Re: [PATCH] kexec_file: remove unused arch_kexec_locate_mem_hole hook

[Mukesh Pilaniya <mpilaniy@redhat.com>]

Hi Sourabh,

The patch touches three files across three subsystems so kexec: would be
a more accurate prefix than kexec_file, for e.g.:

kexec: remove unused arch_kexec_locate_mem_hole hook

On 27/08/26 8:14 pm, Sourabh Jain wrote:
> No architecture provides an implementation of
> arch_kexec_locate_mem_hole(). Use kexec_locate_mem_hole() directly
> and remove the unused fallback wrapper from the kexec header.
> 
> This simplifies the kexec memory allocation path without changing
> its behavior.
> 
Also, it might be worth mentioning in the commit message that this hook
was originally introduced by commit f891f19736bd and that the last arch
override was removed in commit 6e5250eaa665; making it safe to remove now.

Otherwise, the change looks good to me. Feel free to add:
Reviewed-by: Mukesh Pilaniya <mpilaniy@redhat.com>

> Cc: Albert Ou <aou@eecs.berkeley.edu>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Baoquan He <baoquan.he@linux.dev>
> Cc: Mike Rapoport <rppt@kernel.org>
> Cc: Palmer Dabbelt <palmer@dabbelt.com>
> Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
> Cc: Paul Walmsley <pjw@kernel.org>
> Cc: Pratyush Yadav <pratyush@kernel.org>
> Cc: linux-riscv@lists.infradead.org
> Cc: kexec@lists.infradead.org
> Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
> ---
>  arch/riscv/kernel/kexec_elf.c |  2 +-
>  include/linux/kexec.h         | 15 ---------------
>  kernel/kexec_file.c           |  2 +-
>  3 files changed, 2 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/riscv/kernel/kexec_elf.c b/arch/riscv/kernel/kexec_elf.c
> index 3e9a32acb8f2..ca5abbad59e5 100644
> --- a/arch/riscv/kernel/kexec_elf.c
> +++ b/arch/riscv/kernel/kexec_elf.c
> @@ -91,7 +91,7 @@ static int elf_find_pbase(struct kimage *image, unsigned long kernel_len,
>  	kbuf.memsz = ALIGN(kernel_len, PAGE_SIZE);
>  	kbuf.cma = NULL;
>  	kbuf.top_down = false;
> -	ret = arch_kexec_locate_mem_hole(&kbuf);
> +	ret = kexec_locate_mem_hole(&kbuf);
>  	if (!ret) {
>  		*old_pbase = lowest_paddr;
>  		*new_pbase = kbuf.mem;
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index 0af8ae4fdd08..e5f1cfc11fef 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -259,21 +259,6 @@ int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len);
>  extern int kexec_add_buffer(struct kexec_buf *kbuf);
>  int kexec_locate_mem_hole(struct kexec_buf *kbuf);
>  
> -#ifndef arch_kexec_locate_mem_hole
> -/**
> - * arch_kexec_locate_mem_hole - Find free memory to place the segments.
> - * @kbuf:                       Parameters for the memory search.
> - *
> - * On success, kbuf->mem will have the start address of the memory region found.
> - *
> - * Return: 0 on success, negative errno on error.
> - */
> -static inline int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
> -{
> -	return kexec_locate_mem_hole(kbuf);
> -}
> -#endif
> -
>  #ifndef arch_kexec_apply_relocations_add
>  /*
>   * arch_kexec_apply_relocations_add - apply relocations of type RELA
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index 59fb9d71e9d8..9a981359addd 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -784,7 +784,7 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
>  	kbuf->cma = NULL;
>  
>  	/* Walk the RAM ranges and allocate a suitable range for the buffer */
> -	ret = arch_kexec_locate_mem_hole(kbuf);
> +	ret = kexec_locate_mem_hole(kbuf);
>  	if (ret)
>  		return ret;
>  

-- 
Regards,
Mukesh Pilaniya