diff options
-rw-r--r-- | Documentation/kernel-parameters.txt | 3 | ||||
-rw-r--r-- | arch/x86/include/asm/smp.h | 1 | ||||
-rw-r--r-- | arch/x86/kernel/smpboot.c | 2 | ||||
-rw-r--r-- | arch/x86/power/cpu.c | 30 | ||||
-rw-r--r-- | include/linux/suspend.h | 5 | ||||
-rw-r--r-- | kernel/power/Makefile | 2 | ||||
-rw-r--r-- | kernel/power/console.c | 8 | ||||
-rw-r--r-- | kernel/power/hibernate.c | 101 | ||||
-rw-r--r-- | kernel/power/main.c | 11 | ||||
-rw-r--r-- | kernel/power/power.h | 11 | ||||
-rw-r--r-- | kernel/power/process.c | 3 | ||||
-rw-r--r-- | kernel/power/snapshot.c | 940 | ||||
-rw-r--r-- | kernel/power/suspend.c | 10 | ||||
-rw-r--r-- | kernel/power/swap.c | 6 | ||||
-rw-r--r-- | kernel/power/user.c | 14 | ||||
-rw-r--r-- | kernel/workqueue.c | 4 | ||||
-rwxr-xr-x | scripts/analyze_suspend.py | 3641 | ||||
-rw-r--r-- | tools/power/x86/turbostat/Makefile | 4 |
18 files changed, 3147 insertions, 1649 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 82b42c958d1c..07960c24642d 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3594,6 +3594,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. present during boot. nocompress Don't compress/decompress hibernation images. no Disable hibernation and resume. + protect_image Turn on image protection during restoration + (that will set all pages holding image data + during restoration read-only). retain_initrd [RAM] Keep initrd memory after extraction diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 66b057306f40..7427ca895a27 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -135,6 +135,7 @@ int native_cpu_up(unsigned int cpunum, struct task_struct *tidle); int native_cpu_disable(void); int common_cpu_die(unsigned int cpu); void native_cpu_die(unsigned int cpu); +void hlt_play_dead(void); void native_play_dead(void); void play_dead_common(void); void wbinvd_on_cpu(int cpu); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index fafe8b923cac..8264dfad9cf8 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1622,7 +1622,7 @@ static inline void mwait_play_dead(void) } } -static inline void hlt_play_dead(void) +void hlt_play_dead(void) { if (__this_cpu_read(cpu_info.x86) >= 4) wbinvd(); diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index d5f64996394a..b12c26e2e309 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -12,6 +12,7 @@ #include <linux/export.h> #include <linux/smp.h> #include <linux/perf_event.h> +#include <linux/tboot.h> #include <asm/pgtable.h> #include <asm/proto.h> @@ -266,6 +267,35 @@ void notrace restore_processor_state(void) EXPORT_SYMBOL(restore_processor_state); #endif +#if defined(CONFIG_HIBERNATION) && defined(CONFIG_HOTPLUG_CPU) +static void resume_play_dead(void) +{ + play_dead_common(); + tboot_shutdown(TB_SHUTDOWN_WFS); + hlt_play_dead(); +} + +int hibernate_resume_nonboot_cpu_disable(void) +{ + void (*play_dead)(void) = smp_ops.play_dead; + int ret; + + /* + * Ensure that MONITOR/MWAIT will not be used in the "play dead" loop + * during hibernate image restoration, because it is likely that the + * monitored address will be actually written to at that time and then + * the "dead" CPU will attempt to execute instructions again, but the + * address in its instruction pointer may not be possible to resolve + * any more at that point (the page tables used by it previously may + * have been overwritten by hibernate image data). + */ + smp_ops.play_dead = resume_play_dead; + ret = disable_nonboot_cpus(); + smp_ops.play_dead = play_dead; + return ret; +} +#endif + /* * When bsp_check() is called in hibernate and suspend, cpu hotplug * is disabled already. So it's unnessary to handle race condition between diff --git a/include/linux/suspend.h b/include/linux/suspend.h index 8b6ec7ef0854..7693e39b14fe 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -18,12 +18,11 @@ static inline void pm_set_vt_switch(int do_switch) #endif #ifdef CONFIG_VT_CONSOLE_SLEEP -extern int pm_prepare_console(void); +extern void pm_prepare_console(void); extern void pm_restore_console(void); #else -static inline int pm_prepare_console(void) +static inline void pm_prepare_console(void) { - return 0; } static inline void pm_restore_console(void) diff --git a/kernel/power/Makefile b/kernel/power/Makefile index cb880a14cc39..eb4f717705ba 100644 --- a/kernel/power/Makefile +++ b/kernel/power/Makefile @@ -1,6 +1,8 @@ ccflags-$(CONFIG_PM_DEBUG) := -DDEBUG +KASAN_SANITIZE_snapshot.o := n + obj-y += qos.o obj-$(CONFIG_PM) += main.o obj-$(CONFIG_VT_CONSOLE_SLEEP) += console.o diff --git a/kernel/power/console.c b/kernel/power/console.c index aba9c545a0e3..0e781798b0b3 100644 --- a/kernel/power/console.c +++ b/kernel/power/console.c @@ -126,17 +126,17 @@ out: return ret; } -int pm_prepare_console(void) +void pm_prepare_console(void) { if (!pm_vt_switch()) - return 0; + return; orig_fgconsole = vt_move_to_console(SUSPEND_CONSOLE, 1); if (orig_fgconsole < 0) - return 1; + return; orig_kmsg = vt_kmsg_redirect(SUSPEND_CONSOLE); - return 0; + return; } void pm_restore_console(void) diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index fca9254280ee..0ee1df0a0bd6 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -52,6 +52,7 @@ enum { #ifdef CONFIG_SUSPEND HIBERNATION_SUSPEND, #endif + HIBERNATION_TEST_RESUME, /* keep last */ __HIBERNATION_AFTER_LAST }; @@ -409,6 +410,11 @@ int hibernation_snapshot(int platform_mode) goto Close; } +int __weak hibernate_resume_nonboot_cpu_disable(void) +{ + return disable_nonboot_cpus(); +} + /** * resume_target_kernel - Restore system state from a hibernation image. * @platform_mode: Whether or not to use the platform driver. @@ -433,7 +439,7 @@ static int resume_target_kernel(bool platform_mode) if (error) goto Cleanup; - error = disable_nonboot_cpus(); + error = hibernate_resume_nonboot_cpu_disable(); if (error) goto Enable_cpus; @@ -642,12 +648,39 @@ static void power_down(void) cpu_relax(); } +static int load_image_and_restore(void) +{ + int error; + unsigned int flags; + + pr_debug("PM: Loading hibernation image.\n"); + + lock_device_hotplug(); + error = create_basic_memory_bitmaps(); + if (error) + goto Unlock; + + error = swsusp_read(&flags); + swsusp_close(FMODE_READ); + if (!error) + hibernation_restore(flags & SF_PLATFORM_MODE); + + printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n"); + swsusp_free(); + free_basic_memory_bitmaps(); + Unlock: + unlock_device_hotplug(); + + return error; +} + /** * hibernate - Carry out system hibernation, including saving the image. */ int hibernate(void) { - int error; + int error, nr_calls = 0; + bool snapshot_test = false; if (!hibernation_available()) { pr_debug("PM: Hibernation not available.\n"); @@ -662,9 +695,11 @@ int hibernate(void) } pm_prepare_console(); - error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE); - if (error) + error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls); + if (error) { + nr_calls--; goto Exit; + } printk(KERN_INFO "PM: Syncing filesystems ... "); sys_sync(); @@ -697,8 +732,12 @@ int hibernate(void) pr_debug("PM: writing image.\n"); error = swsusp_write(flags); swsusp_free(); - if (!error) - power_down(); + if (!error) { + if (hibernation_mode == HIBERNATION_TEST_RESUME) + snapshot_test = true; + else + power_down(); + } in_suspend = 0; pm_restore_gfp_mask(); } else { @@ -709,12 +748,18 @@ int hibernate(void) free_basic_memory_bitmaps(); Thaw: unlock_device_hotplug(); + if (snapshot_test) { + pr_debug("PM: Checking hibernation image\n"); + error = swsusp_check(); + if (!error) + error = load_image_and_restore(); + } thaw_processes(); /* Don't bother checking whether freezer_test_done is true */ freezer_test_done = false; Exit: - pm_notifier_call_chain(PM_POST_HIBERNATION); + __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL); pm_restore_console(); atomic_inc(&snapshot_device_available); Unlock: @@ -740,8 +785,7 @@ int hibernate(void) */ static int software_resume(void) { - int error; - unsigned int flags; + int error, nr_calls = 0; /* * If the user said "noresume".. bail out early. @@ -827,35 +871,20 @@ static int software_resume(void) } pm_prepare_console(); - error = pm_notifier_call_chain(PM_RESTORE_PREPARE); - if (error) + error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls); + if (error) { + nr_calls--; goto Close_Finish; + } pr_debug("PM: Preparing processes for restore.\n"); error = freeze_processes(); if (error) goto Close_Finish; - - pr_debug("PM: Loading hibernation image.\n"); - - lock_device_hotplug(); - error = create_basic_memory_bitmaps(); - if (error) - goto Thaw; - - error = swsusp_read(&flags); - swsusp_close(FMODE_READ); - if (!error) - hibernation_restore(flags & SF_PLATFORM_MODE); - - printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n"); - swsusp_free(); - free_basic_memory_bitmaps(); - Thaw: - unlock_device_hotplug(); + error = load_image_and_restore(); thaw_processes(); Finish: - pm_notifier_call_chain(PM_POST_RESTORE); + __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL); pm_restore_console(); atomic_inc(&snapshot_device_available); /* For success case, the suspend path will release the lock */ @@ -878,6 +907,7 @@ static const char * const hibernation_modes[] = { #ifdef CONFIG_SUSPEND [HIBERNATION_SUSPEND] = "suspend", #endif + [HIBERNATION_TEST_RESUME] = "test_resume", }; /* @@ -924,6 +954,7 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr, #ifdef CONFIG_SUSPEND case HIBERNATION_SUSPEND: #endif + case HIBERNATION_TEST_RESUME: break; case HIBERNATION_PLATFORM: if (hibernation_ops) @@ -970,6 +1001,7 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr, #ifdef CONFIG_SUSPEND case HIBERNATION_SUSPEND: #endif + case HIBERNATION_TEST_RESUME: hibernation_mode = mode; break; case HIBERNATION_PLATFORM: @@ -1115,13 +1147,16 @@ static int __init resume_offset_setup(char *str) static int __init hibernate_setup(char *str) { - if (!strncmp(str, "noresume", 8)) + if (!strncmp(str, "noresume", 8)) { noresume = 1; - else if (!strncmp(str, "nocompress", 10)) + } else if (!strncmp(str, "nocompress", 10)) { nocompress = 1; - else if (!strncmp(str, "no", 2)) { + } else if (!strncmp(str, "no", 2)) { noresume = 1; nohibernate = 1; + } else if (IS_ENABLED(CONFIG_DEBUG_RODATA) + && !strncmp(str, "protect_image", 13)) { + enable_restore_image_protection(); } return 1; } diff --git a/kernel/power/main.c b/kernel/power/main.c index 27946975eff0..5ea50b1b7595 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -38,12 +38,19 @@ int unregister_pm_notifier(struct notifier_block *nb) } EXPORT_SYMBOL_GPL(unregister_pm_notifier); -int pm_notifier_call_chain(unsigned long val) +int __pm_notifier_call_chain(unsigned long val, int nr_to_call, int *nr_calls) { - int ret = blocking_notifier_call_chain(&pm_chain_head, val, NULL); + int ret; + + ret = __blocking_notifier_call_chain(&pm_chain_head, val, NULL, + nr_to_call, nr_calls); return notifier_to_errno(ret); } +int pm_notifier_call_chain(unsigned long val) +{ + return __pm_notifier_call_chain(val, -1, NULL); +} /* If set, devices may be suspended and resumed asynchronously. */ int pm_async_enabled = 1; diff --git a/kernel/power/power.h b/kernel/power/power.h index efe1b3b17c88..242d8b827dd5 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -38,6 +38,8 @@ static inline char *check_image_kernel(struct swsusp_info *info) } #endif /* CONFIG_ARCH_HIBERNATION_HEADER */ +extern int hibernate_resume_nonboot_cpu_disable(void); + /* * Keep some memory free so that I/O operations can succeed without paging * [Might this be more than 4 MB?] @@ -59,6 +61,13 @@ extern int hibernation_snapshot(int platform_mode); extern int hibernation_restore(int platform_mode); extern int hibernation_platform_enter(void); +#ifdef CONFIG_DEBUG_RODATA +/* kernel/power/snapshot.c */ +extern void enable_restore_image_protection(void); +#else +static inline void enable_restore_image_protection(void) {} +#endif /* CONFIG_DEBUG_RODATA */ + #else /* !CONFIG_HIBERNATION */ static inline void hibernate_reserved_size_init(void) {} @@ -200,6 +209,8 @@ static inline void suspend_test_finish(const char *label) {} #ifdef CONFIG_PM_SLEEP /* kernel/power/main.c */ +extern int __pm_notifier_call_chain(unsigned long val, int nr_to_call, + int *nr_calls); extern int pm_notifier_call_chain(unsigned long val); #endif diff --git a/kernel/power/process.c b/kernel/power/process.c index 0c2ee9761d57..8f27d5a8adf6 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -89,6 +89,9 @@ static int try_to_freeze_tasks(bool user_only) elapsed_msecs / 1000, elapsed_msecs % 1000, todo - wq_busy, wq_busy); + if (wq_busy) + show_workqueue_state(); + if (!wakeup) { read_lock(&tasklist_lock); for_each_process_thread(g, p) { diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 3a970604308f..d90df926b59f 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -38,6 +38,43 @@ #include "power.h" +#ifdef CONFIG_DEBUG_RODATA +static bool hibernate_restore_protection; +static bool hibernate_restore_protection_active; + +void enable_restore_image_protection(void) +{ + hibernate_restore_protection = true; +} + +static inline void hibernate_restore_protection_begin(void) +{ + hibernate_restore_protection_active = hibernate_restore_protection; +} + +static inline void hibernate_restore_protection_end(void) +{ + hibernate_restore_protection_active = false; +} + +static inline void hibernate_restore_protect_page(void *page_address) +{ + if (hibernate_restore_protection_active) + set_memory_ro((unsigned long)page_address, 1); +} + +static inline void hibernate_restore_unprotect_page(void *page_address) +{ + if (hibernate_restore_protection_active) + set_memory_rw((unsigned long)page_address, 1); +} +#else +static inline void hibernate_restore_protection_begin(void) {} +static inline void hibernate_restore_protection_end(void) {} +static inline void hibernate_restore_protect_page(void *page_address) {} +static inline void hibernate_restore_unprotect_page(void *page_address) {} +#endif /* CONFIG_DEBUG_RODATA */ + static int swsusp_page_is_free(struct page *); static void swsusp_set_page_forbidden(struct page *); static void swsusp_unset_page_forbidden(struct page *); @@ -67,25 +104,32 @@ void __init hibernate_image_size_init(void) image_size = ((totalram_pages * 2) / 5) * PAGE_SIZE; } -/* List of PBEs needed for restoring the pages that were allocated before +/* + * List of PBEs needed for restoring the pages that were allocated before * the suspend and included in the suspend image, but have also been * allocated by the "resume" kernel, so their contents cannot be written * directly to their "original" page frames. */ struct pbe *restore_pblist; -/* Pointer to an auxiliary buffer (1 page) */ -static void *buffer; +/* struct linked_page is used to build chains of pages */ -/** - * @safe_needed - on resume, for storing the PBE list and the image, - * we can only use memory pages that do not conflict with the pages - * used before suspend. The unsafe pages have PageNosaveFree set - * and we count them using unsafe_pages. - * - * Each allocated image page is marked as PageNosave and PageNosaveFree - * so that swsusp_free() can release it. +#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *)) + +struct linked_page { + struct linked_page *next; + char data[LINKED_PAGE_DATA_SIZE]; +} __packed; + +/* + * List of "safe" pages (ie. pages that were not used by the image kernel + * before hibernation) that may be used as temporary storage for image kernel + * memory contents. */ +static struct linked_page *safe_pages_list; + +/* Pointer to an auxiliary buffer (1 page) */ +static void *buffer; #define PG_ANY 0 #define PG_SAFE 1 @@ -94,6 +138,19 @@ static void *buffer; static unsigned int allocated_unsafe_pages; +/** + * get_image_page - Allocate a page for a hibernation image. + * @gfp_mask: GFP mask for the allocation. + * @safe_needed: Get pages that were not used before hibernation (restore only) + * + * During image restoration, for storing the PBE list and the image data, we can + * only use memory pages that do not conflict with the pages used before + * hibernation. The "unsafe" pages have PageNosaveFree set and we count them + * using allocated_unsafe_pages. + * + * Each allocated image page is marked as PageNosave and PageNosaveFree so that + * swsusp_free() can release it. + */ static void *get_image_page(gfp_t gfp_mask, int safe_needed) { void *res; @@ -113,9 +170,21 @@ static void *get_image_page(gfp_t gfp_mask, int safe_needed) return res; } +static void *__get_safe_page(gfp_t gfp_mask) +{ + if (safe_pages_list) { + void *ret = safe_pages_list; + + safe_pages_list = safe_pages_list->next; + memset(ret, 0, PAGE_SIZE); + return ret; + } + return get_image_page(gfp_mask, PG_SAFE); +} + unsigned long get_safe_page(gfp_t gfp_mask) { - return (unsigned long)get_image_page(gfp_mask, PG_SAFE); + return (unsigned long)__get_safe_page(gfp_mask); } static struct page *alloc_image_page(gfp_t gfp_mask) @@ -130,11 +199,22 @@ static struct page *alloc_image_page(gfp_t gfp_mask) return page; } +static void recycle_safe_page(void *page_address) +{ + struct linked_page *lp = page_address; + + lp->next = safe_pages_list; + safe_pages_list = lp; +} + /** - * free_image_page - free page represented by @addr, allocated with - * get_image_page (page flags set by it must be cleared) + * free_image_page - Free a page allocated for hibernation image. + * @addr: Address of the page to free. + * @clear_nosave_free: If set, clear the PageNosaveFree bit for the page. + * + * The page to free should have been allocated by get_image_page() (page flags + * set by it are affected). */ - static inline void free_image_page(void *addr, int clear_nosave_free) { struct page *page; @@ -150,17 +230,8 @@ static inline void free_image_page(void *addr, int clear_nosave_free) __free_page(page); } -/* struct linked_page is used to build chains of pages */ - -#define LINKED_PAGE_DATA_SIZE (PAGE_SIZE - sizeof(void *)) - -struct linked_page { - struct linked_page *next; - char data[LINKED_PAGE_DATA_SIZE]; -} __packed; - -static inline void -free_list_of_pages(struct linked_page *list, int clear_page_nosave) +static inline void free_list_of_pages(struct linked_page *list, + int clear_page_nosave) { while (list) { struct linked_page *lp = list->next; @@ -170,30 +241,28 @@ free_list_of_pages(struct linked_page *list, int clear_page_nosave) } } -/** - * struct chain_allocator is used for allocating small objects out of - * a linked list of pages called 'the chain'. - * - * The chain grows each time when there is no room for a new object in - * the current page. The allocated objects cannot be freed individually. - * It is only possible to free them all at once, by freeing the entire - * chain. - * - * NOTE: The chain allocator may be inefficient if the allocated objects - * are not much smaller than PAGE_SIZE. - */ - +/* + * struct chain_allocator is used for allocating small objects out of + * a linked list of pages called 'the chain'. + * + * The chain grows each time when there is no room for a new object in + * the current page. The allocated objects cannot be freed individually. + * It is only possible to free them all at once, by freeing the entire + * chain. + * + * NOTE: The chain allocator may be inefficient if the allocated objects + * are not much smaller than PAGE_SIZE. + */ struct chain_allocator { struct linked_page *chain; /* the chain */ unsigned int used_space; /* total size of objects allocated out - * of the current page - */ + of the current page */ gfp_t gfp_mask; /* mask for allocating pages */ int safe_needed; /* if set, only "safe" pages are allocated */ }; -static void -chain_init(struct chain_allocator *ca, gfp_t gfp_mask, int safe_needed) +static void chain_init(struct chain_allocator *ca, gfp_t gfp_mask, + int safe_needed) { ca->chain = NULL; ca->used_space = LINKED_PAGE_DATA_SIZE; @@ -208,7 +277,8 @@ static void *chain_alloc(struct chain_allocator *ca, unsigned int size) if (LINKED_PAGE_DATA_SIZE - ca->used_space < size) { struct linked_page *lp; - lp = get_image_page(ca->gfp_mask, ca->safe_needed); + lp = ca->safe_needed ? __get_safe_page(ca->gfp_mask) : + get_image_page(ca->gfp_mask, PG_ANY); if (!lp) return NULL; @@ -222,44 +292,44 @@ static void *chain_alloc(struct chain_allocator *ca, unsigned int size) } /** - * Data types related to memory bitmaps. + * Data types related to memory bitmaps. * - * Memory bitmap is a structure consiting of many linked lists of - * objects. The main list's elements are of type struct zone_bitmap - * and each of them corresonds to one zone. For each zone bitmap - * object there is a list of objects of type struct bm_block that - * represent each blocks of bitmap in which information is stored. + * Memory bitmap is a structure consiting of many linked lists of + * objects. The main list's elements are of type struct zone_bitmap + * and each of them corresonds to one zone. For each zone bitmap + * object there is a list of objects of type struct bm_block that + * represent each blocks of bitmap in which information is stored. * - * struct memory_bitmap contains a pointer to the main list of zone - * bitmap objects, a struct bm_position used for browsing the bitmap, - * and a pointer to the list of pages used for allocating all of the - * zone bitmap objects and bitmap block objects. + * struct memory_bitmap contains a pointer to the main list of zone + * bitmap objects, a struct bm_position used for browsing the bitmap, + * and a pointer to the list of pages used for allocating all of the + * zone bitmap objects and bitmap block objects. * - * NOTE: It has to be possible to lay out the bitmap in memory - * using only allocations of order 0. Additionally, the bitmap is - * designed to work with arbitrary number of zones (this is over the - * top for now, but let's avoid making unnecessary assumptions ;-). + * NOTE: It has to be possible to lay out the bitmap in memory + * using only allocations of order 0. Additionally, the bitmap is + * designed to work with arbitrary number of zones (this is over the + * top for now, but let's avoid making unnecessary assumptions ;-). * - * struct zone_bitmap contains a pointer to a list of bitmap block - * objects and a pointer to the bitmap block object that has been - * most recently used for setting bits. Additionally, it contains the - * pfns that correspond to the start and end of the represented zone. + * struct zone_bitmap contains a pointer to a list of bitmap block + * objects and a pointer to the bitmap block object that has been + * most recently used for setting bits. Additionally, it contains the + * PFNs that correspond to the start and end of the represented zone. * - * struct bm_block contains a pointer to the memory page in which - * information is stored (in the form of a block of bitmap) - * It also contains the pfns that correspond to the start and end of - * the represented memory area. + * struct bm_block contains a pointer to the memory page in which + * information is stored (in the form of a block of bitmap) + * It also contains the pfns that correspond to the start and end of + * the represented memory area. * - * The memory bitmap is organized as a radix tree to guarantee fast random - * access to the bits. There is one radix tree for each zone (as returned - * from create_mem_extents). + * The memory bitmap is organized as a radix tree to guarantee fast random + * access to the bits. There is one radix tree for each zone (as returned + * from create_mem_extents). * - * One radix tree is represented by one struct mem_zone_bm_rtree. There are - * two linked lists for the nodes of the tree, one for the inner nodes and - * one for the leave nodes. The linked leave nodes are used for fast linear - * access of the memory bitmap. + * One radix tree is represented by one struct mem_zone_bm_rtree. There are + * two linked lists for the nodes of the tree, one for the inner nodes and + * one for the leave nodes. The linked leave nodes are used for fast linear + * access of the memory bitmap. * - * The struct rtree_node represents one node of the radix tree. + * The struct rtree_node represents one node of the radix tree. */ #define BM_END_OF_MAP (~0UL) @@ -305,9 +375,8 @@ struct bm_position { struct memory_bitmap { struct list_head zones; struct linked_page *p_list; /* list of pages used to store zone - * bitmap objects and bitmap block - * objects - */ + bitmap objects and bitmap block + objects */ struct bm_position cur; /* most recently used bit position */ }; @@ -321,12 +390,12 @@ struct memory_bitmap { #endif #define BM_RTREE_LEVEL_MASK ((1UL << BM_RTREE_LEVEL_SHIFT) - 1) -/* - * alloc_rtree_node - Allocate a new node and add it to the radix tree. +/** + * alloc_rtree_node - Allocate a new node and add it to the radix tree. * - * This function is used to allocate inner nodes as well as the - * leave nodes of the radix tree. It also adds the node to the - * corresponding linked list passed in by the *list parameter. + * This function is used to allocate inner nodes as well as the + * leave nodes of the radix tree. It also adds the node to the + * corresponding linked list passed in by the *list parameter. */ static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed, struct chain_allocator *ca, @@ -347,12 +416,12 @@ static struct rtree_node *alloc_rtree_node(gfp_t gfp_mask, int safe_needed, return node; } -/* - * add_rtree_block - Add a new leave node to the radix tree +/** + * add_rtree_block - Add a new leave node to the radix tree. * - * The leave nodes need to be allocated in order to keep the leaves - * linked list in order. This is guaranteed by the zone->blocks - * counter. + * The leave nodes need to be allocated in order to keep the leaves + * linked list in order. This is guaranteed by the zone->blocks + * counter. */ static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask, int safe_needed, struct chain_allocator *ca) @@ -417,17 +486,18 @@ static int add_rtree_block(struct mem_zone_bm_rtree *zone, gfp_t gfp_mask, static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone, int clear_nosave_free); -/* - * create_zone_bm_rtree - create a radix tree for one zone +/** + * create_zone_bm_rtree - Create a radix tree for one zone. * - * Allocated the mem_zone_bm_rtree structure and initializes it. - * This function also allocated and builds the radix tree for the - * zone. + * Allocated the mem_zone_bm_rtree structure and initializes it. + * This function also allocated and builds the radix tree for the + * zone. */ -static struct mem_zone_bm_rtree * -create_zone_bm_rtree(gfp_t gfp_mask, int safe_needed, - struct chain_allocator *ca, - unsigned long start, unsigned long end) +static struct mem_zone_bm_rtree *create_zone_bm_rtree(gfp_t gfp_mask, + int safe_needed, + struct chain_allocator *ca, + unsigned long start, + unsigned long end) { struct mem_zone_bm_rtree *zone; unsigned int i, nr_blocks; @@ -454,12 +524,12 @@ create_zone_bm_rtree(gfp_t gfp_mask, int safe_needed, return zone; } -/* - * free_zone_bm_rtree - Free the memory of the radix tree +/** + * free_zone_bm_rtree - Free the memory of the radix tree. * - * Free all node pages of the radix tree. The mem_zone_bm_rtree - * structure itself is not freed here nor are the rtree_node - * structs. + * Free all node pages of the radix tree. The mem_zone_bm_rtree + * structure itself is not freed here nor are the rtree_node + * structs. */ static void free_zone_bm_rtree(struct mem_zone_bm_rtree *zone, int clear_nosave_free) @@ -492,8 +562,8 @@ struct mem_extent { }; /** - * free_mem_extents - free a list of memory extents - * @list - list of extents to empty + * free_mem_extents - Free a list of memory extents. + * @list: List of extents to free. */ static void free_mem_extents(struct list_head *list) { @@ -506,10 +576,11 @@ static void free_mem_extents(struct list_head *list) } /** - * create_mem_extents - create a list of memory extents representing - * contiguous ranges of PFNs - * @list - list to put the extents into - * @gfp_mask - mask to use for memory allocations + * create_mem_extents - Create a list of memory extents. + * @list: List to put the extents into. + * @gfp_mask: Mask to use for memory allocations. + * + * The extents represent contiguous ranges of PFNs. */ static int create_mem_extents(struct list_head *list, gfp_t gfp_mask) { @@ -565,10 +636,10 @@ static int create_mem_extents(struct list_head *list, gfp_t gfp_mask) } /** - * memory_bm_create - allocate memory for a memory bitmap - */ -static int -memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed) + * memory_bm_create - Allocate memory for a memory bitmap. + */ +static int memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, + int safe_needed) { struct chain_allocator ca; struct list_head mem_extents; @@ -607,8 +678,9 @@ memory_bm_create(struct memory_bitmap *bm, gfp_t gfp_mask, int safe_needed) } /** - * memory_bm_free - free memory occupied by the memory bitmap @bm - */ + * memory_bm_free - Free memory occupied by the memory bitmap. + * @bm: Memory bitmap. + */ static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free) { struct mem_zone_bm_rtree *zone; @@ -622,14 +694,13 @@ static void memory_bm_free(struct memory_bitmap *bm, int clear_nosave_free) } /** - * memory_bm_find_bit - Find the bit for pfn in the memory - * bitmap + * memory_bm_find_bit - Find the bit for a given PFN in a memory bitmap. * - * Find the bit in the bitmap @bm that corresponds to given pfn. - * The cur.zone, cur.block and cur.node_pfn member of @bm are - * updated. - * It walks the radix tree to find the page which contains the bit for - * pfn and returns the bit position in **addr and *bit_nr. + * Find the bit in memory bitmap @bm that corresponds to the given PFN. + * The cur.zone, cur.block and cur.node_pfn members of @bm are updated. + * + * Walk the radix tree to find the page containing the bit that represents @pfn + * and return the position of the bit in @addr and @bit_nr. */ static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn, void **addr, unsigned int *bit_nr) @@ -658,10 +729,9 @@ static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn, zone_found: /* - * We have a zone. Now walk the radix tree to find the leave - * node for our pfn. + * We have found the zone. Now walk the radix tree to find the leaf node + * for our PFN. */ - node = bm->cur.node; if (((pfn - zone->start_pfn) & ~BM_BLOCK_MASK) == bm->cur.node_pfn) goto node_found; @@ -754,14 +824,14 @@ static bool memory_bm_pfn_present(struct memory_bitmap *bm, unsigned long pfn) } /* - * rtree_next_node - Jumps to the next leave node + * rtree_next_node - Jump to the next leaf node. * - * Sets the position to the beginning of the next node in the - * memory bitmap. This is either the next node in the current - * zone's radix tree or the first node in the radix tree of the - * next zone. + * Set the position to the beginning of the next node |