[PATCH] powerpc: export cpu_smallcore_map for modules

[PATCH] powerpc: export cpu_smallcore_map for modules

[Randy Dunlap]

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@infradead.org>
Cc: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: amd-gfx@lists.freedesktop.org
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
---
 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);

Re: [PATCH] powerpc: export cpu_smallcore_map for modules

[Felix Kuehling]

On 2022-08-19 17:01, Randy Dunlap 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@infradead.org>
> Cc: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Nicholas Piggin <npiggin@gmail.com>
> Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: amd-gfx@lists.freedesktop.org
> Cc: Felix Kuehling <Felix.Kuehling@amd.com>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>

Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>


> ---
>   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);

Re: [PATCH] powerpc: export cpu_smallcore_map for modules

[Alex Deucher]

On Fri, Aug 19, 2022 at 6:18 PM Randy Dunlap <rdunlap@infradead.org> 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@infradead.org>
> Cc: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Nicholas Piggin <npiggin@gmail.com>
> Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: amd-gfx@lists.freedesktop.org
> Cc: Felix Kuehling <Felix.Kuehling@amd.com>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>

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

> ---
>  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);

Re: [PATCH] powerpc: export cpu_smallcore_map for modules

[Michael Ellerman]

Randy Dunlap <rdunlap@infradead.org> writes:
> 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")

That 2nd commit is not in mainline, only linux-next.

I don't mind merging this fix preemptively, but is that SHA stable?

cheers

Re: [PATCH] powerpc: export cpu_smallcore_map for modules

[Randy Dunlap]

On 8/21/22 20:40, Michael Ellerman wrote:
> Randy Dunlap <rdunlap@infradead.org> writes:
>> 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")
> 
> That 2nd commit is not in mainline, only linux-next.
> 
> I don't mind merging this fix preemptively, but is that SHA stable?

Felix, Alex, can you answer that, please?

-- 
~Randy

Re: [PATCH] powerpc: export cpu_smallcore_map for modules

[Christoph Hellwig]

On Mon, Aug 22, 2022 at 01:40:23PM +1000, Michael Ellerman wrote:
> Randy Dunlap <rdunlap@infradead.org> writes:
> > 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")
> 
> That 2nd commit is not in mainline, only linux-next.
> 
> I don't mind merging this fix preemptively, but is that SHA stable?

I really do not think this has any business being exported at all.

kfd_queue_work is not something that should be done in a driver.
Something like this belongs into the workqueue core, not in an
underdocumented helper in a random driver.

Drm guys:  once again, please please work with the maintainers instead
of just making up random stuff in the drivers.

Re: [PATCH] powerpc: export cpu_smallcore_map for modules

[Alex Deucher]

On Mon, Aug 22, 2022 at 9:16 AM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Mon, Aug 22, 2022 at 01:40:23PM +1000, Michael Ellerman wrote:
> > Randy Dunlap <rdunlap@infradead.org> writes:
> > > 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")
> >
> > That 2nd commit is not in mainline, only linux-next.
> >
> > I don't mind merging this fix preemptively, but is that SHA stable?
>
> I really do not think this has any business being exported at all.
>
> kfd_queue_work is not something that should be done in a driver.
> Something like this belongs into the workqueue core, not in an
> underdocumented helper in a random driver.
>
> Drm guys:  once again, please please work with the maintainers instead
> of just making up random stuff in the drivers.

Discussions are already ongoing with the workqueue folks.  I'll drop
this for now.

Alex