On 06/15/16 at 01:21pm, Thiago Jung Bauermann wrote:
> Hello Dave,
>
> Am Mittwoch, 15 Juni 2016, 15:33:02 schrieb Dave Young:
> > > @@ -472,14 +498,16 @@ int kexec_add_buffer(struct kimage *image, char
> > > *buffer, unsigned long bufsz,>
> > > kbuf->top_down = top_down;
> > >
> > > /* Walk the RAM ranges and allocate a suitable range for the buffer */
> > >
> > > - if (image->type == KEXEC_TYPE_CRASH)
> > > - ret = walk_iomem_res_desc(crashk_res.desc,
> > > - IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
> > > - crashk_res.start, crashk_res.end, kbuf,
> > > - locate_mem_hole_callback);
> > > - else
> > > - ret = walk_system_ram_res(0, -1, kbuf,
> > > - locate_mem_hole_callback);
> > > + if (image->type == KEXEC_TYPE_CRASH) {
> > > + start = crashk_res.start;
> > > + end = crashk_res.end;
> > > + } else {
> > > + start = 0;
> > > + end = ULONG_MAX;
> > > + }
> >
> > For crashk_res, start and end is global, the non-crash values are
> > hard coded, thus it is not necessary to pass these two in arguments.
> >
> > Moving above to arch_kexec_walk_mem will make it cleaner.
>
> That's true. What about this version?
>
> []'s
> Thiago Jung Bauermann
> IBM Linux Technology Center
>
>
> kexec_file: Generalize kexec_add_buffer.
>
> Allow architectures to specify different memory walking functions for
> kexec_add_buffer. Intel uses iomem to track reserved memory ranges,
> but PowerPC uses the memblock subsystem.
>
> Signed-off-by: Thiago Jung Bauermann <bauerman at linux.vnet.ibm.com>
> Cc: Eric Biederman <ebiederm at xmission.com>
> Cc: Dave Young <dyoung at redhat.com>
> Cc: kexec at lists.infradead.org
> Cc: linux-kernel at vger.kernel.org
>
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index e8acb2b43dd9..9b02f907b40a 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -315,6 +315,8 @@ int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr,
> Elf_Shdr *sechdrs, unsigned int relsec);
> int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
> unsigned int relsec);
> +int __weak arch_kexec_walk_mem(unsigned int image_type, bool top_down,
> + void *data, int (*func)(u64, u64, void *));
> void arch_kexec_protect_crashkres(void);
> void arch_kexec_unprotect_crashkres(void);
>
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index b6eec7527e9f..2d066c458222 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -428,6 +428,29 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg)
> return locate_mem_hole_bottom_up(start, end, kbuf);
> }
>
> +/**
> + * arch_kexec_walk_mem - call func(data) on free memory regions
> + * @image_type: kimage.type
> + * @top_down: Start from the highest address?
> + * @data: Argument to pass to @func.
> + * @func: Function to call for each memory region.
> + *
> + * Return: The memory walk will stop when func returns a non-zero value
> + * and that value will be returned. If all free regions are visited without
> + * func returning non-zero, then zero will be returned.
> + */
> +int __weak arch_kexec_walk_mem(unsigned int image_type, bool top_down,
> + void *data, int (*func)(u64, u64, void *))
> +{
top_down is also not used?
Rethink about the argument name type should be better than image_type,
it is obvious in the comments and the code and simpler.
> + if (image_type == KEXEC_TYPE_CRASH)
> + return walk_iomem_res_desc(crashk_res.desc,
> + IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
> + crashk_res.start, crashk_res.end,
> + data, func);
> + else
> + return walk_system_ram_res(0, ULONG_MAX, data, func);
> +}
> +
> /*
> * Helper function for placing a buffer in a kexec segment. This assumes
> * that kexec_mutex is held.
> @@ -472,14 +495,8 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
> kbuf->top_down = top_down;
>
> /* Walk the RAM ranges and allocate a suitable range for the buffer */
> - if (image->type == KEXEC_TYPE_CRASH)
> - ret = walk_iomem_res_desc(crashk_res.desc,
> - IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
> - crashk_res.start, crashk_res.end, kbuf,
> - locate_mem_hole_callback);
> - else
> - ret = walk_system_ram_res(0, -1, kbuf,
> - locate_mem_hole_callback);
> + ret = arch_kexec_walk_mem(image->type, top_down, kbuf,
> + locate_mem_hole_callback);
> if (ret != 1) {
> /* A suitable memory range could not be found for buffer */
> return -EADDRNOTAVAIL;
>
