[PATCH 7/9] powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel
Hari Bathini
hbathini at linux.ibm.com
Fri Dec 21 06:01:05 AEDT 2018
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 at linux.ibm.com>
---
arch/powerpc/Kconfig | 9 ++++++
arch/powerpc/include/asm/fadump.h | 12 ++++----
arch/powerpc/kernel/Makefile | 6 +++-
arch/powerpc/kernel/fadump.c | 41 ++++++++++++++++++++++----
arch/powerpc/kernel/fadump_internal.h | 6 ++++
arch/powerpc/kernel/prom.c | 4 +--
arch/powerpc/platforms/powernv/Makefile | 6 +++-
arch/powerpc/platforms/powernv/opal-fadump.c | 35 ++++++++++++++++++++++
8 files changed, 104 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 08add7a..afa4e79 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -579,6 +579,15 @@ 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 db9465f..92a9ddf 100644
--- a/arch/powerpc/include/asm/fadump.h
+++ b/arch/powerpc/include/asm/fadump.h
@@ -22,14 +22,16 @@
#ifndef __PPC64_FA_DUMP_H__
#define __PPC64_FA_DUMP_H__
-#ifdef 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
+#ifdef CONFIG_FA_DUMP
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);
@@ -41,4 +43,4 @@ static inline int is_fadump_active(void) { return 0; }
static inline int should_fadump_crash(void) { return 0; }
static inline void crash_fadump(struct pt_regs *regs, const char *str) { }
#endif
-#endif
+#endif /* __PPC64_FA_DUMP_H__ */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 8e4bade..8ed84d2 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -65,7 +65,11 @@ 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_internal.o
+ifeq ($(CONFIG_FA_DUMP),y)
+obj-y += fadump.o fadump_internal.o
+else
+obj-$(CONFIG_PRESERVE_FA_DUMP) += fadump.o
+endif
ifdef CONFIG_PPC32
obj-$(CONFIG_E500) += idle_e500.o
endif
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index d9cf809..2c9457b 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -47,6 +47,7 @@
static struct fw_dump fw_dump;
+#ifdef CONFIG_FA_DUMP
#ifdef CONFIG_CMA
static struct cma *fadump_cma;
#endif
@@ -117,6 +118,7 @@ int __init fadump_cma_init(void)
#else
static int __init fadump_cma_init(void) { return 1; }
#endif /* CONFIG_CMA */
+#endif /* CONFIG_FA_DUMP */
/* Scan the Firmware Assisted dump configuration details. */
int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
@@ -125,8 +127,10 @@ int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
if (depth != 1)
return 0;
+#ifdef CONFIG_FA_DUMP
if (strcmp(uname, "rtas") == 0)
return pseries_dt_scan_fadump(&fw_dump, node);
+#endif
if (strcmp(uname, "ibm,opal") == 0)
return opal_dt_scan_fadump(&fw_dump, node);
@@ -134,6 +138,7 @@ int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
return 0;
}
+#ifdef CONFIG_FA_DUMP
/*
* If fadump is registered, check if the memory provided
* falls within boot memory area and reserved memory area.
@@ -366,6 +371,7 @@ static int __init fadump_get_rmr_regions(void)
return ret;
}
+#endif /* CONFIG_FA_DUMP */
/* Preserve everything above the base address */
static void __init fadump_reserve_crash_area(unsigned long base)
@@ -384,7 +390,7 @@ 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);
}
@@ -392,26 +398,46 @@ static void __init fadump_reserve_crash_area(unsigned long base)
int __init fadump_reserve_mem(void)
{
- unsigned long base, size, memory_boundary;
+ unsigned long base;
+#ifndef CONFIG_PRESERVE_FA_DUMP
+ unsigned long size, memory_boundary;
if (!fw_dump.fadump_enabled)
return 0;
if (!fw_dump.fadump_supported) {
- printk(KERN_INFO "Firmware-assisted dump is not supported on"
- " this hardware\n");
+ pr_info("Firmware-assisted dump is not supported on this hardware\n");
fw_dump.fadump_enabled = 0;
return 0;
}
+#endif
/*
* Initialize boot memory size
* If dump is active then we have already calculated the size during
* first kernel.
*/
- if (fw_dump.dump_active)
+ if (fw_dump.dump_active) {
fw_dump.boot_memory_size = fw_dump.rmr_source_len;
- else {
+
+ /*
+ * 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.
+ */
+#ifdef CONFIG_PRESERVE_FA_DUMP
+ pr_info("Preserving crash data for processing in next boot.\n");
+ 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 /* CONFIG_PRESERVE_FA_DUMP */
+ } else {
fw_dump.boot_memory_size = fadump_calculate_reserve_size();
#ifdef CONFIG_CMA
if (!fw_dump.nocma)
@@ -499,6 +525,7 @@ int __init fadump_reserve_mem(void)
fw_dump.reserve_dump_area_start = base;
return fadump_cma_init();
}
+#endif /* !CONFIG_PRESERVE_FA_DUMP */
return 1;
}
@@ -507,6 +534,7 @@ unsigned long __init arch_reserved_kernel_pages(void)
return memblock_reserved_size() / PAGE_SIZE;
}
+#ifdef CONFIG_FA_DUMP
/* Look for fadump= cmdline option. */
static int __init early_fadump_param(char *p)
{
@@ -1234,3 +1262,4 @@ int __init setup_fadump(void)
return 1;
}
subsys_initcall(setup_fadump);
+#endif /* CONFIG_FA_DUMP */
diff --git a/arch/powerpc/kernel/fadump_internal.h b/arch/powerpc/kernel/fadump_internal.h
index a117f60..ce4c0f9 100644
--- a/arch/powerpc/kernel/fadump_internal.h
+++ b/arch/powerpc/kernel/fadump_internal.h
@@ -13,6 +13,7 @@
#ifndef __PPC64_FA_DUMP_INTERNAL_H__
#define __PPC64_FA_DUMP_INTERNAL_H__
+#ifdef CONFIG_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
@@ -106,6 +107,7 @@ struct fadump_backup_area {
* the version field.
*/
};
+#endif /* CONFIG_FA_DUMP */
/* Firmware-Assited Dump platforms */
enum fadump_platform_type {
@@ -166,9 +168,12 @@ struct fw_dump {
unsigned long nocma:1;
enum fadump_platform_type fadump_platform;
+#ifdef CONFIG_FA_DUMP
struct fadump_ops *ops;
+#endif
};
+#ifdef CONFIG_FA_DUMP
struct fadump_ops {
ulong (*init_fadump_mem_struct)(struct fw_dump *fadump_config);
ulong (*init_fadump_header)(struct fw_dump *fadump_config);
@@ -198,6 +203,7 @@ int is_boot_memory_area_contiguous(struct fw_dump *fadump_conf);
int is_reserved_memory_area_contiguous(struct fw_dump *fadump_conf);
void init_fadump_backup_area(struct fw_dump *fadump_conf);
unsigned long fadump_populate_backup_area(struct fw_dump *fadump_conf);
+#endif /* CONFIG_FA_DUMP */
#ifdef CONFIG_PPC_PSERIES
extern int pseries_dt_scan_fadump(struct fw_dump *fadump_config, ulong node);
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index fe758ce..aa425ad 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -705,7 +705,7 @@ 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
@@ -732,7 +732,7 @@ 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 9420631..750675e 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -6,7 +6,11 @@ obj-y += opal-msglog.o opal-hmi.o opal-power.o opal-irqchip.o
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-$(CONFIG_FA_DUMP) += opal-fadump.o opal-core.o
+ifeq ($(CONFIG_FA_DUMP),y)
+obj-y += opal-fadump.o opal-core.o
+else
+obj-$(CONFIG_PRESERVE_FA_DUMP) += opal-fadump.o
+endif
obj-$(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 5bd0a0f..b3f3903 100644
--- a/arch/powerpc/platforms/powernv/opal-fadump.c
+++ b/arch/powerpc/platforms/powernv/opal-fadump.c
@@ -27,13 +27,16 @@
#include "../../kernel/fadump_internal.h"
#include "opal-fadump.h"
+#ifdef CONFIG_FA_DUMP
#include "opal-core.h"
static struct opal_fadump_mem_struct fdm;
static struct opalcore_config oc_config;
+#endif
static const struct opal_fadump_mem_struct *fdm_active;
unsigned long fdm_actual_size;
+#ifndef CONFIG_PRESERVE_FA_DUMP
/*
* Backup area is not available in older format. In the newer fadump
* header format (v2), backup info is stored at the end of elfcorehdrs
@@ -74,6 +77,7 @@ static void opal_set_preserv_area_start(struct fw_dump *fadump_conf)
pr_debug("Preserve area start address: 0x%lx\n",
fadump_conf->preserv_area_start);
}
+#endif /* !CONFIG_PRESERVE_FA_DUMP */
static void update_fadump_config(struct fw_dump *fadump_conf,
const struct opal_fadump_mem_struct *fdm)
@@ -142,11 +146,41 @@ static void update_fadump_config(struct fw_dump *fadump_conf,
fadump_conf->rmr_regions_cnt);
}
+#ifndef CONFIG_PRESERVE_FA_DUMP
fadump_set_meta_area_start(fadump_conf);
opal_set_preserv_area_start(fadump_conf);
opal_set_backup_area_start(fadump_conf);
+#endif
}
+/*
+ * 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;
+
+ 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.
+ */
+ fdm_active = of_get_flat_dt_prop(dn, "result-table", NULL);
+ if (fdm_active) {
+ pr_info("Firmware-assisted dump is active.\n");
+ fadump_conf->dump_active = 1;
+ update_fadump_config(fadump_conf, (void *)__pa(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;
@@ -618,3 +652,4 @@ int __init opal_dt_scan_fadump(struct fw_dump *fadump_conf, ulong node)
return 1;
}
+#endif /* !CONFIG_PRESERVE_FA_DUMP */
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