arch/hexagon/mm/vm_tlb.c

   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  */
  38 void 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  */
  50 void 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  */
  60 void 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  */
  69 void 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  */
  79 void 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  */
  91 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
  92 {
  93                 __vmclrmap((void *)start, end - start);
  94 }