LXR linux/arch/hexagon/mm/vm

   1/*
   2 * Hexagon Virtual Machine TLB functions
   3 *
   4 * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 and
   8 * only version 2 as published by the Free Software Foundation.
   9 *
  10 * This program is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 * GNU General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU General Public License
  16 * along with this program; if not, write to the Free Software
  17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18 * 02110-1301, USA.
  19 */
  20
  21/*
  22 * The Hexagon Virtual Machine conceals the real workings of
  23 * the TLB, but there are one or two functions that need to
  24 * be instantiated for it, differently from a native build.
  25 */
  26#include <linux/mm.h>
  27#include <linux/sched.h>
  28#include <asm/page.h>
  29#include <asm/hexagon_vm.h>
  30
  31/*
  32 * Initial VM implementation has only one map active at a time, with
  33 * TLB purgings on changes.  So either we're nuking the current map,
  34 * or it's a no-op.  This operation is messy on true SMPs where other
  35 * processors must be induced to flush the copies in their local TLBs,
  36 * but Hexagon thread-based virtual processors share the same MMU.
  37 */
  38void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
  39                        unsigned long end)
  40{
  41        struct mm_struct *mm = vma->vm_mm;
  42
  43        if (mm->context.ptbase == current->active_mm->context.ptbase)
  44                __vmclrmap((void *)start, end - start);
  45}
  46
  47/*
  48 * Flush a page from the kernel virtual map - used by highmem
  49 */
  50void flush_tlb_one(unsigned long vaddr)
  51{
  52        __vmclrmap((void *)vaddr, PAGE_SIZE);
  53}
  54
  55/*
  56 * Flush all TLBs across all CPUs, virtual or real.
  57 * A single Hexagon core has 6 thread contexts but
  58 * only one TLB.
  59 */
  60void tlb_flush_all(void)
  61{
  62        /*  should probably use that fixaddr end or whateve label  */
  63        __vmclrmap(0, 0xffff0000);
  64}
  65
  66/*
  67 * Flush TLB entries associated with a given mm_struct mapping.
  68 */
  69void flush_tlb_mm(struct mm_struct *mm)
  70{
  71        /* Current Virtual Machine has only one map active at a time */
  72        if (current->active_mm->context.ptbase == mm->context.ptbase)
  73                tlb_flush_all();
  74}
  75
  76/*
  77 * Flush TLB state associated with a page of a vma.
  78 */
  79void flush_tlb_page(struct vm_area_struct *vma, unsigned long vaddr)
  80{
  81        struct mm_struct *mm = vma->vm_mm;
  82
  83        if (mm->context.ptbase  == current->active_mm->context.ptbase)
  84                __vmclrmap((void *)vaddr, PAGE_SIZE);
  85}
  86
  87/*
  88 * Flush TLB entries associated with a kernel address range.
  89 * Like flush range, but without the check on the vma->vm_mm.
  90 */
  91void flush_tlb_kernel_range(unsigned long start, unsigned long end)
  92{
  93                __vmclrmap((void *)start, end - start);
  94}
  95