Add the architecture bits needed to enable CONFIG_KEXEC_HANDOVER on powerpc.
Set ARCH_SUPPORTS_KEXEC_HANDOVER for PPC64. On the boot path, check for KHO information in the device tree before unflatten_device_tree(). This allows a kernel booted via KHO kexec to recover the FDT and scratch region left by the previous kernel. Move early_init_dt_check_kho() out of the device tree implementation and call it from setup_arch() before the device tree is unflattened. Note: Crashkernel reservation impacts KHO scratch reservation. Crashkernel memory is reserved first using memblock, and this memory is included when calculating the KHO scratch size. As a result, a large crashkernel reservation can increase the KHO scratch size and may cause the KHO scratch reservation to fail. This issue also exists on other architectures and will be handled separately. Cc: Aditya Gupta <[email protected]> Cc: Alexander Graf <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Baoquan He <[email protected]> Cc: Christophe Leroy (CS GROUP) <[email protected]> Cc: Hari Bathini <[email protected]> Cc: Madhavan Srinivasan <[email protected]> Cc: Mahesh Salgaonkar <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Mike Rapoport <[email protected]> Cc: Nicholas Piggin <[email protected]> Cc: Pasha Tatashin <[email protected]> Cc: Pratyush Yadav <[email protected]> Cc: Ritesh Harjani (IBM) <[email protected]> Cc: Shivang Upadhyay <[email protected]> Cc: Shrikanth Hegde <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Sourabh Jain <[email protected]> --- arch/powerpc/Kconfig | 3 +++ arch/powerpc/kernel/setup-common.c | 2 ++ drivers/of/fdt.c | 2 +- include/linux/of_fdt.h | 1 + 4 files changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 2580e27e4328..3517d74949d0 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -716,6 +716,9 @@ config ARCH_SELECTS_CRASH_DUMP depends on CRASH_DUMP select RELOCATABLE if PPC64 || 44x || PPC_85xx +config ARCH_SUPPORTS_KEXEC_HANDOVER + def_bool PPC64 + config ARCH_SUPPORTS_CRASH_HOTPLUG def_bool y depends on PPC64 diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 4afaba19b586..53c2f1897bfe 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -923,6 +923,8 @@ void __init setup_arch(char **cmdline_p) /* Set a half-reasonable default so udelay does something sensible */ loops_per_jiffy = 500000000 / HZ; + early_init_dt_check_kho(); + /* Unflatten the device-tree passed by prom_init or kexec */ unflatten_device_tree(); diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index a64afc3ded3d..69e6ad868fa3 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -926,7 +926,7 @@ void __init early_init_dt_check_for_usable_mem_range(void) /** * early_init_dt_check_kho - Decode info required for kexec handover from DT */ -static void __init early_init_dt_check_kho(void) +void __init early_init_dt_check_kho(void) { unsigned long node = chosen_node_offset; u64 fdt_start, fdt_size, scratch_start, scratch_size; diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index 51dadbaa3d63..5e9d6af0c7dd 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -83,6 +83,7 @@ extern int early_init_dt_scan_root(void); extern bool early_init_dt_scan(void *dt_virt, phys_addr_t dt_phys); extern bool early_init_dt_verify(void *dt_virt, phys_addr_t dt_phys); extern void early_init_dt_scan_nodes(void); +extern void early_init_dt_check_kho(void); extern const char *of_flat_dt_get_machine_name(void); extern const void *of_flat_dt_match_machine(const void *default_match, -- 2.55.0
