linux/kernel/crash_reserve.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * crash.c - kernel crash support code.
 * Copyright (C) 2002-2004 Eric Biederman  <[email protected]>
 */

#include <linux/buildid.h>
#include <linux/init.h>
#include <linux/utsname.h>
#include <linux/vmalloc.h>
#include <linux/sizes.h>
#include <linux/kexec.h>
#include <linux/memory.h>
#include <linux/cpuhotplug.h>
#include <linux/memblock.h>
#include <linux/kmemleak.h>

#include <asm/page.h>
#include <asm/sections.h>

#include <crypto/sha1.h>

#include "kallsyms_internal.h"
#include "kexec_internal.h"

/* Location of the reserved area for the crash kernel */
struct resource crashk_res = …;
struct resource crashk_low_res = …;

/*
 * parsing the "crashkernel" commandline
 *
 * this code is intended to be called from architecture specific code
 */


/*
 * This function parses command lines in the format
 *
 *   crashkernel=ramsize-range:size[,...][@offset]
 *
 * The function returns 0 on success and -EINVAL on failure.
 */
static int __init parse_crashkernel_mem(char *cmdline,
					unsigned long long system_ram,
					unsigned long long *crash_size,
					unsigned long long *crash_base)
{ … }

/*
 * That function parses "simple" (old) crashkernel command lines like
 *
 *	crashkernel=size[@offset]
 *
 * It returns 0 on success and -EINVAL on failure.
 */
static int __init parse_crashkernel_simple(char *cmdline,
					   unsigned long long *crash_size,
					   unsigned long long *crash_base)
{ … }

#define SUFFIX_HIGH …
#define SUFFIX_LOW …
#define SUFFIX_NULL …
static __initdata char *suffix_tbl[] = …;

/*
 * That function parses "suffix"  crashkernel command lines like
 *
 *	crashkernel=size,[high|low]
 *
 * It returns 0 on success and -EINVAL on failure.
 */
static int __init parse_crashkernel_suffix(char *cmdline,
					   unsigned long long *crash_size,
					   const char *suffix)
{ … }

static __init char *get_last_crashkernel(char *cmdline,
			     const char *name,
			     const char *suffix)
{ … }

static int __init __parse_crashkernel(char *cmdline,
			     unsigned long long system_ram,
			     unsigned long long *crash_size,
			     unsigned long long *crash_base,
			     const char *suffix)
{ … }

/*
 * That function is the entry point for command line parsing and should be
 * called from the arch-specific code.
 *
 * If crashkernel=,high|low is supported on architecture, non-NULL values
 * should be passed to parameters 'low_size' and 'high'.
 */
int __init parse_crashkernel(char *cmdline,
			     unsigned long long system_ram,
			     unsigned long long *crash_size,
			     unsigned long long *crash_base,
			     unsigned long long *low_size,
			     bool *high)
{ … }

/*
 * Add a dummy early_param handler to mark crashkernel= as a known command line
 * parameter and suppress incorrect warnings in init/main.c.
 */
static int __init parse_crashkernel_dummy(char *arg)
{ … }
early_param(…);

#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
static int __init reserve_crashkernel_low(unsigned long long low_size)
{ … }

void __init reserve_crashkernel_generic(char *cmdline,
			     unsigned long long crash_size,
			     unsigned long long crash_base,
			     unsigned long long crash_low_size,
			     bool high)
{ … }

#ifndef HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY
static __init int insert_crashkernel_resources(void)
{
	if (crashk_res.start < crashk_res.end)
		insert_resource(&iomem_resource, &crashk_res);

	if (crashk_low_res.start < crashk_low_res.end)
		insert_resource(&iomem_resource, &crashk_low_res);

	return 0;
}
early_initcall(insert_crashkernel_resources);
#endif
#endif