Subject: [PATCH linux-next v2 3/3] powerpc/kdump: Split KEXEC_CORE and CRASH_DUMP dependency

From: Hari Bathini <[email-masked]>
Date: Mon, 26 Feb 2024 16:00:10 +0530

Remove CONFIG_CRASH_DUMP dependency on CONFIG_KEXEC. CONFIG_KEXEC_CORE
was used at places where CONFIG_CRASH_DUMP or CONFIG_CRASH_RESERVE was
appropriate. Replace with appropriate #ifdefs to support CONFIG_KEXEC
and !CONFIG_CRASH_DUMP configuration option. Also, make CONFIG_FA_DUMP
dependent on CONFIG_CRASH_DUMP to avoid unmet dependencies for FA_DUMP
with !CONFIG_KEXEC_CORE configuration option.

Signed-off-by: Hari Bathini <[email-masked]>
---

Changes in v2:
* Fixed a compile error for POWERNV build reported by Sourabh.

 arch/powerpc/Kconfig                 |  9 +--
 arch/powerpc/include/asm/kexec.h     | 98 ++++++++++++++--------------
 arch/powerpc/kernel/prom.c           |  2 +-
 arch/powerpc/kernel/setup-common.c   |  2 +-
 arch/powerpc/kernel/smp.c            |  4 +-
 arch/powerpc/kexec/Makefile          |  3 +-
 arch/powerpc/kexec/core.c            |  4 ++
 arch/powerpc/platforms/powernv/smp.c |  2 +-
 8 files changed, 61 insertions(+), 63 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 5cf8ad8d7e8e..e377deefa2dc 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -607,11 +607,6 @@ config PPC64_SUPPORTS_MEMORY_FAILURE
 config ARCH_SUPPORTS_KEXEC
 	def_bool PPC_BOOK3S || PPC_E500 || (44x && !SMP)
 
-config ARCH_SELECTS_KEXEC
-	def_bool y
-	depends on KEXEC
-	select CRASH_DUMP
-
 config ARCH_SUPPORTS_KEXEC_FILE
 	def_bool PPC64
 
@@ -622,7 +617,6 @@ config ARCH_SELECTS_KEXEC_FILE
 	def_bool y
 	depends on KEXEC_FILE
 	select KEXEC_ELF
-	select CRASH_DUMP
 	select HAVE_IMA_KEXEC if IMA
 
 config PPC64_BIG_ENDIAN_ELF_ABI_V2
@@ -694,8 +688,7 @@ config ARCH_SELECTS_CRASH_DUMP
 
 config FA_DUMP
 	bool "Firmware-assisted dump"
-	depends on PPC64 && (PPC_RTAS || PPC_POWERNV)
-	select CRASH_DUMP
+	depends on CRASH_DUMP && PPC64 && (PPC_RTAS || PPC_POWERNV)
 	help
 	  A robust mechanism to get reliable kernel crash dump with
 	  assistance from firmware. This approach does not use kexec,
diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index e1b43aa12175..fdb90e24dc74 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -55,59 +55,18 @@
 typedef void (*crash_shutdown_t)(void);
 
 #ifdef CONFIG_KEXEC_CORE
-
-/*
- * This function is responsible for capturing register states if coming
- * via panic or invoking dump using sysrq-trigger.
- */
-static inline void crash_setup_regs(struct pt_regs *newregs,
-					struct pt_regs *oldregs)
-{
-	if (oldregs)
-		memcpy(newregs, oldregs, sizeof(*newregs));
-	else
-		ppc_save_regs(newregs);
-}
+struct kimage;
+struct pt_regs;
 
 extern void kexec_smp_wait(void);	/* get and clear naca physid, wait for
 					  master to copy new code to 0 */
-extern int crashing_cpu;
-extern void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *));
-extern void crash_ipi_callback(struct pt_regs *);
-extern int crash_wake_offline;
-
-struct kimage;
-struct pt_regs;
 extern void default_machine_kexec(struct kimage *image);
-extern void default_machine_crash_shutdown(struct pt_regs *regs);
-extern int crash_shutdown_register(crash_shutdown_t handler);
-extern int crash_shutdown_unregister(crash_shutdown_t handler);
-
-extern void crash_kexec_prepare(void);
-extern void crash_kexec_secondary(struct pt_regs *regs);
-int __init overlaps_crashkernel(unsigned long start, unsigned long size);
-extern void reserve_crashkernel(void);
 extern void machine_kexec_mask_interrupts(void);
 
-static inline bool kdump_in_progress(void)
-{
-	return crashing_cpu >= 0;
-}
-
 void relocate_new_kernel(unsigned long indirection_page, unsigned long reboot_code_buffer,
 			 unsigned long start_address) __noreturn;
-
 void kexec_copy_flush(struct kimage *image);
 
-#if defined(CONFIG_CRASH_DUMP)
-bool is_kdump_kernel(void);
-#define is_kdump_kernel			is_kdump_kernel
-#if defined(CONFIG_PPC_RTAS)
-void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
-#define crash_free_reserved_phys_range crash_free_reserved_phys_range
-#endif /* CONFIG_PPC_RTAS */
-#endif /* CONFIG_CRASH_DUMP */
-
 #ifdef CONFIG_KEXEC_FILE
 extern const struct kexec_file_ops kexec_elf64_ops;
 
@@ -152,15 +111,56 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt,
 
 #endif /* CONFIG_KEXEC_FILE */
 
-#else /* !CONFIG_KEXEC_CORE */
-static inline void crash_kexec_secondary(struct pt_regs *regs) { }
+#endif /* CONFIG_KEXEC_CORE */
+
+#ifdef CONFIG_CRASH_RESERVE
+int __init overlaps_crashkernel(unsigned long start, unsigned long size);
+extern void reserve_crashkernel(void);
+#else
+static inline void reserve_crashkernel(void) {}
+static inline int overlaps_crashkernel(unsigned long start, unsigned long size) { return 0; }
+#endif
 
-static inline int overlaps_crashkernel(unsigned long start, unsigned long size)
+#if defined(CONFIG_CRASH_DUMP)
+/*
+ * This function is responsible for capturing register states if coming
+ * via panic or invoking dump using sysrq-trigger.
+ */
+static inline void crash_setup_regs(struct pt_regs *newregs,
+					struct pt_regs *oldregs)
 {
-	return 0;
+	if (oldregs)
+		memcpy(newregs, oldregs, sizeof(*newregs));
+	else
+		ppc_save_regs(newregs);
+}
+
+extern int crashing_cpu;
+extern void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *));
+extern void crash_ipi_callback(struct pt_regs *regs);
+extern int crash_wake_offline;
+
+extern int crash_shutdown_register(crash_shutdown_t handler);
+extern int crash_shutdown_unregister(crash_shutdown_t handler);
+extern void default_machine_crash_shutdown(struct pt_regs *regs);
+
+extern void crash_kexec_prepare(void);
+extern void crash_kexec_secondary(struct pt_regs *regs);
+
+static inline bool kdump_in_progress(void)
+{
+	return crashing_cpu >= 0;
 }
 
-static inline void reserve_crashkernel(void) { ; }
+bool is_kdump_kernel(void);
+#define is_kdump_kernel			is_kdump_kernel
+#if defined(CONFIG_PPC_RTAS)
+void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
+#define crash_free_reserved_phys_range crash_free_reserved_phys_range
+#endif /* CONFIG_PPC_RTAS */
+
+#else /* !CONFIG_CRASH_DUMP */
+static inline void crash_kexec_secondary(struct pt_regs *regs) { }
 
 static inline int crash_shutdown_register(crash_shutdown_t handler)
 {
@@ -183,7 +183,7 @@ static inline void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
 {
 }
 
-#endif /* CONFIG_KEXEC_CORE */
+#endif /* CONFIG_CRASH_DUMP */
 
 #ifdef CONFIG_PPC_BOOK3S_64
 #include <asm/book3s/64/kexec.h>
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 1dc32a058156..cd8d8883de90 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -475,7 +475,7 @@ static int __init early_init_dt_scan_chosen_ppc(unsigned long node,
 		tce_alloc_end = *lprop;
 #endif
 
-#ifdef CONFIG_KEXEC_CORE
+#ifdef CONFIG_CRASH_RESERVE
 	lprop = of_get_flat_dt_prop(node, "linux,crashkernel-base", NULL);
 	if (lprop)
 		crashk_res.start = *lprop;
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 8cb84d46319e..34aef8f753f9 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -110,7 +110,7 @@ int ppc_do_canonicalize_irqs;
 EXPORT_SYMBOL(ppc_do_canonicalize_irqs);
 #endif
 
-#ifdef CONFIG_VMCORE_INFO
+#ifdef CONFIG_CRASH_DUMP
 /* This keeps a track of which one is the crashing cpu. */
 int crashing_cpu = -1;
 #endif
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 693334c20d07..aa81c95c73a4 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -588,7 +588,7 @@ void smp_send_debugger_break(void)
 }
 #endif
 
-#ifdef CONFIG_KEXEC_CORE
+#ifdef CONFIG_CRASH_DUMP
 void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
 {
 	int cpu;
@@ -631,7 +631,7 @@ void crash_smp_send_stop(void)
 
 	stopped = true;
 
-#ifdef CONFIG_KEXEC_CORE
+#ifdef CONFIG_CRASH_DUMP
 	if (kexec_crash_image) {
 		crash_kexec_prepare();
 		return;
diff --git a/arch/powerpc/kexec/Makefile b/arch/powerpc/kexec/Makefile
index 91e96f5168b7..8e469c4da3f8 100644
--- a/arch/powerpc/kexec/Makefile
+++ b/arch/powerpc/kexec/Makefile
@@ -3,12 +3,13 @@
 # Makefile for the linux kernel.
 #
 
-obj-y				+= core.o crash.o core_$(BITS).o
+obj-y				+= core.o core_$(BITS).o
 
 obj-$(CONFIG_PPC32)		+= relocate_32.o
 
 obj-$(CONFIG_KEXEC_FILE)	+= file_load.o ranges.o file_load_$(BITS).o elf_$(BITS).o
 obj-$(CONFIG_VMCORE_INFO)	+= vmcore_info.o
+obj-$(CONFIG_CRASH_DUMP)	+= crash.o
 
 # Disable GCOV, KCOV & sanitizers in odd or sensitive code
 GCOV_PROFILE_core_$(BITS).o := n
diff --git a/arch/powerpc/kexec/core.c b/arch/powerpc/kexec/core.c
index 3ff4411ed496..b8333a49ea5d 100644
--- a/arch/powerpc/kexec/core.c
+++ b/arch/powerpc/kexec/core.c
@@ -44,10 +44,12 @@ void machine_kexec_mask_interrupts(void) {
 	}
 }
 
+#ifdef CONFIG_CRASH_DUMP
 void machine_crash_shutdown(struct pt_regs *regs)
 {
 	default_machine_crash_shutdown(regs);
 }
+#endif
 
 void machine_kexec_cleanup(struct kimage *image)
 {
@@ -77,6 +79,7 @@ void machine_kexec(struct kimage *image)
 	for(;;);
 }
 
+#ifdef CONFIG_CRASH_RESERVE
 void __init reserve_crashkernel(void)
 {
 	unsigned long long crash_size, crash_base, total_mem_sz;
@@ -251,3 +254,4 @@ static int __init kexec_setup(void)
 	return 0;
 }
 late_initcall(kexec_setup);
+#endif /* CONFIG_CRASH_RESERVE */
diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c
index 9e1a25398f98..8f14f0581a21 100644
--- a/arch/powerpc/platforms/powernv/smp.c
+++ b/arch/powerpc/platforms/powernv/smp.c
@@ -434,7 +434,7 @@ void __init pnv_smp_init(void)
 	smp_ops = &pnv_smp_ops;
 
 #ifdef CONFIG_HOTPLUG_CPU
-#ifdef CONFIG_KEXEC_CORE
+#ifdef CONFIG_CRASH_DUMP
 	crash_wake_offline = 1;
 #endif
 #endif
-- 
2.43.2