arch/openrisc/mm/cache.c

   1 /*
   2  * OpenRISC cache.c
   3  *
   4  * Linux architectural port borrowing liberally from similar works of
   5  * others.  All original copyrights apply as per the original source
   6  * declaration.
   7  *
   8  * Modifications for the OpenRISC architecture:
   9  * Copyright (C) 2015 Jan Henrik Weinstock <jan.weinstock@rwth-aachen.de>
  10  *
  11  *      This program is free software; you can redistribute it and/or
  12  *      modify it under the terms of the GNU General Public License
  13  *      as published by the Free Software Foundation; either version
  14  *      2 of the License, or (at your option) any later version.
  15  */
  16
  17 #include <asm/spr.h>
  18 #include <asm/spr_defs.h>
  19 #include <asm/cache.h>
  20 #include <asm/cacheflush.h>
  21 #include <asm/tlbflush.h>
  22
  23 static void cache_loop(struct page *page, const unsigned int reg)
  24 {
  25         unsigned long paddr = page_to_pfn(page) << PAGE_SHIFT;
  26         unsigned long line = paddr & ~(L1_CACHE_BYTES - 1);
  27
  28         while (line < paddr + PAGE_SIZE) {
  29                 mtspr(reg, line);
  30                 line += L1_CACHE_BYTES;
  31         }
  32 }
  33
  34 void local_dcache_page_flush(struct page *page)
  35 {
  36         cache_loop(page, SPR_DCBFR);
  37 }
  38 EXPORT_SYMBOL(local_dcache_page_flush);
  39
  40 void local_icache_page_inv(struct page *page)
  41 {
  42         cache_loop(page, SPR_ICBIR);
  43 }
  44 EXPORT_SYMBOL(local_icache_page_inv);
  45
  46 void update_cache(struct vm_area_struct *vma, unsigned long address,
  47         pte_t *pte)
  48 {
  49         unsigned long pfn = pte_val(*pte) >> PAGE_SHIFT;
  50         struct page *page = pfn_to_page(pfn);
  51         int dirty = !test_and_set_bit(PG_dc_clean, &page->flags);
  52
  53         /*
  54          * Since icaches do not snoop for updated data on OpenRISC, we
  55          * must write back and invalidate any dirty pages manually. We
  56          * can skip data pages, since they will not end up in icaches.
  57          */
  58         if ((vma->vm_flags & VM_EXEC) && dirty)
  59                 sync_icache_dcache(page);
  60 }
  61