arch/sh/mm/pg-sh4.c

   1 /*
   2  * arch/sh/mm/pg-sh4.c
   3  *
   4  * Copyright (C) 1999, 2000, 2002  Niibe Yutaka
   5  * Copyright (C) 2002 - 2005  Paul Mundt
   6  *
   7  * Released under the terms of the GNU GPL v2.0.
   8  */
   9 #include <linux/init.h>
  10 #include <linux/mman.h>
  11 #include <linux/mm.h>
  12 #include <linux/threads.h>
  13 #include <asm/addrspace.h>
  14 #include <asm/page.h>
  15 #include <asm/pgtable.h>
  16 #include <asm/processor.h>
  17 #include <asm/cache.h>
  18 #include <asm/io.h>
  19 #include <asm/uaccess.h>
  20 #include <asm/pgalloc.h>
  21 #include <asm/mmu_context.h>
  22 #include <asm/cacheflush.h>
  23
  24 extern struct semaphore p3map_sem[];
  25
  26 #define CACHE_ALIAS (cpu_data->dcache.alias_mask)
  27
  28 /*
  29  * clear_user_page
  30  * @to: P1 address
  31  * @address: U0 address to be mapped
  32  * @page: page (virt_to_page(to))
  33  */
  34 void clear_user_page(void *to, unsigned long address, struct page *page)
  35 {
  36         __set_bit(PG_mapped, &page->flags);
  37         if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)
  38                 clear_page(to);
  39         else {
  40                 unsigned long phys_addr = PHYSADDR(to);
  41                 unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);
  42                 pgd_t *pgd = pgd_offset_k(p3_addr);
  43                 pud_t *pud = pud_offset(pgd, p3_addr);
  44                 pmd_t *pmd = pmd_offset(pud, p3_addr);
  45                 pte_t *pte = pte_offset_kernel(pmd, p3_addr);
  46                 pte_t entry;
  47                 unsigned long flags;
  48
  49                 entry = pfn_pte(phys_addr >> PAGE_SHIFT, PAGE_KERNEL);
  50                 down(&p3map_sem[(address & CACHE_ALIAS)>>12]);
  51                 set_pte(pte, entry);
  52                 local_irq_save(flags);
  53                 __flush_tlb_page(get_asid(), p3_addr);
  54                 local_irq_restore(flags);
  55                 update_mmu_cache(NULL, p3_addr, entry);
  56                 __clear_user_page((void *)p3_addr, to);
  57                 pte_clear(&init_mm, p3_addr, pte);
  58                 up(&p3map_sem[(address & CACHE_ALIAS)>>12]);
  59         }
  60 }
  61
  62 /*
  63  * copy_user_page
  64  * @to: P1 address
  65  * @from: P1 address
  66  * @address: U0 address to be mapped
  67  * @page: page (virt_to_page(to))
  68  */
  69 void copy_user_page(void *to, void *from, unsigned long address,
  70                     struct page *page)
  71 {
  72         __set_bit(PG_mapped, &page->flags);
  73         if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)
  74                 copy_page(to, from);
  75         else {
  76                 unsigned long phys_addr = PHYSADDR(to);
  77                 unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);
  78                 pgd_t *pgd = pgd_offset_k(p3_addr);
  79                 pud_t *pud = pud_offset(pgd, p3_addr);
  80                 pmd_t *pmd = pmd_offset(pud, p3_addr);
  81                 pte_t *pte = pte_offset_kernel(pmd, p3_addr);
  82                 pte_t entry;
  83                 unsigned long flags;
  84
  85                 entry = pfn_pte(phys_addr >> PAGE_SHIFT, PAGE_KERNEL);
  86                 down(&p3map_sem[(address & CACHE_ALIAS)>>12]);
  87                 set_pte(pte, entry);
  88                 local_irq_save(flags);
  89                 __flush_tlb_page(get_asid(), p3_addr);
  90                 local_irq_restore(flags);
  91                 update_mmu_cache(NULL, p3_addr, entry);
  92                 __copy_user_page((void *)p3_addr, from, to);
  93                 pte_clear(&init_mm, p3_addr, pte);
  94                 up(&p3map_sem[(address & CACHE_ALIAS)>>12]);
  95         }
  96 }
  97
  98 /*
  99  * For SH-4, we have our own implementation for ptep_get_and_clear
 100  */
 101 inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 102 {
 103         pte_t pte = *ptep;
 104
 105         pte_clear(mm, addr, ptep);
 106         if (!pte_not_present(pte)) {
 107                 unsigned long pfn = pte_pfn(pte);
 108                 if (pfn_valid(pfn)) {
 109                         struct page *page = pfn_to_page(pfn);
 110                         struct address_space *mapping = page_mapping(page);
 111                         if (!mapping || !mapping_writably_mapped(mapping))
 112                                 __clear_bit(PG_mapped, &page->flags);
 113                 }
 114         }
 115         return pte;
 116 }
 117