Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20220218075727.2737623-1-davidgow@google.com> <20220218075727.2737623-2-davidgow@google.com>
 <ef8eee23-ba8c-e76a-d32d-68658841708d@amd.com>
In-Reply-To: <ef8eee23-ba8c-e76a-d32d-68658841708d@amd.com>
From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Fri, 18 Feb 2022 11:40:47 -0500
Message-ID: <CADnq5_Nxjq6+8k1bjs3LJfTzXgX1YRd0-=Fd55224V3_nOshAg@mail.gmail.com>
Subject: Re: [PATCH 1/4] drm/amdgpu: Fix compilation under UML
To:     Felix Kuehling <felix.kuehling@amd.com>
Cc:     David Gow <davidgow@google.com>, Jeff Dike <jdike@addtoit.com>,
        Richard Weinberger <richard@nod.at>,
        Anton Ivanov <anton.ivanov@cambridgegreys.com>,
        Shuah Khan <skhan@linuxfoundation.org>,
        Brendan Higgins <brendanhiggins@google.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        linux-rdma <linux-rdma@vger.kernel.org>, X86 ML <x86@kernel.org>,
        linux-um@lists.infradead.org, LKML <linux-kernel@vger.kernel.org>,
        Maling list - DRI developers 
        <dri-devel@lists.freedesktop.org>,
        amd-gfx list <amd-gfx@lists.freedesktop.org>,
        linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Fri, Feb 18, 2022 at 11:39 AM Felix Kuehling <felix.kuehling@amd.com> wr=
ote:
>
>
> Am 2022-02-18 um 02:57 schrieb David Gow:
> > From: Randy Dunlap <rdunlap@infradead.org>
> >
> > cpuinfo_x86 and its associated macros are not available under ARCH=3Dum=
,
> > 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 =E2=80=98cpu_data=E2=80=99
> >    return cpu_data(first_cpu_of_numa_node).apicid;
> >           ^~~~~~~~
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_topology.c:1560:1: error: c=
ontrol reaches end of non-void function [-Werror=3Dreturn-type]
> >
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_crat.c: In function =E2=80=
=98kfd_fill_iolink_info_for_cpu=E2=80=99:
> > ../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 ex=
pansion of macro =E2=80=98cpu_data=E2=80=99
> >    struct cpuinfo_x86 *c =3D &cpu_data(0);
> >                             ^~~~~~~~
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_crat.c:1691:7: error: deref=
erencing pointer to incomplete type =E2=80=98struct cpuinfo_x86=E2=80=99
> >    if (c->x86_vendor =3D=3D X86_VENDOR_AMD)
> >         ^~
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_crat.c:1691:23: error: =E2=
=80=98X86_VENDOR_AMD=E2=80=99 undeclared (first use in this function); did =
you mean =E2=80=98X86_VENDOR_ANY=E2=80=99?
> >    if (c->x86_vendor =3D=3D X86_VENDOR_AMD)
> >                         ^~~~~~~~~~~~~~
> >                         X86_VENDOR_ANY
> >
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_crat.c: In function =E2=80=
=98kfd_create_vcrat_image_cpu=E2=80=99:
> > ../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_crat.c:1742:11: warning: un=
used variable =E2=80=98entries=E2=80=99 [-Wunused-variable]
> >    uint32_t entries =3D 0;
> >
> > Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> > Signed-off-by: David Gow <davidgow@google.com>
> > ---
> >   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/am=
d/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_nod=
e_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 =3D *size;
> >       int numa_node_id;
> > -#ifdef CONFIG_X86_64
> > +#if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
> >       uint32_t entries =3D 0;
> >   #endif
> >       int ret =3D 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 =3D kfd_fill_iolink_info_for_cpu(numa_node_id, &avail=
_size,
> >                               &entries,
> >                               (struct crat_subtype_iolink *)sub_type_hd=
r);
> > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/dr=
m/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 cp=
umask *cpumask)
> >       first_cpu_of_numa_node =3D cpumask_first(cpumask);
> >       if (first_cpu_of_numa_node >=3D 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;