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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * kexec for arm64
 *
 * Copyright (C) Linaro.
 * Copyright (C) Huawei Futurewei Technologies.
 */

#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/daifflags.h>
#include <asm/memory.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);

	/*
	 * Although we've killed off the secondary CPUs, we don't update
	 * the online mask if we're handling a crash kernel and consequently
	 * need to avoid flush_icache_range(), which will attempt to IPI
	 * the offline CPUs. Therefore, we must use the __* variant here.
	 */
	__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");

	local_daif_mask();

	/*
	 * 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.
	 * In kexec case, kimage->start points to purgatory assuming that
	 * kernel entry and dtb address are embedded in purgatory by
	 * userspace (kexec-tools).
	 * In kexec_file case, the kernel starts directly without purgatory.
	 */
	cpu_soft_restart(reboot_code_buffer_phys, kimage->head, kimage->start,
#ifdef CONFIG_KEXEC_FILE
						kimage->arch.dtb_mem);
#else
						0);
#endif

	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 */
	crash_smp_send_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 as memory was allocated via memblock_reserve().
 *
 * 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);
		free_reserved_page(page);
	}
}
#endif /* CONFIG_HIBERNATION */
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
d28f6df1 GL	2	/*
	3	* kexec for arm64
	4	*
	5	* Copyright (C) Linaro.
	6	* Copyright (C) Huawei Futurewei Technologies.
d28f6df1 GL	7	*/
d28f6df1 GL	8
78fd584c AT	9	#include <linux/interrupt.h>
	10	#include <linux/irq.h>
	11	#include <linux/kernel.h>
d28f6df1	12	#include <linux/kexec.h>
254a41c0	13	#include <linux/page-flags.h>
d28f6df1 GL	14	#include <linux/smp.h>
	15
	16	#include <asm/cacheflush.h>
	17	#include <asm/cpu_ops.h>
0fbeb318	18	#include <asm/daifflags.h>
20a16624	19	#include <asm/memory.h>
98d2e153	20	#include <asm/mmu.h>
d28f6df1	21	#include <asm/mmu_context.h>
98d2e153	22	#include <asm/page.h>
d28f6df1 GL	23
	24	#include "cpu-reset.h"
	25
	26	/* Global variables for the arm64_relocate_new_kernel routine. */
	27	extern const unsigned char arm64_relocate_new_kernel[];
	28	extern const unsigned long arm64_relocate_new_kernel_size;
	29
221f2c77 GL	30	/**
	31	* kexec_image_info - For debugging output.
	32	*/
	33	#define kexec_image_info(_i) _kexec_image_info(__func__, __LINE__, _i)
	34	static void _kexec_image_info(const char *func, int line,
	35	const struct kimage *kimage)
	36	{
	37	unsigned long i;
	38
	39	pr_debug("%s:%d:\n", func, line);
	40	pr_debug(" kexec kimage info:\n");
	41	pr_debug(" type: %d\n", kimage->type);
	42	pr_debug(" start: %lx\n", kimage->start);
	43	pr_debug(" head: %lx\n", kimage->head);
	44	pr_debug(" nr_segments: %lu\n", kimage->nr_segments);
	45
	46	for (i = 0; i < kimage->nr_segments; i++) {
	47	pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
	48	i,
	49	kimage->segment[i].mem,
	50	kimage->segment[i].mem + kimage->segment[i].memsz,
	51	kimage->segment[i].memsz,
	52	kimage->segment[i].memsz / PAGE_SIZE);
	53	}
	54	}
	55
d28f6df1 GL	56	void machine_kexec_cleanup(struct kimage *kimage)
	57	{
	58	/* Empty routine needed to avoid build errors. */
	59	}
	60
	61	/**
	62	* machine_kexec_prepare - Prepare for a kexec reboot.
	63	*
	64	* Called from the core kexec code when a kernel image is loaded.
	65	* Forbid loading a kexec kernel if we have no way of hotplugging cpus or cpus
	66	* are stuck in the kernel. This avoids a panic once we hit machine_kexec().
	67	*/
	68	int machine_kexec_prepare(struct kimage *kimage)
	69	{
221f2c77 GL	70	kexec_image_info(kimage);
221f2c77 GL	71
d28f6df1 GL	72	if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) {
	73	pr_err("Can't kexec: CPUs are stuck in the kernel.\n");
	74	return -EBUSY;
	75	}
	76
	77	return 0;
	78	}
	79
	80	/**
	81	* kexec_list_flush - Helper to flush the kimage list and source pages to PoC.
	82	*/
	83	static void kexec_list_flush(struct kimage *kimage)
	84	{
	85	kimage_entry_t *entry;
	86
	87	for (entry = &kimage->head; ; entry++) {
	88	unsigned int flag;
	89	void *addr;
	90
	91	/* flush the list entries. */
	92	__flush_dcache_area(entry, sizeof(kimage_entry_t));
	93
	94	flag = *entry & IND_FLAGS;
	95	if (flag == IND_DONE)
	96	break;
	97
	98	addr = phys_to_virt(*entry & PAGE_MASK);
	99
	100	switch (flag) {
	101	case IND_INDIRECTION:
	102	/* Set entry point just before the new list page. */
	103	entry = (kimage_entry_t *)addr - 1;
	104	break;
	105	case IND_SOURCE:
	106	/* flush the source pages. */
	107	__flush_dcache_area(addr, PAGE_SIZE);
	108	break;
	109	case IND_DESTINATION:
	110	break;
	111	default:
	112	BUG();
	113	}
	114	}
	115	}
	116
	117	/**
	118	* kexec_segment_flush - Helper to flush the kimage segments to PoC.
	119	*/
	120	static void kexec_segment_flush(const struct kimage *kimage)
	121	{
	122	unsigned long i;
	123
	124	pr_debug("%s:\n", __func__);
	125
	126	for (i = 0; i < kimage->nr_segments; i++) {
	127	pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
	128	i,
	129	kimage->segment[i].mem,
	130	kimage->segment[i].mem + kimage->segment[i].memsz,
	131	kimage->segment[i].memsz,
	132	kimage->segment[i].memsz / PAGE_SIZE);
	133
	134	__flush_dcache_area(phys_to_virt(kimage->segment[i].mem),
	135	kimage->segment[i].memsz);
136	}
137	}
138
139	/**
140	* machine_kexec - Do the kexec reboot.
141	*
142	* Called from the core kexec code for a sys_reboot with LINUX_REBOOT_CMD_KEXEC.
143	*/
144	void machine_kexec(struct kimage *kimage)
145	{
146	phys_addr_t reboot_code_buffer_phys;
147	void *reboot_code_buffer;
78fd584c AT	148	bool in_kexec_crash = (kimage == kexec_crash_image);
78fd584c AT	149	bool stuck_cpus = cpus_are_stuck_in_kernel();
d28f6df1 GL	150
	151	/*
	152	* New cpus may have become stuck_in_kernel after we loaded the image.
	153	*/
78fd584c AT	154	BUG_ON(!in_kexec_crash && (stuck_cpus \|\| (num_online_cpus() > 1)));
	155	WARN(in_kexec_crash && (stuck_cpus \|\| smp_crash_stop_failed()),
	156	"Some CPUs may be stale, kdump will be unreliable.\n");
d28f6df1 GL	157
	158	reboot_code_buffer_phys = page_to_phys(kimage->control_code_page);
	159	reboot_code_buffer = phys_to_virt(reboot_code_buffer_phys);
	160
221f2c77 GL	161	kexec_image_info(kimage);
	162
	163	pr_debug("%s:%d: control_code_page: %p\n", __func__, __LINE__,
	164	kimage->control_code_page);
	165	pr_debug("%s:%d: reboot_code_buffer_phys: %pa\n", __func__, __LINE__,
	166	&reboot_code_buffer_phys);
	167	pr_debug("%s:%d: reboot_code_buffer: %p\n", __func__, __LINE__,
	168	reboot_code_buffer);
	169	pr_debug("%s:%d: relocate_new_kernel: %p\n", __func__, __LINE__,
	170	arm64_relocate_new_kernel);
	171	pr_debug("%s:%d: relocate_new_kernel_size: 0x%lx(%lu) bytes\n",
	172	__func__, __LINE__, arm64_relocate_new_kernel_size,
	173	arm64_relocate_new_kernel_size);
	174
d28f6df1 GL	175	/*
	176	* Copy arm64_relocate_new_kernel to the reboot_code_buffer for use
	177	* after the kernel is shut down.
	178	*/
	179	memcpy(reboot_code_buffer, arm64_relocate_new_kernel,
	180	arm64_relocate_new_kernel_size);
	181
	182	/* Flush the reboot_code_buffer in preparation for its execution. */
	183	__flush_dcache_area(reboot_code_buffer, arm64_relocate_new_kernel_size);
dcab90d9 WD	184
	185	/*
	186	* Although we've killed off the secondary CPUs, we don't update
	187	* the online mask if we're handling a crash kernel and consequently
	188	* need to avoid flush_icache_range(), which will attempt to IPI
	189	* the offline CPUs. Therefore, we must use the __* variant here.
	190	*/
140aada4	191	__flush_icache_range((uintptr_t)reboot_code_buffer,
dcab90d9	192	arm64_relocate_new_kernel_size);
d28f6df1 GL	193
	194	/* Flush the kimage list and its buffers. */
	195	kexec_list_flush(kimage);
	196
	197	/* Flush the new image if already in place. */
98d2e153	198	if ((kimage != kexec_crash_image) && (kimage->head & IND_DONE))
d28f6df1 GL	199	kexec_segment_flush(kimage);
	200
	201	pr_info("Bye!\n");
	202
0fbeb318	203	local_daif_mask();
d28f6df1 GL	204
	205	/*
	206	* cpu_soft_restart will shutdown the MMU, disable data caches, then
	207	* transfer control to the reboot_code_buffer which contains a copy of
	208	* the arm64_relocate_new_kernel routine. arm64_relocate_new_kernel
	209	* uses physical addressing to relocate the new image to its final
	210	* position and transfers control to the image entry point when the
	211	* relocation is complete.
4c9e7e64 AT	212	* In kexec case, kimage->start points to purgatory assuming that
	213	* kernel entry and dtb address are embedded in purgatory by
	214	* userspace (kexec-tools).
	215	* In kexec_file case, the kernel starts directly without purgatory.
d28f6df1	216	*/
4c9e7e64 AT	217	cpu_soft_restart(reboot_code_buffer_phys, kimage->head, kimage->start,
	218	#ifdef CONFIG_KEXEC_FILE
	219	kimage->arch.dtb_mem);
	220	#else
	221	0);
	222	#endif
d28f6df1 GL	223
	224	BUG(); /* Should never get here. */
	225	}
	226
78fd584c AT	227	static void machine_kexec_mask_interrupts(void)
	228	{
	229	unsigned int i;
	230	struct irq_desc *desc;
	231
	232	for_each_irq_desc(i, desc) {
	233	struct irq_chip *chip;
	234	int ret;
	235
	236	chip = irq_desc_get_chip(desc);
	237	if (!chip)
	238	continue;
	239
	240	/*
	241	* First try to remove the active state. If this
	242	* fails, try to EOI the interrupt.
	243	*/
	244	ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
	245
	246	if (ret && irqd_irq_inprogress(&desc->irq_data) &&
	247	chip->irq_eoi)
	248	chip->irq_eoi(&desc->irq_data);
	249
	250	if (chip->irq_mask)
	251	chip->irq_mask(&desc->irq_data);
	252
	253	if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
	254	chip->irq_disable(&desc->irq_data);
	255	}
	256	}
	257
	258	/**
	259	* machine_crash_shutdown - shutdown non-crashing cpus and save registers
	260	*/
d28f6df1 GL	261	void machine_crash_shutdown(struct pt_regs *regs)
d28f6df1 GL	262	{
78fd584c AT	263	local_irq_disable();
	264
	265	/* shutdown non-crashing cpus */
a88ce63b	266	crash_smp_send_stop();
78fd584c AT	267
	268	/* for crashing cpu */
	269	crash_save_cpu(regs, smp_processor_id());
	270	machine_kexec_mask_interrupts();
	271
	272	pr_info("Starting crashdump kernel...\n");
d28f6df1	273	}
98d2e153 TA	274
	275	void arch_kexec_protect_crashkres(void)
	276	{
	277	int i;
	278
	279	kexec_segment_flush(kexec_crash_image);
	280
	281	for (i = 0; i < kexec_crash_image->nr_segments; i++)
	282	set_memory_valid(
	283	__phys_to_virt(kexec_crash_image->segment[i].mem),
	284	kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 0);
	285	}
	286
	287	void arch_kexec_unprotect_crashkres(void)
	288	{
	289	int i;
	290
	291	for (i = 0; i < kexec_crash_image->nr_segments; i++)
	292	set_memory_valid(
	293	__phys_to_virt(kexec_crash_image->segment[i].mem),
	294	kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 1);
	295	}
254a41c0 AT	296
	297	#ifdef CONFIG_HIBERNATION
	298	/*
	299	* To preserve the crash dump kernel image, the relevant memory segments
	300	* should be mapped again around the hibernation.
	301	*/
	302	void crash_prepare_suspend(void)
	303	{
	304	if (kexec_crash_image)
	305	arch_kexec_unprotect_crashkres();
	306	}
	307
	308	void crash_post_resume(void)
	309	{
	310	if (kexec_crash_image)
	311	arch_kexec_protect_crashkres();
	312	}
	313
	314	/*
	315	* crash_is_nosave
	316	*
	317	* Return true only if a page is part of reserved memory for crash dump kernel,
	318	* but does not hold any data of loaded kernel image.
	319	*
	320	* Note that all the pages in crash dump kernel memory have been initially
d9fa9d95	321	* marked as Reserved as memory was allocated via memblock_reserve().
254a41c0 AT	322	*
	323	* In hibernation, the pages which are Reserved and yet "nosave" are excluded
	324	* from the hibernation iamge. crash_is_nosave() does thich check for crash
	325	* dump kernel and will reduce the total size of hibernation image.
	326	*/
	327
	328	bool crash_is_nosave(unsigned long pfn)
	329	{
	330	int i;
	331	phys_addr_t addr;
	332
	333	if (!crashk_res.end)
	334	return false;
	335
	336	/* in reserved memory? */
	337	addr = __pfn_to_phys(pfn);
	338	if ((addr < crashk_res.start) \|\| (crashk_res.end < addr))
	339	return false;
	340
	341	if (!kexec_crash_image)
	342	return true;
	343
	344	/* not part of loaded kernel image? */
	345	for (i = 0; i < kexec_crash_image->nr_segments; i++)
	346	if (addr >= kexec_crash_image->segment[i].mem &&
	347	addr < (kexec_crash_image->segment[i].mem +
	348	kexec_crash_image->segment[i].memsz))
	349	return false;
	350
	351	return true;
	352	}
	353
	354	void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
	355	{
	356	unsigned long addr;
	357	struct page *page;
	358
	359	for (addr = begin; addr < end; addr += PAGE_SIZE) {
	360	page = phys_to_page(addr);
254a41c0 AT	361	free_reserved_page(page);
	362	}
	363	}
	364	#endif /* CONFIG_HIBERNATION */