arch/mn10300/mm/cache.c

   1 /* MN10300 Cache flushing routines
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  */
  11 #include <linux/module.h>
  12 #include <linux/mm.h>
  13 #include <linux/mman.h>
  14 #include <linux/threads.h>
  15 #include <asm/page.h>
  16 #include <asm/pgtable.h>
  17 #include <asm/processor.h>
  18 #include <asm/cacheflush.h>
  19 #include <asm/io.h>
  20 #include <asm/uaccess.h>
  21
  22 EXPORT_SYMBOL(mn10300_icache_inv);
  23 EXPORT_SYMBOL(mn10300_dcache_inv);
  24 EXPORT_SYMBOL(mn10300_dcache_inv_range);
  25 EXPORT_SYMBOL(mn10300_dcache_inv_range2);
  26 EXPORT_SYMBOL(mn10300_dcache_inv_page);
  27
  28 #ifdef CONFIG_MN10300_CACHE_WBACK
  29 EXPORT_SYMBOL(mn10300_dcache_flush);
  30 EXPORT_SYMBOL(mn10300_dcache_flush_inv);
  31 EXPORT_SYMBOL(mn10300_dcache_flush_inv_range);
  32 EXPORT_SYMBOL(mn10300_dcache_flush_inv_range2);
  33 EXPORT_SYMBOL(mn10300_dcache_flush_inv_page);
  34 EXPORT_SYMBOL(mn10300_dcache_flush_range);
  35 EXPORT_SYMBOL(mn10300_dcache_flush_range2);
  36 EXPORT_SYMBOL(mn10300_dcache_flush_page);
  37 #endif
  38
  39 /*
  40  * write a page back from the dcache and invalidate the icache so that we can
  41  * run code from it that we've just written into it
  42  */
  43 void flush_icache_page(struct vm_area_struct *vma, struct page *page)
  44 {
  45         mn10300_dcache_flush_page(page_to_phys(page));
  46         mn10300_icache_inv();
  47 }
  48 EXPORT_SYMBOL(flush_icache_page);
  49
  50 /*
  51  * write some code we've just written back from the dcache and invalidate the
  52  * icache so that we can run that code
  53  */
  54 void flush_icache_range(unsigned long start, unsigned long end)
  55 {
  56 #ifdef CONFIG_MN10300_CACHE_WBACK
  57         unsigned long addr, size, base, off;
  58         struct page *page;
  59         pgd_t *pgd;
  60         pud_t *pud;
  61         pmd_t *pmd;
  62         pte_t *ppte, pte;
  63
  64         if (end > 0x80000000UL) {
  65                 /* addresses above 0xa0000000 do not go through the cache */
  66                 if (end > 0xa0000000UL) {
  67                         end = 0xa0000000UL;
  68                         if (start >= end)
  69                                 return;
  70                 }
  71
  72                 /* kernel addresses between 0x80000000 and 0x9fffffff do not
  73                  * require page tables, so we just map such addresses directly */
  74                 base = (start >= 0x80000000UL) ? start : 0x80000000UL;
  75                 mn10300_dcache_flush_range(base, end);
  76                 if (base == start)
  77                         goto invalidate;
  78                 end = base;
  79         }
  80
  81         for (; start < end; start += size) {
  82                 /* work out how much of the page to flush */
  83                 off = start & (PAGE_SIZE - 1);
  84
  85                 size = end - start;
  86                 if (size > PAGE_SIZE - off)
  87                         size = PAGE_SIZE - off;
  88
  89                 /* get the physical address the page is mapped to from the page
  90                  * tables */
  91                 pgd = pgd_offset(current->mm, start);
  92                 if (!pgd || !pgd_val(*pgd))
  93                         continue;
  94
  95                 pud = pud_offset(pgd, start);
  96                 if (!pud || !pud_val(*pud))
  97                         continue;
  98
  99                 pmd = pmd_offset(pud, start);
 100                 if (!pmd || !pmd_val(*pmd))
 101                         continue;
 102
 103                 ppte = pte_offset_map(pmd, start);
 104                 if (!ppte)
 105                         continue;
 106                 pte = *ppte;
 107                 pte_unmap(ppte);
 108
 109                 if (pte_none(pte))
 110                         continue;
 111
 112                 page = pte_page(pte);
 113                 if (!page)
 114                         continue;
 115
 116                 addr = page_to_phys(page);
 117
 118                 /* flush the dcache and invalidate the icache coverage on that
 119                  * region */
 120                 mn10300_dcache_flush_range2(addr + off, size);
 121         }
 122 #endif
 123
 124 invalidate:
 125         mn10300_icache_inv();
 126 }
 127 EXPORT_SYMBOL(flush_icache_range);
 128
 129 /*
 130  * allow userspace to flush the instruction cache
 131  */
 132 asmlinkage long sys_cacheflush(unsigned long start, unsigned long end)
 133 {
 134         if (end < start)
 135                 return -EINVAL;
 136
 137         flush_icache_range(start, end);
 138         return 0;
 139 }