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

Dave Young
2016-07-11T03:22:13Z

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@linux.vnet.ibm.com>
> Cc: Eric Biederman <ebiederm@xmission.com>
> Cc: Dave Young <dyoung@redhat.com>
> ---
> 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@redhat.com>

Thanks
Dave