arch/openrisc/mm/cache.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * OpenRISC cache.c
   4  *
   5  * Linux architectural port borrowing liberally from similar works of
   6  * others.  All original copyrights apply as per the original source
   7  * declaration.
   8  *
   9  * Modifications for the OpenRISC architecture:
  10  * Copyright (C) 2015 Jan Henrik Weinstock <jan.weinstock@rwth-aachen.de>
  11  */
  12
  13 #include <asm/spr.h>
  14 #include <asm/spr_defs.h>
  15 #include <asm/cache.h>
  16 #include <asm/cacheflush.h>
  17 #include <asm/tlbflush.h>
  18
  19 static __always_inline void cache_loop(struct page *page, const unsigned int reg)
  20 {
  21         unsigned long paddr = page_to_pfn(page) << PAGE_SHIFT;
  22         unsigned long line = paddr & ~(L1_CACHE_BYTES - 1);
  23
  24         while (line < paddr + PAGE_SIZE) {
  25                 mtspr(reg, line);
  26                 line += L1_CACHE_BYTES;
  27         }
  28 }
  29
  30 void local_dcache_page_flush(struct page *page)
  31 {
  32         cache_loop(page, SPR_DCBFR);
  33 }
  34 EXPORT_SYMBOL(local_dcache_page_flush);
  35
  36 void local_icache_page_inv(struct page *page)
  37 {
  38         cache_loop(page, SPR_ICBIR);
  39 }
  40 EXPORT_SYMBOL(local_icache_page_inv);
  41
  42 void update_cache(struct vm_area_struct *vma, unsigned long address,
  43         pte_t *pte)
  44 {
  45         unsigned long pfn = pte_val(*pte) >> PAGE_SHIFT;
  46         struct page *page = pfn_to_page(pfn);
  47         int dirty = !test_and_set_bit(PG_dc_clean, &page->flags);
  48
  49         /*
  50          * Since icaches do not snoop for updated data on OpenRISC, we
  51          * must write back and invalidate any dirty pages manually. We
  52          * can skip data pages, since they will not end up in icaches.
  53          */
  54         if ((vma->vm_flags & VM_EXEC) && dirty)
  55                 sync_icache_dcache(page);
  56 }
  57