0709db6072
Make swsusp call create_basic_memory_bitmaps() before processes are frozen, so that GFP_KERNEL allocations can be made in it. Additionally, ensure that the swsusp's userland interface won't be used while either pm_suspend_disk() or software_resume() is being executed. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1948 lines
50 KiB
C
1948 lines
50 KiB
C
/*
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* linux/kernel/power/snapshot.c
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*
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* This file provides system snapshot/restore functionality for swsusp.
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*
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* Copyright (C) 1998-2005 Pavel Machek <pavel@suse.cz>
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* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
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*
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* This file is released under the GPLv2.
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*
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*/
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#include <linux/version.h>
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/suspend.h>
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#include <linux/smp_lock.h>
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#include <linux/delay.h>
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#include <linux/bitops.h>
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#include <linux/spinlock.h>
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#include <linux/kernel.h>
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#include <linux/pm.h>
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/bootmem.h>
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#include <linux/syscalls.h>
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#include <linux/console.h>
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#include <linux/highmem.h>
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#include <asm/uaccess.h>
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#include <asm/mmu_context.h>
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#include <asm/pgtable.h>
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#include <asm/tlbflush.h>
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#include <asm/io.h>
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#include "power.h"
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static int swsusp_page_is_free(struct page *);
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static void swsusp_set_page_forbidden(struct page *);
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static void swsusp_unset_page_forbidden(struct page *);
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/* List of PBEs needed for restoring the pages that were allocated before
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* the suspend and included in the suspend image, but have also been
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* allocated by the "resume" kernel, so their contents cannot be written
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* directly to their "original" page frames.
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*/
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struct pbe *restore_pblist;
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/* Pointer to an auxiliary buffer (1 page) */
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static void *buffer;
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/**
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* @safe_needed - on resume, for storing the PBE list and the image,
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* we can only use memory pages that do not conflict with the pages
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* used before suspend. The unsafe pages have PageNosaveFree set
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* and we count them using unsafe_pages.
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*
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* Each allocated image page is marked as PageNosave and PageNosaveFree
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* so that swsusp_free() can release it.
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*/
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#define PG_ANY 0
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#define PG_SAFE 1
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#define PG_UNSAFE_CLEAR 1
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#define PG_UNSAFE_KEEP 0
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static unsigned int allocated_unsafe_pages;
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static void *get_image_page(gfp_t gfp_mask, int safe_needed)
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{
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void *res;
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res = (void *)get_zeroed_page(gfp_mask);
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if (safe_needed)
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while (res && swsusp_page_is_free(virt_to_page(res))) {
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/* The page is unsafe, mark it for swsusp_free() */
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swsusp_set_page_forbidden(virt_to_page(res));
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allocated_unsafe_pages++;
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res = (void *)get_zeroed_page(gfp_mask);
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}
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if (res) {
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swsusp_set_page_forbidden(virt_to_page(res));
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swsusp_set_page_free(virt_to_page(res));
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}
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return res;
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}
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unsigned long get_safe_page(gfp_t gfp_mask)
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{
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return (unsigned long)get_image_page(gfp_mask, PG_SAFE);
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}
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static struct page *alloc_image_page(gfp_t gfp_mask)
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{
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struct page *page;
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page = alloc_page(gfp_mask);
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if (page) {
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swsusp_set_page_forbidden(page);
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swsusp_set_page_free(page);
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}
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return page;
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}
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/**
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* free_image_page - free page represented by @addr, allocated with
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* get_image_page (page flags set by it must be cleared)
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*/
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static inline void free_image_page(void *addr, int clear_nosave_free)
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{
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struct page *page;
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BUG_ON(!virt_addr_valid(addr));
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page = virt_to_page(addr);
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swsusp_unset_page_forbidden(page);
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if (clear_nosave_free)
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swsusp_unset_page_free(page);
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__free_page(page);
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}
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/* struct linked_page is used to build chains of pages */
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#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *))
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struct linked_page {
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struct linked_page *next;
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char data[LINKED_PAGE_DATA_SIZE];
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} __attribute__((packed));
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static inline void
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free_list_of_pages(struct linked_page *list, int clear_page_nosave)
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{
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while (list) {
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struct linked_page *lp = list->next;
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free_image_page(list, clear_page_nosave);
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list = lp;
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}
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}
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/**
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* struct chain_allocator is used for allocating small objects out of
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* a linked list of pages called 'the chain'.
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*
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* The chain grows each time when there is no room for a new object in
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* the current page. The allocated objects cannot be freed individually.
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* It is only possible to free them all at once, by freeing the entire
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* chain.
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*
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* NOTE: The chain allocator may be inefficient if the allocated objects
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* are not much smaller than PAGE_SIZE.
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*/
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struct chain_allocator {
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struct linked_page *chain; /* the chain */
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unsigned int used_space; /* total size of objects allocated out
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* of the current page
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*/
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gfp_t gfp_mask; /* mask for allocating pages */
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int safe_needed; /* if set, only "safe" pages are allocated */
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};
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static void
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chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed)
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{
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ca->chain = NULL;
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ca->used_space = LINKED_PAGE_DATA_SIZE;
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ca->gfp_mask = gfp_mask;
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ca->safe_needed = safe_needed;
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}
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static void *chain_alloc(struct chain_allocator *ca, unsigned int size)
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{
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void *ret;
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if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) {
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struct linked_page *lp;
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lp = get_image_page(ca->gfp_mask, ca->safe_needed);
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if (!lp)
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return NULL;
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lp->next = ca->chain;
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ca->chain = lp;
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ca->used_space = 0;
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}
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ret = ca->chain->data + ca->used_space;
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ca->used_space += size;
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return ret;
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}
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static void chain_free(struct chain_allocator *ca, int clear_page_nosave)
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{
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free_list_of_pages(ca->chain, clear_page_nosave);
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memset(ca, 0, sizeof(struct chain_allocator));
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}
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/**
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* Data types related to memory bitmaps.
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*
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* Memory bitmap is a structure consiting of many linked lists of
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* objects. The main list's elements are of type struct zone_bitmap
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* and each of them corresonds to one zone. For each zone bitmap
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* object there is a list of objects of type struct bm_block that
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* represent each blocks of bit chunks in which information is
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* stored.
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*
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* struct memory_bitmap contains a pointer to the main list of zone
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* bitmap objects, a struct bm_position used for browsing the bitmap,
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* and a pointer to the list of pages used for allocating all of the
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* zone bitmap objects and bitmap block objects.
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*
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* NOTE: It has to be possible to lay out the bitmap in memory
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* using only allocations of order 0. Additionally, the bitmap is
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* designed to work with arbitrary number of zones (this is over the
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* top for now, but let's avoid making unnecessary assumptions ;-).
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*
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* struct zone_bitmap contains a pointer to a list of bitmap block
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* objects and a pointer to the bitmap block object that has been
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* most recently used for setting bits. Additionally, it contains the
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* pfns that correspond to the start and end of the represented zone.
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*
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* struct bm_block contains a pointer to the memory page in which
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* information is stored (in the form of a block of bit chunks
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* of type unsigned long each). It also contains the pfns that
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* correspond to the start and end of the represented memory area and
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* the number of bit chunks in the block.
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*/
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#define BM_END_OF_MAP (~0UL)
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#define BM_CHUNKS_PER_BLOCK (PAGE_SIZE / sizeof(long))
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#define BM_BITS_PER_CHUNK (sizeof(long) << 3)
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#define BM_BITS_PER_BLOCK (PAGE_SIZE << 3)
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struct bm_block {
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struct bm_block *next; /* next element of the list */
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unsigned long start_pfn; /* pfn represented by the first bit */
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unsigned long end_pfn; /* pfn represented by the last bit plus 1 */
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unsigned int size; /* number of bit chunks */
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unsigned long *data; /* chunks of bits representing pages */
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};
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struct zone_bitmap {
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struct zone_bitmap *next; /* next element of the list */
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unsigned long start_pfn; /* minimal pfn in this zone */
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unsigned long end_pfn; /* maximal pfn in this zone plus 1 */
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struct bm_block *bm_blocks; /* list of bitmap blocks */
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struct bm_block *cur_block; /* recently used bitmap block */
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};
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/* strcut bm_position is used for browsing memory bitmaps */
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struct bm_position {
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struct zone_bitmap *zone_bm;
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struct bm_block *block;
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int chunk;
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int bit;
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};
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struct memory_bitmap {
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struct zone_bitmap *zone_bm_list; /* list of zone bitmaps */
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struct linked_page *p_list; /* list of pages used to store zone
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* bitmap objects and bitmap block
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* objects
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*/
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struct bm_position cur; /* most recently used bit position */
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};
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/* Functions that operate on memory bitmaps */
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static inline void memory_bm_reset_chunk(struct memory_bitmap *bm)
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{
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bm->cur.chunk = 0;
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bm->cur.bit = -1;
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}
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static void memory_bm_position_reset(struct memory_bitmap *bm)
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{
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struct zone_bitmap *zone_bm;
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zone_bm = bm->zone_bm_list;
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bm->cur.zone_bm = zone_bm;
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bm->cur.block = zone_bm->bm_blocks;
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memory_bm_reset_chunk(bm);
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}
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static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free);
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/**
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* create_bm_block_list - create a list of block bitmap objects
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*/
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static inline struct bm_block *
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create_bm_block_list(unsigned int nr_blocks, struct chain_allocator *ca)
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{
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struct bm_block *bblist = NULL;
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while (nr_blocks-- > 0) {
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struct bm_block *bb;
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bb = chain_alloc(ca, sizeof(struct bm_block));
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if (!bb)
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return NULL;
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bb->next = bblist;
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bblist = bb;
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}
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return bblist;
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}
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/**
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* create_zone_bm_list - create a list of zone bitmap objects
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*/
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static inline struct zone_bitmap *
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create_zone_bm_list(unsigned int nr_zones, struct chain_allocator *ca)
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{
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struct zone_bitmap *zbmlist = NULL;
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while (nr_zones-- > 0) {
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struct zone_bitmap *zbm;
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zbm = chain_alloc(ca, sizeof(struct zone_bitmap));
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if (!zbm)
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return NULL;
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zbm->next = zbmlist;
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zbmlist = zbm;
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}
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return zbmlist;
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}
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/**
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* memory_bm_create - allocate memory for a memory bitmap
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*/
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static int
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memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed)
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{
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struct chain_allocator ca;
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struct zone *zone;
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struct zone_bitmap *zone_bm;
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struct bm_block *bb;
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unsigned int nr;
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chain_init(&ca, gfp_mask, safe_needed);
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/* Compute the number of zones */
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nr = 0;
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for_each_zone(zone)
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if (populated_zone(zone))
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nr++;
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/* Allocate the list of zones bitmap objects */
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zone_bm = create_zone_bm_list(nr, &ca);
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bm->zone_bm_list = zone_bm;
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if (!zone_bm) {
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chain_free(&ca, PG_UNSAFE_CLEAR);
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return -ENOMEM;
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}
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/* Initialize the zone bitmap objects */
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for_each_zone(zone) {
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unsigned long pfn;
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if (!populated_zone(zone))
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continue;
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zone_bm->start_pfn = zone->zone_start_pfn;
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zone_bm->end_pfn = zone->zone_start_pfn + zone->spanned_pages;
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/* Allocate the list of bitmap block objects */
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nr = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
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bb = create_bm_block_list(nr, &ca);
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zone_bm->bm_blocks = bb;
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zone_bm->cur_block = bb;
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if (!bb)
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goto Free;
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nr = zone->spanned_pages;
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pfn = zone->zone_start_pfn;
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/* Initialize the bitmap block objects */
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while (bb) {
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unsigned long *ptr;
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ptr = get_image_page(gfp_mask, safe_needed);
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bb->data = ptr;
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if (!ptr)
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goto Free;
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bb->start_pfn = pfn;
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if (nr >= BM_BITS_PER_BLOCK) {
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pfn += BM_BITS_PER_BLOCK;
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bb->size = BM_CHUNKS_PER_BLOCK;
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nr -= BM_BITS_PER_BLOCK;
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} else {
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/* This is executed only once in the loop */
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pfn += nr;
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bb->size = DIV_ROUND_UP(nr, BM_BITS_PER_CHUNK);
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}
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bb->end_pfn = pfn;
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bb = bb->next;
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}
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zone_bm = zone_bm->next;
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}
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bm->p_list = ca.chain;
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memory_bm_position_reset(bm);
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return 0;
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Free:
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bm->p_list = ca.chain;
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memory_bm_free(bm, PG_UNSAFE_CLEAR);
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return -ENOMEM;
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}
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/**
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* memory_bm_free - free memory occupied by the memory bitmap @bm
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*/
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static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free)
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{
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struct zone_bitmap *zone_bm;
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/* Free the list of bit blocks for each zone_bitmap object */
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zone_bm = bm->zone_bm_list;
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while (zone_bm) {
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struct bm_block *bb;
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bb = zone_bm->bm_blocks;
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while (bb) {
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if (bb->data)
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free_image_page(bb->data, clear_nosave_free);
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bb = bb->next;
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}
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zone_bm = zone_bm->next;
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}
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free_list_of_pages(bm->p_list, clear_nosave_free);
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bm->zone_bm_list = NULL;
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}
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/**
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* memory_bm_find_bit - find the bit in the bitmap @bm that corresponds
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* to given pfn. The cur_zone_bm member of @bm and the cur_block member
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* of @bm->cur_zone_bm are updated.
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*/
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static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
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void **addr, unsigned int *bit_nr)
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{
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struct zone_bitmap *zone_bm;
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struct bm_block *bb;
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/* Check if the pfn is from the current zone */
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zone_bm = bm->cur.zone_bm;
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if (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
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zone_bm = bm->zone_bm_list;
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/* We don't assume that the zones are sorted by pfns */
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while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) {
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zone_bm = zone_bm->next;
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BUG_ON(!zone_bm);
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}
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bm->cur.zone_bm = zone_bm;
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}
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/* Check if the pfn corresponds to the current bitmap block */
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bb = zone_bm->cur_block;
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if (pfn < bb->start_pfn)
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bb = zone_bm->bm_blocks;
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while (pfn >= bb->end_pfn) {
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bb = bb->next;
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BUG_ON(!bb);
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}
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zone_bm->cur_block = bb;
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pfn -= bb->start_pfn;
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*bit_nr = pfn % BM_BITS_PER_CHUNK;
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*addr = bb->data + pfn / BM_BITS_PER_CHUNK;
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}
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static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
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{
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void *addr;
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unsigned int bit;
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memory_bm_find_bit(bm, pfn, &addr, &bit);
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set_bit(bit, addr);
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}
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static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
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{
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void *addr;
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unsigned int bit;
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memory_bm_find_bit(bm, pfn, &addr, &bit);
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clear_bit(bit, addr);
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}
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static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
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{
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void *addr;
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unsigned int bit;
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memory_bm_find_bit(bm, pfn, &addr, &bit);
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return test_bit(bit, addr);
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}
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/* Two auxiliary functions for memory_bm_next_pfn */
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/* Find the first set bit in the given chunk, if there is one */
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static inline int next_bit_in_chunk(int bit, unsigned long *chunk_p)
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{
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bit++;
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while (bit < BM_BITS_PER_CHUNK) {
|
|
if (test_bit(bit, chunk_p))
|
|
return bit;
|
|
|
|
bit++;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/* Find a chunk containing some bits set in given block of bits */
|
|
|
|
static inline int next_chunk_in_block(int n, struct bm_block *bb)
|
|
{
|
|
n++;
|
|
while (n < bb->size) {
|
|
if (bb->data[n])
|
|
return n;
|
|
|
|
n++;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* memory_bm_next_pfn - find the pfn that corresponds to the next set bit
|
|
* in the bitmap @bm. If the pfn cannot be found, BM_END_OF_MAP is
|
|
* returned.
|
|
*
|
|
* It is required to run memory_bm_position_reset() before the first call to
|
|
* this function.
|
|
*/
|
|
|
|
static unsigned long memory_bm_next_pfn(struct memory_bitmap *bm)
|
|
{
|
|
struct zone_bitmap *zone_bm;
|
|
struct bm_block *bb;
|
|
int chunk;
|
|
int bit;
|
|
|
|
do {
|
|
bb = bm->cur.block;
|
|
do {
|
|
chunk = bm->cur.chunk;
|
|
bit = bm->cur.bit;
|
|
do {
|
|
bit = next_bit_in_chunk(bit, bb->data + chunk);
|
|
if (bit >= 0)
|
|
goto Return_pfn;
|
|
|
|
chunk = next_chunk_in_block(chunk, bb);
|
|
bit = -1;
|
|
} while (chunk >= 0);
|
|
bb = bb->next;
|
|
bm->cur.block = bb;
|
|
memory_bm_reset_chunk(bm);
|
|
} while (bb);
|
|
zone_bm = bm->cur.zone_bm->next;
|
|
if (zone_bm) {
|
|
bm->cur.zone_bm = zone_bm;
|
|
bm->cur.block = zone_bm->bm_blocks;
|
|
memory_bm_reset_chunk(bm);
|
|
}
|
|
} while (zone_bm);
|
|
memory_bm_position_reset(bm);
|
|
return BM_END_OF_MAP;
|
|
|
|
Return_pfn:
|
|
bm->cur.chunk = chunk;
|
|
bm->cur.bit = bit;
|
|
return bb->start_pfn + chunk * BM_BITS_PER_CHUNK + bit;
|
|
}
|
|
|
|
/**
|
|
* This structure represents a range of page frames the contents of which
|
|
* should not be saved during the suspend.
|
|
*/
|
|
|
|
struct nosave_region {
|
|
struct list_head list;
|
|
unsigned long start_pfn;
|
|
unsigned long end_pfn;
|
|
};
|
|
|
|
static LIST_HEAD(nosave_regions);
|
|
|
|
/**
|
|
* 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)
|
|
*/
|
|
|
|
void __init
|
|
register_nosave_region(unsigned long start_pfn, unsigned long end_pfn)
|
|
{
|
|
struct nosave_region *region;
|
|
|
|
if (start_pfn >= end_pfn)
|
|
return;
|
|
|
|
if (!list_empty(&nosave_regions)) {
|
|
/* Try to extend the previous region (they should be sorted) */
|
|
region = list_entry(nosave_regions.prev,
|
|
struct nosave_region, list);
|
|
if (region->end_pfn == start_pfn) {
|
|
region->end_pfn = end_pfn;
|
|
goto Report;
|
|
}
|
|
}
|
|
/* This allocation cannot fail */
|
|
region = alloc_bootmem_low(sizeof(struct nosave_region));
|
|
region->start_pfn = start_pfn;
|
|
region->end_pfn = end_pfn;
|
|
list_add_tail(®ion->list, &nosave_regions);
|
|
Report:
|
|
printk("swsusp: Registered nosave memory region: %016lx - %016lx\n",
|
|
start_pfn << PAGE_SHIFT, end_pfn << PAGE_SHIFT);
|
|
}
|
|
|
|
/*
|
|
* Set bits in this map correspond to the page frames the contents of which
|
|
* should not be saved during the suspend.
|
|
*/
|
|
static struct memory_bitmap *forbidden_pages_map;
|
|
|
|
/* Set bits in this map correspond to free page frames. */
|
|
static struct memory_bitmap *free_pages_map;
|
|
|
|
/*
|
|
* Each page frame allocated for creating the image is marked by setting the
|
|
* corresponding bits in forbidden_pages_map and free_pages_map simultaneously
|
|
*/
|
|
|
|
void swsusp_set_page_free(struct page *page)
|
|
{
|
|
if (free_pages_map)
|
|
memory_bm_set_bit(free_pages_map, page_to_pfn(page));
|
|
}
|
|
|
|
static int swsusp_page_is_free(struct page *page)
|
|
{
|
|
return free_pages_map ?
|
|
memory_bm_test_bit(free_pages_map, page_to_pfn(page)) : 0;
|
|
}
|
|
|
|
void swsusp_unset_page_free(struct page *page)
|
|
{
|
|
if (free_pages_map)
|
|
memory_bm_clear_bit(free_pages_map, page_to_pfn(page));
|
|
}
|
|
|
|
static void swsusp_set_page_forbidden(struct page *page)
|
|
{
|
|
if (forbidden_pages_map)
|
|
memory_bm_set_bit(forbidden_pages_map, page_to_pfn(page));
|
|
}
|
|
|
|
int swsusp_page_is_forbidden(struct page *page)
|
|
{
|
|
return forbidden_pages_map ?
|
|
memory_bm_test_bit(forbidden_pages_map, page_to_pfn(page)) : 0;
|
|
}
|
|
|
|
static void swsusp_unset_page_forbidden(struct page *page)
|
|
{
|
|
if (forbidden_pages_map)
|
|
memory_bm_clear_bit(forbidden_pages_map, page_to_pfn(page));
|
|
}
|
|
|
|
/**
|
|
* mark_nosave_pages - set bits corresponding to the page frames the
|
|
* contents of which should not be saved in a given bitmap.
|
|
*/
|
|
|
|
static void mark_nosave_pages(struct memory_bitmap *bm)
|
|
{
|
|
struct nosave_region *region;
|
|
|
|
if (list_empty(&nosave_regions))
|
|
return;
|
|
|
|
list_for_each_entry(region, &nosave_regions, list) {
|
|
unsigned long pfn;
|
|
|
|
printk("swsusp: Marking nosave pages: %016lx - %016lx\n",
|
|
region->start_pfn << PAGE_SHIFT,
|
|
region->end_pfn << PAGE_SHIFT);
|
|
|
|
for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++)
|
|
memory_bm_set_bit(bm, pfn);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
|
|
int create_basic_memory_bitmaps(void)
|
|
{
|
|
struct memory_bitmap *bm1, *bm2;
|
|
int error = 0;
|
|
|
|
BUG_ON(forbidden_pages_map || free_pages_map);
|
|
|
|
bm1 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
|
|
if (!bm1)
|
|
return -ENOMEM;
|
|
|
|
error = memory_bm_create(bm1, GFP_KERNEL, PG_ANY);
|
|
if (error)
|
|
goto Free_first_object;
|
|
|
|
bm2 = kzalloc(sizeof(struct memory_bitmap), GFP_KERNEL);
|
|
if (!bm2)
|
|
goto Free_first_bitmap;
|
|
|
|
error = memory_bm_create(bm2, GFP_KERNEL, PG_ANY);
|
|
if (error)
|
|
goto Free_second_object;
|
|
|
|
forbidden_pages_map = bm1;
|
|
free_pages_map = bm2;
|
|
mark_nosave_pages(forbidden_pages_map);
|
|
|
|
printk("swsusp: Basic memory bitmaps created\n");
|
|
|
|
return 0;
|
|
|
|
Free_second_object:
|
|
kfree(bm2);
|
|
Free_first_bitmap:
|
|
memory_bm_free(bm1, PG_UNSAFE_CLEAR);
|
|
Free_first_object:
|
|
kfree(bm1);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
|
|
void free_basic_memory_bitmaps(void)
|
|
{
|
|
struct memory_bitmap *bm1, *bm2;
|
|
|
|
BUG_ON(!(forbidden_pages_map && free_pages_map));
|
|
|
|
bm1 = forbidden_pages_map;
|
|
bm2 = free_pages_map;
|
|
forbidden_pages_map = NULL;
|
|
free_pages_map = NULL;
|
|
memory_bm_free(bm1, PG_UNSAFE_CLEAR);
|
|
kfree(bm1);
|
|
memory_bm_free(bm2, PG_UNSAFE_CLEAR);
|
|
kfree(bm2);
|
|
|
|
printk("swsusp: Basic memory bitmaps freed\n");
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
*/
|
|
|
|
unsigned int snapshot_additional_pages(struct zone *zone)
|
|
{
|
|
unsigned int res;
|
|
|
|
res = DIV_ROUND_UP(zone->spanned_pages, BM_BITS_PER_BLOCK);
|
|
res += DIV_ROUND_UP(res * sizeof(struct bm_block), PAGE_SIZE);
|
|
return 2 * res;
|
|
}
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
/**
|
|
* count_free_highmem_pages - compute the total number of free highmem
|
|
* pages, system-wide.
|
|
*/
|
|
|
|
static unsigned int count_free_highmem_pages(void)
|
|
{
|
|
struct zone *zone;
|
|
unsigned int cnt = 0;
|
|
|
|
for_each_zone(zone)
|
|
if (populated_zone(zone) && is_highmem(zone))
|
|
cnt += zone_page_state(zone, NR_FREE_PAGES);
|
|
|
|
return cnt;
|
|
}
|
|
|
|
/**
|
|
* saveable_highmem_page - Determine whether a highmem page should be
|
|
* included in the suspend 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.
|
|
*/
|
|
|
|
static struct page *saveable_highmem_page(unsigned long pfn)
|
|
{
|
|
struct page *page;
|
|
|
|
if (!pfn_valid(pfn))
|
|
return NULL;
|
|
|
|
page = pfn_to_page(pfn);
|
|
|
|
BUG_ON(!PageHighMem(page));
|
|
|
|
if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page) ||
|
|
PageReserved(page))
|
|
return NULL;
|
|
|
|
return page;
|
|
}
|
|
|
|
/**
|
|
* count_highmem_pages - compute the total number of saveable highmem
|
|
* pages.
|
|
*/
|
|
|
|
unsigned int count_highmem_pages(void)
|
|
{
|
|
struct zone *zone;
|
|
unsigned int n = 0;
|
|
|
|
for_each_zone(zone) {
|
|
unsigned long pfn, max_zone_pfn;
|
|
|
|
if (!is_highmem(zone))
|
|
continue;
|
|
|
|
mark_free_pages(zone);
|
|
max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
|
|
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
|
|
if (saveable_highmem_page(pfn))
|
|
n++;
|
|
}
|
|
return n;
|
|
}
|
|
#else
|
|
static inline void *saveable_highmem_page(unsigned long pfn) { return NULL; }
|
|
static inline unsigned int count_highmem_pages(void) { return 0; }
|
|
#endif /* CONFIG_HIGHMEM */
|
|
|
|
/**
|
|
* saveable - Determine whether a non-highmem page should be included in
|
|
* the suspend 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.
|
|
*/
|
|
|
|
static struct page *saveable_page(unsigned long pfn)
|
|
{
|
|
struct page *page;
|
|
|
|
if (!pfn_valid(pfn))
|
|
return NULL;
|
|
|
|
page = pfn_to_page(pfn);
|
|
|
|
BUG_ON(PageHighMem(page));
|
|
|
|
if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
|
|
return NULL;
|
|
|
|
if (PageReserved(page) && pfn_is_nosave(pfn))
|
|
return NULL;
|
|
|
|
return page;
|
|
}
|
|
|
|
/**
|
|
* count_data_pages - compute the total number of saveable non-highmem
|
|
* pages.
|
|
*/
|
|
|
|
unsigned int count_data_pages(void)
|
|
{
|
|
struct zone *zone;
|
|
unsigned long pfn, max_zone_pfn;
|
|
unsigned int n = 0;
|
|
|
|
for_each_zone(zone) {
|
|
if (is_highmem(zone))
|
|
continue;
|
|
|
|
mark_free_pages(zone);
|
|
max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
|
|
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
|
|
if(saveable_page(pfn))
|
|
n++;
|
|
}
|
|
return n;
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
int n;
|
|
|
|
for (n = PAGE_SIZE / sizeof(long); n; n--)
|
|
*dst++ = *src++;
|
|
}
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
static inline struct page *
|
|
page_is_saveable(struct zone *zone, unsigned long pfn)
|
|
{
|
|
return is_highmem(zone) ?
|
|
saveable_highmem_page(pfn) : saveable_page(pfn);
|
|
}
|
|
|
|
static inline void
|
|
copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
|
|
{
|
|
struct page *s_page, *d_page;
|
|
void *src, *dst;
|
|
|
|
s_page = pfn_to_page(src_pfn);
|
|
d_page = pfn_to_page(dst_pfn);
|
|
if (PageHighMem(s_page)) {
|
|
src = kmap_atomic(s_page, KM_USER0);
|
|
dst = kmap_atomic(d_page, KM_USER1);
|
|
do_copy_page(dst, src);
|
|
kunmap_atomic(src, KM_USER0);
|
|
kunmap_atomic(dst, KM_USER1);
|
|
} else {
|
|
src = page_address(s_page);
|
|
if (PageHighMem(d_page)) {
|
|
/* Page pointed to by src may contain some kernel
|
|
* data modified by kmap_atomic()
|
|
*/
|
|
do_copy_page(buffer, src);
|
|
dst = kmap_atomic(pfn_to_page(dst_pfn), KM_USER0);
|
|
memcpy(dst, buffer, PAGE_SIZE);
|
|
kunmap_atomic(dst, KM_USER0);
|
|
} else {
|
|
dst = page_address(d_page);
|
|
do_copy_page(dst, src);
|
|
}
|
|
}
|
|
}
|
|
#else
|
|
#define page_is_saveable(zone, pfn) saveable_page(pfn)
|
|
|
|
static inline void
|
|
copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
|
|
{
|
|
do_copy_page(page_address(pfn_to_page(dst_pfn)),
|
|
page_address(pfn_to_page(src_pfn)));
|
|
}
|
|
#endif /* CONFIG_HIGHMEM */
|
|
|
|
static void
|
|
copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
|
|
{
|
|
struct zone *zone;
|
|
unsigned long pfn;
|
|
|
|
for_each_zone(zone) {
|
|
unsigned long max_zone_pfn;
|
|
|
|
mark_free_pages(zone);
|
|
max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
|
|
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
|
|
if (page_is_saveable(zone, pfn))
|
|
memory_bm_set_bit(orig_bm, pfn);
|
|
}
|
|
memory_bm_position_reset(orig_bm);
|
|
memory_bm_position_reset(copy_bm);
|
|
do {
|
|
pfn = memory_bm_next_pfn(orig_bm);
|
|
if (likely(pfn != BM_END_OF_MAP))
|
|
copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
|
|
} while (pfn != BM_END_OF_MAP);
|
|
}
|
|
|
|
/* Total number of image pages */
|
|
static unsigned int nr_copy_pages;
|
|
/* Number of pages needed for saving the original pfns of the image pages */
|
|
static unsigned int nr_meta_pages;
|
|
|
|
/**
|
|
* swsusp_free - free pages allocated for the suspend.
|
|
*
|
|
* Suspend pages are alocated before the atomic copy is made, so we
|
|
* need to release them after the resume.
|
|
*/
|
|
|
|
void swsusp_free(void)
|
|
{
|
|
struct zone *zone;
|
|
unsigned long pfn, max_zone_pfn;
|
|
|
|
for_each_zone(zone) {
|
|
max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
|
|
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
|
|
if (pfn_valid(pfn)) {
|
|
struct page *page = pfn_to_page(pfn);
|
|
|
|
if (swsusp_page_is_forbidden(page) &&
|
|
swsusp_page_is_free(page)) {
|
|
swsusp_unset_page_forbidden(page);
|
|
swsusp_unset_page_free(page);
|
|
__free_page(page);
|
|
}
|
|
}
|
|
}
|
|
nr_copy_pages = 0;
|
|
nr_meta_pages = 0;
|
|
restore_pblist = NULL;
|
|
buffer = NULL;
|
|
}
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
/**
|
|
* count_pages_for_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();
|
|
|
|
if (free_highmem >= nr_highmem)
|
|
nr_highmem = 0;
|
|
else
|
|
nr_highmem -= free_highmem;
|
|
|
|
return nr_highmem;
|
|
}
|
|
#else
|
|
static unsigned int
|
|
count_pages_for_highmem(unsigned int nr_highmem) { return 0; }
|
|
#endif /* CONFIG_HIGHMEM */
|
|
|
|
/**
|
|
* enough_free_mem - Make sure we have enough free memory for the
|
|
* snapshot image.
|
|
*/
|
|
|
|
static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem)
|
|
{
|
|
struct zone *zone;
|
|
unsigned int free = 0, meta = 0;
|
|
|
|
for_each_zone(zone) {
|
|
meta += snapshot_additional_pages(zone);
|
|
if (!is_highmem(zone))
|
|
free += zone_page_state(zone, NR_FREE_PAGES);
|
|
}
|
|
|
|
nr_pages += count_pages_for_highmem(nr_highmem);
|
|
pr_debug("swsusp: Normal pages needed: %u + %u + %u, available pages: %u\n",
|
|
nr_pages, PAGES_FOR_IO, meta, free);
|
|
|
|
return free > nr_pages + PAGES_FOR_IO + meta;
|
|
}
|
|
|
|
#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.
|
|
*/
|
|
|
|
static inline int get_highmem_buffer(int safe_needed)
|
|
{
|
|
buffer = get_image_page(GFP_ATOMIC | __GFP_COLD, safe_needed);
|
|
return buffer ? 0 : -ENOMEM;
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
|
|
static inline unsigned int
|
|
alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int nr_highmem)
|
|
{
|
|
unsigned int to_alloc = count_free_highmem_pages();
|
|
|
|
if (to_alloc > nr_highmem)
|
|
to_alloc = nr_highmem;
|
|
|
|
nr_highmem -= to_alloc;
|
|
while (to_alloc-- > 0) {
|
|
struct page *page;
|
|
|
|
page = alloc_image_page(__GFP_HIGHMEM);
|
|
memory_bm_set_bit(bm, page_to_pfn(page));
|
|
}
|
|
return nr_highmem;
|
|
}
|
|
#else
|
|
static inline int get_highmem_buffer(int safe_needed) { return 0; }
|
|
|
|
static inline unsigned int
|
|
alloc_highmem_image_pages(struct memory_bitmap *bm, unsigned int n) { return 0; }
|
|
#endif /* CONFIG_HIGHMEM */
|
|
|
|
/**
|
|
* swsusp_alloc - allocate memory for the suspend 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.
|
|
*
|
|
* 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)
|
|
{
|
|
int error;
|
|
|
|
error = memory_bm_create(orig_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY);
|
|
if (error)
|
|
goto Free;
|
|
|
|
error = memory_bm_create(copy_bm, GFP_ATOMIC | __GFP_COLD, PG_ANY);
|
|
if (error)
|
|
goto Free;
|
|
|
|
if (nr_highmem > 0) {
|
|
error = get_highmem_buffer(PG_ANY);
|
|
if (error)
|
|
goto Free;
|
|
|
|
nr_pages += alloc_highmem_image_pages(copy_bm, nr_highmem);
|
|
}
|
|
while (nr_pages-- > 0) {
|
|
struct page *page = alloc_image_page(GFP_ATOMIC | __GFP_COLD);
|
|
|
|
if (!page)
|
|
goto Free;
|
|
|
|
memory_bm_set_bit(copy_bm, page_to_pfn(page));
|
|
}
|
|
return 0;
|
|
|
|
Free:
|
|
swsusp_free();
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Memory bitmap used for marking saveable pages (during suspend) or the
|
|
* suspend image pages (during resume)
|
|
*/
|
|
static struct memory_bitmap orig_bm;
|
|
/* Memory bitmap used on suspend for marking allocated pages that will contain
|
|
* the copies of saveable pages. During resume it is initially used for
|
|
* marking the suspend image pages, but then its set bits are duplicated in
|
|
* @orig_bm and it is released. Next, on systems with high memory, it may be
|
|
* used for marking "safe" highmem pages, but it has to be reinitialized for
|
|
* this purpose.
|
|
*/
|
|
static struct memory_bitmap copy_bm;
|
|
|
|
asmlinkage int swsusp_save(void)
|
|
{
|
|
unsigned int nr_pages, nr_highmem;
|
|
|
|
printk("swsusp: critical section: \n");
|
|
|
|
drain_local_pages();
|
|
nr_pages = count_data_pages();
|
|
nr_highmem = count_highmem_pages();
|
|
printk("swsusp: Need to copy %u pages\n", nr_pages + nr_highmem);
|
|
|
|
if (!enough_free_mem(nr_pages, nr_highmem)) {
|
|
printk(KERN_ERR "swsusp: Not enough free memory\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (swsusp_alloc(&orig_bm, ©_bm, nr_pages, nr_highmem)) {
|
|
printk(KERN_ERR "swsusp: Memory allocation failed\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* During allocating of suspend pagedir, new cold pages may appear.
|
|
* Kill them.
|
|
*/
|
|
drain_local_pages();
|
|
copy_data_pages(©_bm, &orig_bm);
|
|
|
|
/*
|
|
* End of critical section. From now on, we can write to memory,
|
|
* but we should not touch disk. This specially means we must _not_
|
|
* touch swap space! Except we must write out our image of course.
|
|
*/
|
|
|
|
nr_pages += nr_highmem;
|
|
nr_copy_pages = nr_pages;
|
|
nr_meta_pages = DIV_ROUND_UP(nr_pages * sizeof(long), PAGE_SIZE);
|
|
|
|
printk("swsusp: critical section/: done (%d pages copied)\n", nr_pages);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void init_header(struct swsusp_info *info)
|
|
{
|
|
memset(info, 0, sizeof(struct swsusp_info));
|
|
info->version_code = LINUX_VERSION_CODE;
|
|
info->num_physpages = num_physpages;
|
|
memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
|
|
info->cpus = num_online_cpus();
|
|
info->image_pages = nr_copy_pages;
|
|
info->pages = nr_copy_pages + nr_meta_pages + 1;
|
|
info->size = info->pages;
|
|
info->size <<= PAGE_SHIFT;
|
|
}
|
|
|
|
/**
|
|
* 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_pfns(unsigned long *buf, struct memory_bitmap *bm)
|
|
{
|
|
int j;
|
|
|
|
for (j = 0; j < PAGE_SIZE / sizeof(long); j++) {
|
|
buf[j] = memory_bm_next_pfn(bm);
|
|
if (unlikely(buf[j] == BM_END_OF_MAP))
|
|
break;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* snapshot_read_next - used for reading the system memory snapshot.
|
|
*
|
|
* 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.
|
|
*
|
|
* The @count parameter should contain the number of bytes the caller
|
|
* wants to read from the snapshot. It must not be zero.
|
|
*
|
|
* 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 number returned
|
|
* may be smaller than @count, but this only happens if the read would
|
|
* cross a page boundary otherwise.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
int snapshot_read_next(struct snapshot_handle *handle, size_t count)
|
|
{
|
|
if (handle->cur > nr_meta_pages + nr_copy_pages)
|
|
return 0;
|
|
|
|
if (!buffer) {
|
|
/* This makes the buffer be freed by swsusp_free() */
|
|
buffer = get_image_page(GFP_ATOMIC, PG_ANY);
|
|
if (!buffer)
|
|
return -ENOMEM;
|
|
}
|
|
if (!handle->offset) {
|
|
init_header((struct swsusp_info *)buffer);
|
|
handle->buffer = buffer;
|
|
memory_bm_position_reset(&orig_bm);
|
|
memory_bm_position_reset(©_bm);
|
|
}
|
|
if (handle->prev < handle->cur) {
|
|
if (handle->cur <= nr_meta_pages) {
|
|
memset(buffer, 0, PAGE_SIZE);
|
|
pack_pfns(buffer, &orig_bm);
|
|
} else {
|
|
struct page *page;
|
|
|
|
page = pfn_to_page(memory_bm_next_pfn(©_bm));
|
|
if (PageHighMem(page)) {
|
|
/* Highmem pages are copied to the buffer,
|
|
* because we can't return with a kmapped
|
|
* highmem page (we may not be called again).
|
|
*/
|
|
void *kaddr;
|
|
|
|
kaddr = kmap_atomic(page, KM_USER0);
|
|
memcpy(buffer, kaddr, PAGE_SIZE);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
handle->buffer = buffer;
|
|
} else {
|
|
handle->buffer = page_address(page);
|
|
}
|
|
}
|
|
handle->prev = handle->cur;
|
|
}
|
|
handle->buf_offset = handle->cur_offset;
|
|
if (handle->cur_offset + count >= PAGE_SIZE) {
|
|
count = PAGE_SIZE - handle->cur_offset;
|
|
handle->cur_offset = 0;
|
|
handle->cur++;
|
|
} else {
|
|
handle->cur_offset += count;
|
|
}
|
|
handle->offset += count;
|
|
return count;
|
|
}
|
|
|
|
/**
|
|
* 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
|
|
*/
|
|
|
|
static int mark_unsafe_pages(struct memory_bitmap *bm)
|
|
{
|
|
struct zone *zone;
|
|
unsigned long pfn, max_zone_pfn;
|
|
|
|
/* Clear page flags */
|
|
for_each_zone(zone) {
|
|
max_zone_pfn = zone->zone_start_pfn + zone->spanned_pages;
|
|
for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++)
|
|
if (pfn_valid(pfn))
|
|
swsusp_unset_page_free(pfn_to_page(pfn));
|
|
}
|
|
|
|
/* 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)))
|
|
swsusp_set_page_free(pfn_to_page(pfn));
|
|
else
|
|
return -EFAULT;
|
|
}
|
|
} while (pfn != BM_END_OF_MAP);
|
|
|
|
allocated_unsafe_pages = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
duplicate_memory_bitmap(struct memory_bitmap *dst, struct memory_bitmap *src)
|
|
{
|
|
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 inline int check_header(struct swsusp_info *info)
|
|
{
|
|
char *reason = NULL;
|
|
|
|
if (info->version_code != LINUX_VERSION_CODE)
|
|
reason = "kernel version";
|
|
if (info->num_physpages != num_physpages)
|
|
reason = "memory size";
|
|
if (strcmp(info->uts.sysname,init_utsname()->sysname))
|
|
reason = "system type";
|
|
if (strcmp(info->uts.release,init_utsname()->release))
|
|
reason = "kernel release";
|
|
if (strcmp(info->uts.version,init_utsname()->version))
|
|
reason = "version";
|
|
if (strcmp(info->uts.machine,init_utsname()->machine))
|
|
reason = "machine";
|
|
if (reason) {
|
|
printk(KERN_ERR "swsusp: Resume mismatch: %s\n", reason);
|
|
return -EPERM;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* load header - check the image header and copy data from it
|
|
*/
|
|
|
|
static int
|
|
load_header(struct swsusp_info *info)
|
|
{
|
|
int error;
|
|
|
|
restore_pblist = NULL;
|
|
error = check_header(info);
|
|
if (!error) {
|
|
nr_copy_pages = info->image_pages;
|
|
nr_meta_pages = info->pages - info->image_pages - 1;
|
|
}
|
|
return error;
|
|
}
|
|
|
|
/**
|
|
* unpack_orig_pfns - for each element of @buf[] (1 page at a time) set
|
|
* the corresponding bit in the memory bitmap @bm
|
|
*/
|
|
|
|
static inline void
|
|
unpack_orig_pfns(unsigned long *buf, struct memory_bitmap *bm)
|
|
{
|
|
int j;
|
|
|
|
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]);
|
|
}
|
|
}
|
|
|
|
/* List of "safe" pages that may be used to store data loaded from the suspend
|
|
* image
|
|
*/
|
|
static struct linked_page *safe_pages_list;
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
/* 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 {
|
|
struct page *copy_page; /* data is here now */
|
|
struct page *orig_page; /* data was here before the suspend */
|
|
struct highmem_pbe *next;
|
|
};
|
|
|
|
/* 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.
|
|
*/
|
|
|
|
static unsigned int count_highmem_image_pages(struct memory_bitmap *bm)
|
|
{
|
|
unsigned long pfn;
|
|
unsigned int cnt = 0;
|
|
|
|
memory_bm_position_reset(bm);
|
|
pfn = memory_bm_next_pfn(bm);
|
|
while (pfn != BM_END_OF_MAP) {
|
|
if (PageHighMem(pfn_to_page(pfn)))
|
|
cnt++;
|
|
|
|
pfn = memory_bm_next_pfn(bm);
|
|
}
|
|
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;
|
|
|
|
static int
|
|
prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
|
|
{
|
|
unsigned int to_alloc;
|
|
|
|
if (memory_bm_create(bm, GFP_ATOMIC, PG_SAFE))
|
|
return -ENOMEM;
|
|
|
|
if (get_highmem_buffer(PG_SAFE))
|
|
return -ENOMEM;
|
|
|
|
to_alloc = count_free_highmem_pages();
|
|
if (to_alloc > *nr_highmem_p)
|
|
to_alloc = *nr_highmem_p;
|
|
else
|
|
*nr_highmem_p = to_alloc;
|
|
|
|
safe_highmem_pages = 0;
|
|
while (to_alloc-- > 0) {
|
|
struct page *page;
|
|
|
|
page = alloc_page(__GFP_HIGHMEM);
|
|
if (!swsusp_page_is_free(page)) {
|
|
/* The page is "safe", set its bit the bitmap */
|
|
memory_bm_set_bit(bm, page_to_pfn(page));
|
|
safe_highmem_pages++;
|
|
}
|
|
/* Mark the page as allocated */
|
|
swsusp_set_page_forbidden(page);
|
|
swsusp_set_page_free(page);
|
|
}
|
|
memory_bm_position_reset(bm);
|
|
safe_highmem_bm = bm;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* get_highmem_page_buffer - for given highmem image page find the buffer
|
|
* that suspend_write_next() should set for 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 @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)
|
|
{
|
|
struct highmem_pbe *pbe;
|
|
void *kaddr;
|
|
|
|
if (swsusp_page_is_forbidden(page) && swsusp_page_is_free(page)) {
|
|
/* 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
|
|
* use a "safe" page frame to store the loaded page.
|
|
*/
|
|
pbe = chain_alloc(ca, sizeof(struct highmem_pbe));
|
|
if (!pbe) {
|
|
swsusp_free();
|
|
return NULL;
|
|
}
|
|
pbe->orig_page = page;
|
|
if (safe_highmem_pages > 0) {
|
|
struct page *tmp;
|
|
|
|
/* Copy of the page will be stored in high memory */
|
|
kaddr = buffer;
|
|
tmp = pfn_to_page(memory_bm_next_pfn(safe_highmem_bm));
|
|
safe_highmem_pages--;
|
|
last_highmem_page = tmp;
|
|
pbe->copy_page = tmp;
|
|
} else {
|
|
/* Copy of the page will be stored in normal memory */
|
|
kaddr = safe_pages_list;
|
|
safe_pages_list = safe_pages_list->next;
|
|
pbe->copy_page = virt_to_page(kaddr);
|
|
}
|
|
pbe->next = highmem_pblist;
|
|
highmem_pblist = pbe;
|
|
return kaddr;
|
|
}
|
|
|
|
/**
|
|
* 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 .
|
|
*/
|
|
|
|
static void copy_last_highmem_page(void)
|
|
{
|
|
if (last_highmem_page) {
|
|
void *dst;
|
|
|
|
dst = kmap_atomic(last_highmem_page, KM_USER0);
|
|
memcpy(dst, buffer, PAGE_SIZE);
|
|
kunmap_atomic(dst, KM_USER0);
|
|
last_highmem_page = NULL;
|
|
}
|
|
}
|
|
|
|
static inline int last_highmem_page_copied(void)
|
|
{
|
|
return !last_highmem_page;
|
|
}
|
|
|
|
static inline void free_highmem_data(void)
|
|
{
|
|
if (safe_highmem_bm)
|
|
memory_bm_free(safe_highmem_bm, PG_UNSAFE_CLEAR);
|
|
|
|
if (buffer)
|
|
free_image_page(buffer, PG_UNSAFE_CLEAR);
|
|
}
|
|
#else
|
|
static inline int get_safe_write_buffer(void) { return 0; }
|
|
|
|
static unsigned int
|
|
count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
|
|
|
|
static inline int
|
|
prepare_highmem_image(struct memory_bitmap *bm, unsigned int *nr_highmem_p)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void *
|
|
get_highmem_page_buffer(struct page *page, struct chain_allocator *ca)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static inline void copy_last_highmem_page(void) {}
|
|
static inline int last_highmem_page_copied(void) { return 1; }
|
|
static inline void free_highmem_data(void) {}
|
|
#endif /* CONFIG_HIGHMEM */
|
|
|
|
/**
|
|
* 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 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.
|
|
*/
|
|
|
|
#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;
|
|
struct linked_page *sp_list, *lp;
|
|
int error;
|
|
|
|
/* If there is no highmem, the buffer will not be necessary */
|
|
free_image_page(buffer, PG_UNSAFE_CLEAR);
|
|
buffer = NULL;
|
|
|
|
nr_highmem = count_highmem_image_pages(bm);
|
|
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);
|
|
if (nr_highmem > 0) {
|
|
error = prepare_highmem_image(bm, &nr_highmem);
|
|
if (error)
|
|
goto Free;
|
|
}
|
|
/* 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 - nr_highmem - allocated_unsafe_pages;
|
|
nr_pages = DIV_ROUND_UP(nr_pages, PBES_PER_LINKED_PAGE);
|
|
while (nr_pages > 0) {
|
|
lp = get_image_page(GFP_ATOMIC, PG_SAFE);
|
|
if (!lp) {
|
|
error = -ENOMEM;
|
|
goto Free;
|
|
}
|
|
lp->next = sp_list;
|
|
sp_list = lp;
|
|
nr_pages--;
|
|
}
|
|
/* Preallocate memory for the image */
|
|
safe_pages_list = NULL;
|
|
nr_pages = nr_copy_pages - nr_highmem - allocated_unsafe_pages;
|
|
while (nr_pages > 0) {
|
|
lp = (struct linked_page *)get_zeroed_page(GFP_ATOMIC);
|
|
if (!lp) {
|
|
error = -ENOMEM;
|
|
goto Free;
|
|
}
|
|
if (!swsusp_page_is_free(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 */
|
|
swsusp_set_page_forbidden(virt_to_page(lp));
|
|
swsusp_set_page_free(virt_to_page(lp));
|
|
nr_pages--;
|
|
}
|
|
/* 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;
|
|
}
|
|
|
|
/**
|
|
* 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;
|
|
struct page *page = pfn_to_page(memory_bm_next_pfn(bm));
|
|
|
|
if (PageHighMem(page))
|
|
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
|
|
* use it directly to store the loaded 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 = chain_alloc(ca, sizeof(struct pbe));
|
|
if (!pbe) {
|
|
swsusp_free();
|
|
return NULL;
|
|
}
|
|
pbe->orig_address = page_address(page);
|
|
pbe->address = safe_pages_list;
|
|
safe_pages_list = safe_pages_list->next;
|
|
pbe->next = restore_pblist;
|
|
restore_pblist = pbe;
|
|
return pbe->address;
|
|
}
|
|
|
|
/**
|
|
* snapshot_write_next - used for writing the system memory snapshot.
|
|
*
|
|
* 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.
|
|
*
|
|
* The @count parameter should contain the number of bytes the caller
|
|
* wants to write to the image. It must not be zero.
|
|
*
|
|
* 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 number returned
|
|
* may be smaller than @count, but this only happens if the write would
|
|
* cross a page boundary otherwise.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
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 (handle->offset == 0) {
|
|
if (!buffer)
|
|
/* This makes the buffer be freed by swsusp_free() */
|
|
buffer = get_image_page(GFP_ATOMIC, PG_ANY);
|
|
|
|
if (!buffer)
|
|
return -ENOMEM;
|
|
|
|
handle->buffer = buffer;
|
|
}
|
|
handle->sync_read = 1;
|
|
if (handle->prev < handle->cur) {
|
|
if (handle->prev == 0) {
|
|
error = load_header(buffer);
|
|
if (error)
|
|
return error;
|
|
|
|
error = memory_bm_create(©_bm, GFP_ATOMIC, PG_ANY);
|
|
if (error)
|
|
return error;
|
|
|
|
} else if (handle->prev <= nr_meta_pages) {
|
|
unpack_orig_pfns(buffer, ©_bm);
|
|
if (handle->prev == nr_meta_pages) {
|
|
error = prepare_image(&orig_bm, ©_bm);
|
|
if (error)
|
|
return error;
|
|
|
|
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 {
|
|
copy_last_highmem_page();
|
|
handle->buffer = get_buffer(&orig_bm, &ca);
|
|
if (handle->buffer != buffer)
|
|
handle->sync_read = 0;
|
|
}
|
|
handle->prev = handle->cur;
|
|
}
|
|
handle->buf_offset = handle->cur_offset;
|
|
if (handle->cur_offset + count >= PAGE_SIZE) {
|
|
count = PAGE_SIZE - handle->cur_offset;
|
|
handle->cur_offset = 0;
|
|
handle->cur++;
|
|
} else {
|
|
handle->cur_offset += count;
|
|
}
|
|
handle->offset += count;
|
|
return count;
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
|
|
void snapshot_write_finalize(struct snapshot_handle *handle)
|
|
{
|
|
copy_last_highmem_page();
|
|
/* 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);
|
|
free_highmem_data();
|
|
}
|
|
}
|
|
|
|
int snapshot_image_loaded(struct snapshot_handle *handle)
|
|
{
|
|
return !(!nr_copy_pages || !last_highmem_page_copied() ||
|
|
handle->cur <= nr_meta_pages + nr_copy_pages);
|
|
}
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
/* Assumes that @buf is ready and points to a "safe" page */
|
|
static inline void
|
|
swap_two_pages_data(struct page *p1, struct page *p2, void *buf)
|
|
{
|
|
void *kaddr1, *kaddr2;
|
|
|
|
kaddr1 = kmap_atomic(p1, KM_USER0);
|
|
kaddr2 = kmap_atomic(p2, KM_USER1);
|
|
memcpy(buf, kaddr1, PAGE_SIZE);
|
|
memcpy(kaddr1, kaddr2, PAGE_SIZE);
|
|
memcpy(kaddr2, buf, PAGE_SIZE);
|
|
kunmap_atomic(kaddr1, KM_USER0);
|
|
kunmap_atomic(kaddr2, KM_USER1);
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
*
|
|
* If the resume eventually fails, we can call this function once
|
|
* again and restore the "before resume" highmem state.
|
|
*/
|
|
|
|
int restore_highmem(void)
|
|
{
|
|
struct highmem_pbe *pbe = highmem_pblist;
|
|
void *buf;
|
|
|
|
if (!pbe)
|
|
return 0;
|
|
|
|
buf = get_image_page(GFP_ATOMIC, PG_SAFE);
|
|
if (!buf)
|
|
return -ENOMEM;
|
|
|
|
while (pbe) {
|
|
swap_two_pages_data(pbe->copy_page, pbe->orig_page, buf);
|
|
pbe = pbe->next;
|
|
}
|
|
free_image_page(buf, PG_UNSAFE_CLEAR);
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_HIGHMEM */
|