Re: [PATCH v4 3/9] kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer.

[Dave Young]

On 07/07/16 at 01:23pm, Thiago Jung Bauermann wrote:
> kexec_locate_mem_hole will be used by the PowerPC kexec_file_load
> implementation to find free memory for the purgatory stack.
> 
> Signed-off-by: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxxxxxxx>
> Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
> Cc: Dave Young <dyoung@xxxxxxxxxx>
> ---
>  include/linux/kexec.h |  1 +
>  kernel/kexec_file.c   | 25 ++++++++++++++++++++-----
>  2 files changed, 21 insertions(+), 5 deletions(-)
> 
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index ff5fa7707bd7..803f563df81d 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -174,6 +174,7 @@ struct kexec_buf {
>  int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
>  			       int (*func)(u64, u64, void *));
>  extern int kexec_add_buffer(struct kexec_buf *kbuf);
> +int kexec_locate_mem_hole(struct kexec_buf *kbuf);
>  #endif /* CONFIG_KEXEC_FILE */
>  
>  struct kimage {
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index 82ccfc4ee97e..3125d1689712 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -450,6 +450,23 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
>  }
>  
>  /**
> + * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
> + * @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.
> + */
> +int kexec_locate_mem_hole(struct kexec_buf *kbuf)
> +{
> +	int ret;
> +
> +	ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
> +
> +	return ret == 1 ? 0 : -EADDRNOTAVAIL;
> +}
> +
> +/**
>   * kexec_add_buffer - place a buffer in a kexec segment
>   * @kbuf:	Buffer contents and memory parameters.
>   *
> @@ -489,11 +506,9 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
>  	kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
>  
>  	/* Walk the RAM ranges and allocate a suitable range for the buffer */
> -	ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
> -	if (ret != 1) {
> -		/* A suitable memory range could not be found for buffer */
> -		return -EADDRNOTAVAIL;
> -	}
> +	ret = kexec_locate_mem_hole(kbuf);
> +	if (ret)
> +		return ret;
>  
>  	/* Found a suitable memory range */
>  	ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
> -- 
> 1.9.1
> 

Acked-by: Dave Young <dyoung@xxxxxxxxxx>

Thanks
Dave