arch/sparc/mm/generic_32.c

   1 /*
   2  * generic.c: Generic Sparc mm routines that are not dependent upon
   3  *            MMU type but are Sparc specific.
   4  *
   5  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/mm.h>
  10 #include <linux/swap.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/export.h>
  13
  14 #include <asm/pgalloc.h>
  15 #include <asm/pgtable.h>
  16 #include <asm/page.h>
  17 #include <asm/cacheflush.h>
  18 #include <asm/tlbflush.h>
  19
  20 /* Remap IO memory, the same way as remap_pfn_range(), but use
  21  * the obio memory space.
  22  *
  23  * They use a pgprot that sets PAGE_IO and does not check the
  24  * mem_map table as this is independent of normal memory.
  25  */
  26 static inline void io_remap_pte_range(struct mm_struct *mm, pte_t * pte, unsigned long address, unsigned long size,
  27         unsigned long offset, pgprot_t prot, int space)
  28 {
  29         unsigned long end;
  30
  31         address &= ~PMD_MASK;
  32         end = address + size;
  33         if (end > PMD_SIZE)
  34                 end = PMD_SIZE;
  35         do {
  36                 set_pte_at(mm, address, pte, mk_pte_io(offset, prot, space));
  37                 address += PAGE_SIZE;
  38                 offset += PAGE_SIZE;
  39                 pte++;
  40         } while (address < end);
  41 }
  42
  43 static inline int io_remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size,
  44         unsigned long offset, pgprot_t prot, int space)
  45 {
  46         unsigned long end;
  47
  48         address &= ~PGDIR_MASK;
  49         end = address + size;
  50         if (end > PGDIR_SIZE)
  51                 end = PGDIR_SIZE;
  52         offset -= address;
  53         do {
  54                 pte_t *pte = pte_alloc_map(mm, NULL, pmd, address);
  55                 if (!pte)
  56                         return -ENOMEM;
  57                 io_remap_pte_range(mm, pte, address, end - address, address + offset, prot, space);
  58                 address = (address + PMD_SIZE) & PMD_MASK;
  59                 pmd++;
  60         } while (address < end);
  61         return 0;
  62 }
  63
  64 int io_remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
  65                        unsigned long pfn, unsigned long size, pgprot_t prot)
  66 {
  67         int error = 0;
  68         pgd_t * dir;
  69         unsigned long beg = from;
  70         unsigned long end = from + size;
  71         struct mm_struct *mm = vma->vm_mm;
  72         int space = GET_IOSPACE(pfn);
  73         unsigned long offset = GET_PFN(pfn) << PAGE_SHIFT;
  74
  75         /* See comment in mm/memory.c remap_pfn_range */
  76         vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
  77         vma->vm_pgoff = (offset >> PAGE_SHIFT) |
  78                 ((unsigned long)space << 28UL);
  79
  80         offset -= from;
  81         dir = pgd_offset(mm, from);
  82         flush_cache_range(vma, beg, end);
  83
  84         while (from < end) {
  85                 pmd_t *pmd = pmd_alloc(mm, dir, from);
  86                 error = -ENOMEM;
  87                 if (!pmd)
  88                         break;
  89                 error = io_remap_pmd_range(mm, pmd, from, end - from, offset + from, prot, space);
  90                 if (error)
  91                         break;
  92                 from = (from + PGDIR_SIZE) & PGDIR_MASK;
  93                 dir++;
  94         }
  95
  96         flush_tlb_range(vma, beg, end);
  97         return error;
  98 }
  99 EXPORT_SYMBOL(io_remap_pfn_range);