C++ (Cpp) pte_chain_alloc Examples

Example #1

/* mmlist_lock and vma->vm_mm->page_table_lock are held */
static inline void unuse_pmd(struct vm_area_struct * vma, pmd_t *dir,
	unsigned long address, unsigned long size, unsigned long offset,
	swp_entry_t entry, struct page* page)
{
	struct pte_chain * pte_chain = NULL;
	pte_t *pte, *mapping;
	unsigned long end;

	if (pmd_none(*dir))
		return;
	if (pmd_bad(*dir)) {
		pmd_ERROR(*dir);
		pmd_clear(dir);
		return;
	}
	mapping = pte = pte_offset_map(dir, address);
	offset += address & PMD_MASK;
	address &= ~PMD_MASK;
	end = address + size;
	if (end > PMD_SIZE)
		end = PMD_SIZE;
	do {
		/*
		 * FIXME: handle pte_chain_alloc() failures
		 */
		if (pte_chain == NULL)
			pte_chain = pte_chain_alloc(GFP_ATOMIC);
		unuse_pte(vma, offset+address-vma->vm_start,
			       pte, entry, page, &pte_chain);
		address += PAGE_SIZE;
		pte++;
	} while (address && (address < end));
	pte_unmap(mapping);
	pte_chain_free(pte_chain);
}

Example #2

static int move_one_page(struct vm_area_struct *vma, unsigned long old_addr, unsigned long new_addr)
{
	struct mm_struct *mm = vma->vm_mm;
	struct pte_chain * pte_chain;
	int error = 0;
	pte_t *src, *dst;

	pte_chain = pte_chain_alloc(GFP_KERNEL);
	if (!pte_chain)
		return -1;
	spin_lock(&mm->page_table_lock);
	src = get_one_pte_map_nested(mm, old_addr);
	if (src) {
		/*
		 * Look to see whether alloc_one_pte_map needs to perform a
		 * memory allocation.  If it does then we need to drop the
		 * atomic kmap
		 */
		if (!page_table_present(mm, new_addr)) {
			pte_unmap_nested(src);
			src = NULL;
		}
		dst = alloc_one_pte_map(mm, new_addr);
		if (src == NULL)
			src = get_one_pte_map_nested(mm, old_addr);
		if (src) {
			error = copy_one_pte(vma, src, dst, old_addr, new_addr, &pte_chain);
			pte_unmap_nested(src);
		}
		pte_unmap(dst);
	}
	flush_tlb_page(vma, old_addr);
	spin_unlock(&mm->page_table_lock);
	pte_chain_free(pte_chain);
	return error;
}