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/*
* 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 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 <asm/tlbflush.h>
#include <asm/tlb.h>
#include "mmu_decl.h"
/*
* 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,
0 /* tsize unused for now */, 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,
0 /* tsize unused for now */, 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);
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