Both kdump and fa_dump of ppc rely on crashkernel reservation. Move the
relevant codes into separate files:
crash_reserve.c, include/linux/crash_reserve.h.

And also add config item CRASH_RESERVE to control its enabling of the
codes. And update config items which has relationship with crashkernel
reservation.

And also change ifdeffery from CONFIG_CRASH_CORE to CONFIG_CRASH_RESERVE
when those scopes are only crashkernel reservation related.

And also rename arch/XXX/include/asm/{crash_core.h => crash_reserve.h}
on arm64, x86 and risc-v because those architectures' crash_core.h
is only related to crashkernel reservation.

Signed-off-by: Baoquan He <redacted>
---
  arch/arm64/Kconfig                            |   2 +-
  .../asm/{crash_core.h => crash_reserve.h}     |   4 +-
  arch/powerpc/Kconfig                          |   1 +
  arch/powerpc/mm/nohash/kaslr_booke.c          |   4 +-
  arch/riscv/Kconfig                            |   2 +-
  .../asm/{crash_core.h => crash_reserve.h}     |   4 +-
  arch/x86/Kconfig                              |   2 +-
  .../asm/{crash_core.h => crash_reserve.h}     |   6 +-
  include/linux/crash_core.h                    |  40 --
  include/linux/crash_reserve.h                 |  48 ++
  include/linux/kexec.h                         |   1 +
  kernel/Kconfig.kexec                          |   5 +-
  kernel/Makefile                               |   1 +
  kernel/crash_core.c                           | 438 -----------------
  kernel/crash_reserve.c                        | 464 ++++++++++++++++++
  15 files changed, 531 insertions(+), 491 deletions(-)
  rename arch/arm64/include/asm/{crash_core.h => crash_reserve.h} (81%)
  rename arch/riscv/include/asm/{crash_core.h => crash_reserve.h} (78%)
  rename arch/x86/include/asm/{crash_core.h => crash_reserve.h} (92%)
  create mode 100644 include/linux/crash_reserve.h
  create mode 100644 kernel/crash_reserve.c

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index ea01a2c43efa..d96bc3c67ec6 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig

@@ -1501,7 +1501,7 @@ config ARCH_SUPPORTS_CRASH_DUMP
  	def_bool y
  
  config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
-	def_bool CRASH_CORE
+	def_bool CRASH_RESERVE
  
  config TRANS_TABLE
  	def_bool y

diff --git a/arch/arm64/include/asm/crash_core.h b/arch/arm64/include/asm/crash_reserve.h
similarity index 81%
rename from arch/arm64/include/asm/crash_core.h
rename to arch/arm64/include/asm/crash_reserve.h
index 9f5c8d339f44..4afe027a4e7b 100644
--- a/arch/arm64/include/asm/crash_core.h
+++ b/arch/arm64/include/asm/crash_reserve.h

@@ -1,6 +1,6 @@
  /* SPDX-License-Identifier: GPL-2.0-only */
-#ifndef _ARM64_CRASH_CORE_H
-#define _ARM64_CRASH_CORE_H
+#ifndef _ARM64_CRASH_RESERVE_H
+#define _ARM64_CRASH_RESERVE_H
  
  /* Current arm64 boot protocol requires 2MB alignment */
  #define CRASH_ALIGN                     SZ_2M

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 414b978b8010..6aeab95f0edd 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig

@@ -691,6 +691,7 @@ config FA_DUMP
  	bool "Firmware-assisted dump"
  	depends on PPC64 && (PPC_RTAS || PPC_POWERNV)
  	select CRASH_CORE
+	select CRASH_RESERVE
  	select CRASH_DUMP
  	help
  	  A robust mechanism to get reliable kernel crash dump with

diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c
index b4f2786a7d2b..cdff129abb14 100644
--- a/arch/powerpc/mm/nohash/kaslr_booke.c
+++ b/arch/powerpc/mm/nohash/kaslr_booke.c

@@ -13,7 +13,7 @@
  #include <linux/delay.h>
  #include <linux/memblock.h>
  #include <linux/libfdt.h>
-#include <linux/crash_core.h>
+#include <linux/crash_reserve.h>
  #include <linux/of.h>
  #include <linux/of_fdt.h>
  #include <asm/cacheflush.h>

@@ -173,7 +173,7 @@ static __init bool overlaps_region(const void *fdt, u32 start,
  
  static void __init get_crash_kernel(void *fdt, unsigned long size)
  {
-#ifdef CONFIG_CRASH_CORE
+#ifdef CONFIG_CRASH_RESERVE
  	unsigned long long crash_size, crash_base;
  	int ret;
  

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index b549499eb363..37a438c23deb 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig

@@ -712,7 +712,7 @@ config ARCH_SUPPORTS_CRASH_DUMP
  	def_bool y
  
  config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
-	def_bool CRASH_CORE
+	def_bool CRASH_RESERVE
  
  config COMPAT
  	bool "Kernel support for 32-bit U-mode"

diff --git a/arch/riscv/include/asm/crash_core.h b/arch/riscv/include/asm/crash_reserve.h
similarity index 78%
rename from arch/riscv/include/asm/crash_core.h
rename to arch/riscv/include/asm/crash_reserve.h
index e1874b23feaf..013962e63587 100644
--- a/arch/riscv/include/asm/crash_core.h
+++ b/arch/riscv/include/asm/crash_reserve.h

@@ -1,6 +1,6 @@
  /* SPDX-License-Identifier: GPL-2.0-only */
-#ifndef _RISCV_CRASH_CORE_H
-#define _RISCV_CRASH_CORE_H
+#ifndef _RISCV_CRASH_RESERVE_H
+#define _RISCV_CRASH_RESERVE_H
  
  #define CRASH_ALIGN			PMD_SIZE
  

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5edec175b9bf..71417c5b228c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig

@@ -2106,7 +2106,7 @@ config ARCH_SUPPORTS_CRASH_HOTPLUG
  	def_bool y
  
  config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
-	def_bool CRASH_CORE
+	def_bool CRASH_RESEERVE