[PATCH 1/2] LoongArch: kdump: Add the same binary implementation

[Youling Tang]

This feature depends on the relocation function, so the relocation configuration
CONFIG_RELOCATABLE will be enabled.

Add the same set of binary implementations for kdump, and then no longer need to
compile two kernels (the production kernel and the capture kernel share the same
binary).

CONFIG_CRASH_DUMP is enabled by default (CONFIG_RELOCATABLE is also enabled).

Signed-off-by: Youling Tang <tangyouling@xxxxxxxxxxx>
---
 arch/loongarch/Kconfig                     | 12 +-----------
 arch/loongarch/Makefile                    |  4 ----
 arch/loongarch/configs/loongson3_defconfig |  1 +
 arch/loongarch/include/asm/addrspace.h     |  2 ++
 arch/loongarch/kernel/head.S               |  2 +-
 5 files changed, 5 insertions(+), 16 deletions(-)

diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index ab4c2ab146ab..84f220273296 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -502,6 +502,7 @@ config KEXEC
 
 config CRASH_DUMP
 	bool "Build kdump crash kernel"
+	select RELOCATABLE
 	help
 	  Generate crash dump after being started by kexec. This should
 	  be normally only set in special crash dump kernels which are
@@ -511,17 +512,6 @@ config CRASH_DUMP
 
 	  For more details see Documentation/admin-guide/kdump/kdump.rst
 
-config PHYSICAL_START
-	hex "Physical address where the kernel is loaded"
-	default "0x90000000a0000000"
-	depends on CRASH_DUMP
-	help
-	  This gives the XKPRANGE address where the kernel is loaded.
-	  If you plan to use kernel for capturing the crash dump change
-	  this value to start of the reserved region (the "X" value as
-	  specified in the "crashkernel=YM@XM" command line boot parameter
-	  passed to the panic-ed kernel).
-
 config RELOCATABLE
 	bool "Relocatable kernel"
 	help
diff --git a/arch/loongarch/Makefile b/arch/loongarch/Makefile
index 2aba6ff30436..8304fed7aa42 100644
--- a/arch/loongarch/Makefile
+++ b/arch/loongarch/Makefile
@@ -79,11 +79,7 @@ endif
 cflags-y += -ffreestanding
 cflags-y += $(call cc-option, -mno-check-zero-division)
 
-ifndef CONFIG_PHYSICAL_START
 load-y		= 0x9000000000200000
-else
-load-y		= $(CONFIG_PHYSICAL_START)
-endif
 bootvars-y	= VMLINUX_LOAD_ADDRESS=$(load-y)
 
 drivers-$(CONFIG_PCI)		+= arch/loongarch/pci/
diff --git a/arch/loongarch/configs/loongson3_defconfig b/arch/loongarch/configs/loongson3_defconfig
index cb52774c80e8..7885f6e5de93 100644
--- a/arch/loongarch/configs/loongson3_defconfig
+++ b/arch/loongarch/configs/loongson3_defconfig
@@ -48,6 +48,7 @@ CONFIG_HOTPLUG_CPU=y
 CONFIG_NR_CPUS=64
 CONFIG_NUMA=y
 CONFIG_KEXEC=y
+CONFIG_CRASH_DUMP=y
 CONFIG_SUSPEND=y
 CONFIG_HIBERNATION=y
 CONFIG_ACPI=y
diff --git a/arch/loongarch/include/asm/addrspace.h b/arch/loongarch/include/asm/addrspace.h
index d342935e5a72..4edcb3c21cf5 100644
--- a/arch/loongarch/include/asm/addrspace.h
+++ b/arch/loongarch/include/asm/addrspace.h
@@ -125,4 +125,6 @@ extern unsigned long vm_map_base;
 #define ISA_IOSIZE	SZ_16K
 #define IO_SPACE_LIMIT	(PCI_IOSIZE - 1)
 
+#define PHYS_LINK_ADDR	PHYSADDR(VMLINUX_LOAD_ADDRESS)
+
 #endif /* _ASM_ADDRSPACE_H */
diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S
index b12f459ad73a..57962ff08f6d 100644
--- a/arch/loongarch/kernel/head.S
+++ b/arch/loongarch/kernel/head.S
@@ -24,7 +24,7 @@ _head:
 	.org	0x8
 	.dword	kernel_entry		/* Kernel entry point */
 	.dword	_end - _text		/* Kernel image effective size */
-	.quad	0			/* Kernel image load offset from start of RAM */
+	.quad	PHYS_LINK_ADDR		/* Kernel image load offset from start of RAM */
 	.org	0x38			/* 0x20 ~ 0x37 reserved */
 	.long	LINUX_PE_MAGIC
 	.long	pe_header - _head	/* Offset to the PE header */
-- 
2.37.3