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-rw-r--r--include/linux/suspend.h9
-rw-r--r--kernel/power/power.h11
-rw-r--r--kernel/power/snapshot.c416
-rw-r--r--kernel/power/swap.c4
-rw-r--r--kernel/power/user.c1
5 files changed, 186 insertions, 255 deletions
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index c11cacf1a13b..b1237f16ecde 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -16,15 +16,6 @@ struct pbe {
struct pbe *next;
};
-#define for_each_pbe(pbe, pblist) \
- for (pbe = pblist ; pbe ; pbe = pbe->next)
-
-#define PBES_PER_PAGE (PAGE_SIZE/sizeof(struct pbe))
-#define PB_PAGE_SKIP (PBES_PER_PAGE-1)
-
-#define for_each_pb_page(pbe, pblist) \
- for (pbe = pblist ; pbe ; pbe = (pbe+PB_PAGE_SKIP)->next)
-
/* mm/page_alloc.c */
extern void drain_local_pages(void);
extern void mark_free_pages(struct zone *zone);
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 6e9e2acc34f8..bfe999f7b272 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -81,16 +81,6 @@ struct snapshot_handle {
unsigned int prev; /* number of the block of PAGE_SIZE bytes that
* was the current one previously
*/
- struct pbe *pbe; /* PBE that corresponds to 'buffer' */
- struct pbe *last_pbe; /* When the image is restored (eg. read
- * from disk) we can store some image
- * data directly in the page frames
- * in which they were before suspend.
- * In such a case the PBEs that
- * correspond to them will be unused.
- * This is the last PBE, so far, that
- * does not correspond to such data.
- */
void *buffer; /* address of the block to read from
* or write to
*/
@@ -113,6 +103,7 @@ extern unsigned int snapshot_additional_pages(struct zone *zone);
extern int snapshot_read_next(struct snapshot_handle *handle, size_t count);
extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
extern int snapshot_image_loaded(struct snapshot_handle *handle);
+extern void snapshot_free_unused_memory(struct snapshot_handle *handle);
#define SNAPSHOT_IOC_MAGIC '3'
#define SNAPSHOT_FREEZE _IO(SNAPSHOT_IOC_MAGIC, 1)
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 852e0df41719..1b84313cbab5 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -39,7 +39,7 @@ struct pbe *restore_pblist;
static unsigned int nr_copy_pages;
static unsigned int nr_meta_pages;
-static unsigned long *buffer;
+static void *buffer;
#ifdef CONFIG_HIGHMEM
unsigned int count_highmem_pages(void)
@@ -172,7 +172,7 @@ static inline int restore_highmem(void) {return 0;}
#define PG_UNSAFE_CLEAR 1
#define PG_UNSAFE_KEEP 0
-static unsigned int unsafe_pages;
+static unsigned int allocated_unsafe_pages;
static void *alloc_image_page(gfp_t gfp_mask, int safe_needed)
{
@@ -183,7 +183,7 @@ static void *alloc_image_page(gfp_t gfp_mask, int safe_needed)
while (res && PageNosaveFree(virt_to_page(res))) {
/* The page is unsafe, mark it for swsusp_free() */
SetPageNosave(virt_to_page(res));
- unsafe_pages++;
+ allocated_unsafe_pages++;
res = (void *)get_zeroed_page(gfp_mask);
}
if (res) {
@@ -772,101 +772,10 @@ copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
}
/**
- * free_pagedir - free pages allocated with alloc_pagedir()
- */
-
-static void free_pagedir(struct pbe *pblist, int clear_nosave_free)
-{
- struct pbe *pbe;
-
- while (pblist) {
- pbe = (pblist + PB_PAGE_SKIP)->next;
- free_image_page(pblist, clear_nosave_free);
- pblist = pbe;
- }
-}
-
-/**
- * fill_pb_page - Create a list of PBEs on a given memory page
- */
-
-static inline void fill_pb_page(struct pbe *pbpage, unsigned int n)
-{
- struct pbe *p;
-
- p = pbpage;
- pbpage += n - 1;
- do
- p->next = p + 1;
- while (++p < pbpage);
-}
-
-/**
- * create_pbe_list - Create a list of PBEs on top of a given chain
- * of memory pages allocated with alloc_pagedir()
+ * swsusp_free - free pages allocated for the suspend.
*
- * This function assumes that pages allocated by alloc_image_page() will
- * always be zeroed.
- */
-
-static inline void create_pbe_list(struct pbe *pblist, unsigned int nr_pages)
-{
- struct pbe *pbpage;
- unsigned int num = PBES_PER_PAGE;
-
- for_each_pb_page (pbpage, pblist) {
- if (num >= nr_pages)
- break;
-
- fill_pb_page(pbpage, PBES_PER_PAGE);
- num += PBES_PER_PAGE;
- }
- if (pbpage) {
- num -= PBES_PER_PAGE;
- fill_pb_page(pbpage, nr_pages - num);
- }
-}
-
-/**
- * alloc_pagedir - Allocate the page directory.
- *
- * First, determine exactly how many pages we need and
- * allocate them.
- *
- * We arrange the pages in a chain: each page is an array of PBES_PER_PAGE
- * struct pbe elements (pbes) and the last element in the page points
- * to the next page.
- *
- * On each page we set up a list of struct_pbe elements.
- */
-
-static struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask,
- int safe_needed)
-{
- unsigned int num;
- struct pbe *pblist, *pbe;
-
- if (!nr_pages)
- return NULL;
-
- pblist = alloc_image_page(gfp_mask, safe_needed);
- pbe = pblist;
- for (num = PBES_PER_PAGE; num < nr_pages; num += PBES_PER_PAGE) {
- if (!pbe) {
- free_pagedir(pblist, PG_UNSAFE_CLEAR);
- return NULL;
- }
- pbe += PB_PAGE_SKIP;
- pbe->next = alloc_image_page(gfp_mask, safe_needed);
- pbe = pbe->next;
- }
- create_pbe_list(pblist, nr_pages);
- return pblist;
-}
-
-/**
- * Free pages we allocated for suspend. Suspend pages are alocated
- * before atomic copy, so we need to free them after resume.
+ * Suspend pages are alocated before the atomic copy is made, so we
+ * need to release them after the resume.
*/
void swsusp_free(void)
@@ -904,14 +813,18 @@ void swsusp_free(void)
static int enough_free_mem(unsigned int nr_pages)
{
struct zone *zone;
- unsigned int n = 0;
+ unsigned int free = 0, meta = 0;
for_each_zone (zone)
- if (!is_highmem(zone))
- n += zone->free_pages;
- pr_debug("swsusp: available memory: %u pages\n", n);
- return n > (nr_pages + PAGES_FOR_IO +
- (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
+ if (!is_highmem(zone)) {
+ free += zone->free_pages;
+ meta += snapshot_additional_pages(zone);
+ }
+
+ pr_debug("swsusp: pages needed: %u + %u + %u, available pages: %u\n",
+ nr_pages, PAGES_FOR_IO, meta, free);
+
+ return free > nr_pages + PAGES_FOR_IO + meta;
}
static int
@@ -961,11 +874,6 @@ asmlinkage int swsusp_save(void)
nr_pages = count_data_pages();
printk("swsusp: Need to copy %u pages\n", nr_pages);
- pr_debug("swsusp: pages needed: %u + %lu + %u, free: %u\n",
- nr_pages,
- (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE,
- PAGES_FOR_IO, nr_free_pages());
-
if (!enough_free_mem(nr_pages)) {
printk(KERN_ERR "swsusp: Not enough free memory\n");
return -ENOMEM;
@@ -1007,22 +915,19 @@ static void init_header(struct swsusp_info *info)
}
/**
- * pack_addresses - the addresses corresponding to pfns found in the
- * bitmap @bm are stored in the array @buf[] (1 page)
+ * pack_pfns - pfns corresponding to the set bits found in the bitmap @bm
+ * are stored in the array @buf[] (1 page at a time)
*/
static inline void
-pack_addresses(unsigned long *buf, struct memory_bitmap *bm)
+pack_pfns(unsigned long *buf, struct memory_bitmap *bm)
{
int j;
for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
- unsigned long pfn = memory_bm_next_pfn(bm);
-
- if (unlikely(pfn == BM_END_OF_MAP))
+ buf[j] = memory_bm_next_pfn(bm);
+ if (unlikely(buf[j] == BM_END_OF_MAP))
break;
-
- buf[j] = (unsigned long)page_address(pfn_to_page(pfn));
}
}
@@ -1068,7 +973,7 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
if (handle->prev < handle->cur) {
if (handle->cur <= nr_meta_pages) {
memset(buffer, 0, PAGE_SIZE);
- pack_addresses(buffer, &orig_bm);
+ pack_pfns(buffer, &orig_bm);
} else {
unsigned long pfn = memory_bm_next_pfn(&copy_bm);
@@ -1094,14 +999,10 @@ int snapshot_read_next(struct snapshot_handle *handle, size_t count)
* had been used before suspend
*/
-static int mark_unsafe_pages(struct pbe *pblist)
+static int mark_unsafe_pages(struct memory_bitmap *bm)
{
struct zone *zone;
unsigned long pfn, max_zone_pfn;
- struct pbe *p;
-
- if (!pblist) /* a sanity check */
- return -EINVAL;
/* Clear page flags */
for_each_zone (zone) {
@@ -1111,30 +1012,37 @@ static int mark_unsafe_pages(struct pbe *pblist)
ClearPageNosaveFree(pfn_to_page(pfn));
}
- /* Mark orig addresses */
- for_each_pbe (p, pblist) {
- if (virt_addr_valid(p->orig_address))
- SetPageNosaveFree(virt_to_page(p->orig_address));
- else
- return -EFAULT;
- }
+ /* Mark pages that correspond to the "original" pfns as "unsafe" */
+ memory_bm_position_reset(bm);
+ do {
+ pfn = memory_bm_next_pfn(bm);
+ if (likely(pfn != BM_END_OF_MAP)) {
+ if (likely(pfn_valid(pfn)))
+ SetPageNosaveFree(pfn_to_page(pfn));
+ else
+ return -EFAULT;
+ }
+ } while (pfn != BM_END_OF_MAP);
- unsafe_pages = 0;
+ allocated_unsafe_pages = 0;
return 0;
}
-static void copy_page_backup_list(struct pbe *dst, struct pbe *src)
+static void
+duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src)
{
- /* We assume both lists contain the same number of elements */
- while (src) {
- dst->orig_address = src->orig_address;
- dst = dst->next;
- src = src->next;
+ unsigned long pfn;
+
+ memory_bm_position_reset(src);
+ pfn = memory_bm_next_pfn(src);
+ while (pfn != BM_END_OF_MAP) {
+ memory_bm_set_bit(dst, pfn);
+ pfn = memory_bm_next_pfn(src);
}
}
-static int check_header(struct swsusp_info *info)
+static inline int check_header(struct swsusp_info *info)
{
char *reason = NULL;
@@ -1161,19 +1069,14 @@ static int check_header(struct swsusp_info *info)
* load header - check the image header and copy data from it
*/
-static int load_header(struct snapshot_handle *handle,
- struct swsusp_info *info)
+static int
+load_header(struct swsusp_info *info)
{
int error;
- struct pbe *pblist;
+ restore_pblist = NULL;
error = check_header(info);
if (!error) {
- pblist = alloc_pagedir(info->image_pages, GFP_ATOMIC, PG_ANY);
- if (!pblist)
- return -ENOMEM;
- restore_pblist = pblist;
- handle->pbe = pblist;
nr_copy_pages = info->image_pages;
nr_meta_pages = info->pages - info->image_pages - 1;
}
@@ -1181,108 +1084,137 @@ static int load_header(struct snapshot_handle *handle,
}
/**
- * unpack_orig_addresses - copy the elements of @buf[] (1 page) to
- * the PBEs in the list starting at @pbe
+ * unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
+ * the corresponding bit in the memory bitmap @bm
*/
-static inline struct pbe *unpack_orig_addresses(unsigned long *buf,
- struct pbe *pbe)
+static inline void
+unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
{
int j;
- for (j = 0; j < PAGE_SIZE / sizeof(long) && pbe; j++) {
- pbe->orig_address = buf[j];
- pbe = pbe->next;
+ for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
+ if (unlikely(buf[j] == BM_END_OF_MAP))
+ break;
+
+ memory_bm_set_bit(bm, buf[j]);
}
- return pbe;
}
/**
- * prepare_image - use metadata contained in the PBE list
- * pointed to by restore_pblist to mark the pages that will
- * be overwritten in the process of restoring the system
- * memory state from the image ("unsafe" pages) and allocate
- * memory for the image
+ * 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.
*
- * The idea is to allocate the PBE list first and then
- * allocate as many pages as it's needed for the image data,
- * but not to assign these pages to the PBEs initially.
- * Instead, we just mark them as allocated and create a list
- * of "safe" which will be used later
+ * 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 list of "safe" pages that will be used later.
*/
-static struct linked_page *safe_pages;
+#define PBES_PER_LINKED_PAGE (LINKED_PAGE_DATA_SIZE / sizeof(struct pbe))
+
+static struct linked_page *safe_pages_list;
-static int prepare_image(struct snapshot_handle *handle)
+static int
+prepare_image(struct memory_bitmap *new_bm, struct memory_bitmap *bm)
{
- int error = 0;
- unsigned int nr_pages = nr_copy_pages;
- struct pbe *p, *pblist = NULL;
+ unsigned int nr_pages;
+ struct linked_page *sp_list, *lp;
+ int error;
- p = restore_pblist;
- error = mark_unsafe_pages(p);
- if (!error) {
- pblist = alloc_pagedir(nr_pages, GFP_ATOMIC, PG_SAFE);
- if (pblist)
- copy_page_backup_list(pblist, p);
- free_pagedir(p, PG_UNSAFE_KEEP);
- if (!pblist)
+ error = mark_unsafe_pages(bm);
+ if (error)
+ goto Free;
+
+ error = memory_bm_create(new_bm, GFP_ATOMIC, PG_SAFE);
+ if (error)
+ goto Free;
+
+ duplicate_memory_bitmap(new_bm, bm);
+ memory_bm_free(bm, PG_UNSAFE_KEEP);
+ /* 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
+ * nr_copy_pages cannot be greater than 50% of the memory anyway.
+ */
+ sp_list = NULL;
+ /* nr_copy_pages cannot be lesser than allocated_unsafe_pages */
+ nr_pages = nr_copy_pages - allocated_unsafe_pages;
+ nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
+ while (nr_pages > 0) {
+ lp = alloc_image_page(GFP_ATOMIC, PG_SAFE);
+ if (!lp) {
error = -ENOMEM;
+ goto Free;
+ }
+ lp->next = sp_list;
+ sp_list = lp;
+ nr_pages--;
}
- safe_pages = NULL;
- if (!error && nr_pages > unsafe_pages) {
- nr_pages -= unsafe_pages;
- while (nr_pages--) {
- struct linked_page *ptr;
-
- ptr = (void *)get_zeroed_page(GFP_ATOMIC);
- if (!ptr) {
- error = -ENOMEM;
- break;
- }
- if (!PageNosaveFree(virt_to_page(ptr))) {
- /* The page is "safe", add it to the list */
- ptr->next = safe_pages;
- safe_pages = ptr;
- }
- /* Mark the page as allocated */
- SetPageNosave(virt_to_page(ptr));
- SetPageNosaveFree(virt_to_page(ptr));
+ /* Preallocate memory for the image */
+ safe_pages_list = NULL;
+ nr_pages = nr_copy_pages - allocated_unsafe_pages;
+ while (nr_pages > 0) {
+ lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
+ if (!lp) {
+ error = -ENOMEM;
+ goto Free;
+ }
+ if (!PageNosaveFree(virt_to_page(lp))) {
+ /* The page is "safe", add it to the list */
+ lp->next = safe_pages_list;
+ safe_pages_list = lp;
}
+ /* Mark the page as allocated */
+ SetPageNosave(virt_to_page(lp));
+ SetPageNosaveFree(virt_to_page(lp));
+ nr_pages--;
}
- if (!error) {
- restore_pblist = pblist;
- } else {
- handle->pbe = NULL;
- swsusp_free();
+ /* Free the reserved safe pages so that chain_alloc() can use them */
+ while (sp_list) {
+ lp = sp_list->next;
+ free_image_page(sp_list, PG_UNSAFE_CLEAR);
+ sp_list = lp;
}
+ return 0;
+
+Free:
+ swsusp_free();
return error;
}
-static void *get_buffer(struct snapshot_handle *handle)
+/**
+ * get_buffer - compute the address that snapshot_write_next() should
+ * set for its caller to write to.
+ */
+
+static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
{
- struct pbe *pbe = handle->pbe, *last = handle->last_pbe;
- struct page *page = virt_to_page(pbe->orig_address);
+ struct pbe *pbe;
+ struct page *page = pfn_to_page(memory_bm_next_pfn(bm));
- if (PageNosave(page) && PageNosaveFree(page)) {
- /*
- * We have allocated the "original" page frame and we can
- * use it directly to store the read page
+ if (PageNosave(page) && PageNosaveFree(page))
+ /* We have allocated the "original" page frame and we can
+ * use it directly to store the loaded page.
*/
- pbe->address = 0;
- if (last && last->next)
- last->next = NULL;
- return (void *)pbe->orig_address;
- }
- /*
- * The "original" page frame has not been allocated and we have to
- * use a "safe" page frame to store the read page
+ return page_address(page);
+
+ /* The "original" page frame has not been allocated and we have to
+ * use a "safe" page frame to store the loaded page.
*/
- pbe->address = (unsigned long)safe_pages;
- safe_pages = safe_pages->next;
- if (last)
- last->next = pbe;
- handle->last_pbe = pbe;
+ pbe = chain_alloc(ca, sizeof(struct pbe));
+ if (!pbe) {
+ swsusp_free();
+ return NULL;
+ }
+ pbe->orig_address = (unsigned long)page_address(page);
+ pbe->address = (unsigned long)safe_pages_list;
+ safe_pages_list = safe_pages_list->next;
+ pbe->next = restore_pblist;
+ restore_pblist = pbe;
return (void *)pbe->address;
}
@@ -1310,10 +1242,13 @@ static void *get_buffer(struct snapshot_handle *handle)
int snapshot_write_next(struct snapshot_handle *handle, size_t count)
{
+ static struct chain_allocator ca;
int error = 0;
+ /* Check if we have already loaded the entire image */
if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages)
return 0;
+
if (!buffer) {
/* This makes the buffer be freed by swsusp_free() */
buffer = alloc_image_page(GFP_ATOMIC, PG_ANY);
@@ -1324,26 +1259,32 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count)
handle->buffer = buffer;
handle->sync_read = 1;
if (handle->prev < handle->cur) {
- if (!handle->prev) {
- error = load_header(handle,
- (struct swsusp_info *)buffer);
+ if (handle->prev == 0) {
+ error = load_header(buffer);
+ if (error)
+ return error;
+
+ error = memory_bm_create(&copy_bm, GFP_ATOMIC, PG_ANY);
if (error)
return error;
+
} else if (handle->prev <= nr_meta_pages) {
- handle->pbe = unpack_orig_addresses(buffer,
- handle->pbe);
- if (!handle->pbe) {
- error = prepare_image(handle);
+ unpack_orig_pfns(buffer, &copy_bm);
+ if (handle->prev == nr_meta_pages) {
+ error = prepare_image(&orig_bm, &copy_bm);
if (error)
return error;
- handle->pbe = restore_pblist;
- handle->last_pbe = NULL;
- handle->buffer = get_buffer(handle);
+
+ chain_init(&ca, GFP_ATOMIC, PG_SAFE);
+ memory_bm_position_reset(&orig_bm);
+ restore_pblist = NULL;
+ handle->buffer = get_buffer(&orig_bm, &ca);
handle->sync_read = 0;
+ if (!handle->buffer)
+ return -ENOMEM;
}
} else {
- handle->pbe = handle->pbe->next;
- handle->buffer = get_buffer(handle);
+ handle->buffer = get_buffer(&orig_bm, &ca);
handle->sync_read = 0;
}
handle->prev = handle->cur;
@@ -1362,6 +1303,13 @@ int snapshot_write_next(struct snapshot_handle *handle, size_t count)
int snapshot_image_loaded(struct snapshot_handle *handle)
{
- return !(!handle->pbe || handle->pbe->next || !nr_copy_pages ||
- handle->cur <= nr_meta_pages + nr_copy_pages);
+ return !(!nr_copy_pages ||
+ handle->cur <= nr_meta_pages + nr_copy_pages);
+}
+
+void snapshot_free_unused_memory(struct snapshot_handle *handle)
+{
+ /* Free only if we have loaded the image entirely */
+ if (handle->prev && handle->cur > nr_meta_pages + nr_copy_pages)
+ memory_bm_free(&orig_bm, PG_UNSAFE_CLEAR);
}
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 8309d20b2563..9b2ee5344dee 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -331,8 +331,7 @@ static int enough_swap(unsigned int nr_pages)
unsigned int free_swap = count_swap_pages(root_swap, 1);
pr_debug("swsusp: free swap pages: %u\n", free_swap);
- return free_swap > (nr_pages + PAGES_FOR_IO +
- (nr_pages + PBES_PER_PAGE - 1) / PBES_PER_PAGE);
+ return free_swap > nr_pages + PAGES_FOR_IO;
}
/**
@@ -547,6 +546,7 @@ static int load_image(struct swap_map_handle *handle,
error = err2;
if (!error) {
printk("\b\b\b\bdone\n");
+ snapshot_free_unused_memory(snapshot);
if (!snapshot_image_loaded(snapshot))
error = -ENODATA;
}
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 0ef5e4ba39e5..2e4499f3e4d9 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -193,6 +193,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp,
error = -EPERM;
break;
}
+ snapshot_free_unused_memory(&data->handle);
down(&pm_sem);
pm_prepare_console();
error = device_suspend(PMSG_FREEZE);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.