Re: [PATCH 1/4] drm/amdgpu: Fix compilation under UML

[Alex Deucher]

On Fri, Feb 18, 2022 at 11:39 AM Felix Kuehling <felix.kuehling@xxxxxxx> wrote:
>
>
> Am 2022-02-18 um 02:57 schrieb David Gow:
> > From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> >
> > cpuinfo_x86 and its associated macros are not available under ARCH=um,
> > even though CONFIG_X86_64 is defined.
> >
> > This patch (and discussion) were originally posted here:
> > https://lkml.org/lkml/2022/1/24/1547
> >
> > This produces the following build errors:
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_topology.c:1556:9: note: in expansion of macro ‘cpu_data’
> >    return cpu_data(first_cpu_of_numa_node).apicid;
> >           ^~~~~~~~
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_topology.c:1560:1: error: control reaches end of non-void function [-Werror=return-type]
> >
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_crat.c: In function ‘kfd_fill_iolink_info_for_cpu’:
> > ../arch/um/include/asm/processor-generic.h:103:19: error: called object is not a function or function pointer
> >   #define cpu_data (&boot_cpu_data)
> >                    ~^~~~~~~~~~~~~~~
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_crat.c:1688:27: note: in expansion of macro ‘cpu_data’
> >    struct cpuinfo_x86 *c = &cpu_data(0);
> >                             ^~~~~~~~
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_crat.c:1691:7: error: dereferencing pointer to incomplete type ‘struct cpuinfo_x86’
> >    if (c->x86_vendor == X86_VENDOR_AMD)
> >         ^~
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_crat.c:1691:23: error: ‘X86_VENDOR_AMD’ undeclared (first use in this function); did you mean ‘X86_VENDOR_ANY’?
> >    if (c->x86_vendor == X86_VENDOR_AMD)
> >                         ^~~~~~~~~~~~~~
> >                         X86_VENDOR_ANY
> >
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_crat.c: In function ‘kfd_create_vcrat_image_cpu’:
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_crat.c:1742:11: warning: unused variable ‘entries’ [-Wunused-variable]
> >    uint32_t entries = 0;
> >
> > Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> > Signed-off-by: David Gow <davidgow@xxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/amd/amdkfd/kfd_crat.c     | 6 +++---
> >   drivers/gpu/drm/amd/amdkfd/kfd_topology.c | 2 +-
> >   2 files changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
> > index 9624bbe8b501..b1e2d117be3d 100644
> > --- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
> > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
> > @@ -1682,7 +1682,7 @@ static int kfd_fill_mem_info_for_cpu(int numa_node_id, int *avail_size,
> >       return 0;
> >   }
> >
> > -#ifdef CONFIG_X86_64
> > +#if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
>
> I don't think it makes sense to compile a hardware device driver in a
> UML config. Instead of scattering UML #ifdefs through our code, I would
> recommend adding this to Kconfig:
>
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -254,7 +254,7 @@ source "drivers/gpu/drm/radeon/Kconfig"
>
>   config DRM_AMDGPU
>          tristate "AMD GPU"
> -       depends on DRM && PCI && MMU
> +       depends on DRM && PCI && MMU && !UML
>          select FW_LOADER
>          select DRM_KMS_HELPER
>          select DRM_SCHED
>
> That would address patch 2 of this series as well.

I agree.  Otherwise, we are always going to be chasing these issues.

Alex

>
> Regards,
>    Felix
>
>
> >   static int kfd_fill_iolink_info_for_cpu(int numa_node_id, int *avail_size,
> >                               uint32_t *num_entries,
> >                               struct crat_subtype_iolink *sub_type_hdr)
> > @@ -1741,7 +1741,7 @@ static int kfd_create_vcrat_image_cpu(void *pcrat_image, size_t *size)
> >       struct crat_subtype_generic *sub_type_hdr;
> >       int avail_size = *size;
> >       int numa_node_id;
> > -#ifdef CONFIG_X86_64
> > +#if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
> >       uint32_t entries = 0;
> >   #endif
> >       int ret = 0;
> > @@ -1806,7 +1806,7 @@ static int kfd_create_vcrat_image_cpu(void *pcrat_image, size_t *size)
> >                       sub_type_hdr->length);
> >
> >               /* Fill in Subtype: IO Link */
> > -#ifdef CONFIG_X86_64
> > +#if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
> >               ret = kfd_fill_iolink_info_for_cpu(numa_node_id, &avail_size,
> >                               &entries,
> >                               (struct crat_subtype_iolink *)sub_type_hdr);
> > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
> > index 948fbb39336e..b38fc530ffe2 100644
> > --- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
> > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
> > @@ -1552,7 +1552,7 @@ static int kfd_cpumask_to_apic_id(const struct cpumask *cpumask)
> >       first_cpu_of_numa_node = cpumask_first(cpumask);
> >       if (first_cpu_of_numa_node >= nr_cpu_ids)
> >               return -1;
> > -#ifdef CONFIG_X86_64
> > +#if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
> >       return cpu_data(first_cpu_of_numa_node).apicid;
> >   #else
> >       return first_cpu_of_numa_node;