image_size = ((totalram_pages * 2) / 5) * PAGE_SIZE;
}
-/* List of PBEs needed for restoring the pages that were allocated before
+/*
+ * List of PBEs needed for restoring the pages that were allocated before
* the suspend and included in the suspend image, but have also been
* allocated by the "resume" kernel, so their contents cannot be written
* directly to their "original" page frames.
/* Pointer to an auxiliary buffer (1 page) */
static void *buffer;
-/**
- * @safe_needed - on resume, for storing the PBE list and the image,
- * we can only use memory pages that do not conflict with the pages
- * used before suspend. The unsafe pages have PageNosaveFree set
- * and we count them using unsafe_pages.
- *
- * Each allocated image page is marked as PageNosave and PageNosaveFree
- * so that swsusp_free() can release it.
- */
-
#define PG_ANY 0
#define PG_SAFE 1
#define PG_UNSAFE_CLEAR 1
static unsigned int allocated_unsafe_pages;
+/**
+ * get_image_page - Allocate a page for a hibernation image.
+ * @gfp_mask: GFP mask for the allocation.
+ * @safe_needed: Get pages that were not used before hibernation (restore only)
+ *
+ * During image restoration, for storing the PBE list and the image data, we can
+ * only use memory pages that do not conflict with the pages used before
+ * hibernation. The "unsafe" pages have PageNosaveFree set and we count them
+ * using allocated_unsafe_pages.
+ *
+ * Each allocated image page is marked as PageNosave and PageNosaveFree so that
+ * swsusp_free() can release it.
+ */
static void *get_image_page(gfp_t gfp_mask, int safe_needed)
{
void *res;
}
/**
- * free_image_page - free page represented by @addr, allocated with
- * get_image_page (page flags set by it must be cleared)
+ * free_image_page - Free a page allocated for hibernation image.
+ * @addr: Address of the page to free.
+ * @clear_nosave_free: If set, clear the PageNosaveFree bit for the page.
+ *
+ * The page to free should have been allocated by get_image_page() (page flags
+ * set by it are affected).
*/
-
static inline void free_image_page(void *addr, int clear_nosave_free)
{
struct page *page;
}
}
-/**
- * struct chain_allocator is used for allocating small objects out of
- * a linked list of pages called 'the chain'.
- *
- * The chain grows each time when there is no room for a new object in
- * the current page. The allocated objects cannot be freed individually.
- * It is only possible to free them all at once, by freeing the entire
- * chain.
- *
- * NOTE: The chain allocator may be inefficient if the allocated objects
- * are not much smaller than PAGE_SIZE.
- */
-
+/*
+ * struct chain_allocator is used for allocating small objects out of
+ * a linked list of pages called 'the chain'.
+ *
+ * The chain grows each time when there is no room for a new object in
+ * the current page. The allocated objects cannot be freed individually.
+ * It is only possible to free them all at once, by freeing the entire
+ * chain.
+ *
+ * NOTE: The chain allocator may be inefficient if the allocated objects
+ * are not much smaller than PAGE_SIZE.
+ */
struct chain_allocator {
struct linked_page *chain; /* the chain */
unsigned int used_space; /* total size of objects allocated out
- * of the current page
- */
+ of the current page */
gfp_t gfp_mask; /* mask for allocating pages */
int safe_needed; /* if set, only "safe" pages are allocated */
};
}
/**
- * Data types related to memory bitmaps.
+ * Data types related to memory bitmaps.
*
- * Memory bitmap is a structure consiting of many linked lists of
- * objects. The main list's elements are of type struct zone_bitmap
- * and each of them corresonds to one zone. For each zone bitmap
- * object there is a list of objects of type struct bm_block that
- * represent each blocks of bitmap in which information is stored.
+ * Memory bitmap is a structure consiting of many linked lists of
+ * objects. The main list's elements are of type struct zone_bitmap
+ * and each of them corresonds to one zone. For each zone bitmap
+ * object there is a list of objects of type struct bm_block that
+ * represent each blocks of bitmap in which information is stored.
*
- * struct memory_bitmap contains a pointer to the main list of zone
- * bitmap objects, a struct bm_position used for browsing the bitmap,
- * and a pointer to the list of pages used for allocating all of the
- * zone bitmap objects and bitmap block objects.
+ * struct memory_bitmap contains a pointer to the main list of zone
+ * bitmap objects, a struct bm_position used for browsing the bitmap,
+ * and a pointer to the list of pages used for allocating all of the
+ * zone bitmap objects and bitmap block objects.
*
- * NOTE: It has to be possible to lay out the bitmap in memory
- * using only allocations of order 0. Additionally, the bitmap is
- * designed to work with arbitrary number of zones (this is over the
- * top for now, but let's avoid making unnecessary assumptions ;-).
+ * NOTE: It has to be possible to lay out the bitmap in memory
+ * using only allocations of order 0. Additionally, the bitmap is
+ * designed to work with arbitrary number of zones (this is over the
+ * top for now, but let's avoid making unnecessary assumptions ;-).
*
- * struct zone_bitmap contains a pointer to a list of bitmap block
- * objects and a pointer to the bitmap block object that has been
- * most recently used for setting bits. Additionally, it contains the
- * pfns that correspond to the start and end of the represented zone.
+ * struct zone_bitmap contains a pointer to a list of bitmap block
+ * objects and a pointer to the bitmap block object that has been
+ * most recently used for setting bits. Additionally, it contains the
+ * PFNs that correspond to the start and end of the represented zone.
*
- * struct bm_block contains a pointer to the memory page in which
- * information is stored (in the form of a block of bitmap)
- * It also contains the pfns that correspond to the start and end of
- * the represented memory area.
+ * struct bm_block contains a pointer to the memory page in which
+ * information is stored (in the form of a block of bitmap)
+ * It also contains the pfns that correspond to the start and end of
+ * the represented memory area.
*
- * The memory bitmap is organized as a radix tree to guarantee fast random
- * access to the bits. There is one radix tree for each zone (as returned
- * from create_mem_extents).
+ * The memory bitmap is organized as a radix tree to guarantee fast random
+ * access to the bits. There is one radix tree for each zone (as returned
+ * from create_mem_extents).
*
- * One radix tree is represented by one struct mem_zone_bm_rtree. There are
- * two linked lists for the nodes of the tree, one for the inner nodes and
- * one for the leave nodes. The linked leave nodes are used for fast linear
- * access of the memory bitmap.
+ * One radix tree is represented by one struct mem_zone_bm_rtree. There are
+ * two linked lists for the nodes of the tree, one for the inner nodes and
+ * one for the leave nodes. The linked leave nodes are used for fast linear
+ * access of the memory bitmap.
*
- * The struct rtree_node represents one node of the radix tree.
+ * The struct rtree_node represents one node of the radix tree.
*/
#define BM_END_OF_MAP (~0UL)
struct memory_bitmap {
struct list_head zones;
struct linked_page *p_list; /* list of pages used to store zone
- * bitmap objects and bitmap block
- * objects
- */
+ bitmap objects and bitmap block
+ objects */
struct bm_position cur; /* most recently used bit position */
};
#endif
#define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1)
-/*
- * alloc_rtree_node - Allocate a new node and add it to the radix tree.
+/**
+ * alloc_rtree_node - Allocate a new node and add it to the radix tree.
*
- * This function is used to allocate inner nodes as well as the
- * leave nodes of the radix tree. It also adds the node to the
- * corresponding linked list passed in by the *list parameter.
+ * This function is used to allocate inner nodes as well as the
+ * leave nodes of the radix tree. It also adds the node to the
+ * corresponding linked list passed in by the *list parameter.
*/
static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed,
struct chain_allocator *ca,
return node;
}
-/*
- * add_rtree_block - Add a new leave node to the radix tree
+/**
+ * add_rtree_block - Add a new leave node to the radix tree.
*
- * The leave nodes need to be allocated in order to keep the leaves
- * linked list in order. This is guaranteed by the zone->blocks
- * counter.
+ * The leave nodes need to be allocated in order to keep the leaves
+ * linked list in order. This is guaranteed by the zone->blocks
+ * counter.
*/
static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask,
int safe_needed, struct chain_allocator *ca)
static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
int clear_nosave_free);
-/*
- * create_zone_bm_rtree - create a radix tree for one zone
+/**
+ * create_zone_bm_rtree - Create a radix tree for one zone.
*
- * Allocated the mem_zone_bm_rtree structure and initializes it.
- * This function also allocated and builds the radix tree for the
- * zone.
+ * Allocated the mem_zone_bm_rtree structure and initializes it.
+ * This function also allocated and builds the radix tree for the
+ * zone.
*/
static struct mem_zone_bm_rtree *create_zone_bm_rtree(gfp_t gfp_mask,
int safe_needed,
return zone;
}
-/*
- * free_zone_bm_rtree - Free the memory of the radix tree
+/**
+ * free_zone_bm_rtree - Free the memory of the radix tree.
*
- * Free all node pages of the radix tree. The mem_zone_bm_rtree
- * structure itself is not freed here nor are the rtree_node
- * structs.
+ * Free all node pages of the radix tree. The mem_zone_bm_rtree
+ * structure itself is not freed here nor are the rtree_node
+ * structs.
*/
static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone,
int clear_nosave_free)
};
/**
- * free_mem_extents - free a list of memory extents
- * @list - list of extents to empty
+ * free_mem_extents - Free a list of memory extents.
+ * @list: List of extents to free.
*/
static void free_mem_extents(struct list_head *list)
{
}
/**
- * create_mem_extents - create a list of memory extents representing
- * contiguous ranges of PFNs
- * @list - list to put the extents into
- * @gfp_mask - mask to use for memory allocations
+ * create_mem_extents - Create a list of memory extents.
+ * @list: List to put the extents into.
+ * @gfp_mask: Mask to use for memory allocations.
+ *
+ * The extents represent contiguous ranges of PFNs.
*/
static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
{
}
/**
- * memory_bm_create - allocate memory for a memory bitmap
- */
+ * memory_bm_create - Allocate memory for a memory bitmap.
+ */
static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask,
int safe_needed)
{
}
/**
- * memory_bm_free - free memory occupied by the memory bitmap @bm
- */
+ * memory_bm_free - Free memory occupied by the memory bitmap.
+ * @bm: Memory bitmap.
+ */
static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
{
struct mem_zone_bm_rtree *zone;
}
/**
- * memory_bm_find_bit - Find the bit for pfn in the memory
- * bitmap
+ * memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap.
*
- * Find the bit in the bitmap @bm that corresponds to given pfn.
- * The cur.zone, cur.block and cur.node_pfn member of @bm are
- * updated.
- * It walks the radix tree to find the page which contains the bit for
- * pfn and returns the bit position in **addr and *bit_nr.
+ * Find the bit in memory bitmap @bm that corresponds to the given PFN.
+ * The cur.zone, cur.block and cur.node_pfn members of @bm are updated.
+ *
+ * Walk the radix tree to find the page containing the bit that represents @pfn
+ * and return the position of the bit in @addr and @bit_nr.
*/
static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
void **addr, unsigned int *bit_nr)
zone_found:
/*
- * We have a zone. Now walk the radix tree to find the leave
- * node for our pfn.
+ * We have found the zone. Now walk the radix tree to find the leaf node
+ * for our PFN.
*/
-
node = bm->cur.node;
if (((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn)
goto node_found;
}
/*
- * rtree_next_node - Jumps to the next leave node
+ * rtree_next_node - Jump to the next leaf node.
*
- * Sets the position to the beginning of the next node in the
- * memory bitmap. This is either the next node in the current
- * zone's radix tree or the first node in the radix tree of the
- * next zone.
+ * Set the position to the beginning of the next node in the
+ * memory bitmap. This is either the next node in the current
+ * zone's radix tree or the first node in the radix tree of the
+ * next zone.
*
- * Returns true if there is a next node, false otherwise.
+ * Return true if there is a next node, false otherwise.
*/
static bool rtree_next_node(struct memory_bitmap *bm)
{
}
/**
- * memory_bm_rtree_next_pfn - Find the next set bit in the bitmap @bm
+ * memory_bm_rtree_next_pfn - Find the next set bit in a memory bitmap.
+ * @bm: Memory bitmap.
*
- * Starting from the last returned position this function searches
- * for the next set bit in the memory bitmap and returns its
- * number. If no more bit is set BM_END_OF_MAP is returned.
+ * Starting from the last returned position this function searches for the next
+ * set bit in @bm and returns the PFN represented by it. If no more bits are
+ * set, BM_END_OF_MAP is returned.
*
- * It is required to run memory_bm_position_reset() before the
- * first call to this function.
+ * It is required to run memory_bm_position_reset() before the first call to
+ * this function for the given memory bitmap.
*/
static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
{
return BM_END_OF_MAP;
}
-/**
- * This structure represents a range of page frames the contents of which
- * should not be saved during the suspend.
+/*
+ * This structure represents a range of page frames the contents of which
+ * should not be saved during hibernation.
*/
-
struct nosave_region {
struct list_head list;
unsigned long start_pfn;
}
/**
- * register_nosave_region - register a range of page frames the contents
- * of which should not be saved during the suspend (to be used in the early
- * initialization code)
+ * register_nosave_region - Register a region of unsaveable memory.
+ *
+ * Register a range of page frames the contents of which should not be saved
+ * during hibernation (to be used in the early initialization code).
*/
-
void __init __register_nosave_region(unsigned long start_pfn,
unsigned long end_pfn, int use_kmalloc)
{
}
}
if (use_kmalloc) {
- /* during init, this shouldn't fail */
+ /* During init, this shouldn't fail */
region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
BUG_ON(!region);
} else
}
/**
- * mark_nosave_pages - set bits corresponding to the page frames the
- * contents of which should not be saved in a given bitmap.
+ * mark_nosave_pages - Mark pages that should not be saved.
+ * @bm: Memory bitmap.
+ *
+ * Set the bits in @bm that correspond to the page frames the contents of which
+ * should not be saved.
*/
-
static void mark_nosave_pages(struct memory_bitmap *bm)
{
struct nosave_region *region;
}
/**
- * create_basic_memory_bitmaps - create bitmaps needed for marking page
- * frames that should not be saved and free page frames. The pointers
- * forbidden_pages_map and free_pages_map are only modified if everything
- * goes well, because we don't want the bits to be used before both bitmaps
- * are set up.
+ * create_basic_memory_bitmaps - Create bitmaps to hold basic page information.
+ *
+ * Create bitmaps needed for marking page frames that should not be saved and
+ * free page frames. The forbidden_pages_map and free_pages_map pointers are
+ * only modified if everything goes well, because we don't want the bits to be
+ * touched before both bitmaps are set up.
*/
-
int create_basic_memory_bitmaps(void)
{
struct memory_bitmap *bm1, *bm2;
}
/**
- * free_basic_memory_bitmaps - free memory bitmaps allocated by
- * create_basic_memory_bitmaps(). The auxiliary pointers are necessary
- * so that the bitmaps themselves are not referred to while they are being
- * freed.
+ * free_basic_memory_bitmaps - Free memory bitmaps holding basic information.
+ *
+ * Free memory bitmaps allocated by create_basic_memory_bitmaps(). The
+ * auxiliary pointers are necessary so that the bitmaps themselves are not
+ * referred to while they are being freed.
*/
-
void free_basic_memory_bitmaps(void)
{
struct memory_bitmap *bm1, *bm2;
}
/**
- * snapshot_additional_pages - estimate the number of additional pages
- * be needed for setting up the suspend image data structures for given
- * zone (usually the returned value is greater than the exact number)
+ * snapshot_additional_pages - Estimate the number of extra pages needed.
+ * @zone: Memory zone to carry out the computation for.
+ *
+ * Estimate the number of additional pages needed for setting up a hibernation
+ * image data structures for @zone (usually, the returned value is greater than
+ * the exact number).
*/
-
unsigned int snapshot_additional_pages(struct zone *zone)
{
unsigned int rtree, nodes;
#ifdef CONFIG_HIGHMEM
/**
- * count_free_highmem_pages - compute the total number of free highmem
- * pages, system-wide.
+ * count_free_highmem_pages - Compute the total number of free highmem pages.
+ *
+ * The returned number is system-wide.
*/
-
static unsigned int count_free_highmem_pages(void)
{
struct zone *zone;
}
/**
- * saveable_highmem_page - Determine whether a highmem page should be
- * included in the suspend image.
+ * saveable_highmem_page - Check if a highmem page is saveable.
+ *
+ * Determine whether a highmem page should be included in a hibernation image.
*
- * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
- * and it isn't a part of a free chunk of pages.
+ * We should save the page if it isn't Nosave or NosaveFree, or Reserved,
+ * and it isn't part of a free chunk of pages.
*/
static struct page *saveable_highmem_page(struct zone *zone, unsigned long pfn)
{
}
/**
- * count_highmem_pages - compute the total number of saveable highmem
- * pages.
+ * count_highmem_pages - Compute the total number of saveable highmem pages.
*/
-
static unsigned int count_highmem_pages(void)
{
struct zone *zone;
#endif /* CONFIG_HIGHMEM */
/**
- * saveable_page - Determine whether a non-highmem page should be included
- * in the suspend image.
+ * saveable_page - Check if the given page is saveable.
+ *
+ * Determine whether a non-highmem page should be included in a hibernation
+ * image.
*
- * We should save the page if it isn't Nosave, and is not in the range
- * of pages statically defined as 'unsaveable', and it isn't a part of
- * a free chunk of pages.
+ * We should save the page if it isn't Nosave, and is not in the range
+ * of pages statically defined as 'unsaveable', and it isn't part of
+ * a free chunk of pages.
*/
static struct page *saveable_page(struct zone *zone, unsigned long pfn)
{
}
/**
- * count_data_pages - compute the total number of saveable non-highmem
- * pages.
+ * count_data_pages - Compute the total number of saveable non-highmem pages.
*/
-
static unsigned int count_data_pages(void)
{
struct zone *zone;
return n;
}
-/* This is needed, because copy_page and memcpy are not usable for copying
+/*
+ * This is needed, because copy_page and memcpy are not usable for copying
* task structs.
*/
static inline void do_copy_page(long *dst, long *src)
*dst++ = *src++;
}
-
/**
- * safe_copy_page - check if the page we are going to copy is marked as
- * present in the kernel page tables (this always is the case if
- * CONFIG_DEBUG_PAGEALLOC is not set and in that case
- * kernel_page_present() always returns 'true').
+ * safe_copy_page - Copy a page in a safe way.
+ *
+ * Check if the page we are going to copy is marked as present in the kernel
+ * page tables (this always is the case if CONFIG_DEBUG_PAGEALLOC is not set
+ * and in that case kernel_page_present() always returns 'true').
*/
static void safe_copy_page(void *dst, struct page *s_page)
{
}
}
-
#ifdef CONFIG_HIGHMEM
static inline struct page *page_is_saveable(struct zone *zone, unsigned long pfn)
{
kunmap_atomic(src);
} else {
if (PageHighMem(d_page)) {
- /* Page pointed to by src may contain some kernel
+ /*
+ * The page pointed to by src may contain some kernel
* data modified by kmap_atomic()
*/
safe_copy_page(buffer, s_page);
static struct memory_bitmap copy_bm;
/**
- * swsusp_free - free pages allocated for the suspend.
+ * swsusp_free - Free pages allocated for hibernation image.
*
- * Suspend pages are alocated before the atomic copy is made, so we
- * need to release them after the resume.
+ * Image pages are alocated before snapshot creation, so they need to be
+ * released after resume.
*/
-
void swsusp_free(void)
{
unsigned long fb_pfn, fr_pfn;
#define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
/**
- * preallocate_image_pages - Allocate a number of pages for hibernation image
+ * preallocate_image_pages - Allocate a number of pages for hibernation image.
* @nr_pages: Number of page frames to allocate.
* @mask: GFP flags to use for the allocation.
*
}
/**
- * __fraction - Compute (an approximation of) x * (multiplier / base)
+ * __fraction - Compute (an approximation of) x * (multiplier / base).
*/
static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
{
#endif /* CONFIG_HIGHMEM */
/**
- * free_unnecessary_pages - Release preallocated pages not needed for the image
+ * free_unnecessary_pages - Release preallocated pages not needed for the image.
*/
static unsigned long free_unnecessary_pages(void)
{
}
/**
- * minimum_image_size - Estimate the minimum acceptable size of an image
+ * minimum_image_size - Estimate the minimum acceptable size of an image.
* @saveable: Number of saveable pages in the system.
*
* We want to avoid attempting to free too much memory too hard, so estimate the
}
/**
- * hibernate_preallocate_memory - Preallocate memory for hibernation image
+ * hibernate_preallocate_memory - Preallocate memory for hibernation image.
*
* To create a hibernation image it is necessary to make a copy of every page
* frame in use. We also need a number of page frames to be free during
#ifdef CONFIG_HIGHMEM
/**
- * count_pages_for_highmem - compute the number of non-highmem pages
- * that will be necessary for creating copies of highmem pages.
- */
-
+ * count_pages_for_highmem - Count non-highmem pages needed for copying highmem.
+ *
+ * Compute the number of non-highmem pages that will be necessary for creating
+ * copies of highmem pages.
+ */
static unsigned int count_pages_for_highmem(unsigned int nr_highmem)
{
unsigned int free_highmem = count_free_highmem_pages() + alloc_highmem;
#endif /* CONFIG_HIGHMEM */
/**
- * enough_free_mem - Make sure we have enough free memory for the
- * snapshot image.
+ * enough_free_mem - Check if there is enough free memory for the image.
*/
-
static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
{
struct zone *zone;
#ifdef CONFIG_HIGHMEM
/**
- * get_highmem_buffer - if there are some highmem pages in the suspend
- * image, we may need the buffer to copy them and/or load their data.
+ * get_highmem_buffer - Allocate a buffer for highmem pages.
+ *
+ * If there are some highmem pages in the hibernation image, we may need a
+ * buffer to copy them and/or load their data.
*/
-
static inline int get_highmem_buffer(int safe_needed)
{
buffer = get_image_page(GFP_ATOMIC | __GFP_COLD, safe_needed);
}
/**
- * alloc_highmem_image_pages - allocate some highmem pages for the image.
- * Try to allocate as many pages as needed, but if the number of free
- * highmem pages is lesser than that, allocate them all.
+ * alloc_highmem_image_pages - Allocate some highmem pages for the image.
+ *
+ * Try to allocate as many pages as needed, but if the number of free highmem
+ * pages is less than that, allocate them all.
*/
-
static inline unsigned int alloc_highmem_pages(struct memory_bitmap *bm,
unsigned int nr_highmem)
{
#endif /* CONFIG_HIGHMEM */
/**
- * swsusp_alloc - allocate memory for the suspend image
+ * swsusp_alloc - Allocate memory for hibernation image.
*
- * We first try to allocate as many highmem pages as there are
- * saveable highmem pages in the system. If that fails, we allocate
- * non-highmem pages for the copies of the remaining highmem ones.
+ * We first try to allocate as many highmem pages as there are
+ * saveable highmem pages in the system. If that fails, we allocate
+ * non-highmem pages for the copies of the remaining highmem ones.
*
- * In this approach it is likely that the copies of highmem pages will
- * also be located in the high memory, because of the way in which
- * copy_data_pages() works.
+ * In this approach it is likely that the copies of highmem pages will
+ * also be located in the high memory, because of the way in which
+ * copy_data_pages() works.
*/
-
static int swsusp_alloc(struct memory_bitmap *orig_bm,
struct memory_bitmap *copy_bm,
unsigned int nr_pages, unsigned int nr_highmem)
return -ENOMEM;
}
- /* During allocating of suspend pagedir, new cold pages may appear.
+ /*
+ * During allocating of suspend pagedir, new cold pages may appear.
* Kill them.
*/
drain_local_pages(NULL);
}
/**
- * pack_pfns - pfns corresponding to the set bits found in the bitmap @bm
- * are stored in the array @buf[] (1 page at a time)
+ * pack_pfns - Prepare PFNs for saving.
+ * @bm: Memory bitmap.
+ * @buf: Memory buffer to store the PFNs in.
+ *
+ * PFNs corresponding to set bits in @bm are stored in the area of memory
+ * pointed to by @buf (1 page at a time).
*/
-
static inline void pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
{
int j;
}
/**
- * snapshot_read_next - used for reading the system memory snapshot.
+ * snapshot_read_next - Get the address to read the next image page from.
+ * @handle: Snapshot handle to be used for the reading.
*
- * On the first call to it @handle should point to a zeroed
- * snapshot_handle structure. The structure gets updated and a pointer
- * to it should be passed to this function every next time.
+ * On the first call, @handle should point to a zeroed snapshot_handle
+ * structure. The structure gets populated then and a pointer to it should be
+ * passed to this function every next time.
*
- * On success the function returns a positive number. Then, the caller
- * is allowed to read up to the returned number of bytes from the memory
- * location computed by the data_of() macro.
+ * On success, the function returns a positive number. Then, the caller
+ * is allowed to read up to the returned number of bytes from the memory
+ * location computed by the data_of() macro.
*
- * The function returns 0 to indicate the end of data stream condition,
- * and a negative number is returned on error. In such cases the
- * structure pointed to by @handle is not updated and should not be used
- * any more.
+ * The function returns 0 to indicate the end of the data stream condition,
+ * and negative numbers are returned on errors. If that happens, the structure
+ * pointed to by @handle is not updated and should not be used any more.
*/
-
int snapshot_read_next(struct snapshot_handle *handle)
{
if (handle->cur > nr_meta_pages + nr_copy_pages)
page = pfn_to_page(memory_bm_next_pfn(©_bm));
if (PageHighMem(page)) {
- /* Highmem pages are copied to the buffer,
+ /*
+ * Highmem pages are copied to the buffer,
* because we can't return with a kmapped
* highmem page (we may not be called again).
*/
}
/**
- * mark_unsafe_pages - mark the pages that cannot be used for storing
- * the image during resume, because they conflict with the pages that
- * had been used before suspend
+ * mark_unsafe_pages - Mark pages that were used before hibernation.
+ *
+ * Mark the pages that cannot be used for storing the image during restoration,
+ * because they conflict with the pages that had been used before hibernation.
*/
-
static void mark_unsafe_pages(struct memory_bitmap *bm)
{
unsigned long pfn;
}
/**
- * load header - check the image header and copy data from it
+ * load header - Check the image header and copy the data from it.
*/
-
static int load_header(struct swsusp_info *info)
{
int error;
}
/**
- * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
- * the corresponding bit in the memory bitmap @bm
+ * unpack_orig_pfns - Set bits corresponding to given PFNs in a memory bitmap.
+ * @bm: Memory bitmap.
+ * @buf: Area of memory containing the PFNs.
+ *
+ * For each element of the array pointed to by @buf (1 page at a time), set the
+ * corresponding bit in @bm.
*/
static int unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
{
}
#ifdef CONFIG_HIGHMEM
-/* struct highmem_pbe is used for creating the list of highmem pages that
+/*
+ * struct highmem_pbe is used for creating the list of highmem pages that
* should be restored atomically during the resume from disk, because the page
* frames they have occupied before the suspend are in use.
*/
struct highmem_pbe *next;
};
-/* List of highmem PBEs needed for restoring the highmem pages that were
+/*
+ * List of highmem PBEs needed for restoring the highmem pages that were
* allocated before the suspend and included in the suspend image, but have
* also been allocated by the "resume" kernel, so their contents cannot be
* written directly to their "original" page frames.
static struct highmem_pbe *highmem_pblist;
/**
- * count_highmem_image_pages - compute the number of highmem pages in the
- * suspend image. The bits in the memory bitmap @bm that correspond to the
- * image pages are assumed to be set.
+ * count_highmem_image_pages - Compute the number of highmem pages in the image.
+ * @bm: Memory bitmap.
+ *
+ * The bits in @bm that correspond to image pages are assumed to be set.
*/
-
static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
{
unsigned long pfn;
return cnt;
}
-/**
- * prepare_highmem_image - try to allocate as many highmem pages as
- * there are highmem image pages (@nr_highmem_p points to the variable
- * containing the number of highmem image pages). The pages that are
- * "safe" (ie. will not be overwritten when the suspend image is
- * restored) have the corresponding bits set in @bm (it must be
- * unitialized).
- *
- * NOTE: This function should not be called if there are no highmem
- * image pages.
- */
-
static unsigned int safe_highmem_pages;
static struct memory_bitmap *safe_highmem_bm;
+/**
+ * prepare_highmem_image - Allocate memory for loading highmem data from image.
+ * @bm: Pointer to an uninitialized memory bitmap structure.
+ * @nr_highmem_p: Pointer to the number of highmem image pages.
+ *
+ * Try to allocate as many highmem pages as there are highmem image pages
+ * (@nr_highmem_p points to the variable containing the number of highmem image
+ * pages). The pages that are "safe" (ie. will not be overwritten when the
+ * hibernation image is restored entirely) have the corresponding bits set in
+ * @bm (it must be unitialized).
+ *
+ * NOTE: This function should not be called if there are no highmem image pages.
+ */
static int prepare_highmem_image(struct memory_bitmap *bm,
unsigned int *nr_highmem_p)
{
return 0;
}
+static struct page *last_highmem_page;
+
/**
- * get_highmem_page_buffer - for given highmem image page find the buffer
- * that suspend_write_next() should set for its caller to write to.
+ * get_highmem_page_buffer - Prepare a buffer to store a highmem image page.
+ *
+ * For a given highmem image page get a buffer that suspend_write_next() should
+ * return to its caller to write to.
*
- * If the page is to be saved to its "original" page frame or a copy of
- * the page is to be made in the highmem, @buffer is returned. Otherwise,
- * the copy of the page is to be made in normal memory, so the address of
- * the copy is returned.
+ * If the page is to be saved to its "original" page frame or a copy of
+ * the page is to be made in the highmem, @buffer is returned. Otherwise,
+ * the copy of the page is to be made in normal memory, so the address of
+ * the copy is returned.
*
- * If @buffer is returned, the caller of suspend_write_next() will write
- * the page's contents to @buffer, so they will have to be copied to the
- * right location on the next call to suspend_write_next() and it is done
- * with the help of copy_last_highmem_page(). For this purpose, if
- * @buffer is returned, @last_highmem page is set to the page to which
- * the data will have to be copied from @buffer.
+ * If @buffer is returned, the caller of suspend_write_next() will write
+ * the page's contents to @buffer, so they will have to be copied to the
+ * right location on the next call to suspend_write_next() and it is done
+ * with the help of copy_last_highmem_page(). For this purpose, if
+ * @buffer is returned, @last_highmem_page is set to the page to which
+ * the data will have to be copied from @buffer.
*/
-
-static struct page *last_highmem_page;
-
static void *get_highmem_page_buffer(struct page *page,
struct chain_allocator *ca)
{
void *kaddr;
if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
- /* We have allocated the "original" page frame and we can
+ /*
+ * We have allocated the "original" page frame and we can
* use it directly to store the loaded page.
*/
last_highmem_page = page;
return buffer;
}
- /* The "original" page frame has not been allocated and we have to
+ /*
+ * The "original" page frame has not been allocated and we have to
* use a "safe" page frame to store the loaded page.
*/
pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
}
/**
- * copy_last_highmem_page - copy the contents of a highmem image from
- * @buffer, where the caller of snapshot_write_next() has place them,
- * to the right location represented by @last_highmem_page .
+ * copy_last_highmem_page - Copy most the most recent highmem image page.
+ *
+ * Copy the contents of a highmem image from @buffer, where the caller of
+ * snapshot_write_next() has stored them, to the right location represented by
+ * @last_highmem_page .
*/
-
static void copy_last_highmem_page(void)
{
if (last_highmem_page) {
static inline void free_highmem_data(void) {}
#endif /* CONFIG_HIGHMEM */
+#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
+
/**
- * prepare_image - use the memory bitmap @bm to mark the pages that will
- * be overwritten in the process of restoring the system memory state
- * from the suspend image ("unsafe" pages) and allocate memory for the
- * image.
+ * prepare_image - Make room for loading hibernation image.
+ * @new_bm: Unitialized memory bitmap structure.
+ * @bm: Memory bitmap with unsafe pages marked.
+ *
+ * Use @bm to mark the pages that will be overwritten in the process of
+ * restoring the system memory state from the suspend image ("unsafe" pages)
+ * and allocate memory for the image.
*
- * The idea is to allocate a new memory bitmap first and then allocate
- * as many pages as needed for the image data, but not to assign these
- * pages to specific tasks initially. Instead, we just mark them as
- * allocated and create a lists of "safe" pages that will be used
- * later. On systems with high memory a list of "safe" highmem pages is
- * also created.
+ * The idea is to allocate a new memory bitmap first and then allocate
+ * as many pages as needed for image data, but without specifying what those
+ * pages will be used for just yet. Instead, we mark them all as allocated and
+ * create a lists of "safe" pages to be used later. On systems with high
+ * memory a list of "safe" highmem pages is created too.
*/
-
-#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
-
static int prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
{
unsigned int nr_pages, nr_highmem;
if (error)
goto Free;
}
- /* Reserve some safe pages for potential later use.
+ /*
+ * Reserve some safe pages for potential later use.
*
* NOTE: This way we make sure there will be enough safe pages for the
* chain_alloc() in get_buffer(). It is a bit wasteful, but
}
/**
- * get_buffer - compute the address that snapshot_write_next() should
- * set for its caller to write to.
+ * get_buffer - Get the address to store the next image data page.
+ *
+ * Get the address that snapshot_write_next() should return to its caller to
+ * write to.
*/
-
static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
{
struct pbe *pbe;
return get_highmem_page_buffer(page, ca);
if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page))
- /* We have allocated the "original" page frame and we can
+ /*
+ * We have allocated the "original" page frame and we can
* use it directly to store the loaded page.
*/
return page_address(page);
- /* The "original" page frame has not been allocated and we have to
+ /*
+ * The "original" page frame has not been allocated and we have to
* use a "safe" page frame to store the loaded page.
*/
pbe = chain_alloc(ca, sizeof(struct pbe));
}
/**
- * snapshot_write_next - used for writing the system memory snapshot.
+ * snapshot_write_next - Get the address to store the next image page.
+ * @handle: Snapshot handle structure to guide the writing.
*
- * On the first call to it @handle should point to a zeroed
- * snapshot_handle structure. The structure gets updated and a pointer
- * to it should be passed to this function every next time.
+ * On the first call, @handle should point to a zeroed snapshot_handle
+ * structure. The structure gets populated then and a pointer to it should be
+ * passed to this function every next time.
*
- * On success the function returns a positive number. Then, the caller
- * is allowed to write up to the returned number of bytes to the memory
- * location computed by the data_of() macro.
+ * On success, the function returns a positive number. Then, the caller
+ * is allowed to write up to the returned number of bytes to the memory
+ * location computed by the data_of() macro.
*
- * The function returns 0 to indicate the "end of file" condition,
- * and a negative number is returned on error. In such cases the
- * structure pointed to by @handle is not updated and should not be used
- * any more.
+ * The function returns 0 to indicate the "end of file" condition. Negative
+ * numbers are returned on errors, in which cases the structure pointed to by
+ * @handle is not updated and should not be used any more.
*/
-
int snapshot_write_next(struct snapshot_handle *handle)
{
static struct chain_allocator ca;
}
/**
- * snapshot_write_finalize - must be called after the last call to
- * snapshot_write_next() in case the last page in the image happens
- * to be a highmem page and its contents should be stored in the
- * highmem. Additionally, it releases the memory that will not be
- * used any more.
+ * snapshot_write_finalize - Complete the loading of a hibernation image.
+ *
+ * Must be called after the last call to snapshot_write_next() in case the last
+ * page in the image happens to be a highmem page and its contents should be
+ * stored in highmem. Additionally, it recycles bitmap memory that's not
+ * necessary any more.
*/
-
void snapshot_write_finalize(struct snapshot_handle *handle)
{
copy_last_highmem_page();
}
/**
- * restore_highmem - for each highmem page that was allocated before
- * the suspend and included in the suspend image, and also has been
- * allocated by the "resume" kernel swap its current (ie. "before
- * resume") contents with the previous (ie. "before suspend") one.
+ * restore_highmem - Put highmem image pages into their original locations.
+ *
+ * For each highmem page that was in use before hibernation and is included in
+ * the image, and also has been allocated by the "restore" kernel, swap its
+ * current contents with the previous (ie. "before hibernation") ones.
*
- * If the resume eventually fails, we can call this function once
- * again and restore the "before resume" highmem state.
+ * If the restore eventually fails, we can call this function once again and
+ * restore the highmem state as seen by the restore kernel.
*/
-
int restore_highmem(void)
{
struct highmem_pbe *pbe = highmem_pblist;
projects / cascardo / linux.git / blobdiff