Re: [RFC v2 3/6] crash hp: definitions and prototype changes

From: Baoquan He
Date: Wed Jan 19 2022 - 03:23:34 EST


On 12/07/21 at 02:52pm, Eric DeVolder wrote:
> This change adds members to struct kimage to facilitate crash
> hotplug support.
>
> This change also defines crash hotplug events and associated
> prototypes.
>
> Signed-off-by: Eric DeVolder <eric.devolder@xxxxxxxxxx>
> ---
> include/linux/kexec.h | 21 +++++++++++++++++++--
> 1 file changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index 0c994ae37729..068f853f1c65 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -221,8 +221,9 @@ struct crash_mem {
> extern int crash_exclude_mem_range(struct crash_mem *mem,
> unsigned long long mstart,
> unsigned long long mend);
> -extern int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
> - void **addr, unsigned long *sz);
> +extern int crash_prepare_elf64_headers(struct kimage *image,
> + struct crash_mem *mem, int kernel_map,
> + void **addr, unsigned long *sz);
> #endif /* CONFIG_KEXEC_FILE */
>
> #ifdef CONFIG_KEXEC_ELF
> @@ -299,6 +300,13 @@ struct kimage {
>
> /* Information for loading purgatory */
> struct purgatory_info purgatory_info;
> +
> +#ifdef CONFIG_CRASH_HOTPLUG
> + bool hotplug_event;
> + int offlinecpu;
> + bool elf_index_valid;
> + int elf_index;

Do we really need elf_index_valid? Can we initialize elf_index to , e.g '-1',
then check if the value is valid?

> +#endif
> #endif
>
> #ifdef CONFIG_IMA_KEXEC
> @@ -315,6 +323,15 @@ struct kimage {
> unsigned long elf_load_addr;
> };
>
> +#ifdef CONFIG_CRASH_HOTPLUG
> +void arch_crash_hotplug_handler(struct kimage *image,
> + unsigned int hp_action, unsigned long a, unsigned long b);
> +#define KEXEC_CRASH_HP_REMOVE_CPU 0
> +#define KEXEC_CRASH_HP_ADD_CPU 1
> +#define KEXEC_CRASH_HP_REMOVE_MEMORY 2
> +#define KEXEC_CRASH_HP_ADD_MEMORY 3
> +#endif /* CONFIG_CRASH_HOTPLUG */
> +
> /* kexec interface functions */
> extern void machine_kexec(struct kimage *image);
> extern int machine_kexec_prepare(struct kimage *image);
> --
> 2.27.0
>