linux/arch/tile/kernel/tlb.c
Chris Metcalf abe3265a6d tile: do less L1 I-cache eviction
We had been doing an automatic full eviction of the L1 I$
everywhere whenever we did a kernel-space TLB flush.  It turns
out this isn't necessary, since all the callers already handle
doing a flush if necessary.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
2013-08-30 11:56:34 -04:00

105 lines
3.0 KiB
C

/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* 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, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*
*/
#include <linux/cpumask.h>
#include <linux/module.h>
#include <linux/hugetlb.h>
#include <asm/tlbflush.h>
#include <asm/homecache.h>
#include <hv/hypervisor.h>
/* From tlbflush.h */
DEFINE_PER_CPU(int, current_asid);
int min_asid, max_asid;
/*
* Note that we flush the L1I (for VM_EXEC pages) as well as the TLB
* so that when we are unmapping an executable page, we also flush it.
* Combined with flushing the L1I at context switch time, this means
* we don't have to do any other icache flushes.
*/
void flush_tlb_mm(struct mm_struct *mm)
{
HV_Remote_ASID asids[NR_CPUS];
int i = 0, cpu;
for_each_cpu(cpu, mm_cpumask(mm)) {
HV_Remote_ASID *asid = &asids[i++];
asid->y = cpu / smp_topology.width;
asid->x = cpu % smp_topology.width;
asid->asid = per_cpu(current_asid, cpu);
}
flush_remote(0, HV_FLUSH_EVICT_L1I, mm_cpumask(mm),
0, 0, 0, NULL, asids, i);
}
void flush_tlb_current_task(void)
{
flush_tlb_mm(current->mm);
}
void flush_tlb_page_mm(struct vm_area_struct *vma, struct mm_struct *mm,
unsigned long va)
{
unsigned long size = vma_kernel_pagesize(vma);
int cache = (vma->vm_flags & VM_EXEC) ? HV_FLUSH_EVICT_L1I : 0;
flush_remote(0, cache, mm_cpumask(mm),
va, size, size, mm_cpumask(mm), NULL, 0);
}
void flush_tlb_page(struct vm_area_struct *vma, unsigned long va)
{
flush_tlb_page_mm(vma, vma->vm_mm, va);
}
EXPORT_SYMBOL(flush_tlb_page);
void flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
unsigned long size = vma_kernel_pagesize(vma);
struct mm_struct *mm = vma->vm_mm;
int cache = (vma->vm_flags & VM_EXEC) ? HV_FLUSH_EVICT_L1I : 0;
flush_remote(0, cache, mm_cpumask(mm), start, end - start, size,
mm_cpumask(mm), NULL, 0);
}
void flush_tlb_all(void)
{
int i;
for (i = 0; ; ++i) {
HV_VirtAddrRange r = hv_inquire_virtual(i);
if (r.size == 0)
break;
flush_remote(0, HV_FLUSH_EVICT_L1I, cpu_online_mask,
r.start, r.size, PAGE_SIZE, cpu_online_mask,
NULL, 0);
flush_remote(0, 0, NULL,
r.start, r.size, HPAGE_SIZE, cpu_online_mask,
NULL, 0);
}
}
/*
* Callers need to flush the L1I themselves if necessary, e.g. for
* kernel module unload. Otherwise we assume callers are not using
* executable pgprot_t's. Using EVICT_L1I means that dataplane cpus
* will get an unnecessary interrupt otherwise.
*/
void flush_tlb_kernel_range(unsigned long start, unsigned long end)
{
flush_remote(0, 0, NULL,
start, end - start, PAGE_SIZE, cpu_online_mask, NULL, 0);
}