init_64.c

/*
 * Use this when you have no reliable task/vma, typically from interrupt
 * context. It is less reliable than using the task's vma and may give
 * false positives:
 */
int in_gate_area_no_task(unsigned long addr)
{
	return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
}

const char *arch_vma_name(struct vm_area_struct *vma)
{
	if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
		return "[vdso]";
	if (vma == &gate_vma)
		return "[vsyscall]";
	return NULL;
}

#ifdef CONFIG_SPARSEMEM_VMEMMAP
/*
 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.
 */
static long __meminitdata addr_start, addr_end;
static void __meminitdata *p_start, *p_end;
static int __meminitdata node_start;

int __meminit
vmemmap_populate(struct page *start_page, unsigned long size, int node)
{
	unsigned long addr = (unsigned long)start_page;
	unsigned long end = (unsigned long)(start_page + size);
	unsigned long next;
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;

	for (; addr < end; addr = next) {
		void *p = NULL;

		pgd = vmemmap_pgd_populate(addr, node);
		if (!pgd)
			return -ENOMEM;

		pud = vmemmap_pud_populate(pgd, addr, node);
		if (!pud)
			return -ENOMEM;

		if (!cpu_has_pse) {
			next = (addr + PAGE_SIZE) & PAGE_MASK;
			pmd = vmemmap_pmd_populate(pud, addr, node);

			if (!pmd)
				return -ENOMEM;

			p = vmemmap_pte_populate(pmd, addr, node);

			if (!p)
				return -ENOMEM;

			addr_end = addr + PAGE_SIZE;
			p_end = p + PAGE_SIZE;
		} else {
			next = pmd_addr_end(addr, end);

			pmd = pmd_offset(pud, addr);
			if (pmd_none(*pmd)) {
				pte_t entry;

				p = vmemmap_alloc_block(PMD_SIZE, node);
				if (!p)
					return -ENOMEM;

				entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
						PAGE_KERNEL_LARGE);
				set_pmd(pmd, __pmd(pte_val(entry)));

				/* check to see if we have contiguous blocks */
				if (p_end != p || node_start != node) {
					if (p_start)
						printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
						       addr_start, addr_end-1, p_start, p_end-1, node_start);
					addr_start = addr;
					node_start = node;
					p_start = p;
				}

				addr_end = addr + PMD_SIZE;
				p_end = p + PMD_SIZE;
			} else
				vmemmap_verify((pte_t *)pmd, node, addr, next);
		}

	}
	return 0;
}

void __meminit vmemmap_populate_print_last(void)
{
	if (p_start) {
		printk(KERN_DEBUG " [%lx-%lx] PMD -> [%p-%p] on node %d\n",
			addr_start, addr_end-1, p_start, p_end-1, node_start);
		p_start = NULL;
		p_end = NULL;
		node_start = 0;
	}
}
#endif