Re: [PATCH] powerpc/kexec_file: fix implicit decl error

[Sourabh Jain]

On 04/02/23 22:52, Randy Dunlap wrote:
> kexec (PPC64) code calls memory_hotplug_max(). Add the header declaration
> for it from <asm/mmzone.h>. Using <linux/mmzone.h> does not work since
> the #include for <asm/mmzone.h> depends on CONFIG_NUMA=y, which is not
> set in this kernel config file.

I didn't realize that linux/mmzone.h includes asm/mmzone.h under 
CONFIG_NUMA.

from linux/mmzone.h

#else /* CONFIG_NUMA */

#include <asm/mmzone.h>

#endif /* !CONFIG_NUMA */

> Fixes this build error/warning:
>
> ../arch/powerpc/kexec/file_load_64.c: In function 'kexec_extra_fdt_size_ppc64':
> ../arch/powerpc/kexec/file_load_64.c:993:33: error: implicit declaration of function 'memory_hotplug_max' [-Werror=implicit-function-declaration]
>    993 |                 usm_entries = ((memory_hotplug_max() / drmem_lmb_size()) +
>        |                                 ^~~~~~~~~~~~~~~~~~
>
> Fixes: fc546faa5595 ("powerpc/kexec_file: Count hot-pluggable memory in FDT estimate")
> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Cc: Sourabh Jain <sourabhjain@xxxxxxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
> ---
>   arch/powerpc/kexec/file_load_64.c |    1 +
>   1 file changed, 1 insertion(+)
>
> diff -- a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c
> --- a/arch/powerpc/kexec/file_load_64.c
> +++ b/arch/powerpc/kexec/file_load_64.c
> @@ -26,6 +26,7 @@
>   #include <asm/firmware.h>
>   #include <asm/kexec_ranges.h>
>   #include <asm/crashdump-ppc64.h>
> +#include <asm/mmzone.h>

Yes including the asm/mmzone.h will fix the build issue.

- Sourabh

>   #include <asm/prom.h>
>   
>   struct umem_info {