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 <b...@redhat.com>
---
 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 3d2300aca238..96fb363d2f52 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1520,7 +1520,7 @@ 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 b9fc064d38d2..7f704ae5c5ef 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 69d24f513922..7c6869e43a4a 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -767,7 +767,7 @@ 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 502986237cb6..a9243e0948a3 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
 
 config PHYSICAL_START
        hex "Physical address where the kernel is loaded" if (EXPERT || 
CRASH_DUMP)
diff --git a/arch/x86/include/asm/crash_core.h 
b/arch/x86/include/asm/crash_reserve.h
similarity index 92%
rename from arch/x86/include/asm/crash_core.h
rename to arch/x86/include/asm/crash_reserve.h
index 76af98f4e801..152239f95541 100644
--- a/arch/x86/include/asm/crash_core.h
+++ b/arch/x86/include/asm/crash_reserve.h
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _X86_CRASH_CORE_H
-#define _X86_CRASH_CORE_H
+#ifndef _X86_CRASH_RESERVE_H
+#define _X86_CRASH_RESERVE_H
 
 /* 16M alignment for crash kernel regions */
 #define CRASH_ALIGN             SZ_16M
@@ -39,4 +39,4 @@ static inline unsigned long crash_low_size_default(void)
 #endif
 }
 
-#endif /* _X86_CRASH_CORE_H */
+#endif /* _X86_CRASH_RESERVE_H */
diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
index 9eaeaafe0cad..1fde49246fa6 100644
--- a/include/linux/crash_core.h
+++ b/include/linux/crash_core.h
@@ -5,14 +5,6 @@
 #include <linux/linkage.h>
 #include <linux/elfcore.h>
 #include <linux/elf.h>
-#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
-#include <asm/crash_core.h>
-#endif
-
-/* Location of a reserved region to hold the crash kernel.
- */
-extern struct resource crashk_res;
-extern struct resource crashk_low_res;
 
 #define CRASH_CORE_NOTE_NAME      "CORE"
 #define CRASH_CORE_NOTE_HEAD_BYTES ALIGN(sizeof(struct elf_note), 4)
@@ -87,38 +79,6 @@ Elf_Word *append_elf_note(Elf_Word *buf, char *name, 
unsigned int type,
                          void *data, size_t data_len);
 void final_note(Elf_Word *buf);
 
-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);
-
-#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
-#ifndef DEFAULT_CRASH_KERNEL_LOW_SIZE
-#define DEFAULT_CRASH_KERNEL_LOW_SIZE  (128UL << 20)
-#endif
-#ifndef CRASH_ALIGN
-#define CRASH_ALIGN                    SZ_2M
-#endif
-#ifndef CRASH_ADDR_LOW_MAX
-#define CRASH_ADDR_LOW_MAX             SZ_4G
-#endif
-#ifndef CRASH_ADDR_HIGH_MAX
-#define CRASH_ADDR_HIGH_MAX            memblock_end_of_DRAM()
-#endif
-
-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);
-#else
-static inline 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)
-{}
-#endif
-
 /* Alignment required for elf header segment */
 #define ELF_CORE_HEADER_ALIGN   4096
 
diff --git a/include/linux/crash_reserve.h b/include/linux/crash_reserve.h
new file mode 100644
index 000000000000..5a9df944fb80
--- /dev/null
+++ b/include/linux/crash_reserve.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef LINUX_CRASH_RESERVE_H
+#define LINUX_CRASH_RESERVE_H
+
+#include <linux/linkage.h>
+#include <linux/elfcore.h>
+#include <linux/elf.h>
+#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
+#include <asm/crash_reserve.h>
+#endif
+
+/* Location of a reserved region to hold the crash kernel.
+ */
+extern struct resource crashk_res;
+extern struct resource crashk_low_res;
+
+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);
+
+#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
+#ifndef DEFAULT_CRASH_KERNEL_LOW_SIZE
+#define DEFAULT_CRASH_KERNEL_LOW_SIZE  (128UL << 20)
+#endif
+#ifndef CRASH_ALIGN
+#define CRASH_ALIGN                    SZ_2M
+#endif
+#ifndef CRASH_ADDR_LOW_MAX
+#define CRASH_ADDR_LOW_MAX             SZ_4G
+#endif
+#ifndef CRASH_ADDR_HIGH_MAX
+#define CRASH_ADDR_HIGH_MAX            memblock_end_of_DRAM()
+#endif
+
+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);
+#else
+static inline 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)
+{}
+#endif
+#endif /* LINUX_CRASH_RESERVE_H */
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 400cb6c02176..6d79bfb52e5b 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -16,6 +16,7 @@
 #if !defined(__ASSEMBLY__)
 
 #include <linux/crash_core.h>
+#include <linux/crash_reserve.h>
 #include <asm/io.h>
 #include <linux/range.h>
 
diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec
index 946dffa048b7..8b7be71edd85 100644
--- a/kernel/Kconfig.kexec
+++ b/kernel/Kconfig.kexec
@@ -2,11 +2,15 @@
 
 menu "Kexec and crash features"
 
+config CRASH_RESERVE
+       bool
+
 config CRASH_CORE
        bool
 
 config KEXEC_CORE
        select CRASH_CORE
+       select CRASH_RESERVE
        bool
 
 config KEXEC_ELF
@@ -96,7 +100,6 @@ config KEXEC_JUMP
 config CRASH_DUMP
        bool "kernel crash dumps"
        depends on ARCH_SUPPORTS_CRASH_DUMP
-       select CRASH_CORE
        select KEXEC_CORE
        help
          Generate crash dump after being started by kexec.
diff --git a/kernel/Makefile b/kernel/Makefile
index ce105a5558fc..05fa88b3ab74 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_KALLSYMS) += kallsyms.o
 obj-$(CONFIG_KALLSYMS_SELFTEST) += kallsyms_selftest.o
 obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
 obj-$(CONFIG_CRASH_CORE) += crash_core.o
+obj-$(CONFIG_CRASH_RESERVE) += crash_reserve.o
 obj-$(CONFIG_KEXEC_CORE) += kexec_core.o
 obj-$(CONFIG_KEXEC) += kexec.o
 obj-$(CONFIG_KEXEC_FILE) += kexec_file.o
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 49b31e59d3cc..ae0d1ce89b46 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -34,444 +34,6 @@ u32 *vmcoreinfo_note;
 /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
 static unsigned char *vmcoreinfo_data_safecopy;
 
-/* Location of the reserved area for the crash kernel */
-struct resource crashk_res = {
-       .name  = "Crash kernel",
-       .start = 0,
-       .end   = 0,
-       .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
-       .desc  = IORES_DESC_CRASH_KERNEL
-};
-struct resource crashk_low_res = {
-       .name  = "Crash kernel",
-       .start = 0,
-       .end   = 0,
-       .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
-       .desc  = IORES_DESC_CRASH_KERNEL
-};
-
-/*
- * 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)
-{
-       char *cur = cmdline, *tmp;
-       unsigned long long total_mem = system_ram;
-
-       /*
-        * Firmware sometimes reserves some memory regions for its own use,
-        * so the system memory size is less than the actual physical memory
-        * size. Work around this by rounding up the total size to 128M,
-        * which is enough for most test cases.
-        */
-       total_mem = roundup(total_mem, SZ_128M);
-
-       /* for each entry of the comma-separated list */
-       do {
-               unsigned long long start, end = ULLONG_MAX, size;
-
-               /* get the start of the range */
-               start = memparse(cur, &tmp);
-               if (cur == tmp) {
-                       pr_warn("crashkernel: Memory value expected\n");
-                       return -EINVAL;
-               }
-               cur = tmp;
-               if (*cur != '-') {
-                       pr_warn("crashkernel: '-' expected\n");
-                       return -EINVAL;
-               }
-               cur++;
-
-               /* if no ':' is here, than we read the end */
-               if (*cur != ':') {
-                       end = memparse(cur, &tmp);
-                       if (cur == tmp) {
-                               pr_warn("crashkernel: Memory value expected\n");
-                               return -EINVAL;
-                       }
-                       cur = tmp;
-                       if (end <= start) {
-                               pr_warn("crashkernel: end <= start\n");
-                               return -EINVAL;
-                       }
-               }
-
-               if (*cur != ':') {
-                       pr_warn("crashkernel: ':' expected\n");
-                       return -EINVAL;
-               }
-               cur++;
-
-               size = memparse(cur, &tmp);
-               if (cur == tmp) {
-                       pr_warn("Memory value expected\n");
-                       return -EINVAL;
-               }
-               cur = tmp;
-               if (size >= total_mem) {
-                       pr_warn("crashkernel: invalid size\n");
-                       return -EINVAL;
-               }
-
-               /* match ? */
-               if (total_mem >= start && total_mem < end) {
-                       *crash_size = size;
-                       break;
-               }
-       } while (*cur++ == ',');
-
-       if (*crash_size > 0) {
-               while (*cur && *cur != ' ' && *cur != '@')
-                       cur++;
-               if (*cur == '@') {
-                       cur++;
-                       *crash_base = memparse(cur, &tmp);
-                       if (cur == tmp) {
-                               pr_warn("Memory value expected after '@'\n");
-                               return -EINVAL;
-                       }
-               }
-       } else
-               pr_info("crashkernel size resulted in zero bytes\n");
-
-       return 0;
-}
-
-/*
- * 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)
-{
-       char *cur = cmdline;
-
-       *crash_size = memparse(cmdline, &cur);
-       if (cmdline == cur) {
-               pr_warn("crashkernel: memory value expected\n");
-               return -EINVAL;
-       }
-
-       if (*cur == '@')
-               *crash_base = memparse(cur+1, &cur);
-       else if (*cur != ' ' && *cur != '\0') {
-               pr_warn("crashkernel: unrecognized char: %c\n", *cur);
-               return -EINVAL;
-       }
-
-       return 0;
-}
-
-#define SUFFIX_HIGH 0
-#define SUFFIX_LOW  1
-#define SUFFIX_NULL 2
-static __initdata char *suffix_tbl[] = {
-       [SUFFIX_HIGH] = ",high",
-       [SUFFIX_LOW]  = ",low",
-       [SUFFIX_NULL] = NULL,
-};
-
-/*
- * 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)
-{
-       char *cur = cmdline;
-
-       *crash_size = memparse(cmdline, &cur);
-       if (cmdline == cur) {
-               pr_warn("crashkernel: memory value expected\n");
-               return -EINVAL;
-       }
-
-       /* check with suffix */
-       if (strncmp(cur, suffix, strlen(suffix))) {
-               pr_warn("crashkernel: unrecognized char: %c\n", *cur);
-               return -EINVAL;
-       }
-       cur += strlen(suffix);
-       if (*cur != ' ' && *cur != '\0') {
-               pr_warn("crashkernel: unrecognized char: %c\n", *cur);
-               return -EINVAL;
-       }
-
-       return 0;
-}
-
-static __init char *get_last_crashkernel(char *cmdline,
-                            const char *name,
-                            const char *suffix)
-{
-       char *p = cmdline, *ck_cmdline = NULL;
-
-       /* find crashkernel and use the last one if there are more */
-       p = strstr(p, name);
-       while (p) {
-               char *end_p = strchr(p, ' ');
-               char *q;
-
-               if (!end_p)
-                       end_p = p + strlen(p);
-
-               if (!suffix) {
-                       int i;
-
-                       /* skip the one with any known suffix */
-                       for (i = 0; suffix_tbl[i]; i++) {
-                               q = end_p - strlen(suffix_tbl[i]);
-                               if (!strncmp(q, suffix_tbl[i],
-                                            strlen(suffix_tbl[i])))
-                                       goto next;
-                       }
-                       ck_cmdline = p;
-               } else {
-                       q = end_p - strlen(suffix);
-                       if (!strncmp(q, suffix, strlen(suffix)))
-                               ck_cmdline = p;
-               }
-next:
-               p = strstr(p+1, name);
-       }
-
-       return ck_cmdline;
-}
-
-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)
-{
-       char *first_colon, *first_space;
-       char *ck_cmdline;
-       char *name = "crashkernel=";
-
-       BUG_ON(!crash_size || !crash_base);
-       *crash_size = 0;
-       *crash_base = 0;
-
-       ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
-       if (!ck_cmdline)
-               return -ENOENT;
-
-       ck_cmdline += strlen(name);
-
-       if (suffix)
-               return parse_crashkernel_suffix(ck_cmdline, crash_size,
-                               suffix);
-       /*
-        * if the commandline contains a ':', then that's the extended
-        * syntax -- if not, it must be the classic syntax
-        */
-       first_colon = strchr(ck_cmdline, ':');
-       first_space = strchr(ck_cmdline, ' ');
-       if (first_colon && (!first_space || first_colon < first_space))
-               return parse_crashkernel_mem(ck_cmdline, system_ram,
-                               crash_size, crash_base);
-
-       return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
-}
-
-/*
- * 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)
-{
-       int ret;
-
-       /* crashkernel=X[@offset] */
-       ret = __parse_crashkernel(cmdline, system_ram, crash_size,
-                               crash_base, NULL);
-#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
-       /*
-        * If non-NULL 'high' passed in and no normal crashkernel
-        * setting detected, try parsing crashkernel=,high|low.
-        */
-       if (high && ret == -ENOENT) {
-               ret = __parse_crashkernel(cmdline, 0, crash_size,
-                               crash_base, suffix_tbl[SUFFIX_HIGH]);
-               if (ret || !*crash_size)
-                       return -EINVAL;
-
-               /*
-                * crashkernel=Y,low can be specified or not, but invalid value
-                * is not allowed.
-                */
-               ret = __parse_crashkernel(cmdline, 0, low_size,
-                               crash_base, suffix_tbl[SUFFIX_LOW]);
-               if (ret == -ENOENT) {
-                       *low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
-                       ret = 0;
-               } else if (ret) {
-                       return ret;
-               }
-
-               *high = true;
-       }
-#endif
-       if (!*crash_size)
-               ret = -EINVAL;
-
-       return ret;
-}
-
-/*
- * 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)
-{
-       return 0;
-}
-early_param("crashkernel", parse_crashkernel_dummy);
-
-#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
-static int __init reserve_crashkernel_low(unsigned long long low_size)
-{
-#ifdef CONFIG_64BIT
-       unsigned long long low_base;
-
-       low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, 
CRASH_ADDR_LOW_MAX);
-       if (!low_base) {
-               pr_err("cannot allocate crashkernel low memory 
(size:0x%llx).\n", low_size);
-               return -ENOMEM;
-       }
-
-       pr_info("crashkernel low memory reserved: 0x%08llx - 0x%08llx (%lld 
MB)\n",
-               low_base, low_base + low_size, low_size >> 20);
-
-       crashk_low_res.start = low_base;
-       crashk_low_res.end   = low_base + low_size - 1;
-#endif
-       return 0;
-}
-
-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)
-{
-       unsigned long long search_end = CRASH_ADDR_LOW_MAX, search_base = 0;
-       bool fixed_base = false;
-
-       /* User specifies base address explicitly. */
-       if (crash_base) {
-               fixed_base = true;
-               search_base = crash_base;
-               search_end = crash_base + crash_size;
-       } else if (high) {
-               search_base = CRASH_ADDR_LOW_MAX;
-               search_end = CRASH_ADDR_HIGH_MAX;
-       }
-
-retry:
-       crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
-                                              search_base, search_end);
-       if (!crash_base) {
-               /*
-                * For crashkernel=size[KMG]@offset[KMG], print out failure
-                * message if can't reserve the specified region.
-                */
-               if (fixed_base) {
-                       pr_warn("crashkernel reservation failed - memory is in 
use.\n");
-                       return;
-               }
-
-               /*
-                * For crashkernel=size[KMG], if the first attempt was for
-                * low memory, fall back to high memory, the minimum required
-                * low memory will be reserved later.
-                */
-               if (!high && search_end == CRASH_ADDR_LOW_MAX) {
-                       search_end = CRASH_ADDR_HIGH_MAX;
-                       search_base = CRASH_ADDR_LOW_MAX;
-                       crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
-                       goto retry;
-               }
-
-               /*
-                * For crashkernel=size[KMG],high, if the first attempt was
-                * for high memory, fall back to low memory.
-                */
-               if (high && search_end == CRASH_ADDR_HIGH_MAX) {
-                       search_end = CRASH_ADDR_LOW_MAX;
-                       search_base = 0;
-                       goto retry;
-               }
-               pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
-                       crash_size);
-               return;
-       }
-
-       if ((crash_base >= CRASH_ADDR_LOW_MAX) &&
-            crash_low_size && reserve_crashkernel_low(crash_low_size)) {
-               memblock_phys_free(crash_base, crash_size);
-               return;
-       }
-
-       pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
-               crash_base, crash_base + crash_size, crash_size >> 20);
-
-       /*
-        * The crashkernel memory will be removed from the kernel linear
-        * map. Inform kmemleak so that it won't try to access it.
-        */
-       kmemleak_ignore_phys(crash_base);
-       if (crashk_low_res.end)
-               kmemleak_ignore_phys(crashk_low_res.start);
-
-       crashk_res.start = crash_base;
-       crashk_res.end = crash_base + crash_size - 1;
-}
-
-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
-
 int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
                          void **addr, unsigned long *sz)
 {
diff --git a/kernel/crash_reserve.c b/kernel/crash_reserve.c
new file mode 100644
index 000000000000..bbb6c3cb00e4
--- /dev/null
+++ b/kernel/crash_reserve.c
@@ -0,0 +1,464 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * crash.c - kernel crash support code.
+ * Copyright (C) 2002-2004 Eric Biederman  <ebied...@xmission.com>
+ */
+
+#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/kexec.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 = {
+       .name  = "Crash kernel",
+       .start = 0,
+       .end   = 0,
+       .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
+       .desc  = IORES_DESC_CRASH_KERNEL
+};
+struct resource crashk_low_res = {
+       .name  = "Crash kernel",
+       .start = 0,
+       .end   = 0,
+       .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
+       .desc  = IORES_DESC_CRASH_KERNEL
+};
+
+/*
+ * 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)
+{
+       char *cur = cmdline, *tmp;
+       unsigned long long total_mem = system_ram;
+
+       /*
+        * Firmware sometimes reserves some memory regions for its own use,
+        * so the system memory size is less than the actual physical memory
+        * size. Work around this by rounding up the total size to 128M,
+        * which is enough for most test cases.
+        */
+       total_mem = roundup(total_mem, SZ_128M);
+
+       /* for each entry of the comma-separated list */
+       do {
+               unsigned long long start, end = ULLONG_MAX, size;
+
+               /* get the start of the range */
+               start = memparse(cur, &tmp);
+               if (cur == tmp) {
+                       pr_warn("crashkernel: Memory value expected\n");
+                       return -EINVAL;
+               }
+               cur = tmp;
+               if (*cur != '-') {
+                       pr_warn("crashkernel: '-' expected\n");
+                       return -EINVAL;
+               }
+               cur++;
+
+               /* if no ':' is here, than we read the end */
+               if (*cur != ':') {
+                       end = memparse(cur, &tmp);
+                       if (cur == tmp) {
+                               pr_warn("crashkernel: Memory value expected\n");
+                               return -EINVAL;
+                       }
+                       cur = tmp;
+                       if (end <= start) {
+                               pr_warn("crashkernel: end <= start\n");
+                               return -EINVAL;
+                       }
+               }
+
+               if (*cur != ':') {
+                       pr_warn("crashkernel: ':' expected\n");
+                       return -EINVAL;
+               }
+               cur++;
+
+               size = memparse(cur, &tmp);
+               if (cur == tmp) {
+                       pr_warn("Memory value expected\n");
+                       return -EINVAL;
+               }
+               cur = tmp;
+               if (size >= total_mem) {
+                       pr_warn("crashkernel: invalid size\n");
+                       return -EINVAL;
+               }
+
+               /* match ? */
+               if (total_mem >= start && total_mem < end) {
+                       *crash_size = size;
+                       break;
+               }
+       } while (*cur++ == ',');
+
+       if (*crash_size > 0) {
+               while (*cur && *cur != ' ' && *cur != '@')
+                       cur++;
+               if (*cur == '@') {
+                       cur++;
+                       *crash_base = memparse(cur, &tmp);
+                       if (cur == tmp) {
+                               pr_warn("Memory value expected after '@'\n");
+                               return -EINVAL;
+                       }
+               }
+       } else
+               pr_info("crashkernel size resulted in zero bytes\n");
+
+       return 0;
+}
+
+/*
+ * 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)
+{
+       char *cur = cmdline;
+
+       *crash_size = memparse(cmdline, &cur);
+       if (cmdline == cur) {
+               pr_warn("crashkernel: memory value expected\n");
+               return -EINVAL;
+       }
+
+       if (*cur == '@')
+               *crash_base = memparse(cur+1, &cur);
+       else if (*cur != ' ' && *cur != '\0') {
+               pr_warn("crashkernel: unrecognized char: %c\n", *cur);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+#define SUFFIX_HIGH 0
+#define SUFFIX_LOW  1
+#define SUFFIX_NULL 2
+static __initdata char *suffix_tbl[] = {
+       [SUFFIX_HIGH] = ",high",
+       [SUFFIX_LOW]  = ",low",
+       [SUFFIX_NULL] = NULL,
+};
+
+/*
+ * 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)
+{
+       char *cur = cmdline;
+
+       *crash_size = memparse(cmdline, &cur);
+       if (cmdline == cur) {
+               pr_warn("crashkernel: memory value expected\n");
+               return -EINVAL;
+       }
+
+       /* check with suffix */
+       if (strncmp(cur, suffix, strlen(suffix))) {
+               pr_warn("crashkernel: unrecognized char: %c\n", *cur);
+               return -EINVAL;
+       }
+       cur += strlen(suffix);
+       if (*cur != ' ' && *cur != '\0') {
+               pr_warn("crashkernel: unrecognized char: %c\n", *cur);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static __init char *get_last_crashkernel(char *cmdline,
+                            const char *name,
+                            const char *suffix)
+{
+       char *p = cmdline, *ck_cmdline = NULL;
+
+       /* find crashkernel and use the last one if there are more */
+       p = strstr(p, name);
+       while (p) {
+               char *end_p = strchr(p, ' ');
+               char *q;
+
+               if (!end_p)
+                       end_p = p + strlen(p);
+
+               if (!suffix) {
+                       int i;
+
+                       /* skip the one with any known suffix */
+                       for (i = 0; suffix_tbl[i]; i++) {
+                               q = end_p - strlen(suffix_tbl[i]);
+                               if (!strncmp(q, suffix_tbl[i],
+                                            strlen(suffix_tbl[i])))
+                                       goto next;
+                       }
+                       ck_cmdline = p;
+               } else {
+                       q = end_p - strlen(suffix);
+                       if (!strncmp(q, suffix, strlen(suffix)))
+                               ck_cmdline = p;
+               }
+next:
+               p = strstr(p+1, name);
+       }
+
+       return ck_cmdline;
+}
+
+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)
+{
+       char *first_colon, *first_space;
+       char *ck_cmdline;
+       char *name = "crashkernel=";
+
+       BUG_ON(!crash_size || !crash_base);
+       *crash_size = 0;
+       *crash_base = 0;
+
+       ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
+       if (!ck_cmdline)
+               return -ENOENT;
+
+       ck_cmdline += strlen(name);
+
+       if (suffix)
+               return parse_crashkernel_suffix(ck_cmdline, crash_size,
+                               suffix);
+       /*
+        * if the commandline contains a ':', then that's the extended
+        * syntax -- if not, it must be the classic syntax
+        */
+       first_colon = strchr(ck_cmdline, ':');
+       first_space = strchr(ck_cmdline, ' ');
+       if (first_colon && (!first_space || first_colon < first_space))
+               return parse_crashkernel_mem(ck_cmdline, system_ram,
+                               crash_size, crash_base);
+
+       return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
+}
+
+/*
+ * 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)
+{
+       int ret;
+
+       /* crashkernel=X[@offset] */
+       ret = __parse_crashkernel(cmdline, system_ram, crash_size,
+                               crash_base, NULL);
+#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
+       /*
+        * If non-NULL 'high' passed in and no normal crashkernel
+        * setting detected, try parsing crashkernel=,high|low.
+        */
+       if (high && ret == -ENOENT) {
+               ret = __parse_crashkernel(cmdline, 0, crash_size,
+                               crash_base, suffix_tbl[SUFFIX_HIGH]);
+               if (ret || !*crash_size)
+                       return -EINVAL;
+
+               /*
+                * crashkernel=Y,low can be specified or not, but invalid value
+                * is not allowed.
+                */
+               ret = __parse_crashkernel(cmdline, 0, low_size,
+                               crash_base, suffix_tbl[SUFFIX_LOW]);
+               if (ret == -ENOENT) {
+                       *low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
+                       ret = 0;
+               } else if (ret) {
+                       return ret;
+               }
+
+               *high = true;
+       }
+#endif
+       if (!*crash_size)
+               ret = -EINVAL;
+
+       return ret;
+}
+
+/*
+ * 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)
+{
+       return 0;
+}
+early_param("crashkernel", parse_crashkernel_dummy);
+
+#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
+static int __init reserve_crashkernel_low(unsigned long long low_size)
+{
+#ifdef CONFIG_64BIT
+       unsigned long long low_base;
+
+       low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, 
CRASH_ADDR_LOW_MAX);
+       if (!low_base) {
+               pr_err("cannot allocate crashkernel low memory 
(size:0x%llx).\n", low_size);
+               return -ENOMEM;
+       }
+
+       pr_info("crashkernel low memory reserved: 0x%08llx - 0x%08llx (%lld 
MB)\n",
+               low_base, low_base + low_size, low_size >> 20);
+
+       crashk_low_res.start = low_base;
+       crashk_low_res.end   = low_base + low_size - 1;
+       insert_resource(&iomem_resource, &crashk_low_res);
+#endif
+       return 0;
+}
+
+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)
+{
+       unsigned long long search_end = CRASH_ADDR_LOW_MAX, search_base = 0;
+       bool fixed_base = false;
+
+       /* User specifies base address explicitly. */
+       if (crash_base) {
+               fixed_base = true;
+               search_base = crash_base;
+               search_end = crash_base + crash_size;
+       } else if (high) {
+               search_base = CRASH_ADDR_LOW_MAX;
+               search_end = CRASH_ADDR_HIGH_MAX;
+       }
+
+retry:
+       crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
+                                              search_base, search_end);
+       if (!crash_base) {
+               /*
+                * For crashkernel=size[KMG]@offset[KMG], print out failure
+                * message if can't reserve the specified region.
+                */
+               if (fixed_base) {
+                       pr_warn("crashkernel reservation failed - memory is in 
use.\n");
+                       return;
+               }
+
+               /*
+                * For crashkernel=size[KMG], if the first attempt was for
+                * low memory, fall back to high memory, the minimum required
+                * low memory will be reserved later.
+                */
+               if (!high && search_end == CRASH_ADDR_LOW_MAX) {
+                       search_end = CRASH_ADDR_HIGH_MAX;
+                       search_base = CRASH_ADDR_LOW_MAX;
+                       crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
+                       goto retry;
+               }
+
+               /*
+                * For crashkernel=size[KMG],high, if the first attempt was
+                * for high memory, fall back to low memory.
+                */
+               if (high && search_end == CRASH_ADDR_HIGH_MAX) {
+                       search_end = CRASH_ADDR_LOW_MAX;
+                       search_base = 0;
+                       goto retry;
+               }
+               pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
+                       crash_size);
+               return;
+       }
+
+       if ((crash_base >= CRASH_ADDR_LOW_MAX) &&
+            crash_low_size && reserve_crashkernel_low(crash_low_size)) {
+               memblock_phys_free(crash_base, crash_size);
+               return;
+       }
+
+       pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
+               crash_base, crash_base + crash_size, crash_size >> 20);
+
+       /*
+        * The crashkernel memory will be removed from the kernel linear
+        * map. Inform kmemleak so that it won't try to access it.
+        */
+       kmemleak_ignore_phys(crash_base);
+       if (crashk_low_res.end)
+               kmemleak_ignore_phys(crashk_low_res.start);
+
+       crashk_res.start = crash_base;
+       crashk_res.end = crash_base + crash_size - 1;
+}
+
+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
-- 
2.41.0

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