__asm__ __volatile__()

in kernel/sys_m68k.c [351:419]

• 55 lines of code
• 16 McCabe index (conditional complexity)

	      __asm__ __volatile__ (".chip 68060\n\t"
				    "cpushp %%dc,(%0)\n\t"
				    ".chip 68k"
				    : : "a" (paddr));
	      break;
	    case FLUSH_CACHE_INSN:
	      __asm__ __volatile__ (".chip 68060\n\t"
				    "cpushp %%ic,(%0)\n\t"
				    ".chip 68k"
				    : : "a" (paddr));
	      break;
	    default:
	    case FLUSH_CACHE_BOTH:
	      __asm__ __volatile__ (".chip 68060\n\t"
				    "cpushp %%bc,(%0)\n\t"
				    ".chip 68k"
				    : : "a" (paddr));
	      break;
	    }
	}
      break;
    }
  return 0;
}

/* sys_cacheflush -- flush (part of) the processor cache.  */
asmlinkage int
sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
{
	int ret = -EINVAL;

	if (scope < FLUSH_SCOPE_LINE || scope > FLUSH_SCOPE_ALL ||
	    cache & ~FLUSH_CACHE_BOTH)
		goto out;

	if (scope == FLUSH_SCOPE_ALL) {
		/* Only the superuser may explicitly flush the whole cache. */
		ret = -EPERM;
		if (!capable(CAP_SYS_ADMIN))
			goto out;

		mmap_read_lock(current->mm);
	} else {
		struct vm_area_struct *vma;

		/* Check for overflow.  */
		if (addr + len < addr)
			goto out;

		/*
		 * Verify that the specified address region actually belongs
		 * to this process.
		 */
		mmap_read_lock(current->mm);
		vma = vma_lookup(current->mm, addr);
		if (!vma || addr + len > vma->vm_end)
			goto out_unlock;
	}

	if (CPU_IS_020_OR_030) {
		if (scope == FLUSH_SCOPE_LINE && len < 256) {
			unsigned long cacr;
			__asm__ ("movec %%cacr, %0" : "=r" (cacr));
			if (cache & FLUSH_CACHE_INSN)
				cacr |= 4;
			if (cache & FLUSH_CACHE_DATA)
				cacr |= 0x400;
			len >>= 2;
			while (len--) {