[mirror_ubuntu-hirsute-kernel.git] / arch / arm64 / kernel / machine_kexec.c

/*
 * kexec for arm64
 *
 * Copyright (C) Linaro.
 * Copyright (C) Huawei Futurewei Technologies.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/kexec.h>
#include <linux/page-flags.h>
#include <linux/smp.h>

#include <asm/cacheflush.h>
#include <asm/cpu_ops.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/page.h>

#include "cpu-reset.h"

/* Global variables for the arm64_relocate_new_kernel routine. */
extern const unsigned char arm64_relocate_new_kernel[];
extern const unsigned long arm64_relocate_new_kernel_size;

/**
 * kexec_image_info - For debugging output.
 */
#define kexec_image_info(_i) _kexec_image_info(__func__, __LINE__, _i)
static void _kexec_image_info(const char *func, int line,
	const struct kimage *kimage)
{
	unsigned long i;

	pr_debug("%s:%d:\n", func, line);
	pr_debug("  kexec kimage info:\n");
	pr_debug("    type:        %d\n", kimage->type);
	pr_debug("    start:       %lx\n", kimage->start);
	pr_debug("    head:        %lx\n", kimage->head);
	pr_debug("    nr_segments: %lu\n", kimage->nr_segments);

	for (i = 0; i < kimage->nr_segments; i++) {
		pr_debug("      segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
			i,
			kimage->segment[i].mem,
			kimage->segment[i].mem + kimage->segment[i].memsz,
			kimage->segment[i].memsz,
			kimage->segment[i].memsz /  PAGE_SIZE);
	}
}

void machine_kexec_cleanup(struct kimage *kimage)
{
	/* Empty routine needed to avoid build errors. */
}

/**
 * machine_kexec_prepare - Prepare for a kexec reboot.
 *
 * Called from the core kexec code when a kernel image is loaded.
 * Forbid loading a kexec kernel if we have no way of hotplugging cpus or cpus
 * are stuck in the kernel. This avoids a panic once we hit machine_kexec().
 */
int machine_kexec_prepare(struct kimage *kimage)
{
	kexec_image_info(kimage);

	if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) {
		pr_err("Can't kexec: CPUs are stuck in the kernel.\n");
		return -EBUSY;
	}

	return 0;
}

/**
 * kexec_list_flush - Helper to flush the kimage list and source pages to PoC.
 */
static void kexec_list_flush(struct kimage *kimage)
{
	kimage_entry_t *entry;

	for (entry = &kimage->head; ; entry++) {
		unsigned int flag;
		void *addr;

		/* flush the list entries. */
		__flush_dcache_area(entry, sizeof(kimage_entry_t));

		flag = *entry & IND_FLAGS;
		if (flag == IND_DONE)
			break;

		addr = phys_to_virt(*entry & PAGE_MASK);

		switch (flag) {
		case IND_INDIRECTION:
			/* Set entry point just before the new list page. */
			entry = (kimage_entry_t *)addr - 1;
			break;
		case IND_SOURCE:
			/* flush the source pages. */
			__flush_dcache_area(addr, PAGE_SIZE);
			break;
		case IND_DESTINATION:
			break;
		default:
			BUG();
		}
	}
}

/**
 * kexec_segment_flush - Helper to flush the kimage segments to PoC.
 */
static void kexec_segment_flush(const struct kimage *kimage)
{
	unsigned long i;

	pr_debug("%s:\n", __func__);

	for (i = 0; i < kimage->nr_segments; i++) {
		pr_debug("  segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
			i,
			kimage->segment[i].mem,
			kimage->segment[i].mem + kimage->segment[i].memsz,
			kimage->segment[i].memsz,
			kimage->segment[i].memsz /  PAGE_SIZE);

		__flush_dcache_area(phys_to_virt(kimage->segment[i].mem),
			kimage->segment[i].memsz);
	}
}

/**
 * machine_kexec - Do the kexec reboot.
 *
 * Called from the core kexec code for a sys_reboot with LINUX_REBOOT_CMD_KEXEC.
 */
void machine_kexec(struct kimage *kimage)
{
	phys_addr_t reboot_code_buffer_phys;
	void *reboot_code_buffer;
	bool in_kexec_crash = (kimage == kexec_crash_image);
	bool stuck_cpus = cpus_are_stuck_in_kernel();

	/*
	 * New cpus may have become stuck_in_kernel after we loaded the image.
	 */
	BUG_ON(!in_kexec_crash && (stuck_cpus || (num_online_cpus() > 1)));
	WARN(in_kexec_crash && (stuck_cpus || smp_crash_stop_failed()),
		"Some CPUs may be stale, kdump will be unreliable.\n");

	reboot_code_buffer_phys = page_to_phys(kimage->control_code_page);
	reboot_code_buffer = phys_to_virt(reboot_code_buffer_phys);

	kexec_image_info(kimage);

	pr_debug("%s:%d: control_code_page:        %p\n", __func__, __LINE__,
		kimage->control_code_page);
	pr_debug("%s:%d: reboot_code_buffer_phys:  %pa\n", __func__, __LINE__,
		&reboot_code_buffer_phys);
	pr_debug("%s:%d: reboot_code_buffer:       %p\n", __func__, __LINE__,
		reboot_code_buffer);
	pr_debug("%s:%d: relocate_new_kernel:      %p\n", __func__, __LINE__,
		arm64_relocate_new_kernel);
	pr_debug("%s:%d: relocate_new_kernel_size: 0x%lx(%lu) bytes\n",
		__func__, __LINE__, arm64_relocate_new_kernel_size,
		arm64_relocate_new_kernel_size);

	/*
	 * Copy arm64_relocate_new_kernel to the reboot_code_buffer for use
	 * after the kernel is shut down.
	 */
	memcpy(reboot_code_buffer, arm64_relocate_new_kernel,
		arm64_relocate_new_kernel_size);

	/* Flush the reboot_code_buffer in preparation for its execution. */
	__flush_dcache_area(reboot_code_buffer, arm64_relocate_new_kernel_size);
	flush_icache_range((uintptr_t)reboot_code_buffer,
		arm64_relocate_new_kernel_size);

	/* Flush the kimage list and its buffers. */
	kexec_list_flush(kimage);

	/* Flush the new image if already in place. */
	if ((kimage != kexec_crash_image) && (kimage->head & IND_DONE))
		kexec_segment_flush(kimage);

	pr_info("Bye!\n");

	/* Disable all DAIF exceptions. */
	asm volatile ("msr daifset, #0xf" : : : "memory");

	/*
	 * cpu_soft_restart will shutdown the MMU, disable data caches, then
	 * transfer control to the reboot_code_buffer which contains a copy of
	 * the arm64_relocate_new_kernel routine.  arm64_relocate_new_kernel
	 * uses physical addressing to relocate the new image to its final
	 * position and transfers control to the image entry point when the
	 * relocation is complete.
	 */

	cpu_soft_restart(kimage != kexec_crash_image,
		reboot_code_buffer_phys, kimage->head, kimage->start, 0);

	BUG(); /* Should never get here. */
}

static void machine_kexec_mask_interrupts(void)
{
	unsigned int i;
	struct irq_desc *desc;

	for_each_irq_desc(i, desc) {
		struct irq_chip *chip;
		int ret;

		chip = irq_desc_get_chip(desc);
		if (!chip)
			continue;

		/*
		 * First try to remove the active state. If this
		 * fails, try to EOI the interrupt.
		 */
		ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);

		if (ret && irqd_irq_inprogress(&desc->irq_data) &&
		    chip->irq_eoi)
			chip->irq_eoi(&desc->irq_data);

		if (chip->irq_mask)
			chip->irq_mask(&desc->irq_data);

		if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
			chip->irq_disable(&desc->irq_data);
	}
}

/**
 * machine_crash_shutdown - shutdown non-crashing cpus and save registers
 */
void machine_crash_shutdown(struct pt_regs *regs)
{
	local_irq_disable();

	/* shutdown non-crashing cpus */
	smp_send_crash_stop();

	/* for crashing cpu */
	crash_save_cpu(regs, smp_processor_id());
	machine_kexec_mask_interrupts();

	pr_info("Starting crashdump kernel...\n");
}

void arch_kexec_protect_crashkres(void)
{
	int i;

	kexec_segment_flush(kexec_crash_image);

	for (i = 0; i < kexec_crash_image->nr_segments; i++)
		set_memory_valid(
			__phys_to_virt(kexec_crash_image->segment[i].mem),
			kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 0);
}

void arch_kexec_unprotect_crashkres(void)
{
	int i;

	for (i = 0; i < kexec_crash_image->nr_segments; i++)
		set_memory_valid(
			__phys_to_virt(kexec_crash_image->segment[i].mem),
			kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 1);
}

#ifdef CONFIG_HIBERNATION
/*
 * To preserve the crash dump kernel image, the relevant memory segments
 * should be mapped again around the hibernation.
 */
void crash_prepare_suspend(void)
{
	if (kexec_crash_image)
		arch_kexec_unprotect_crashkres();
}

void crash_post_resume(void)
{
	if (kexec_crash_image)
		arch_kexec_protect_crashkres();
}

/*
 * crash_is_nosave
 *
 * Return true only if a page is part of reserved memory for crash dump kernel,
 * but does not hold any data of loaded kernel image.
 *
 * Note that all the pages in crash dump kernel memory have been initially
 * marked as Reserved in kexec_reserve_crashkres_pages().
 *
 * In hibernation, the pages which are Reserved and yet "nosave" are excluded
 * from the hibernation iamge. crash_is_nosave() does thich check for crash
 * dump kernel and will reduce the total size of hibernation image.
 */

bool crash_is_nosave(unsigned long pfn)
{
	int i;
	phys_addr_t addr;

	if (!crashk_res.end)
		return false;

	/* in reserved memory? */
	addr = __pfn_to_phys(pfn);
	if ((addr < crashk_res.start) || (crashk_res.end < addr))
		return false;

	if (!kexec_crash_image)
		return true;

	/* not part of loaded kernel image? */
	for (i = 0; i < kexec_crash_image->nr_segments; i++)
		if (addr >= kexec_crash_image->segment[i].mem &&
				addr < (kexec_crash_image->segment[i].mem +
					kexec_crash_image->segment[i].memsz))
			return false;

	return true;
}

void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
{
	unsigned long addr;
	struct page *page;

	for (addr = begin; addr < end; addr += PAGE_SIZE) {
		page = phys_to_page(addr);
		ClearPageReserved(page);
		free_reserved_page(page);
	}
}
#endif /* CONFIG_HIBERNATION */
Commit	Line	Data
d28f6df1 GL	1	/*
	2	* kexec for arm64
	3	*
	4	* Copyright (C) Linaro.
	5	* Copyright (C) Huawei Futurewei Technologies.
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
78fd584c AT	12	#include <linux/interrupt.h>
	13	#include <linux/irq.h>
	14	#include <linux/kernel.h>
d28f6df1	15	#include <linux/kexec.h>
254a41c0	16	#include <linux/page-flags.h>
d28f6df1 GL	17	#include <linux/smp.h>
	18
	19	#include <asm/cacheflush.h>
	20	#include <asm/cpu_ops.h>
98d2e153	21	#include <asm/mmu.h>
d28f6df1	22	#include <asm/mmu_context.h>
98d2e153	23	#include <asm/page.h>
d28f6df1 GL	24
	25	#include "cpu-reset.h"
	26
	27	/* Global variables for the arm64_relocate_new_kernel routine. */
	28	extern const unsigned char arm64_relocate_new_kernel[];
	29	extern const unsigned long arm64_relocate_new_kernel_size;
	30
221f2c77 GL	31	/**
	32	* kexec_image_info - For debugging output.
	33	*/
	34	#define kexec_image_info(_i) _kexec_image_info(__func__, __LINE__, _i)
	35	static void _kexec_image_info(const char *func, int line,
	36	const struct kimage *kimage)
	37	{
	38	unsigned long i;
	39
	40	pr_debug("%s:%d:\n", func, line);
	41	pr_debug(" kexec kimage info:\n");
	42	pr_debug(" type: %d\n", kimage->type);
	43	pr_debug(" start: %lx\n", kimage->start);
	44	pr_debug(" head: %lx\n", kimage->head);
	45	pr_debug(" nr_segments: %lu\n", kimage->nr_segments);
	46
	47	for (i = 0; i < kimage->nr_segments; i++) {
	48	pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
	49	i,
	50	kimage->segment[i].mem,
	51	kimage->segment[i].mem + kimage->segment[i].memsz,
	52	kimage->segment[i].memsz,
	53	kimage->segment[i].memsz / PAGE_SIZE);
	54	}
	55	}
	56
d28f6df1 GL	57	void machine_kexec_cleanup(struct kimage *kimage)
	58	{
	59	/* Empty routine needed to avoid build errors. */
	60	}
	61
	62	/**
	63	* machine_kexec_prepare - Prepare for a kexec reboot.
	64	*
	65	* Called from the core kexec code when a kernel image is loaded.
	66	* Forbid loading a kexec kernel if we have no way of hotplugging cpus or cpus
	67	* are stuck in the kernel. This avoids a panic once we hit machine_kexec().
	68	*/
	69	int machine_kexec_prepare(struct kimage *kimage)
	70	{
221f2c77 GL	71	kexec_image_info(kimage);
221f2c77 GL	72
d28f6df1 GL	73	if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) {
	74	pr_err("Can't kexec: CPUs are stuck in the kernel.\n");
	75	return -EBUSY;
	76	}
	77
	78	return 0;
	79	}
	80
	81	/**
	82	* kexec_list_flush - Helper to flush the kimage list and source pages to PoC.
	83	*/
	84	static void kexec_list_flush(struct kimage *kimage)
	85	{
	86	kimage_entry_t *entry;
	87
	88	for (entry = &kimage->head; ; entry++) {
	89	unsigned int flag;
	90	void *addr;
	91
	92	/* flush the list entries. */
	93	__flush_dcache_area(entry, sizeof(kimage_entry_t));
	94
	95	flag = *entry & IND_FLAGS;
	96	if (flag == IND_DONE)
	97	break;
	98
	99	addr = phys_to_virt(*entry & PAGE_MASK);
	100
	101	switch (flag) {
	102	case IND_INDIRECTION:
	103	/* Set entry point just before the new list page. */
	104	entry = (kimage_entry_t *)addr - 1;
	105	break;
	106	case IND_SOURCE:
	107	/* flush the source pages. */
	108	__flush_dcache_area(addr, PAGE_SIZE);
	109	break;
	110	case IND_DESTINATION:
	111	break;
	112	default:
	113	BUG();
	114	}
	115	}
	116	}
	117
	118	/**
	119	* kexec_segment_flush - Helper to flush the kimage segments to PoC.
	120	*/
	121	static void kexec_segment_flush(const struct kimage *kimage)
	122	{
	123	unsigned long i;
	124
	125	pr_debug("%s:\n", __func__);
	126
	127	for (i = 0; i < kimage->nr_segments; i++) {
	128	pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
	129	i,
	130	kimage->segment[i].mem,
	131	kimage->segment[i].mem + kimage->segment[i].memsz,
	132	kimage->segment[i].memsz,
	133	kimage->segment[i].memsz / PAGE_SIZE);
	134
	135	__flush_dcache_area(phys_to_virt(kimage->segment[i].mem),
	136	kimage->segment[i].memsz);
137	}
138	}
139
140	/**
141	* machine_kexec - Do the kexec reboot.
142	*
143	* Called from the core kexec code for a sys_reboot with LINUX_REBOOT_CMD_KEXEC.
144	*/
145	void machine_kexec(struct kimage *kimage)
146	{
147	phys_addr_t reboot_code_buffer_phys;
148	void *reboot_code_buffer;
78fd584c AT	149	bool in_kexec_crash = (kimage == kexec_crash_image);
78fd584c AT	150	bool stuck_cpus = cpus_are_stuck_in_kernel();
d28f6df1 GL	151
	152	/*
	153	* New cpus may have become stuck_in_kernel after we loaded the image.
	154	*/
78fd584c AT	155	BUG_ON(!in_kexec_crash && (stuck_cpus \|\| (num_online_cpus() > 1)));
	156	WARN(in_kexec_crash && (stuck_cpus \|\| smp_crash_stop_failed()),
	157	"Some CPUs may be stale, kdump will be unreliable.\n");
d28f6df1 GL	158
	159	reboot_code_buffer_phys = page_to_phys(kimage->control_code_page);
	160	reboot_code_buffer = phys_to_virt(reboot_code_buffer_phys);
	161
221f2c77 GL	162	kexec_image_info(kimage);
	163
	164	pr_debug("%s:%d: control_code_page: %p\n", __func__, __LINE__,
	165	kimage->control_code_page);
	166	pr_debug("%s:%d: reboot_code_buffer_phys: %pa\n", __func__, __LINE__,
	167	&reboot_code_buffer_phys);
	168	pr_debug("%s:%d: reboot_code_buffer: %p\n", __func__, __LINE__,
	169	reboot_code_buffer);
	170	pr_debug("%s:%d: relocate_new_kernel: %p\n", __func__, __LINE__,
	171	arm64_relocate_new_kernel);
	172	pr_debug("%s:%d: relocate_new_kernel_size: 0x%lx(%lu) bytes\n",
	173	__func__, __LINE__, arm64_relocate_new_kernel_size,
	174	arm64_relocate_new_kernel_size);
	175
d28f6df1 GL	176	/*
	177	* Copy arm64_relocate_new_kernel to the reboot_code_buffer for use
	178	* after the kernel is shut down.
	179	*/
	180	memcpy(reboot_code_buffer, arm64_relocate_new_kernel,
	181	arm64_relocate_new_kernel_size);
	182
	183	/* Flush the reboot_code_buffer in preparation for its execution. */
	184	__flush_dcache_area(reboot_code_buffer, arm64_relocate_new_kernel_size);
	185	flush_icache_range((uintptr_t)reboot_code_buffer,
	186	arm64_relocate_new_kernel_size);
	187
	188	/* Flush the kimage list and its buffers. */
	189	kexec_list_flush(kimage);
	190
	191	/* Flush the new image if already in place. */
98d2e153	192	if ((kimage != kexec_crash_image) && (kimage->head & IND_DONE))
d28f6df1 GL	193	kexec_segment_flush(kimage);
	194
	195	pr_info("Bye!\n");
	196
	197	/* Disable all DAIF exceptions. */
	198	asm volatile ("msr daifset, #0xf" : : : "memory");
	199
	200	/*
	201	* cpu_soft_restart will shutdown the MMU, disable data caches, then
	202	* transfer control to the reboot_code_buffer which contains a copy of
	203	* the arm64_relocate_new_kernel routine. arm64_relocate_new_kernel
	204	* uses physical addressing to relocate the new image to its final
	205	* position and transfers control to the image entry point when the
	206	* relocation is complete.
	207	*/
	208
78fd584c AT	209	cpu_soft_restart(kimage != kexec_crash_image,
78fd584c AT	210	reboot_code_buffer_phys, kimage->head, kimage->start, 0);
d28f6df1 GL	211
	212	BUG(); /* Should never get here. */
	213	}
	214
78fd584c AT	215	static void machine_kexec_mask_interrupts(void)
	216	{
	217	unsigned int i;
	218	struct irq_desc *desc;
	219
	220	for_each_irq_desc(i, desc) {
	221	struct irq_chip *chip;
	222	int ret;
	223
	224	chip = irq_desc_get_chip(desc);
	225	if (!chip)
	226	continue;
	227
	228	/*
	229	* First try to remove the active state. If this
	230	* fails, try to EOI the interrupt.
	231	*/
	232	ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
	233
	234	if (ret && irqd_irq_inprogress(&desc->irq_data) &&
	235	chip->irq_eoi)
	236	chip->irq_eoi(&desc->irq_data);
	237
	238	if (chip->irq_mask)
	239	chip->irq_mask(&desc->irq_data);
	240
	241	if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
	242	chip->irq_disable(&desc->irq_data);
	243	}
	244	}
	245
	246	/**
	247	* machine_crash_shutdown - shutdown non-crashing cpus and save registers
	248	*/
d28f6df1 GL	249	void machine_crash_shutdown(struct pt_regs *regs)
d28f6df1 GL	250	{
78fd584c AT	251	local_irq_disable();
	252
	253	/* shutdown non-crashing cpus */
	254	smp_send_crash_stop();
	255
	256	/* for crashing cpu */
	257	crash_save_cpu(regs, smp_processor_id());
	258	machine_kexec_mask_interrupts();
	259
	260	pr_info("Starting crashdump kernel...\n");
d28f6df1	261	}
98d2e153 TA	262
	263	void arch_kexec_protect_crashkres(void)
	264	{
	265	int i;
	266
	267	kexec_segment_flush(kexec_crash_image);
	268
	269	for (i = 0; i < kexec_crash_image->nr_segments; i++)
	270	set_memory_valid(
	271	__phys_to_virt(kexec_crash_image->segment[i].mem),
	272	kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 0);
	273	}
	274
	275	void arch_kexec_unprotect_crashkres(void)
	276	{
	277	int i;
	278
	279	for (i = 0; i < kexec_crash_image->nr_segments; i++)
	280	set_memory_valid(
	281	__phys_to_virt(kexec_crash_image->segment[i].mem),
	282	kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 1);
	283	}
254a41c0 AT	284
	285	#ifdef CONFIG_HIBERNATION
	286	/*
	287	* To preserve the crash dump kernel image, the relevant memory segments
	288	* should be mapped again around the hibernation.
	289	*/
	290	void crash_prepare_suspend(void)
	291	{
	292	if (kexec_crash_image)
	293	arch_kexec_unprotect_crashkres();
	294	}
	295
	296	void crash_post_resume(void)
	297	{
	298	if (kexec_crash_image)
	299	arch_kexec_protect_crashkres();
	300	}
	301
	302	/*
	303	* crash_is_nosave
	304	*
	305	* Return true only if a page is part of reserved memory for crash dump kernel,
	306	* but does not hold any data of loaded kernel image.
	307	*
	308	* Note that all the pages in crash dump kernel memory have been initially
	309	* marked as Reserved in kexec_reserve_crashkres_pages().
	310	*
	311	* In hibernation, the pages which are Reserved and yet "nosave" are excluded
	312	* from the hibernation iamge. crash_is_nosave() does thich check for crash
	313	* dump kernel and will reduce the total size of hibernation image.
	314	*/
	315
	316	bool crash_is_nosave(unsigned long pfn)
	317	{
	318	int i;
	319	phys_addr_t addr;
	320
	321	if (!crashk_res.end)
	322	return false;
	323
	324	/* in reserved memory? */
	325	addr = __pfn_to_phys(pfn);
	326	if ((addr < crashk_res.start) \|\| (crashk_res.end < addr))
	327	return false;
	328
	329	if (!kexec_crash_image)
	330	return true;
	331
	332	/* not part of loaded kernel image? */
	333	for (i = 0; i < kexec_crash_image->nr_segments; i++)
	334	if (addr >= kexec_crash_image->segment[i].mem &&
	335	addr < (kexec_crash_image->segment[i].mem +
	336	kexec_crash_image->segment[i].memsz))
	337	return false;
	338
	339	return true;
	340	}
	341
	342	void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
	343	{
	344	unsigned long addr;
	345	struct page *page;
	346
	347	for (addr = begin; addr < end; addr += PAGE_SIZE) {
348	page = phys_to_page(addr);
349	ClearPageReserved(page);
350	free_reserved_page(page);
351	}
352	}
353	#endif /* CONFIG_HIBERNATION */