arch/m68k/kernel/sys_m68k.c

Source file repositories/reference/linux-study-clean/arch/m68k/kernel/sys_m68k.c

File Facts

System
Linux kernel
Corpus path
arch/m68k/kernel/sys_m68k.c
Extension
.c
Size
13610 bytes
Lines
585
Domain
Architecture Layer
Bucket
arch/m68k
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

if ((paddr = virt_to_phys_040(addr))) {
        paddr += addr & ~(PAGE_MASK | 15);
        len = (len + (addr & 15) + 15) >> 4;
      } else {
	unsigned long tmp = PAGE_SIZE - (addr & ~PAGE_MASK);

	if (len <= tmp)
	  return 0;
	addr += tmp;
	len -= tmp;
	tmp = PAGE_SIZE;
	for (;;)
	  {
	    if ((paddr = virt_to_phys_040(addr)))
	      break;
	    if (len <= tmp)
	      return 0;
	    addr += tmp;
	    len -= tmp;
	  }
	len = (len + 15) >> 4;
      }
      i = (PAGE_SIZE - (paddr & ~PAGE_MASK)) >> 4;
      while (len--)
	{
	  switch (cache)
	    {
	    case FLUSH_CACHE_DATA:
	      __asm__ __volatile__ ("nop\n\t"
				    ".chip 68040\n\t"
				    "cpushl %%dc,(%0)\n\t"
				    ".chip 68k"
				    : : "a" (paddr));
	      break;
	    case FLUSH_CACHE_INSN:
	      __asm__ __volatile__ ("nop\n\t"
				    ".chip 68040\n\t"
				    "cpushl %%ic,(%0)\n\t"
				    ".chip 68k"
				    : : "a" (paddr));
	      break;
	    default:
	    case FLUSH_CACHE_BOTH:
	      __asm__ __volatile__ ("nop\n\t"
				    ".chip 68040\n\t"
				    "cpushl %%bc,(%0)\n\t"
				    ".chip 68k"
				    : : "a" (paddr));
	      break;
	    }
	  if (!--i && len)
	    {
	      /*
	       * No need to page align here since it is done by
	       * virt_to_phys_040().
	       */
	      addr += PAGE_SIZE;
	      i = PAGE_SIZE / 16;
	      /* Recompute physical address when crossing a page
	         boundary. */
	      for (;;)
		{
		  if ((paddr = virt_to_phys_040(addr)))
		    break;
		  if (len <= i)
		    return 0;
		  len -= i;
		  addr += PAGE_SIZE;
		}
	    }
	  else
	    paddr += 16;
	}
      break;

    default:
    case FLUSH_SCOPE_PAGE:
      len += (addr & ~PAGE_MASK) + (PAGE_SIZE - 1);
      for (len >>= PAGE_SHIFT; len--; addr += PAGE_SIZE)
	{
	  if (!(paddr = virt_to_phys_040(addr)))
	    continue;
	  switch (cache)
	    {
	    case FLUSH_CACHE_DATA:
	      __asm__ __volatile__ ("nop\n\t"
				    ".chip 68040\n\t"
				    "cpushp %%dc,(%0)\n\t"
				    ".chip 68k"
				    : : "a" (paddr));

Annotation

Implementation Notes