kernel-ark/arch/ia64/mm/tlb.c
2005-10-28 15:27:36 -07:00

194 lines
4.6 KiB
C

/*
* TLB support routines.
*
* Copyright (C) 1998-2001, 2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* 08/02/00 A. Mallick <asit.k.mallick@intel.com>
* Modified RID allocation for SMP
* Goutham Rao <goutham.rao@intel.com>
* IPI based ptc implementation and A-step IPI implementation.
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <asm/delay.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/pal.h>
#include <asm/tlbflush.h>
static struct {
unsigned long mask; /* mask of supported purge page-sizes */
unsigned long max_bits; /* log2() of largest supported purge page-size */
} purge;
struct ia64_ctx ia64_ctx = {
.lock = SPIN_LOCK_UNLOCKED,
.next = 1,
.limit = (1 << 15) - 1, /* start out with the safe (architected) limit */
.max_ctx = ~0U
};
DEFINE_PER_CPU(u8, ia64_need_tlb_flush);
/*
* Acquire the ia64_ctx.lock before calling this function!
*/
void
wrap_mmu_context (struct mm_struct *mm)
{
unsigned long tsk_context, max_ctx = ia64_ctx.max_ctx;
struct task_struct *tsk;
int i;
if (ia64_ctx.next > max_ctx)
ia64_ctx.next = 300; /* skip daemons */
ia64_ctx.limit = max_ctx + 1;
/*
* Scan all the task's mm->context and set proper safe range
*/
read_lock(&tasklist_lock);
repeat:
for_each_process(tsk) {
if (!tsk->mm)
continue;
tsk_context = tsk->mm->context;
if (tsk_context == ia64_ctx.next) {
if (++ia64_ctx.next >= ia64_ctx.limit) {
/* empty range: reset the range limit and start over */
if (ia64_ctx.next > max_ctx)
ia64_ctx.next = 300;
ia64_ctx.limit = max_ctx + 1;
goto repeat;
}
}
if ((tsk_context > ia64_ctx.next) && (tsk_context < ia64_ctx.limit))
ia64_ctx.limit = tsk_context;
}
read_unlock(&tasklist_lock);
/* can't call flush_tlb_all() here because of race condition with O(1) scheduler [EF] */
{
int cpu = get_cpu(); /* prevent preemption/migration */
for_each_online_cpu(i) {
if (i != cpu)
per_cpu(ia64_need_tlb_flush, i) = 1;
}
put_cpu();
}
local_flush_tlb_all();
}
void
ia64_global_tlb_purge (struct mm_struct *mm, unsigned long start, unsigned long end, unsigned long nbits)
{
static DEFINE_SPINLOCK(ptcg_lock);
if (mm != current->active_mm) {
flush_tlb_all();
return;
}
/* HW requires global serialization of ptc.ga. */
spin_lock(&ptcg_lock);
{
do {
/*
* Flush ALAT entries also.
*/
ia64_ptcga(start, (nbits<<2));
ia64_srlz_i();
start += (1UL << nbits);
} while (start < end);
}
spin_unlock(&ptcg_lock);
}
void
local_flush_tlb_all (void)
{
unsigned long i, j, flags, count0, count1, stride0, stride1, addr;
addr = local_cpu_data->ptce_base;
count0 = local_cpu_data->ptce_count[0];
count1 = local_cpu_data->ptce_count[1];
stride0 = local_cpu_data->ptce_stride[0];
stride1 = local_cpu_data->ptce_stride[1];
local_irq_save(flags);
for (i = 0; i < count0; ++i) {
for (j = 0; j < count1; ++j) {
ia64_ptce(addr);
addr += stride1;
}
addr += stride0;
}
local_irq_restore(flags);
ia64_srlz_i(); /* srlz.i implies srlz.d */
}
void
flush_tlb_range (struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long size = end - start;
unsigned long nbits;
#ifndef CONFIG_SMP
if (mm != current->active_mm) {
mm->context = 0;
return;
}
#endif
nbits = ia64_fls(size + 0xfff);
while (unlikely (((1UL << nbits) & purge.mask) == 0) && (nbits < purge.max_bits))
++nbits;
if (nbits > purge.max_bits)
nbits = purge.max_bits;
start &= ~((1UL << nbits) - 1);
# ifdef CONFIG_SMP
platform_global_tlb_purge(mm, start, end, nbits);
# else
do {
ia64_ptcl(start, (nbits<<2));
start += (1UL << nbits);
} while (start < end);
# endif
ia64_srlz_i(); /* srlz.i implies srlz.d */
}
EXPORT_SYMBOL(flush_tlb_range);
void __devinit
ia64_tlb_init (void)
{
ia64_ptce_info_t ptce_info;
unsigned long tr_pgbits;
long status;
if ((status = ia64_pal_vm_page_size(&tr_pgbits, &purge.mask)) != 0) {
printk(KERN_ERR "PAL_VM_PAGE_SIZE failed with status=%ld;"
"defaulting to architected purge page-sizes.\n", status);
purge.mask = 0x115557000UL;
}
purge.max_bits = ia64_fls(purge.mask);
ia64_get_ptce(&ptce_info);
local_cpu_data->ptce_base = ptce_info.base;
local_cpu_data->ptce_count[0] = ptce_info.count[0];
local_cpu_data->ptce_count[1] = ptce_info.count[1];
local_cpu_data->ptce_stride[0] = ptce_info.stride[0];
local_cpu_data->ptce_stride[1] = ptce_info.stride[1];
local_flush_tlb_all(); /* nuke left overs from bootstrapping... */
}