arch/mips/baget/baget.c

   1 /* $Id: baget.c,v 1.1 1999/01/17 03:49:37 ralf Exp $
   2  *
   3  * baget.c: Baget low level stuff
   4  *
   5  * Copyright (C) 1998 Gleb Raiko & Vladimir Roganov
   6  *
   7  */
   8 #include <stdarg.h>
   9
  10 #include <linux/kernel.h>
  11 #include <linux/mm.h>
  12 #include <asm/system.h>
  13 #include <asm/bootinfo.h>
  14 #include <asm/mipsregs.h>
  15 #include <asm/pgtable.h>
  16 #include <asm/pgalloc.h>
  17
  18 #include <asm/baget/baget.h>
  19
  20 /*
  21  *  Following code is based on routines from 'mm/vmalloc.c'
  22  *  Additional parameters  ioaddr  is needed to iterate across real I/O address.
  23  */
  24 static inline int alloc_area_pte(pte_t * pte, unsigned long address,
  25                                  unsigned long size, unsigned long ioaddr)
  26 {
  27         unsigned long end;
  28
  29         address &= ~PMD_MASK;
  30         end = address + size;
  31         if (end > PMD_SIZE)
  32                 end = PMD_SIZE;
  33         while (address < end) {
  34                 unsigned long page;
  35                 if (!pte_none(*pte))
  36                         printk("kseg2_alloc_io: page already exists\n");
  37                 /*
  38                  *  For MIPS looks pretty to have transparent mapping
  39                  *  for KSEG2 areas  -- user can't access one, and no
  40                  *  problems with  virtual <--> physical  translation.
  41                  */
  42                 page = ioaddr & PAGE_MASK;
  43
  44                 set_pte(pte, __pte(page | pgprot_val(PAGE_USERIO) |
  45                                   _PAGE_GLOBAL | __READABLE | __WRITEABLE));
  46                 address += PAGE_SIZE;
  47                 ioaddr  += PAGE_SIZE;
  48                 pte++;
  49         }
  50         return 0;
  51 }
  52
  53 static inline int alloc_area_pmd(pmd_t * pmd, unsigned long address,
  54                                  unsigned long size, unsigned long ioaddr)
  55 {
  56         unsigned long end;
  57
  58         address &= ~PGDIR_MASK;
  59         end = address + size;
  60         if (end > PGDIR_SIZE)
  61                 end = PGDIR_SIZE;
  62         while (address < end) {
  63                 pte_t * pte = pte_alloc_kernel(pmd, address);
  64                 if (!pte)
  65                         return -ENOMEM;
  66                 if (alloc_area_pte(pte, address, end - address, ioaddr))
  67                         return -ENOMEM;
  68                 address = (address + PMD_SIZE) & PMD_MASK;
  69                 ioaddr  += PMD_SIZE;
  70                 pmd++;
  71         }
  72         return 0;
  73 }
  74
  75 int kseg2_alloc_io (unsigned long address, unsigned long size)
  76 {
  77         pgd_t * dir;
  78         unsigned long end = address + size;
  79
  80         dir = pgd_offset_k(address);
  81         flush_cache_all();
  82         while (address < end) {
  83                 pmd_t *pmd;
  84                 pgd_t olddir = *dir;
  85
  86                 pmd = pmd_alloc_kernel(dir, address);
  87                 if (!pmd)
  88                         return -ENOMEM;
  89                 if (alloc_area_pmd(pmd, address, end - address, address))
  90                         return -ENOMEM;
  91                 if (pgd_val(olddir) != pgd_val(*dir))
  92                         set_pgdir(address, *dir);
  93                 address = (address + PGDIR_SIZE) & PGDIR_MASK;
  94                 dir++;
  95         }
  96         flush_tlb_all();
  97         return 0;
  98 }