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                 pgprot_t pgprot = __pgprot(_PAGE_PRESENT |
  41                                            _PAGE_RW | _PAGE_CACHABLE |
  42                                            _PAGE_DIRTY | _PAGE_ACCESSED |
  43                                            _PAGE_HW_SHARED | _PAGE_FLAGS_HARD);
  44                 unsigned long phys_addr = PHYSADDR(to);
  45                 unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);
  46                 pgd_t *pgd = pgd_offset_k(p3_addr);
  47                 pud_t *pud = pud_offset(pgd, p3_addr);
  48                 pmd_t *pmd = pmd_offset(pud, p3_addr);
  49                 pte_t *pte = pte_offset_kernel(pmd, p3_addr);
  50                 pte_t entry;
  51                 unsigned long flags;
  52
  53                 entry = pfn_pte(phys_addr >> PAGE_SHIFT, pgprot);
  54                 down(&p3map_sem[(address & CACHE_ALIAS)>>12]);
  55                 set_pte(pte, entry);
  56                 local_irq_save(flags);
  57                 __flush_tlb_page(get_asid(), p3_addr);
  58                 local_irq_restore(flags);
  59                 update_mmu_cache(NULL, p3_addr, entry);
  60                 __clear_user_page((void *)p3_addr, to);
  61                 pte_clear(&init_mm, p3_addr, pte);
  62                 up(&p3map_sem[(address & CACHE_ALIAS)>>12]);
  63         }
  64 }
  65
  66 /*
  67  * copy_user_page
  68  * @to: P1 address
  69  * @from: P1 address
  70  * @address: U0 address to be mapped
  71  * @page: page (virt_to_page(to))
  72  */
  73 void copy_user_page(void *to, void *from, unsigned long address,
  74                     struct page *page)
  75 {
  76         __set_bit(PG_mapped, &page->flags);
  77         if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)
  78                 copy_page(to, from);
  79         else {
  80                 pgprot_t pgprot = __pgprot(_PAGE_PRESENT |
  81                                            _PAGE_RW | _PAGE_CACHABLE |
  82                                            _PAGE_DIRTY | _PAGE_ACCESSED |
  83                                            _PAGE_HW_SHARED | _PAGE_FLAGS_HARD);
  84                 unsigned long phys_addr = PHYSADDR(to);
  85                 unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);
  86                 pgd_t *pgd = pgd_offset_k(p3_addr);
  87                 pud_t *pud = pud_offset(pgd, p3_addr);
  88                 pmd_t *pmd = pmd_offset(pud, p3_addr);
  89                 pte_t *pte = pte_offset_kernel(pmd, p3_addr);
  90                 pte_t entry;
  91                 unsigned long flags;
  92
  93                 entry = pfn_pte(phys_addr >> PAGE_SHIFT, pgprot);
  94                 down(&p3map_sem[(address & CACHE_ALIAS)>>12]);
  95                 set_pte(pte, entry);
  96                 local_irq_save(flags);
  97                 __flush_tlb_page(get_asid(), p3_addr);
  98                 local_irq_restore(flags);
  99                 update_mmu_cache(NULL, p3_addr, entry);
 100                 __copy_user_page((void *)p3_addr, from, to);
 101                 pte_clear(&init_mm, p3_addr, pte);
 102                 up(&p3map_sem[(address & CACHE_ALIAS)>>12]);
 103         }
 104 }
 105
 106 /*
 107  * For SH-4, we have our own implementation for ptep_get_and_clear
 108  */
 109 inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 110 {
 111         pte_t pte = *ptep;
 112
 113         pte_clear(mm, addr, ptep);
 114         if (!pte_not_present(pte)) {
 115                 unsigned long pfn = pte_pfn(pte);
 116                 if (pfn_valid(pfn)) {
 117                         struct page *page = pfn_to_page(pfn);
 118                         struct address_space *mapping = page_mapping(page);
 119                         if (!mapping || !mapping_writably_mapped(mapping))
 120                                 __clear_bit(PG_mapped, &page->flags);
 121                 }
 122         }
 123         return pte;
 124 }
 125