include/asm-arm/arch-rpc/mm-init.h

   1 /*
   2  * linux/include/asm-arm/arch-rpc/mmap.h
   3  *
   4  * Copyright (C) 1996 Russell King
   5  */
   6
   7 #define HAVE_MAP_VID_MEM
   8
   9 unsigned long map_screen_mem(unsigned long log_start, unsigned long kmem, int update)
  10 {
  11         static int updated = 0;
  12         unsigned long address;
  13         pgd_t *pgd;
  14
  15         if (updated)
  16                 return 0;
  17         updated = update;
  18
  19         address = SCREEN_START | PMD_TYPE_SECT | PMD_DOMAIN(DOMAIN_KERNEL) | PMD_SECT_AP_WRITE;
  20         pgd = swapper_pg_dir + (SCREEN2_BASE >> PGDIR_SHIFT);
  21         pgd_val(pgd[0]) = address;
  22         pgd_val(pgd[1]) = address + (1 << PGDIR_SHIFT);
  23
  24         if (update) {
  25                 unsigned long pgtable = PAGE_ALIGN(kmem), *p;
  26                 int i;
  27
  28                 memzero ((void *)pgtable, 4096);
  29
  30                 pgd_val(pgd[-2]) = __virt_to_phys(pgtable) | PMD_TYPE_TABLE | PMD_DOMAIN(DOMAIN_KERNEL);
  31                 pgd_val(pgd[-1]) = __virt_to_phys(pgtable + PTRS_PER_PTE*4) | PMD_TYPE_TABLE | PMD_DOMAIN(DOMAIN_KERNEL);
  32                 p = (unsigned long *)pgtable;
  33
  34                 i = PTRS_PER_PTE * 2 - ((SCREEN1_END - log_start) >> PAGE_SHIFT);
  35                 address = SCREEN_START | PTE_TYPE_SMALL | PTE_AP_WRITE;
  36
  37                 while (i < PTRS_PER_PTE * 2) {
  38                         p[i++] = address;
  39                         address += PAGE_SIZE;
  40                 }
  41
  42                 flush_page_to_ram(pgtable);
  43
  44                 kmem = pgtable + PAGE_SIZE;
  45         }
  46         return kmem;
  47 }