3  * linux/kernel/power/swap.c
6  * and writing it to a swap partition.
23 #include <linux/swap.h>
48  *	The swap map is a data structure used for keeping track of each page
49  *	written to a swap partition.  It consists of many swap_map_page
50  *	structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
51  *	These structures are stored on the swap and linked together with the
54  *	The swap map is created during suspend.  The swap map pages are
91  *	The swap_map_handle structure is used for handling swap in
119  *	swap pages, so that they can be freed in case of an error.
172  *	alloc_swapdev_block - allocate a swap page and register that it has
176 sector_t alloc_swapdev_block(int swap)  in alloc_swapdev_block()  argument
180 	offset = swp_offset(get_swap_page_of_type(swap));  in alloc_swapdev_block()
183 			swap_free(swp_entry(swap, offset));  in alloc_swapdev_block()
185 			return swapdev_block(swap, offset);  in alloc_swapdev_block()
191  *	free_all_swap_pages - free swap pages allocated for saving image data.
192  *	It also frees the extents used to register which swap entries had been
196 void free_all_swap_pages(int swap)  in free_all_swap_pages()  argument
207 			swap_free(swp_entry(swap, offset));  in free_all_swap_pages()
251 		pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",  in hib_end_io()
322 	if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||  in mark_swapfiles()
333 		pr_err("Swap header not found!\n");  in mark_swapfiles()
340  *	swsusp_swap_check - check if the resume device is a swap device
370  *	write_page - Write one page to given swap location.
372  *	@offset:	Offset of the swap page we're writing to.
424 			pr_err("Cannot find swap device, try swapon -a\n");  in get_swap_writer()
671  * @handle: Swap map handle to use for saving the image.
884  *	enough_swap - Make sure we have enough swap to save the image.
886  *	Returns TRUE or FALSE after checking the total amount of swap
895 	pr_debug("Free swap pages: %u\n", free_swap);  in enough_swap()
922 		pr_err("Cannot get swap writer\n");  in swsusp_write()
927 			pr_err("Not enough free swap\n");  in swsusp_write()
953  *	The following functions allow us to read data using a swap map
1054  *	load_image - load the image using the swap map handle
1161  * @handle: Swap map handle to use for loading data.
1538 			/* Reset swap signature now */  in swsusp_check()
1562  *	swsusp_close - close swap device.