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  Paul Mundt
   6  *
   7  * Released under the terms of the GNU GPL v2.0.
   8  */
   9 #include <linux/config.h>
  10 #include <linux/init.h>
  11 #include <linux/mman.h>
  12 #include <linux/mm.h>
  13 #include <linux/threads.h>
  14 #include <asm/addrspace.h>
  15 #include <asm/page.h>
  16 #include <asm/pgtable.h>
  17 #include <asm/processor.h>
  18 #include <asm/cache.h>
  19 #include <asm/io.h>
  20 #include <asm/uaccess.h>
  21 #include <asm/pgalloc.h>
  22 #include <asm/mmu_context.h>
  23 #include <asm/cacheflush.h>
  24
  25 extern struct semaphore p3map_sem[];
  26
  27 /*
  28  * clear_user_page
  29  * @to: P1 address
  30  * @address: U0 address to be mapped
  31  * @page: page (virt_to_page(to))
  32  */
  33 void clear_user_page(void *to, unsigned long address, struct page *page)
  34 {
  35         __set_bit(PG_mapped, &page->flags);
  36         if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)
  37                 clear_page(to);
  38         else {
  39                 pgprot_t pgprot = __pgprot(_PAGE_PRESENT |
  40                                            _PAGE_RW | _PAGE_CACHABLE |
  41                                            _PAGE_DIRTY | _PAGE_ACCESSED |
  42                                            _PAGE_HW_SHARED | _PAGE_FLAGS_HARD);
  43                 unsigned long phys_addr = PHYSADDR(to);
  44                 unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);
  45                 pgd_t *dir = pgd_offset_k(p3_addr);
  46                 pmd_t *pmd = pmd_offset(dir, p3_addr);
  47                 pte_t *pte = pte_offset_kernel(pmd, p3_addr);
  48                 pte_t entry;
  49                 unsigned long flags;
  50
  51                 entry = pfn_pte(phys_addr >> PAGE_SHIFT, pgprot);
  52                 down(&p3map_sem[(address & CACHE_ALIAS)>>12]);
  53                 set_pte(pte, entry);
  54                 local_irq_save(flags);
  55                 __flush_tlb_page(get_asid(), p3_addr);
  56                 local_irq_restore(flags);
  57                 update_mmu_cache(NULL, p3_addr, entry);
  58                 __clear_user_page((void *)p3_addr, to);
  59                 pte_clear(&init_mm, p3_addr, pte);
  60                 up(&p3map_sem[(address & CACHE_ALIAS)>>12]);
  61         }
  62 }
  63
  64 /*
  65  * copy_user_page
  66  * @to: P1 address
  67  * @from: P1 address
  68  * @address: U0 address to be mapped
  69  * @page: page (virt_to_page(to))
  70  */
  71 void copy_user_page(void *to, void *from, unsigned long address,
  72                     struct page *page)
  73 {
  74         __set_bit(PG_mapped, &page->flags);
  75         if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)
  76                 copy_page(to, from);
  77         else {
  78                 pgprot_t pgprot = __pgprot(_PAGE_PRESENT |
  79                                            _PAGE_RW | _PAGE_CACHABLE |
  80                                            _PAGE_DIRTY | _PAGE_ACCESSED |
  81                                            _PAGE_HW_SHARED | _PAGE_FLAGS_HARD);
  82                 unsigned long phys_addr = PHYSADDR(to);
  83                 unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);
  84                 pgd_t *dir = pgd_offset_k(p3_addr);
  85                 pmd_t *pmd = pmd_offset(dir, p3_addr);
  86                 pte_t *pte = pte_offset_kernel(pmd, p3_addr);
  87                 pte_t entry;
  88                 unsigned long flags;
  89
  90                 entry = pfn_pte(phys_addr >> PAGE_SHIFT, pgprot);
  91                 down(&p3map_sem[(address & CACHE_ALIAS)>>12]);
  92                 set_pte(pte, entry);
  93                 local_irq_save(flags);
  94                 __flush_tlb_page(get_asid(), p3_addr);
  95                 local_irq_restore(flags);
  96                 update_mmu_cache(NULL, p3_addr, entry);
  97                 __copy_user_page((void *)p3_addr, from, to);
  98                 pte_clear(&init_mm, p3_addr, pte);
  99                 up(&p3map_sem[(address & CACHE_ALIAS)>>12]);
 100         }
 101 }
 102
 103 /*
 104  * For SH-4, we have our own implementation for ptep_get_and_clear
 105  */
 106 inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 107 {
 108         pte_t pte = *ptep;
 109
 110         pte_clear(mm, addr, ptep);
 111         if (!pte_not_present(pte)) {
 112                 unsigned long pfn = pte_pfn(pte);
 113                 if (pfn_valid(pfn)) {
 114                         struct page *page = pfn_to_page(pfn);
 115                         struct address_space *mapping = page_mapping(page);
 116                         if (!mapping || !mapping_writably_mapped(mapping))
 117                                 __clear_bit(PG_mapped, &page->flags);
 118                 }
 119         }
 120         return pte;
 121 }
 122