diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 375ff893fa6019d048dcb905bdb82e669b913bb8..62c483133953110323540c532c3fb226a7b0b0be 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -583,6 +583,15 @@ 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-internal.h b/arch/powerpc/include/asm/fadump-internal.h
index 0f2ce85ee7b96ae299ee043a6349cc3887223cc8..6c2868d38bd327dfd84e83e664be43f18ec11a0e 100644
--- a/arch/powerpc/include/asm/fadump-internal.h
+++ b/arch/powerpc/include/asm/fadump-internal.h
@@ -9,6 +9,7 @@
#ifndef _ASM_POWERPC_FADUMP_INTERNAL_H
#define _ASM_POWERPC_FADUMP_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
@@ -146,6 +147,16 @@ void fadump_update_elfcore_header(char *bufp);
bool is_fadump_boot_mem_contiguous(void);
bool is_fadump_reserved_mem_contiguous(void);
+#else /* !CONFIG_PRESERVE_FA_DUMP */
+
+/* Firmware-assisted dump configuration details. */
+struct fw_dump {
+ u64 boot_mem_top;
+ u64 dump_active;
+};
+
+#endif /* CONFIG_PRESERVE_FA_DUMP */
+
#ifdef CONFIG_PPC_PSERIES
extern void rtas_fadump_dt_scan(struct fw_dump *fadump_conf, u64 node);
#else
diff --git a/arch/powerpc/include/asm/fadump.h b/arch/powerpc/include/asm/fadump.h
index fd5002b4c18cb11080bc3c2a47ecc254d8e662ea..526a6a6473128a81ff5b0bdfd1e8315889fa2ca4 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 /* _ASM_POWERPC_FADUMP_H */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 66c54443187da774ab06f43d241bd575162f2bd0..21ab769e8530eb1bfd5f20484c62e83af46a68d3 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -79,7 +79,9 @@ 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
+ifneq ($(CONFIG_FA_DUMP)$(CONFIG_PRESERVE_FA_DUMP),)
+obj-y += 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 6f52a60bc212c22cca0ccdba9e3a649b839bd1be..645d9d4d93324873961324541e1b4722d6f008f7 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -36,6 +36,7 @@ static struct fw_dump fw_dump;
static void __init fadump_reserve_crash_area(u64 base);
+#ifndef CONFIG_PRESERVE_FA_DUMP
static DEFINE_MUTEX(fadump_mutex);
struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0 };
struct fadump_mrange_info reserved_mrange_info = { "reserved", NULL, 0, 0, 0 };
@@ -439,11 +440,6 @@ 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)
{
@@ -1358,6 +1354,39 @@ int __init setup_fadump(void)
return 1;
}
subsys_initcall(setup_fadump);
+#else /* !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,
+ int depth, void *data)
+{
+ if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0))
+ return 0;
+
+ opal_fadump_dt_scan(&fw_dump, node);
+ return 1;
+}
+
+/*
+ * 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) {
+ /*
+ * If last boot has crashed then reserve all the memory
+ * above boot memory to preserve crash data.
+ */
+ pr_info("Preserving crash data for processing in next boot.\n");
+ fadump_reserve_crash_area(fw_dump.boot_mem_top);
+ } else
+ pr_debug("FADump-aware kernel..\n");
+
+ return 1;
+}
+#endif /* CONFIG_PRESERVE_FA_DUMP */
/* Preserve everything above the base address */
static void __init fadump_reserve_crash_area(u64 base)
@@ -1382,3 +1411,8 @@ static void __init fadump_reserve_crash_area(u64 base)
memblock_reserve(mstart, msize);
}
}
+
+unsigned long __init arch_reserved_kernel_pages(void)
+{
+ return memblock_reserved_size() / PAGE_SIZE;
+}
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 5828f1c81dc9bf4d678ee89300154ff9b05ec634..6620f37abe732326c380872b62ead719da2950e0 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -708,7 +708,7 @@ void __init early_init_devtree(void *params)
of_scan_flat_dt(early_init_dt_scan_ultravisor, 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
@@ -735,7 +735,7 @@ 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 3e6d6d6d1ec1fc9abdec2323b53b8b3adb7e3ada..2d13e64623392fe1e47e79f8fb8688bb3db6902c 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -8,6 +8,7 @@ obj-y += ultravisor.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 ad4c18bd8809d4abcbb23f56559bef2641a83271..c66fa96915ae29625f59e6c8d5855f4a1ee6c449 100644
--- a/arch/powerpc/platforms/powernv/opal-fadump.c
+++ b/arch/powerpc/platforms/powernv/opal-fadump.c
@@ -20,6 +20,67 @@
#include "opal-fadump.h"
+
+#ifdef CONFIG_PRESERVE_FA_DUMP
+/*
+ * 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.
+ */
+void __init opal_fadump_dt_scan(struct fw_dump *fadump_conf, u64 node)
+{
+ const struct opal_fadump_mem_struct *opal_fdm_active;
+ const __be32 *prop;
+ unsigned long dn;
+ u64 addr = 0;
+ s64 ret;
+
+ dn = of_get_flat_dt_subnode_by_name(node, "dump");
+ if (dn == -FDT_ERR_NOTFOUND)
+ return;
+
+ /*
+ * Check if dump has been initiated on last reboot.
+ */
+ prop = of_get_flat_dt_prop(dn, "mpipl-boot", NULL);
+ if (!prop)
+ return;
+
+ ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_KERNEL, &addr);
+ if ((ret != OPAL_SUCCESS) || !addr) {
+ pr_debug("Could not get Kernel metadata (%lld)\n", ret);
+ return;
+ }
+
+ /*
+ * Preserve memory only if kernel memory regions are registered
+ * with f/w for MPIPL.
+ */
+ addr = be64_to_cpu(addr);
+ pr_debug("Kernel metadata addr: %llx\n", addr);
+ opal_fdm_active = (void *)addr;
+ if (opal_fdm_active->registered_regions == 0)
+ return;
+
+ ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_BOOT_MEM, &addr);
+ if ((ret != OPAL_SUCCESS) || !addr) {
+ pr_err("Failed to get boot memory tag (%lld)\n", ret);
+ return;
+ }
+
+ /*
+ * Memory below this address can be used for booting a
+ * capture kernel or petitboot kernel. Preserve everything
+ * above this address for processing crashdump.
+ */
+ fadump_conf->boot_mem_top = be64_to_cpu(addr);
+ pr_debug("Preserve everything above %llx\n", fadump_conf->boot_mem_top);
+
+ pr_info("Firmware-assisted dump is active.\n");
+ fadump_conf->dump_active = 1;
+}
+
+#else /* CONFIG_PRESERVE_FA_DUMP */
static const struct opal_fadump_mem_struct *opal_fdm_active;
static const struct opal_mpipl_fadump *opal_cpu_metadata;
static struct opal_fadump_mem_struct *opal_fdm;
@@ -183,6 +244,17 @@ static int opal_fadump_setup_metadata(struct fw_dump *fadump_conf)
err = -EPERM;
}
+ /*
+ * Register boot memory top address with f/w. Should be retrieved
+ * by a kernel that intends to preserve crash'ed kernel's memory.
+ */
+ ret = opal_mpipl_register_tag(OPAL_MPIPL_TAG_BOOT_MEM,
+ fadump_conf->boot_memory_size);
+ if (ret != OPAL_SUCCESS) {
+ pr_err("Failed to set boot memory tag!\n");
+ err = -EPERM;
+ }
+
return err;
}
@@ -649,3 +721,4 @@ void __init opal_fadump_dt_scan(struct fw_dump *fadump_conf, u64 node)
fadump_conf->dump_active = 1;
opal_fadump_get_config(fadump_conf, opal_fdm_active);
}
+#endif /* !CONFIG_PRESERVE_FA_DUMP */