arch/m68k/sun3/dvma.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/arch/m68k/sun3/dvma.c
   4  *
   5  * Written by Sam Creasey
   6  *
   7  * Sun3 IOMMU routines used for dvma accesses.
   8  *
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/mm.h>
  14 #include <linux/memblock.h>
  15 #include <linux/list.h>
  16 #include <asm/page.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 //      pr_info("dvma_remap: addr %lx -> %lx pte %08lx\n", kaddr, vaddr, pte);
  35         if(ptelist[(vaddr & 0xff000) >> PAGE_SHIFT] != pte) {
  36                 sun3_put_pte(vaddr, pte);
  37                 ptelist[(vaddr & 0xff000) >> PAGE_SHIFT] = pte;
  38         }
  39
  40         return (vaddr + (kaddr & ~PAGE_MASK));
  41
  42 }
  43
  44 int dvma_map_iommu(unsigned long kaddr, unsigned long baddr,
  45                               int len)
  46 {
  47
  48         unsigned long end;
  49         unsigned long vaddr;
  50
  51         vaddr = dvma_btov(baddr);
  52
  53         end = vaddr + len;
  54
  55         while(vaddr < end) {
  56                 dvma_page(kaddr, vaddr);
  57                 kaddr += PAGE_SIZE;
  58                 vaddr += PAGE_SIZE;
  59         }
  60
  61         return 0;
  62
  63 }
  64
  65 void __init sun3_dvma_init(void)
  66 {
  67         memset(ptelist, 0, sizeof(ptelist));
  68 }