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/pgtable.h>
  18 #include <asm/sun3mmu.h>
  19 #include <asm/dvma.h>
  20
  21
  22 static unsigned long ptelist[120];
  23
  24 static unsigned long dvma_page(unsigned long kaddr, unsigned long vaddr)
  25 {
  26         unsigned long pte;
  27         unsigned long j;
  28         pte_t ptep;
  29
  30         j = *(volatile unsigned long *)kaddr;
  31         *(volatile unsigned long *)kaddr = j;
  32
  33         ptep = pfn_pte(virt_to_pfn(kaddr), PAGE_KERNEL);
  34         pte = pte_val(ptep);
  35 //      pr_info("dvma_remap: addr %lx -> %lx pte %08lx\n", kaddr, vaddr, pte);
  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 }