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![Jan Beulich](/assets/img/avatar_default.png)
Since alloc_bootmem() will never return inaccessible (via virtual addressing) memory anyway, using the ..._low() variant only makes sense when the physical address range of the allocated memory must fulfill further constraints, espacially since on 64-bits (or more generally in all cases where the pools the two variants allocate from are than the full available range. Probably the use in alloc_tce_table() could also be eliminated (based on code inspection of pci-calgary_64.c), but that seems too risky given I know nothing about that hardware and have no way to test it. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2289 lines
59 KiB
C
2289 lines
59 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/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 <linux/list.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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/*
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* Preferred image size in bytes (tunable via /sys/power/image_size).
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* When it is set to N, swsusp will do its best to ensure the image
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* size will not exceed N bytes, but if that is impossible, it will
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* try to create the smallest image possible.
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*/
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unsigned long image_size = 500 * 1024 * 1024;
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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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/**
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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 bitmap in which information is 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 bitmap)
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* It also contains the pfns that correspond to the start and end of
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* the represented memory area.
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*/
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#define BM_END_OF_MAP (~0UL)
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#define BM_BITS_PER_BLOCK (PAGE_SIZE * BITS_PER_BYTE)
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struct bm_block {
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struct list_head hook; /* hook into a list of bitmap blocks */
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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 long *data; /* bitmap representing pages */
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};
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static inline unsigned long bm_block_bits(struct bm_block *bb)
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{
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return bb->end_pfn - bb->start_pfn;
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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 bm_block *block;
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int bit;
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};
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struct memory_bitmap {
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struct list_head blocks; /* list of bitmap blocks */
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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 void memory_bm_position_reset(struct memory_bitmap *bm)
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{
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bm->cur.block = list_entry(bm->blocks.next, struct bm_block, hook);
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bm->cur.bit = 0;
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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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* @pages - number of pages to track
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* @list - list to put the allocated blocks into
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* @ca - chain allocator to be used for allocating memory
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*/
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static int create_bm_block_list(unsigned long pages,
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struct list_head *list,
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struct chain_allocator *ca)
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{
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unsigned int nr_blocks = DIV_ROUND_UP(pages, BM_BITS_PER_BLOCK);
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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 -ENOMEM;
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list_add(&bb->hook, list);
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}
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return 0;
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}
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struct mem_extent {
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struct list_head hook;
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unsigned long start;
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unsigned long end;
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};
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/**
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* free_mem_extents - free a list of memory extents
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* @list - list of extents to empty
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*/
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static void free_mem_extents(struct list_head *list)
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{
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struct mem_extent *ext, *aux;
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list_for_each_entry_safe(ext, aux, list, hook) {
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list_del(&ext->hook);
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kfree(ext);
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}
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}
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/**
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* create_mem_extents - create a list of memory extents representing
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* contiguous ranges of PFNs
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* @list - list to put the extents into
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* @gfp_mask - mask to use for memory allocations
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*/
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static int create_mem_extents(struct list_head *list, gfp_t gfp_mask)
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{
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struct zone *zone;
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INIT_LIST_HEAD(list);
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for_each_populated_zone(zone) {
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unsigned long zone_start, zone_end;
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struct mem_extent *ext, *cur, *aux;
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zone_start = zone->zone_start_pfn;
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zone_end = zone->zone_start_pfn + zone->spanned_pages;
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list_for_each_entry(ext, list, hook)
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if (zone_start <= ext->end)
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break;
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if (&ext->hook == list || zone_end < ext->start) {
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/* New extent is necessary */
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struct mem_extent *new_ext;
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new_ext = kzalloc(sizeof(struct mem_extent), gfp_mask);
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if (!new_ext) {
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free_mem_extents(list);
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return -ENOMEM;
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}
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new_ext->start = zone_start;
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new_ext->end = zone_end;
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list_add_tail(&new_ext->hook, &ext->hook);
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continue;
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}
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/* Merge this zone's range of PFNs with the existing one */
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if (zone_start < ext->start)
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ext->start = zone_start;
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if (zone_end > ext->end)
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ext->end = zone_end;
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/* More merging may be possible */
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cur = ext;
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list_for_each_entry_safe_continue(cur, aux, list, hook) {
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if (zone_end < cur->start)
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break;
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if (zone_end < cur->end)
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ext->end = cur->end;
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list_del(&cur->hook);
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kfree(cur);
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}
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}
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return 0;
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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 list_head mem_extents;
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struct mem_extent *ext;
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int error;
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chain_init(&ca, gfp_mask, safe_needed);
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INIT_LIST_HEAD(&bm->blocks);
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error = create_mem_extents(&mem_extents, gfp_mask);
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if (error)
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return error;
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list_for_each_entry(ext, &mem_extents, hook) {
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struct bm_block *bb;
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unsigned long pfn = ext->start;
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unsigned long pages = ext->end - ext->start;
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bb = list_entry(bm->blocks.prev, struct bm_block, hook);
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error = create_bm_block_list(pages, bm->blocks.prev, &ca);
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if (error)
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goto Error;
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list_for_each_entry_continue(bb, &bm->blocks, hook) {
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bb->data = get_image_page(gfp_mask, safe_needed);
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if (!bb->data) {
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error = -ENOMEM;
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goto Error;
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}
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bb->start_pfn = pfn;
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if (pages >= BM_BITS_PER_BLOCK) {
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pfn += BM_BITS_PER_BLOCK;
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pages -= 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 += pages;
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}
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bb->end_pfn = pfn;
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}
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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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Exit:
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free_mem_extents(&mem_extents);
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return error;
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Error:
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bm->p_list = ca.chain;
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memory_bm_free(bm, PG_UNSAFE_CLEAR);
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goto Exit;
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}
|
|
|
|
/**
|
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* memory_bm_free - free memory occupied by the memory bitmap @bm
|
|
*/
|
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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 bm_block *bb;
|
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|
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list_for_each_entry(bb, &bm->blocks, hook)
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if (bb->data)
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free_image_page(bb->data, clear_nosave_free);
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|
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free_list_of_pages(bm->p_list, clear_nosave_free);
|
|
|
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INIT_LIST_HEAD(&bm->blocks);
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}
|
|
|
|
/**
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* memory_bm_find_bit - find the bit in the bitmap @bm that corresponds
|
|
* 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 int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn,
|
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void **addr, unsigned int *bit_nr)
|
|
{
|
|
struct bm_block *bb;
|
|
|
|
/*
|
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* Check if the pfn corresponds to the current bitmap block and find
|
|
* the block where it fits if this is not the case.
|
|
*/
|
|
bb = bm->cur.block;
|
|
if (pfn < bb->start_pfn)
|
|
list_for_each_entry_continue_reverse(bb, &bm->blocks, hook)
|
|
if (pfn >= bb->start_pfn)
|
|
break;
|
|
|
|
if (pfn >= bb->end_pfn)
|
|
list_for_each_entry_continue(bb, &bm->blocks, hook)
|
|
if (pfn >= bb->start_pfn && pfn < bb->end_pfn)
|
|
break;
|
|
|
|
if (&bb->hook == &bm->blocks)
|
|
return -EFAULT;
|
|
|
|
/* The block has been found */
|
|
bm->cur.block = bb;
|
|
pfn -= bb->start_pfn;
|
|
bm->cur.bit = pfn + 1;
|
|
*bit_nr = pfn;
|
|
*addr = bb->data;
|
|
return 0;
|
|
}
|
|
|
|
static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn)
|
|
{
|
|
void *addr;
|
|
unsigned int bit;
|
|
int error;
|
|
|
|
error = memory_bm_find_bit(bm, pfn, &addr, &bit);
|
|
BUG_ON(error);
|
|
set_bit(bit, addr);
|
|
}
|
|
|
|
static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn)
|
|
{
|
|
void *addr;
|
|
unsigned int bit;
|
|
int error;
|
|
|
|
error = memory_bm_find_bit(bm, pfn, &addr, &bit);
|
|
if (!error)
|
|
set_bit(bit, addr);
|
|
return error;
|
|
}
|
|
|
|
static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn)
|
|
{
|
|
void *addr;
|
|
unsigned int bit;
|
|
int error;
|
|
|
|
error = memory_bm_find_bit(bm, pfn, &addr, &bit);
|
|
BUG_ON(error);
|
|
clear_bit(bit, addr);
|
|
}
|
|
|
|
static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn)
|
|
{
|
|
void *addr;
|
|
unsigned int bit;
|
|
int error;
|
|
|
|
error = memory_bm_find_bit(bm, pfn, &addr, &bit);
|
|
BUG_ON(error);
|
|
return test_bit(bit, addr);
|
|
}
|
|
|
|
static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn)
|
|
{
|
|
void *addr;
|
|
unsigned int bit;
|
|
|
|
return !memory_bm_find_bit(bm, pfn, &addr, &bit);
|
|
}
|
|
|
|
/**
|
|
* 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 bm_block *bb;
|
|
int bit;
|
|
|
|
bb = bm->cur.block;
|
|
do {
|
|
bit = bm->cur.bit;
|
|
bit = find_next_bit(bb->data, bm_block_bits(bb), bit);
|
|
if (bit < bm_block_bits(bb))
|
|
goto Return_pfn;
|
|
|
|
bb = list_entry(bb->hook.next, struct bm_block, hook);
|
|
bm->cur.block = bb;
|
|
bm->cur.bit = 0;
|
|
} while (&bb->hook != &bm->blocks);
|
|
|
|
memory_bm_position_reset(bm);
|
|
return BM_END_OF_MAP;
|
|
|
|
Return_pfn:
|
|
bm->cur.bit = bit + 1;
|
|
return bb->start_pfn + 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,
|
|
int use_kmalloc)
|
|
{
|
|
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;
|
|
}
|
|
}
|
|
if (use_kmalloc) {
|
|
/* during init, this shouldn't fail */
|
|
region = kmalloc(sizeof(struct nosave_region), GFP_KERNEL);
|
|
BUG_ON(!region);
|
|
} else
|
|
/* This allocation cannot fail */
|
|
region = alloc_bootmem(sizeof(struct nosave_region));
|
|
region->start_pfn = start_pfn;
|
|
region->end_pfn = end_pfn;
|
|
list_add_tail(®ion->list, &nosave_regions);
|
|
Report:
|
|
printk(KERN_INFO "PM: Registered nosave memory: %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;
|
|
|
|
pr_debug("PM: 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++)
|
|
if (pfn_valid(pfn)) {
|
|
/*
|
|
* It is safe to ignore the result of
|
|
* mem_bm_set_bit_check() here, since we won't
|
|
* touch the PFNs for which the error is
|
|
* returned anyway.
|
|
*/
|
|
mem_bm_set_bit_check(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);
|
|
|
|
pr_debug("PM: 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);
|
|
|
|
pr_debug("PM: 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_populated_zone(zone)
|
|
if (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(struct zone *zone, unsigned long pfn)
|
|
{
|
|
struct page *page;
|
|
|
|
if (!pfn_valid(pfn))
|
|
return NULL;
|
|
|
|
page = pfn_to_page(pfn);
|
|
if (page_zone(page) != zone)
|
|
return NULL;
|
|
|
|
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.
|
|
*/
|
|
|
|
static unsigned int count_highmem_pages(void)
|
|
{
|
|
struct zone *zone;
|
|
unsigned int n = 0;
|
|
|
|
for_each_populated_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(zone, pfn))
|
|
n++;
|
|
}
|
|
return n;
|
|
}
|
|
#else
|
|
static inline void *saveable_highmem_page(struct zone *z, unsigned long p)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif /* CONFIG_HIGHMEM */
|
|
|
|
/**
|
|
* saveable_page - 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(struct zone *zone, unsigned long pfn)
|
|
{
|
|
struct page *page;
|
|
|
|
if (!pfn_valid(pfn))
|
|
return NULL;
|
|
|
|
page = pfn_to_page(pfn);
|
|
if (page_zone(page) != zone)
|
|
return NULL;
|
|
|
|
BUG_ON(PageHighMem(page));
|
|
|
|
if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
|
|
return NULL;
|
|
|
|
if (PageReserved(page)
|
|
&& (!kernel_page_present(page) || pfn_is_nosave(pfn)))
|
|
return NULL;
|
|
|
|
return page;
|
|
}
|
|
|
|
/**
|
|
* count_data_pages - compute the total number of saveable non-highmem
|
|
* pages.
|
|
*/
|
|
|
|
static unsigned int count_data_pages(void)
|
|
{
|
|
struct zone *zone;
|
|
unsigned long pfn, max_zone_pfn;
|
|
unsigned int n = 0;
|
|
|
|
for_each_populated_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(zone, 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++;
|
|
}
|
|
|
|
|
|
/**
|
|
* safe_copy_page - check if the page we are going to copy is marked as
|
|
* present in the kernel page tables (this always is the case if
|
|
* CONFIG_DEBUG_PAGEALLOC is not set and in that case
|
|
* kernel_page_present() always returns 'true').
|
|
*/
|
|
static void safe_copy_page(void *dst, struct page *s_page)
|
|
{
|
|
if (kernel_page_present(s_page)) {
|
|
do_copy_page(dst, page_address(s_page));
|
|
} else {
|
|
kernel_map_pages(s_page, 1, 1);
|
|
do_copy_page(dst, page_address(s_page));
|
|
kernel_map_pages(s_page, 1, 0);
|
|
}
|
|
}
|
|
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
static inline struct page *
|
|
page_is_saveable(struct zone *zone, unsigned long pfn)
|
|
{
|
|
return is_highmem(zone) ?
|
|
saveable_highmem_page(zone, pfn) : saveable_page(zone, pfn);
|
|
}
|
|
|
|
static 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 {
|
|
if (PageHighMem(d_page)) {
|
|
/* Page pointed to by src may contain some kernel
|
|
* data modified by kmap_atomic()
|
|
*/
|
|
safe_copy_page(buffer, s_page);
|
|
dst = kmap_atomic(d_page, KM_USER0);
|
|
memcpy(dst, buffer, PAGE_SIZE);
|
|
kunmap_atomic(dst, KM_USER0);
|
|
} else {
|
|
safe_copy_page(page_address(d_page), s_page);
|
|
}
|
|
}
|
|
}
|
|
#else
|
|
#define page_is_saveable(zone, pfn) saveable_page(zone, pfn)
|
|
|
|
static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
|
|
{
|
|
safe_copy_page(page_address(pfn_to_page(dst_pfn)),
|
|
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_populated_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);
|
|
for(;;) {
|
|
pfn = memory_bm_next_pfn(orig_bm);
|
|
if (unlikely(pfn == BM_END_OF_MAP))
|
|
break;
|
|
copy_data_page(memory_bm_next_pfn(copy_bm), pfn);
|
|
}
|
|
}
|
|
|
|
/* 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;
|
|
/*
|
|
* Numbers of normal and highmem page frames allocated for hibernation image
|
|
* before suspending devices.
|
|
*/
|
|
unsigned int alloc_normal, alloc_highmem;
|
|
/*
|
|
* Memory bitmap used for marking saveable pages (during hibernation) or
|
|
* hibernation image pages (during restore)
|
|
*/
|
|
static struct memory_bitmap orig_bm;
|
|
/*
|
|
* Memory bitmap used during hibernation for marking allocated page frames that
|
|
* will contain copies of saveable pages. During restore it is initially used
|
|
* for marking hibernation image pages, but then the set bits from it are
|
|
* duplicated in @orig_bm and it is released. On highmem systems it is next
|
|
* used for marking "safe" highmem pages, but it has to be reinitialized for
|
|
* this purpose.
|
|
*/
|
|
static struct memory_bitmap copy_bm;
|
|
|
|
/**
|
|
* 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_populated_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;
|
|
alloc_normal = 0;
|
|
alloc_highmem = 0;
|
|
}
|
|
|
|
/* Helper functions used for the shrinking of memory. */
|
|
|
|
#define GFP_IMAGE (GFP_KERNEL | __GFP_NOWARN)
|
|
|
|
/**
|
|
* preallocate_image_pages - Allocate a number of pages for hibernation image
|
|
* @nr_pages: Number of page frames to allocate.
|
|
* @mask: GFP flags to use for the allocation.
|
|
*
|
|
* Return value: Number of page frames actually allocated
|
|
*/
|
|
static unsigned long preallocate_image_pages(unsigned long nr_pages, gfp_t mask)
|
|
{
|
|
unsigned long nr_alloc = 0;
|
|
|
|
while (nr_pages > 0) {
|
|
struct page *page;
|
|
|
|
page = alloc_image_page(mask);
|
|
if (!page)
|
|
break;
|
|
memory_bm_set_bit(©_bm, page_to_pfn(page));
|
|
if (PageHighMem(page))
|
|
alloc_highmem++;
|
|
else
|
|
alloc_normal++;
|
|
nr_pages--;
|
|
nr_alloc++;
|
|
}
|
|
|
|
return nr_alloc;
|
|
}
|
|
|
|
static unsigned long preallocate_image_memory(unsigned long nr_pages)
|
|
{
|
|
return preallocate_image_pages(nr_pages, GFP_IMAGE);
|
|
}
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
static unsigned long preallocate_image_highmem(unsigned long nr_pages)
|
|
{
|
|
return preallocate_image_pages(nr_pages, GFP_IMAGE | __GFP_HIGHMEM);
|
|
}
|
|
|
|
/**
|
|
* __fraction - Compute (an approximation of) x * (multiplier / base)
|
|
*/
|
|
static unsigned long __fraction(u64 x, u64 multiplier, u64 base)
|
|
{
|
|
x *= multiplier;
|
|
do_div(x, base);
|
|
return (unsigned long)x;
|
|
}
|
|
|
|
static unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
|
|
unsigned long highmem,
|
|
unsigned long total)
|
|
{
|
|
unsigned long alloc = __fraction(nr_pages, highmem, total);
|
|
|
|
return preallocate_image_pages(alloc, GFP_IMAGE | __GFP_HIGHMEM);
|
|
}
|
|
#else /* CONFIG_HIGHMEM */
|
|
static inline unsigned long preallocate_image_highmem(unsigned long nr_pages)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
|
|
unsigned long highmem,
|
|
unsigned long total)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_HIGHMEM */
|
|
|
|
/**
|
|
* free_unnecessary_pages - Release preallocated pages not needed for the image
|
|
*/
|
|
static void free_unnecessary_pages(void)
|
|
{
|
|
unsigned long save_highmem, to_free_normal, to_free_highmem;
|
|
|
|
to_free_normal = alloc_normal - count_data_pages();
|
|
save_highmem = count_highmem_pages();
|
|
if (alloc_highmem > save_highmem) {
|
|
to_free_highmem = alloc_highmem - save_highmem;
|
|
} else {
|
|
to_free_highmem = 0;
|
|
to_free_normal -= save_highmem - alloc_highmem;
|
|
}
|
|
|
|
memory_bm_position_reset(©_bm);
|
|
|
|
while (to_free_normal > 0 && to_free_highmem > 0) {
|
|
unsigned long pfn = memory_bm_next_pfn(©_bm);
|
|
struct page *page = pfn_to_page(pfn);
|
|
|
|
if (PageHighMem(page)) {
|
|
if (!to_free_highmem)
|
|
continue;
|
|
to_free_highmem--;
|
|
alloc_highmem--;
|
|
} else {
|
|
if (!to_free_normal)
|
|
continue;
|
|
to_free_normal--;
|
|
alloc_normal--;
|
|
}
|
|
memory_bm_clear_bit(©_bm, pfn);
|
|
swsusp_unset_page_forbidden(page);
|
|
swsusp_unset_page_free(page);
|
|
__free_page(page);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* minimum_image_size - Estimate the minimum acceptable size of an image
|
|
* @saveable: Number of saveable pages in the system.
|
|
*
|
|
* We want to avoid attempting to free too much memory too hard, so estimate the
|
|
* minimum acceptable size of a hibernation image to use as the lower limit for
|
|
* preallocating memory.
|
|
*
|
|
* We assume that the minimum image size should be proportional to
|
|
*
|
|
* [number of saveable pages] - [number of pages that can be freed in theory]
|
|
*
|
|
* where the second term is the sum of (1) reclaimable slab pages, (2) active
|
|
* and (3) inactive anonymouns pages, (4) active and (5) inactive file pages,
|
|
* minus mapped file pages.
|
|
*/
|
|
static unsigned long minimum_image_size(unsigned long saveable)
|
|
{
|
|
unsigned long size;
|
|
|
|
size = global_page_state(NR_SLAB_RECLAIMABLE)
|
|
+ global_page_state(NR_ACTIVE_ANON)
|
|
+ global_page_state(NR_INACTIVE_ANON)
|
|
+ global_page_state(NR_ACTIVE_FILE)
|
|
+ global_page_state(NR_INACTIVE_FILE)
|
|
- global_page_state(NR_FILE_MAPPED);
|
|
|
|
return saveable <= size ? 0 : saveable - size;
|
|
}
|
|
|
|
/**
|
|
* hibernate_preallocate_memory - Preallocate memory for hibernation image
|
|
*
|
|
* To create a hibernation image it is necessary to make a copy of every page
|
|
* frame in use. We also need a number of page frames to be free during
|
|
* hibernation for allocations made while saving the image and for device
|
|
* drivers, in case they need to allocate memory from their hibernation
|
|
* callbacks (these two numbers are given by PAGES_FOR_IO and SPARE_PAGES,
|
|
* respectively, both of which are rough estimates). To make this happen, we
|
|
* compute the total number of available page frames and allocate at least
|
|
*
|
|
* ([page frames total] + PAGES_FOR_IO + [metadata pages]) / 2 + 2 * SPARE_PAGES
|
|
*
|
|
* of them, which corresponds to the maximum size of a hibernation image.
|
|
*
|
|
* If image_size is set below the number following from the above formula,
|
|
* the preallocation of memory is continued until the total number of saveable
|
|
* pages in the system is below the requested image size or the minimum
|
|
* acceptable image size returned by minimum_image_size(), whichever is greater.
|
|
*/
|
|
int hibernate_preallocate_memory(void)
|
|
{
|
|
struct zone *zone;
|
|
unsigned long saveable, size, max_size, count, highmem, pages = 0;
|
|
unsigned long alloc, save_highmem, pages_highmem;
|
|
struct timeval start, stop;
|
|
int error;
|
|
|
|
printk(KERN_INFO "PM: Preallocating image memory... ");
|
|
do_gettimeofday(&start);
|
|
|
|
error = memory_bm_create(&orig_bm, GFP_IMAGE, PG_ANY);
|
|
if (error)
|
|
goto err_out;
|
|
|
|
error = memory_bm_create(©_bm, GFP_IMAGE, PG_ANY);
|
|
if (error)
|
|
goto err_out;
|
|
|
|
alloc_normal = 0;
|
|
alloc_highmem = 0;
|
|
|
|
/* Count the number of saveable data pages. */
|
|
save_highmem = count_highmem_pages();
|
|
saveable = count_data_pages();
|
|
|
|
/*
|
|
* Compute the total number of page frames we can use (count) and the
|
|
* number of pages needed for image metadata (size).
|
|
*/
|
|
count = saveable;
|
|
saveable += save_highmem;
|
|
highmem = save_highmem;
|
|
size = 0;
|
|
for_each_populated_zone(zone) {
|
|
size += snapshot_additional_pages(zone);
|
|
if (is_highmem(zone))
|
|
highmem += zone_page_state(zone, NR_FREE_PAGES);
|
|
else
|
|
count += zone_page_state(zone, NR_FREE_PAGES);
|
|
}
|
|
count += highmem;
|
|
count -= totalreserve_pages;
|
|
|
|
/* Compute the maximum number of saveable pages to leave in memory. */
|
|
max_size = (count - (size + PAGES_FOR_IO)) / 2 - 2 * SPARE_PAGES;
|
|
size = DIV_ROUND_UP(image_size, PAGE_SIZE);
|
|
if (size > max_size)
|
|
size = max_size;
|
|
/*
|
|
* If the maximum is not less than the current number of saveable pages
|
|
* in memory, allocate page frames for the image and we're done.
|
|
*/
|
|
if (size >= saveable) {
|
|
pages = preallocate_image_highmem(save_highmem);
|
|
pages += preallocate_image_memory(saveable - pages);
|
|
goto out;
|
|
}
|
|
|
|
/* Estimate the minimum size of the image. */
|
|
pages = minimum_image_size(saveable);
|
|
if (size < pages)
|
|
size = min_t(unsigned long, pages, max_size);
|
|
|
|
/*
|
|
* Let the memory management subsystem know that we're going to need a
|
|
* large number of page frames to allocate and make it free some memory.
|
|
* NOTE: If this is not done, performance will be hurt badly in some
|
|
* test cases.
|
|
*/
|
|
shrink_all_memory(saveable - size);
|
|
|
|
/*
|
|
* The number of saveable pages in memory was too high, so apply some
|
|
* pressure to decrease it. First, make room for the largest possible
|
|
* image and fail if that doesn't work. Next, try to decrease the size
|
|
* of the image as much as indicated by 'size' using allocations from
|
|
* highmem and non-highmem zones separately.
|
|
*/
|
|
pages_highmem = preallocate_image_highmem(highmem / 2);
|
|
alloc = (count - max_size) - pages_highmem;
|
|
pages = preallocate_image_memory(alloc);
|
|
if (pages < alloc)
|
|
goto err_out;
|
|
size = max_size - size;
|
|
alloc = size;
|
|
size = preallocate_highmem_fraction(size, highmem, count);
|
|
pages_highmem += size;
|
|
alloc -= size;
|
|
pages += preallocate_image_memory(alloc);
|
|
pages += pages_highmem;
|
|
|
|
/*
|
|
* We only need as many page frames for the image as there are saveable
|
|
* pages in memory, but we have allocated more. Release the excessive
|
|
* ones now.
|
|
*/
|
|
free_unnecessary_pages();
|
|
|
|
out:
|
|
do_gettimeofday(&stop);
|
|
printk(KERN_CONT "done (allocated %lu pages)\n", pages);
|
|
swsusp_show_speed(&start, &stop, pages, "Allocated");
|
|
|
|
return 0;
|
|
|
|
err_out:
|
|
printk(KERN_CONT "\n");
|
|
swsusp_free();
|
|
return -ENOMEM;
|
|
}
|
|
|
|
#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() + alloc_highmem;
|
|
|
|
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 = alloc_normal;
|
|
|
|
for_each_populated_zone(zone)
|
|
if (!is_highmem(zone))
|
|
free += zone_page_state(zone, NR_FREE_PAGES);
|
|
|
|
nr_pages += count_pages_for_highmem(nr_highmem);
|
|
pr_debug("PM: Normal pages needed: %u + %u, available pages: %u\n",
|
|
nr_pages, PAGES_FOR_IO, free);
|
|
|
|
return free > nr_pages + PAGES_FOR_IO;
|
|
}
|
|
|
|
#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_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_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 = 0;
|
|
|
|
if (nr_highmem > 0) {
|
|
error = get_highmem_buffer(PG_ANY);
|
|
if (error)
|
|
goto err_out;
|
|
if (nr_highmem > alloc_highmem) {
|
|
nr_highmem -= alloc_highmem;
|
|
nr_pages += alloc_highmem_pages(copy_bm, nr_highmem);
|
|
}
|
|
}
|
|
if (nr_pages > alloc_normal) {
|
|
nr_pages -= alloc_normal;
|
|
while (nr_pages-- > 0) {
|
|
struct page *page;
|
|
|
|
page = alloc_image_page(GFP_ATOMIC | __GFP_COLD);
|
|
if (!page)
|
|
goto err_out;
|
|
memory_bm_set_bit(copy_bm, page_to_pfn(page));
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_out:
|
|
swsusp_free();
|
|
return error;
|
|
}
|
|
|
|
asmlinkage int swsusp_save(void)
|
|
{
|
|
unsigned int nr_pages, nr_highmem;
|
|
|
|
printk(KERN_INFO "PM: Creating hibernation image: \n");
|
|
|
|
drain_local_pages(NULL);
|
|
nr_pages = count_data_pages();
|
|
nr_highmem = count_highmem_pages();
|
|
printk(KERN_INFO "PM: Need to copy %u pages\n", nr_pages + nr_highmem);
|
|
|
|
if (!enough_free_mem(nr_pages, nr_highmem)) {
|
|
printk(KERN_ERR "PM: Not enough free memory\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (swsusp_alloc(&orig_bm, ©_bm, nr_pages, nr_highmem)) {
|
|
printk(KERN_ERR "PM: Memory allocation failed\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* During allocating of suspend pagedir, new cold pages may appear.
|
|
* Kill them.
|
|
*/
|
|
drain_local_pages(NULL);
|
|
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(KERN_INFO "PM: Hibernation image created (%d pages copied)\n",
|
|
nr_pages);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifndef CONFIG_ARCH_HIBERNATION_HEADER
|
|
static int init_header_complete(struct swsusp_info *info)
|
|
{
|
|
memcpy(&info->uts, init_utsname(), sizeof(struct new_utsname));
|
|
info->version_code = LINUX_VERSION_CODE;
|
|
return 0;
|
|
}
|
|
|
|
static char *check_image_kernel(struct swsusp_info *info)
|
|
{
|
|
if (info->version_code != LINUX_VERSION_CODE)
|
|
return "kernel version";
|
|
if (strcmp(info->uts.sysname,init_utsname()->sysname))
|
|
return "system type";
|
|
if (strcmp(info->uts.release,init_utsname()->release))
|
|
return "kernel release";
|
|
if (strcmp(info->uts.version,init_utsname()->version))
|
|
return "version";
|
|
if (strcmp(info->uts.machine,init_utsname()->machine))
|
|
return "machine";
|
|
return NULL;
|
|
}
|
|
#endif /* CONFIG_ARCH_HIBERNATION_HEADER */
|
|
|
|
unsigned long snapshot_get_image_size(void)
|
|
{
|
|
return nr_copy_pages + nr_meta_pages + 1;
|
|
}
|
|
|
|
static int init_header(struct swsusp_info *info)
|
|
{
|
|
memset(info, 0, sizeof(struct swsusp_info));
|
|
info->num_physpages = num_physpages;
|
|
info->image_pages = nr_copy_pages;
|
|
info->pages = snapshot_get_image_size();
|
|
info->size = info->pages;
|
|
info->size <<= PAGE_SHIFT;
|
|
return init_header_complete(info);
|
|
}
|
|
|
|
/**
|
|
* 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) {
|
|
int error;
|
|
|
|
error = init_header((struct swsusp_info *)buffer);
|
|
if (error)
|
|
return error;
|
|
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_populated_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 int check_header(struct swsusp_info *info)
|
|
{
|
|
char *reason;
|
|
|
|
reason = check_image_kernel(info);
|
|
if (!reason && info->num_physpages != num_physpages)
|
|
reason = "memory size";
|
|
if (reason) {
|
|
printk(KERN_ERR "PM: Image 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 int 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;
|
|
|
|
if (memory_bm_pfn_present(bm, buf[j]))
|
|
memory_bm_set_bit(bm, buf[j]);
|
|
else
|
|
return -EFAULT;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* 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 ERR_PTR(-ENOMEM);
|
|
}
|
|
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 ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
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;
|
|
unsigned long pfn = memory_bm_next_pfn(bm);
|
|
|
|
if (pfn == BM_END_OF_MAP)
|
|
return ERR_PTR(-EFAULT);
|
|
|
|
page = pfn_to_page(pfn);
|
|
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 ERR_PTR(-ENOMEM);
|
|
}
|
|
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) {
|
|
error = unpack_orig_pfns(buffer, ©_bm);
|
|
if (error)
|
|
return error;
|
|
|
|
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 (IS_ERR(handle->buffer))
|
|
return PTR_ERR(handle->buffer);
|
|
}
|
|
} else {
|
|
copy_last_highmem_page();
|
|
handle->buffer = get_buffer(&orig_bm, &ca);
|
|
if (IS_ERR(handle->buffer))
|
|
return PTR_ERR(handle->buffer);
|
|
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 */
|