);
if (cpu_has_rixi) {
/*
* Enable the no read, no exec bits, and enable large virtual
* address.
*/
u32 pg = PG_RIE | PG_XIE;
#ifdef CONFIG_64BIT
pg |= PG_ELPA;
#endif
write_c0_pagegrain(pg);
}
/* From this point on the ARC firmware is dead. */
local_flush_tlb_all();
/* Did I tell you that ARC SUCKS? */
if (ntlb) {
if (ntlb > 1 && ntlb <= current_cpu_data.tlbsize) {
int wired = current_cpu_data.tlbsize - ntlb;
write_c0_wired(wired);
write_c0_index(wired-1);
printk("Restricting TLB to %d entries\n", ntlb);
} else
printk("Ignoring invalid argument ntlb=%d\n", ntlb);
}
build_tlb_refill_handler();
}
