0186f47e70
Refactor the RCU based pte free code that was used on ppc64 to be used on all powerpc. Additionally refactor pte_free() & pte_free_kernel() into common code between ppc32 & ppc64. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
117 lines
3 KiB
C
117 lines
3 KiB
C
/*
|
|
* This file contains common routines for dealing with free of page tables
|
|
*
|
|
* Derived from arch/powerpc/mm/tlb_64.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
|
|
*
|
|
* Dave Engebretsen <engebret@us.ibm.com>
|
|
* Rework for PPC64 port.
|
|
*
|
|
* 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/percpu.h>
|
|
#include <linux/hardirq.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/tlbflush.h>
|
|
#include <asm/tlb.h>
|
|
|
|
static DEFINE_PER_CPU(struct pte_freelist_batch *, pte_freelist_cur);
|
|
static unsigned long pte_freelist_forced_free;
|
|
|
|
struct pte_freelist_batch
|
|
{
|
|
struct rcu_head rcu;
|
|
unsigned int index;
|
|
pgtable_free_t tables[0];
|
|
};
|
|
|
|
#define PTE_FREELIST_SIZE \
|
|
((PAGE_SIZE - sizeof(struct pte_freelist_batch)) \
|
|
/ sizeof(pgtable_free_t))
|
|
|
|
static void pte_free_smp_sync(void *arg)
|
|
{
|
|
/* Do nothing, just ensure we sync with all CPUs */
|
|
}
|
|
|
|
/* This is only called when we are critically out of memory
|
|
* (and fail to get a page in pte_free_tlb).
|
|
*/
|
|
static void pgtable_free_now(pgtable_free_t pgf)
|
|
{
|
|
pte_freelist_forced_free++;
|
|
|
|
smp_call_function(pte_free_smp_sync, NULL, 1);
|
|
|
|
pgtable_free(pgf);
|
|
}
|
|
|
|
static void pte_free_rcu_callback(struct rcu_head *head)
|
|
{
|
|
struct pte_freelist_batch *batch =
|
|
container_of(head, struct pte_freelist_batch, rcu);
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < batch->index; i++)
|
|
pgtable_free(batch->tables[i]);
|
|
|
|
free_page((unsigned long)batch);
|
|
}
|
|
|
|
static void pte_free_submit(struct pte_freelist_batch *batch)
|
|
{
|
|
INIT_RCU_HEAD(&batch->rcu);
|
|
call_rcu(&batch->rcu, pte_free_rcu_callback);
|
|
}
|
|
|
|
void pgtable_free_tlb(struct mmu_gather *tlb, pgtable_free_t pgf)
|
|
{
|
|
/* This is safe since tlb_gather_mmu has disabled preemption */
|
|
cpumask_t local_cpumask = cpumask_of_cpu(smp_processor_id());
|
|
struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur);
|
|
|
|
if (atomic_read(&tlb->mm->mm_users) < 2 ||
|
|
cpus_equal(tlb->mm->cpu_vm_mask, local_cpumask)) {
|
|
pgtable_free(pgf);
|
|
return;
|
|
}
|
|
|
|
if (*batchp == NULL) {
|
|
*batchp = (struct pte_freelist_batch *)__get_free_page(GFP_ATOMIC);
|
|
if (*batchp == NULL) {
|
|
pgtable_free_now(pgf);
|
|
return;
|
|
}
|
|
(*batchp)->index = 0;
|
|
}
|
|
(*batchp)->tables[(*batchp)->index++] = pgf;
|
|
if ((*batchp)->index == PTE_FREELIST_SIZE) {
|
|
pte_free_submit(*batchp);
|
|
*batchp = NULL;
|
|
}
|
|
}
|
|
|
|
void pte_free_finish(void)
|
|
{
|
|
/* This is safe since tlb_gather_mmu has disabled preemption */
|
|
struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur);
|
|
|
|
if (*batchp == NULL)
|
|
return;
|
|
pte_free_submit(*batchp);
|
|
*batchp = NULL;
|
|
}
|