arch/hexagon/mm/vm_tlb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Hexagon Virtual Machine TLB functions
   4  *
   5  * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
   6  */
   7
   8 /*
   9  * The Hexagon Virtual Machine conceals the real workings of
  10  * the TLB, but there are one or two functions that need to
  11  * be instantiated for it, differently from a native build.
  12  */
  13 #include <linux/mm.h>
  14 #include <linux/sched.h>
  15 #include <asm/page.h>
  16 #include <asm/hexagon_vm.h>
  17
  18 /*
  19  * Initial VM implementation has only one map active at a time, with
  20  * TLB purgings on changes.  So either we're nuking the current map,
  21  * or it's a no-op.  This operation is messy on true SMPs where other
  22  * processors must be induced to flush the copies in their local TLBs,
  23  * but Hexagon thread-based virtual processors share the same MMU.
  24  */
  25 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
  26                         unsigned long end)
  27 {
  28         struct mm_struct *mm = vma->vm_mm;
  29
  30         if (mm->context.ptbase == current->active_mm->context.ptbase)
  31                 __vmclrmap((void *)start, end - start);
  32 }
  33
  34 /*
  35  * Flush a page from the kernel virtual map - used by highmem
  36  */
  37 void flush_tlb_one(unsigned long vaddr)
  38 {
  39         __vmclrmap((void *)vaddr, PAGE_SIZE);
  40 }
  41
  42 /*
  43  * Flush all TLBs across all CPUs, virtual or real.
  44  * A single Hexagon core has 6 thread contexts but
  45  * only one TLB.
  46  */
  47 void tlb_flush_all(void)
  48 {
  49         /*  should probably use that fixaddr end or whateve label  */
  50         __vmclrmap(0, 0xffff0000);
  51 }
  52
  53 /*
  54  * Flush TLB entries associated with a given mm_struct mapping.
  55  */
  56 void flush_tlb_mm(struct mm_struct *mm)
  57 {
  58         /* Current Virtual Machine has only one map active at a time */
  59         if (current->active_mm->context.ptbase == mm->context.ptbase)
  60                 tlb_flush_all();
  61 }
  62
  63 /*
  64  * Flush TLB state associated with a page of a vma.
  65  */
  66 void flush_tlb_page(struct vm_area_struct *vma, unsigned long vaddr)
  67 {
  68         struct mm_struct *mm = vma->vm_mm;
  69
  70         if (mm->context.ptbase  == current->active_mm->context.ptbase)
  71                 __vmclrmap((void *)vaddr, PAGE_SIZE);
  72 }
  73
  74 /*
  75  * Flush TLB entries associated with a kernel address range.
  76  * Like flush range, but without the check on the vma->vm_mm.
  77  */
  78 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
  79 {
  80                 __vmclrmap((void *)start, end - start);
  81 }