diff options
Diffstat (limited to 'arch/powerpc/kexec/crash.c')
| -rw-r--r-- | arch/powerpc/kexec/crash.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c index ef5c2d25ec39..8938a19af12f 100644 --- a/arch/powerpc/kexec/crash.c +++ b/arch/powerpc/kexec/crash.c @@ -16,6 +16,7 @@ #include <linux/delay.h> #include <linux/irq.h> #include <linux/types.h> +#include <linux/libfdt.h> #include <asm/processor.h> #include <asm/machdep.h> @@ -392,3 +393,105 @@ void default_machine_crash_shutdown(struct pt_regs *regs) if (ppc_md.kexec_cpu_down) ppc_md.kexec_cpu_down(1, 0); } + +#ifdef CONFIG_CRASH_HOTPLUG +#undef pr_fmt +#define pr_fmt(fmt) "crash hp: " fmt + +/** + * get_fdt_index - Loop through the kexec segment array and find + * the index of the FDT segment. + * @image: a pointer to kexec_crash_image + * + * Returns the index of FDT segment in the kexec segment array + * if found; otherwise -1. + */ +static int get_fdt_index(struct kimage *image) +{ + void *ptr; + unsigned long mem; + int i, fdt_index = -1; + + /* Find the FDT segment index in kexec segment array. */ + for (i = 0; i < image->nr_segments; i++) { + mem = image->segment[i].mem; + ptr = __va(mem); + + if (ptr && fdt_magic(ptr) == FDT_MAGIC) { + fdt_index = i; + break; + } + } + + return fdt_index; +} + +/** + * update_crash_fdt - updates the cpus node of the crash FDT. + * + * @image: a pointer to kexec_crash_image + */ +static void update_crash_fdt(struct kimage *image) +{ + void *fdt; + int fdt_index; + + fdt_index = get_fdt_index(image); + if (fdt_index < 0) { + pr_err("Unable to locate FDT segment.\n"); + return; + } + + fdt = __va((void *)image->segment[fdt_index].mem); + + /* Temporarily invalidate the crash image while it is replaced */ + xchg(&kexec_crash_image, NULL); + + /* update FDT to reflect changes in CPU resources */ + if (update_cpus_node(fdt)) + pr_err("Failed to update crash FDT"); + + /* The crash image is now valid once again */ + xchg(&kexec_crash_image, image); +} + +int arch_crash_hotplug_support(struct kimage *image, unsigned long kexec_flags) +{ +#ifdef CONFIG_KEXEC_FILE + if (image->file_mode) + return 1; +#endif + return kexec_flags & KEXEC_CRASH_HOTPLUG_SUPPORT; +} + +/** + * arch_crash_handle_hotplug_event - Handle crash CPU/Memory hotplug events to update the + * necessary kexec segments based on the hotplug event. + * @image: a pointer to kexec_crash_image + * @arg: struct memory_notify handler for memory hotplug case and NULL for CPU hotplug case. + * + * Update the kdump image based on the type of hotplug event, represented by image->hp_action. + * CPU add: Update the FDT segment to include the newly added CPU. + * CPU remove: No action is needed, with the assumption that it's okay to have offline CPUs + * part of the FDT. + * Memory add/remove: No action is taken as this is not yet supported. + */ +void arch_crash_handle_hotplug_event(struct kimage *image, void *arg) +{ + switch (image->hp_action) { + case KEXEC_CRASH_HP_REMOVE_CPU: + return; + + case KEXEC_CRASH_HP_ADD_CPU: + update_crash_fdt(image); + break; + + case KEXEC_CRASH_HP_REMOVE_MEMORY: + case KEXEC_CRASH_HP_ADD_MEMORY: + pr_info_once("Crash update is not supported for memory hotplug\n"); + return; + default: + pr_warn_once("Unknown hotplug action\n"); + } +} +#endif /* CONFIG_CRASH_HOTPLUG */ |