Re: [PATCH] powerpc: export cpu_smallcore_map for modules

[Alex Deucher]

On Fri, Aug 19, 2022 at 6:18 PM Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote:
>
> Fix build error when CONFIG_DRM_AMDGPU=m:
>
> ERROR: modpost: "cpu_smallcore_map" [drivers/gpu/drm/amd/amdgpu/amdgpu.ko] undefined!
>
> by exporting 'cpu_smallcore_map' just as other per_cpu
> symbols are exported.
>
> drivers/gpu/drm/amd/amdkfd/kfd_device.c calls cpu_smt_mask().
> This is an inline function on powerpc which references
> cpu_smallcore_map.
>
> Fixes: 425752c63b6f ("powerpc: Detect the presence of big-cores via "ibm, thread-groups"")
> Fixes: 7bc913085765 ("drm/amdkfd: Try to schedule bottom half on same core")
> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Cc: Gautham R. Shenoy <ego@xxxxxxxxxxxxxxxxxx>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
> Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: Felix Kuehling <Felix.Kuehling@xxxxxxx>
> Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> Cc: Christian König <christian.koenig@xxxxxxx>
> Cc: "Pan, Xinhui" <Xinhui.Pan@xxxxxxx>

Acked-by: Alex Deucher <alexander.deucher@xxxxxxx>

> ---
>  arch/powerpc/kernel/smp.c |    1 +
>  1 file changed, 1 insertion(+)
>
> --- a/arch/powerpc/kernel/smp.c
> +++ b/arch/powerpc/kernel/smp.c
> @@ -86,6 +86,7 @@ DEFINE_PER_CPU(cpumask_var_t, cpu_core_m
>  static DEFINE_PER_CPU(cpumask_var_t, cpu_coregroup_map);
>
>  EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
> +EXPORT_PER_CPU_SYMBOL(cpu_smallcore_map);
>  EXPORT_PER_CPU_SYMBOL(cpu_l2_cache_map);
>  EXPORT_PER_CPU_SYMBOL(cpu_core_map);
>  EXPORT_SYMBOL_GPL(has_big_cores);