crash: split crash dumping code out from kexec_core.c

Currently, KEXEC_CORE select CRASH_CORE automatically because crash codes
need be built in to avoid compiling error when building kexec code even
though the crash dumping functionality is not enabled. E.g
--------------------
CONFIG_CRASH_CORE=y
CONFIG_KEXEC_CORE=y
CONFIG_KEXEC=y
CONFIG_KEXEC_FILE=y
---------------------

After splitting out crashkernel reservation code and vmcoreinfo exporting
code, there's only crash related code left in kernel/crash_core.c. Now
move crash related codes from kexec_core.c to crash_core.c and only build it
in when CONFIG_CRASH_DUMP=y.

And also wrap up crash codes inside CONFIG_CRASH_DUMP ifdeffery scope,
or replace inappropriate CONFIG_KEXEC_CORE ifdef with CONFIG_CRASH_DUMP
ifdef in generic kernel files.

With these changes, crash_core codes are abstracted from kexec codes and
can be disabled at all if only kexec reboot feature is wanted.

Link: https://lkml.kernel.org/r/20240124051254.67105-5-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Pingfan Liu <piliu@redhat.com>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Michael Kelley <mhklinux@outlook.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 1 insertions, 44 deletions

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 9c7bb8b56ed6..060835bb82d5 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -15,7 +15,6 @@
 
 #if !defined(__ASSEMBLY__)
 
-#include <linux/crash_core.h>
 #include <linux/vmcore_info.h>
 #include <linux/crash_reserve.h>
 #include <asm/io.h>
@@ -33,6 +32,7 @@ extern note_buf_t __percpu *crash_notes;
 #include <linux/module.h>
 #include <linux/highmem.h>
 #include <asm/kexec.h>
+#include <linux/crash_core.h>
 
 /* Verify architecture specific macros are defined */
 
@@ -380,13 +380,6 @@ extern struct page *kimage_alloc_control_pages(struct kimage *image,
 static inline int machine_kexec_post_load(struct kimage *image) { return 0; }
 #endif
 
-extern void __crash_kexec(struct pt_regs *);
-extern void crash_kexec(struct pt_regs *);
-int kexec_should_crash(struct task_struct *);
-int kexec_crash_loaded(void);
-void crash_save_cpu(struct pt_regs *regs, int cpu);
-extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
-
 extern struct kimage *kexec_image;
 extern struct kimage *kexec_crash_image;
 
@@ -410,24 +403,6 @@ bool kexec_load_permitted(int kexec_image_type);
 /* flag to track if kexec reboot is in progress */
 extern bool kexec_in_progress;
 
-int crash_shrink_memory(unsigned long new_size);
-ssize_t crash_get_memory_size(void);
-
-#ifndef arch_kexec_protect_crashkres
-/*
- * Protection mechanism for crashkernel reserved memory after
- * the kdump kernel is loaded.
- *
- * Provide an empty default implementation here -- architecture
- * code may override this
- */
-static inline void arch_kexec_protect_crashkres(void) { }
-#endif
-
-#ifndef arch_kexec_unprotect_crashkres
-static inline void arch_kexec_unprotect_crashkres(void) { }
-#endif
-
 #ifndef page_to_boot_pfn
 static inline unsigned long page_to_boot_pfn(struct page *page)
 {
@@ -484,24 +459,6 @@ static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, g
 static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
 #endif
 
-#ifndef arch_crash_handle_hotplug_event
-static inline void arch_crash_handle_hotplug_event(struct kimage *image) { }
-#endif
-
-int crash_check_update_elfcorehdr(void);
-
-#ifndef crash_hotplug_cpu_support
-static inline int crash_hotplug_cpu_support(void) { return 0; }
-#endif
-
-#ifndef crash_hotplug_memory_support
-static inline int crash_hotplug_memory_support(void) { return 0; }
-#endif
-
-#ifndef crash_get_elfcorehdr_size
-static inline unsigned int crash_get_elfcorehdr_size(void) { return 0; }
-#endif
-
 extern bool kexec_file_dbg_print;
 
 #define kexec_dprintk(fmt, ...)					\