diff mbox series

[v3,10/16] powernv/fadump: add support to preserve crash data on FADUMP disabled kernel

Message ID 156149562758.9094.5395065020111442197.stgit@hbathini.in.ibm.com
State Superseded
Headers show
Series Add FADump support on PowerNV platform | expand

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Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch next (c7d64b560ce80d8c44f082eee8352f0778a73195)
snowpatch_ozlabs/checkpatch warning total: 0 errors, 0 warnings, 4 checks, 272 lines checked

Commit Message

Hari Bathini June 25, 2019, 8:47 p.m. UTC
Add a new kernel config option, CONFIG_PRESERVE_FA_DUMP that ensures
that crash data, from previously crash'ed kernel, is preserved. This
helps in cases where FADump is not enabled but the subsequent memory
preserving kernel boot is likely to process this crash data. One
typical usecase for this config option is petitboot kernel.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
---
 arch/powerpc/Kconfig                         |    9 ++++
 arch/powerpc/include/asm/fadump.h            |    9 +++-
 arch/powerpc/kernel/Makefile                 |    6 ++-
 arch/powerpc/kernel/fadump-common.h          |    8 +++-
 arch/powerpc/kernel/fadump.c                 |   47 ++++++++++++++++++---
 arch/powerpc/kernel/prom.c                   |    4 +-
 arch/powerpc/platforms/powernv/Makefile      |    1 
 arch/powerpc/platforms/powernv/opal-fadump.c |   59 ++++++++++++++++++++++++++
 8 files changed, 130 insertions(+), 13 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index f124a9b..9b05d15 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -571,6 +571,15 @@  config FA_DUMP
 	  If unsure, say "y". Only special kernels like petitboot may
 	  need to say "N" here.
 
+config PRESERVE_FA_DUMP
+	bool "Preserve Firmware-assisted dump"
+	depends on PPC64 && PPC_POWERNV && !FA_DUMP
+	help
+	  On a kernel with FA_DUMP disabled, this option helps to preserve
+	  crash data from a previously crash'ed kernel. Useful when the next
+	  memory preserving kernel boot would process this crash data.
+	  Petitboot kernel is the typical usecase for this option.
+
 config IRQ_ALL_CPUS
 	bool "Distribute interrupts on all CPUs by default"
 	depends on SMP
diff --git a/arch/powerpc/include/asm/fadump.h b/arch/powerpc/include/asm/fadump.h
index 9a7652c..fd990d8 100644
--- a/arch/powerpc/include/asm/fadump.h
+++ b/arch/powerpc/include/asm/fadump.h
@@ -14,9 +14,6 @@ 
 extern int crashing_cpu;
 
 extern int is_fadump_memory_area(u64 addr, ulong size);
-extern int early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
-				      int depth, void *data);
-extern int fadump_reserve_mem(void);
 extern int setup_fadump(void);
 extern int is_fadump_active(void);
 extern int should_fadump_crash(void);
@@ -29,4 +26,10 @@  static inline int should_fadump_crash(void) { return 0; }
 static inline void crash_fadump(struct pt_regs *regs, const char *str) { }
 static inline void fadump_cleanup(void) { }
 #endif /* !CONFIG_FA_DUMP */
+
+#if defined(CONFIG_FA_DUMP) || defined(CONFIG_PRESERVE_FA_DUMP)
+extern int early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
+				      int depth, void *data);
+extern int fadump_reserve_mem(void);
+#endif
 #endif /* __PPC64_FA_DUMP_H__ */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 23372e3..4c90314 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -77,7 +77,11 @@  obj-$(CONFIG_EEH)              += eeh.o eeh_pe.o eeh_dev.o eeh_cache.o \
 				  eeh_driver.o eeh_event.o eeh_sysfs.o
 obj-$(CONFIG_GENERIC_TBSYNC)	+= smp-tbsync.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
-obj-$(CONFIG_FA_DUMP)		+= fadump.o fadump-common.o
+ifeq ($(CONFIG_FA_DUMP),y)
+obj-y				+= fadump.o fadump-common.o
+else
+obj-$(CONFIG_PRESERVE_FA_DUMP)	+= fadump.o
+endif
 ifdef CONFIG_PPC32
 obj-$(CONFIG_E500)		+= idle_e500.o
 endif
diff --git a/arch/powerpc/kernel/fadump-common.h b/arch/powerpc/kernel/fadump-common.h
index ebebe4d..fea6872 100644
--- a/arch/powerpc/kernel/fadump-common.h
+++ b/arch/powerpc/kernel/fadump-common.h
@@ -13,6 +13,7 @@ 
 #ifndef __PPC64_FA_DUMP_INTERNAL_H__
 #define __PPC64_FA_DUMP_INTERNAL_H__
 
+#ifndef CONFIG_PRESERVE_FA_DUMP
 /*
  * The RMA region will be saved for later dumping when kernel crashes.
  * RMA is Real Mode Area, the first block of logical memory address owned
@@ -88,6 +89,7 @@  struct fadump_crash_info_header {
 
 /* Platform specific callback functions */
 struct fadump_ops;
+#endif /* !CONFIG_PRESERVE_FA_DUMP */
 
 /* Firmware-Assited Dump platforms */
 enum fadump_platform_type {
@@ -157,9 +159,12 @@  struct fw_dump {
 	unsigned long	nocma:1;
 
 	enum fadump_platform_type	fadump_platform;
+#ifndef CONFIG_PRESERVE_FA_DUMP
 	struct fadump_ops		*ops;
+#endif
 };
 
+#ifndef CONFIG_PRESERVE_FA_DUMP
 struct fadump_ops {
 	ulong	(*init_fadump_mem_struct)(struct fw_dump *fadump_config);
 	ulong	(*get_kernel_metadata_size)(void);
@@ -182,8 +187,9 @@  u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs);
 void fadump_update_elfcore_header(struct fw_dump *fadump_config, char *bufp);
 int is_boot_memory_area_contiguous(struct fw_dump *fadump_conf);
 int is_reserved_memory_area_contiguous(struct fw_dump *fadump_conf);
+#endif /* !CONFIG_PRESERVE_FA_DUMP */
 
-#ifdef CONFIG_PPC_PSERIES
+#if !defined(CONFIG_PRESERVE_FA_DUMP) && defined(CONFIG_PPC_PSERIES)
 extern int pseries_dt_scan_fadump(struct fw_dump *fadump_config, ulong node);
 #else
 static inline int
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index ce8c0bf..569221a 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -35,6 +35,7 @@ 
 
 static struct fw_dump fw_dump;
 
+#ifndef CONFIG_PRESERVE_FA_DUMP
 static DEFINE_MUTEX(fadump_mutex);
 struct fadump_memory_range *crash_memory_ranges;
 int crash_memory_ranges_size;
@@ -205,6 +206,9 @@  static void __init early_init_dt_scan_reserved_ranges(unsigned long node)
 		}
 	}
 }
+#else /* !CONFIG_PRESERVE_FA_DUMP */
+static inline void early_init_dt_scan_reserved_ranges(unsigned long node) { }
+#endif /* CONFIG_PRESERVE_FA_DUMP */
 
 /* Scan the Firmware Assisted dump configuration details. */
 int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
@@ -226,6 +230,7 @@  int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
 	return 0;
 }
 
+#ifndef CONFIG_PRESERVE_FA_DUMP
 /*
  * If fadump is registered, check if the memory provided
  * falls within boot memory area and reserved memory area.
@@ -479,6 +484,7 @@  static bool overlaps_with_reserved_ranges(ulong base, ulong end)
 
 	return ret;
 }
+#endif /* !CONFIG_PRESERVE_FA_DUMP */
 
 /* Preserve everything above the base address */
 static void __init fadump_reserve_crash_area(unsigned long base)
@@ -497,12 +503,45 @@  static void __init fadump_reserve_crash_area(unsigned long base)
 			msize -= (base - mstart);
 			mstart = base;
 		}
-		pr_info("Reserving %luMB of memory at %#016lx for saving crash dump",
+		pr_info("Reserving %luMB of memory at %#016lx for preserving crash data",
 			(msize >> 20), mstart);
 		memblock_reserve(mstart, msize);
 	}
 }
 
+unsigned long __init arch_reserved_kernel_pages(void)
+{
+	return memblock_reserved_size() / PAGE_SIZE;
+}
+
+#ifdef CONFIG_PRESERVE_FA_DUMP
+/*
+ * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel,
+ * preserve crash data. The subsequent memory preserving kernel boot
+ * is likely to process this crash data.
+ */
+int __init fadump_reserve_mem(void)
+{
+	if (fw_dump.dump_active) {
+		unsigned long base;
+
+		pr_info("Preserving crash data for processing in next boot.\n");
+		fw_dump.boot_memory_size = fw_dump.rmr_source_len;
+		base = fw_dump.boot_memory_size + fw_dump.boot_memory_hole_size;
+		base = PAGE_ALIGN(base);
+
+		/*
+		 * If last boot has crashed then reserve all the memory
+		 * above boot memory size to preserve crash data.
+		 */
+		fadump_reserve_crash_area(base);
+	} else
+		pr_debug("FADump-aware kernel..\n");
+
+	return 1;
+}
+#else /* CONFIG_PRESERVE_FA_DUMP */
+
 int __init fadump_reserve_mem(void)
 {
 	int ret = 1;
@@ -631,11 +670,6 @@  int __init fadump_reserve_mem(void)
 	return 0;
 }
 
-unsigned long __init arch_reserved_kernel_pages(void)
-{
-	return memblock_reserved_size() / PAGE_SIZE;
-}
-
 /* Look for fadump= cmdline option. */
 static int __init early_fadump_param(char *p)
 {
@@ -1396,3 +1430,4 @@  int __init setup_fadump(void)
 	return 1;
 }
 subsys_initcall(setup_fadump);
+#endif /* !CONFIG_PRESERVE_FA_DUMP */
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 7159e79..9c3861bd 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -704,7 +704,7 @@  void __init early_init_devtree(void *params)
 	of_scan_flat_dt(early_init_dt_scan_opal, NULL);
 #endif
 
-#ifdef CONFIG_FA_DUMP
+#if defined(CONFIG_FA_DUMP) || defined(CONFIG_PRESERVE_FA_DUMP)
 	/* scan tree to see if dump is active during last boot */
 	of_scan_flat_dt(early_init_dt_scan_fw_dump, NULL);
 #endif
@@ -731,7 +731,7 @@  void __init early_init_devtree(void *params)
 	if (PHYSICAL_START > MEMORY_START)
 		memblock_reserve(MEMORY_START, 0x8000);
 	reserve_kdump_trampoline();
-#ifdef CONFIG_FA_DUMP
+#if defined(CONFIG_FA_DUMP) || defined(CONFIG_PRESERVE_FA_DUMP)
 	/*
 	 * If we fail to reserve memory for firmware-assisted dump then
 	 * fallback to kexec based kdump.
diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index 43a6e1c..b4a8022 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -7,6 +7,7 @@  obj-y			+= opal-kmsg.o opal-powercap.o opal-psr.o opal-sensor-groups.o
 
 obj-$(CONFIG_SMP)	+= smp.o subcore.o subcore-asm.o
 obj-$(CONFIG_FA_DUMP)	+= opal-fadump.o
+obj-$(CONFIG_PRESERVE_FA_DUMP)	+= opal-fadump.o
 obj-$(CONFIG_PCI)	+= pci.o pci-ioda.o npu-dma.o pci-ioda-tce.o
 obj-$(CONFIG_CXL_BASE)	+= pci-cxl.o
 obj-$(CONFIG_EEH)	+= eeh-powernv.o
diff --git a/arch/powerpc/platforms/powernv/opal-fadump.c b/arch/powerpc/platforms/powernv/opal-fadump.c
index ed3c35b..b0b2c3d 100644
--- a/arch/powerpc/platforms/powernv/opal-fadump.c
+++ b/arch/powerpc/platforms/powernv/opal-fadump.c
@@ -29,8 +29,10 @@ 
 #include "opal-fadump.h"
 
 static const struct opal_fadump_mem_struct *opal_fdm_active;
+#ifndef CONFIG_PRESERVE_FA_DUMP
 static const struct opal_mpipl_fadump *opal_cpu_metadata;
 static struct opal_fadump_mem_struct *opal_fdm;
+#endif /* !CONFIG_PRESERVE_FA_DUMP */
 
 static void opal_set_preserv_area_start(struct fw_dump *fadump_conf)
 {
@@ -89,6 +91,62 @@  static void update_fadump_config(struct fw_dump *fadump_conf,
 	opal_set_preserv_area_start(fadump_conf);
 }
 
+/*
+ * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel,
+ * ensure crash data is preserved in hope that the subsequent memory
+ * preserving kernel boot is going to process this crash data.
+ */
+#ifdef CONFIG_PRESERVE_FA_DUMP
+int __init opal_dt_scan_fadump(struct fw_dump *fadump_conf, ulong node)
+{
+	unsigned long dn;
+	const __be32 *prop;
+
+	dn = of_get_flat_dt_subnode_by_name(node, "dump");
+	if (dn == -FDT_ERR_NOTFOUND)
+		return 1;
+
+	/*
+	 * Check if dump has been initiated on last reboot.
+	 */
+	prop = of_get_flat_dt_prop(dn, "mpipl-boot", NULL);
+	if (prop) {
+		u8 type;
+		u32 idx = 0;
+		u64 addr = 0;
+		s64 ret;
+
+		do {
+			ret = opal_mpipl_query_tag(idx, &addr);
+			if (ret != OPAL_SUCCESS)
+				break;
+
+			addr = be64_to_cpu(addr);
+			type = *((u8 *)addr);
+			switch (type) {
+			case MPIPL_FADUMP_TYPE_KERNEL:
+				opal_fdm_active = __va(addr);
+				break;
+			}
+
+			idx++;
+		} while (ret == OPAL_SUCCESS);
+
+		if (opal_fdm_active == NULL) {
+			pr_err("kernel metadata not found!\n");
+			return 1;
+		}
+
+		pr_info("Firmware-assisted dump is active.\n");
+		fadump_conf->dump_active = 1;
+		update_fadump_config(fadump_conf,
+				     (void *)__pa(opal_fdm_active));
+	}
+
+	return 1;
+}
+
+#else /* CONFIG_PRESERVE_FA_DUMP */
 static ulong opal_init_fadump_mem_struct(struct fw_dump *fadump_conf)
 {
 	ulong addr = fadump_conf->reserve_dump_area_start;
@@ -614,3 +672,4 @@  int __init opal_dt_scan_fadump(struct fw_dump *fadump_conf, ulong node)
 
 	return 1;
 }
+#endif /* !CONFIG_PRESERVE_FA_DUMP */