arch/m68k/sun3/dvma.c

   1 /*
   2  * linux/arch/m68k/sun3/dvma.c
   3  *
   4  * Written by Sam Creasey
   5  *
   6  * Sun3 IOMMU routines used for dvma accesses.
   7  *
   8  */
   9
  10 #include <linux/init.h>
  11 #include <linux/kernel.h>
  12 #include <linux/mm.h>
  13 #include <linux/bootmem.h>
  14 #include <linux/list.h>
  15 #include <asm/page.h>
  16 #include <asm/pgtable.h>
  17 #include <asm/sun3mmu.h>
  18 #include <asm/dvma.h>
  19
  20
  21 static unsigned long ptelist[120];
  22
  23 static unsigned long dvma_page(unsigned long kaddr, unsigned long vaddr)
  24 {
  25         unsigned long pte;
  26         unsigned long j;
  27         pte_t ptep;
  28
  29         j = *(volatile unsigned long *)kaddr;
  30         *(volatile unsigned long *)kaddr = j;
  31
  32         ptep = pfn_pte(virt_to_pfn(kaddr), PAGE_KERNEL);
  33         pte = pte_val(ptep);
  34 //              printk("dvma_remap: addr %lx -> %lx pte %08lx len %x\n",
  35 //                     kaddr, vaddr, pte, len);
  36         if(ptelist[(vaddr & 0xff000) >> PAGE_SHIFT] != pte) {
  37                 sun3_put_pte(vaddr, pte);
  38                 ptelist[(vaddr & 0xff000) >> PAGE_SHIFT] = pte;
  39         }
  40
  41         return (vaddr + (kaddr & ~PAGE_MASK));
  42
  43 }
  44
  45 int dvma_map_iommu(unsigned long kaddr, unsigned long baddr,
  46                               int len)
  47 {
  48
  49         unsigned long end;
  50         unsigned long vaddr;
  51
  52         vaddr = dvma_btov(baddr);
  53
  54         end = vaddr + len;
  55
  56         while(vaddr < end) {
  57                 dvma_page(kaddr, vaddr);
  58                 kaddr += PAGE_SIZE;
  59                 vaddr += PAGE_SIZE;
  60         }
  61
  62         return 0;
  63
  64 }
  65
  66 void __init sun3_dvma_init(void)
  67 {
  68         memset(ptelist, 0, sizeof(ptelist));
  69 }