kernel/fiasco/src/kern/ppc32/mem_space-cache.cpp

   1 /*
   2  * PPC page cache
   3  */
   4 INTERFACE[ppc32]:
   5
   6
   7 EXTENSION class Mem_space
   8 {
   9 private:
  10   Status v_insert_cache(Pte_base *e, Address virt, size_t size, unsigned page_attribs,
  11                         Dir_type *dir = 0);
  12   unsigned long v_delete_cache(Pt_entry *e, unsigned page_attribs);
  13 };
  14
  15
  16 //------------------------------------------------------------------------------
  17 IMPLEMENTATION[ppc32]:
  18
  19 IMPLEMENT
  20 Mem_space::Status
  21 Mem_space::v_insert_cache(Pte_base *e, Address virt, size_t size,
  22                           unsigned page_attribs, Dir_type *dir = 0)
  23 {
  24   if(!dir) dir = _dir;
  25
  26   Pdir::Iter i = dir->alloc_cast<Mem_space_q_alloc>()
  27     ->walk(Addr(virt), Pdir::Depth,
  28            Mem_space_q_alloc(_quota, Mapped_allocator::allocator()));
  29
  30   if (EXPECT_FALSE(!i.e->valid() && i.shift() != Config::PAGE_SHIFT))
  31     return Insert_err_nomem;
  32
  33   Address i_phys;
  34
  35   //get physical addresses
  36   Pte_htab::pte_lookup(i.e, &i_phys);
  37
  38   if(i.e->valid() && e->addr() == i_phys)
  39     {
  40       Status state = pte_attrib_upgrade(i.e, size, page_attribs);
  41       return state;
  42     }
  43
  44   *i.e = e->raw() | page_attribs;
  45
  46   //if super-page, set Pse_bit in Pdir
  47   if(size == Config::SUPERPAGE_SIZE)
  48     {
  49       i = dir->walk(Addr(virt), Pdir::Super_level);
  50       *i.e = i.e->raw() | Pte_base::Pse_bit;
  51     }
  52
  53   return Insert_ok;
  54 }
  55
  56 IMPLEMENT
  57 unsigned long
  58 Mem_space::v_delete_cache(Pt_entry *e, unsigned page_attribs = Page_all_attribs)
  59 {
  60   unsigned ret;
  61
  62   ret = e->raw() & page_attribs;
  63
  64   if (!(page_attribs & Page_user_accessible))
  65     // downgrade PDE (superpage) rights
  66     e->del_attr(page_attribs);
  67   else
  68     // delete PDE (superpage)
  69     e = 0;
  70
  71   return ret;
  72 }