Linux-2.6.33.2/arch/powerpc/mm/tlb_nohash.c
/*
* This file contains the routines for TLB flushing.
* On machines where the MMU does not use a hash table to store virtual to
* physical translations (ie, SW loaded TLBs or Book3E compilant processors,
* this does -not- include 603 however which shares the implementation with
* hash based processors)
*
* -- BenH
*
* Copyright 2008,2009 Ben Herrenschmidt <benh@kernel.crashing.org>
* IBM Corp.
*
* Derived from arch/ppc/mm/init.c:
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
* and Cort Dougan (PReP) (cort@cs.nmt.edu)
* Copyright (C) 1996 Paul Mackerras
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/preempt.h>
#include <linux/spinlock.h>
#include <linux/lmb.h>
#include <asm/tlbflush.h>
#include <asm/tlb.h>
#include <asm/code-patching.h>
#include "mmu_decl.h"
#ifdef CONFIG_PPC_BOOK3E
struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
[MMU_PAGE_4K] = {
.shift = 12,
.enc = BOOK3E_PAGESZ_4K,
},
[MMU_PAGE_16K] = {
.shift = 14,
.enc = BOOK3E_PAGESZ_16K,
},
[MMU_PAGE_64K] = {
.shift = 16,
.enc = BOOK3E_PAGESZ_64K,
},
[MMU_PAGE_1M] = {
.shift = 20,
.enc = BOOK3E_PAGESZ_1M,
},
[MMU_PAGE_16M] = {
.shift = 24,
.enc = BOOK3E_PAGESZ_16M,
},
[MMU_PAGE_256M] = {
.shift = 28,
.enc = BOOK3E_PAGESZ_256M,
},
[MMU_PAGE_1G] = {
.shift = 30,
.enc = BOOK3E_PAGESZ_1GB,
},
};
static inline int mmu_get_tsize(int psize)
{
return mmu_psize_defs[psize].enc;
}
#else
static inline int mmu_get_tsize(int psize)
{
/* This isn't used on !Book3E for now */
return 0;
}
#endif
/* The variables below are currently only used on 64-bit Book3E
* though this will probably be made common with other nohash
* implementations at some point
*/
#ifdef CONFIG_PPC64
int mmu_linear_psize; /* Page size used for the linear mapping */
int mmu_pte_psize; /* Page size used for PTE pages */
int mmu_vmemmap_psize; /* Page size used for the virtual mem map */
int book3e_htw_enabled; /* Is HW tablewalk enabled ? */
unsigned long linear_map_top; /* Top of linear mapping */
#endif /* CONFIG_PPC64 */
/*
* Base TLB flushing operations:
*
* - flush_tlb_mm(mm) flushes the specified mm context TLB's
* - flush_tlb_page(vma, vmaddr) flushes one page
* - flush_tlb_range(vma, start, end) flushes a range of pages
* - flush_tlb_kernel_range(start, end) flushes kernel pages
*
* - local_* variants of page and mm only apply to the current
* processor
*/
/*
* These are the base non-SMP variants of page and mm flushing
*/
void local_flush_tlb_mm(struct mm_struct *mm)
{
unsigned int pid;
preempt_disable();
pid = mm->context.id;
if (pid != MMU_NO_CONTEXT)
_tlbil_pid(pid);
preempt_enable();
}
EXPORT_SYMBOL(local_flush_tlb_mm);
void __local_flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
int tsize, int ind)
{
unsigned int pid;
preempt_disable();
pid = mm ? mm->context.id : 0;
if (pid != MMU_NO_CONTEXT)
_tlbil_va(vmaddr, pid, tsize, ind);
preempt_enable();
}
void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
{
__local_flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
mmu_get_tsize(mmu_virtual_psize), 0);
}
EXPORT_SYMBOL(local_flush_tlb_page);
/*
* And here are the SMP non-local implementations
*/
#ifdef CONFIG_SMP
static DEFINE_SPINLOCK(tlbivax_lock);
static int mm_is_core_local(struct mm_struct *mm)
{
return cpumask_subset(mm_cpumask(mm),
topology_thread_cpumask(smp_processor_id()));
}
struct tlb_flush_param {
unsigned long addr;
unsigned int pid;
unsigned int tsize;
unsigned int ind;
};
static void do_flush_tlb_mm_ipi(void *param)
{
struct tlb_flush_param *p = param;
_tlbil_pid(p ? p->pid : 0);
}
static void do_flush_tlb_page_ipi(void *param)
{
struct tlb_flush_param *p = param;
_tlbil_va(p->addr, p->pid, p->tsize, p->ind);
}
/* Note on invalidations and PID:
*
* We snapshot the PID with preempt disabled. At this point, it can still
* change either because:
* - our context is being stolen (PID -> NO_CONTEXT) on another CPU
* - we are invaliating some target that isn't currently running here
* and is concurrently acquiring a new PID on another CPU
* - some other CPU is re-acquiring a lost PID for this mm
* etc...
*
* However, this shouldn't be a problem as we only guarantee
* invalidation of TLB entries present prior to this call, so we
* don't care about the PID changing, and invalidating a stale PID
* is generally harmless.
*/
void flush_tlb_mm(struct mm_struct *mm)
{
unsigned int pid;
preempt_disable();
pid = mm->context.id;
if (unlikely(pid == MMU_NO_CONTEXT))
goto no_context;
if (!mm_is_core_local(mm)) {
struct tlb_flush_param p = { .pid = pid };
/* Ignores smp_processor_id() even if set. */
smp_call_function_many(mm_cpumask(mm),
do_flush_tlb_mm_ipi, &p, 1);
}
_tlbil_pid(pid);
no_context:
preempt_enable();
}
EXPORT_SYMBOL(flush_tlb_mm);
void __flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
int tsize, int ind)
{
struct cpumask *cpu_mask;
unsigned int pid;
preempt_disable();
pid = mm ? mm->context.id : 0;
if (unlikely(pid == MMU_NO_CONTEXT))
goto bail;
cpu_mask = mm_cpumask(mm);
if (!mm_is_core_local(mm)) {
/* If broadcast tlbivax is supported, use it */
if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) {
int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL);
if (lock)
spin_lock(&tlbivax_lock);
_tlbivax_bcast(vmaddr, pid, tsize, ind);
if (lock)
spin_unlock(&tlbivax_lock);
goto bail;
} else {
struct tlb_flush_param p = {
.pid = pid,
.addr = vmaddr,
.tsize = tsize,
.ind = ind,
};
/* Ignores smp_processor_id() even if set in cpu_mask */
smp_call_function_many(cpu_mask,
do_flush_tlb_page_ipi, &p, 1);
}
}
_tlbil_va(vmaddr, pid, tsize, ind);
bail:
preempt_enable();
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
{
__flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
mmu_get_tsize(mmu_virtual_psize), 0);
}
EXPORT_SYMBOL(flush_tlb_page);
#endif /* CONFIG_SMP */
/*
* Flush kernel TLB entries in the given range
*/
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
#ifdef CONFIG_SMP
preempt_disable();
smp_call_function(do_flush_tlb_mm_ipi, NULL, 1);
_tlbil_pid(0);
preempt_enable();
#else
_tlbil_pid(0);
#endif
}
EXPORT_SYMBOL(flush_tlb_kernel_range);
/*
* Currently, for range flushing, we just do a full mm flush. This should
* be optimized based on a threshold on the size of the range, since
* some implementation can stack multiple tlbivax before a tlbsync but
* for now, we keep it that way
*/
void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
flush_tlb_mm(vma->vm_mm);
}
EXPORT_SYMBOL(flush_tlb_range);
void tlb_flush(struct mmu_gather *tlb)
{
flush_tlb_mm(tlb->mm);
/* Push out batch of freed page tables */
pte_free_finish();
}
/*
* Below are functions specific to the 64-bit variant of Book3E though that
* may change in the future
*/
#ifdef CONFIG_PPC64
/*
* Handling of virtual linear page tables or indirect TLB entries
* flushing when PTE pages are freed
*/
void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address)
{
int tsize = mmu_psize_defs[mmu_pte_psize].enc;
if (book3e_htw_enabled) {
unsigned long start = address & PMD_MASK;
unsigned long end = address + PMD_SIZE;
unsigned long size = 1UL << mmu_psize_defs[mmu_pte_psize].shift;
/* This isn't the most optimal, ideally we would factor out the
* while preempt & CPU mask mucking around, or even the IPI but
* it will do for now
*/
while (start < end) {
__flush_tlb_page(tlb->mm, start, tsize, 1);
start += size;
}
} else {
unsigned long rmask = 0xf000000000000000ul;
unsigned long rid = (address & rmask) | 0x1000000000000000ul;
unsigned long vpte = address & ~rmask;
#ifdef CONFIG_PPC_64K_PAGES
vpte = (vpte >> (PAGE_SHIFT - 4)) & ~0xfffful;
#else
vpte = (vpte >> (PAGE_SHIFT - 3)) & ~0xffful;
#endif
vpte |= rid;
__flush_tlb_page(tlb->mm, vpte, tsize, 0);
}
}
/*
* Early initialization of the MMU TLB code
*/
static void __early_init_mmu(int boot_cpu)
{
extern unsigned int interrupt_base_book3e;
extern unsigned int exc_data_tlb_miss_htw_book3e;
extern unsigned int exc_instruction_tlb_miss_htw_book3e;
unsigned int *ibase = &interrupt_base_book3e;
unsigned int mas4;
/* XXX This will have to be decided at runtime, but right
* now our boot and TLB miss code hard wires it. Ideally
* we should find out a suitable page size and patch the
* TLB miss code (either that or use the PACA to store
* the value we want)
*/
mmu_linear_psize = MMU_PAGE_1G;
/* XXX This should be decided at runtime based on supported
* page sizes in the TLB, but for now let's assume 16M is
* always there and a good fit (which it probably is)
*/
mmu_vmemmap_psize = MMU_PAGE_16M;
/* Check if HW tablewalk is present, and if yes, enable it by:
*
* - patching the TLB miss handlers to branch to the
* one dedicates to it
*
* - setting the global book3e_htw_enabled
*
* - Set MAS4:INDD and default page size
*/
/* XXX This code only checks for TLB 0 capabilities and doesn't
* check what page size combos are supported by the HW. It
* also doesn't handle the case where a separate array holds
* the IND entries from the array loaded by the PT.
*/
if (boot_cpu) {
unsigned int tlb0cfg = mfspr(SPRN_TLB0CFG);
/* Check if HW loader is supported */
if ((tlb0cfg & TLBnCFG_IND) &&
(tlb0cfg & TLBnCFG_PT)) {
patch_branch(ibase + (0x1c0 / 4),
(unsigned long)&exc_data_tlb_miss_htw_book3e, 0);
patch_branch(ibase + (0x1e0 / 4),
(unsigned long)&exc_instruction_tlb_miss_htw_book3e, 0);
book3e_htw_enabled = 1;
}
pr_info("MMU: Book3E Page Tables %s\n",
book3e_htw_enabled ? "Enabled" : "Disabled");
}
/* Set MAS4 based on page table setting */
mas4 = 0x4 << MAS4_WIMGED_SHIFT;
if (book3e_htw_enabled) {
mas4 |= mas4 | MAS4_INDD;
#ifdef CONFIG_PPC_64K_PAGES
mas4 |= BOOK3E_PAGESZ_256M << MAS4_TSIZED_SHIFT;
mmu_pte_psize = MMU_PAGE_256M;
#else
mas4 |= BOOK3E_PAGESZ_1M << MAS4_TSIZED_SHIFT;
mmu_pte_psize = MMU_PAGE_1M;
#endif
} else {
#ifdef CONFIG_PPC_64K_PAGES
mas4 |= BOOK3E_PAGESZ_64K << MAS4_TSIZED_SHIFT;
#else
mas4 |= BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT;
#endif
mmu_pte_psize = mmu_virtual_psize;
}
mtspr(SPRN_MAS4, mas4);
/* Set the global containing the top of the linear mapping
* for use by the TLB miss code
*/
linear_map_top = lmb_end_of_DRAM();
/* A sync won't hurt us after mucking around with
* the MMU configuration
*/
mb();
}
void __init early_init_mmu(void)
{
__early_init_mmu(1);
}
void __cpuinit early_init_mmu_secondary(void)
{
__early_init_mmu(0);
}
#endif /* CONFIG_PPC64 */