i386/linux/linux-2.3.21/arch/m68k/sun3/dvma.c

   1
   2 /* dvma support routines */
   3
   4 #include <linux/kernel.h>
   5 #include <linux/mm.h>
   6 #include <asm/page.h>
   7 #include <asm/pgtable.h>
   8 #include <asm/sun3mmu.h>
   9 #include <asm/dvma.h>
  10
  11 unsigned long dvma_next_free = DVMA_START;
  12
  13 /* get needed number of free dma pages, or panic if not enough */
  14
  15 void *sun3_dvma_malloc(int len)
  16 {
  17         unsigned long vaddr;
  18
  19         /* if the next free pages have been accessed, skip them */
  20         while((dvma_next_free < DVMA_END) &&
  21               (sun3_get_pte(dvma_next_free) & SUN3_PAGE_ACCESSED))
  22                 dvma_next_free += SUN3_PTE_SIZE;
  23
  24         if((dvma_next_free + len) > DVMA_END)
  25                 panic("sun3_dvma_malloc: out of dvma pages");
  26
  27         vaddr = dvma_next_free;
  28         dvma_next_free = PAGE_ALIGN(dvma_next_free + len);
  29
  30         return (void *)vaddr;
  31 }
  32
  33