Re: [PATCH v2 2/2] drm: share address space for dma bufs

From: Daniel Vetter <daniel@ffwll.ch>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: dri-devel <dri-devel@lists.freedesktop.org>,
	"Rob Herring" <robh@kernel.org>,
	intel-gfx <intel-gfx@lists.freedesktop.org>,
	"Alex Deucher" <alexander.deucher@amd.com>,
	"Christian König" <christian.koenig@amd.com>,
	"David (ChunMing) Zhou" <David1.Zhou@amd.com>,
	"David Airlie" <airlied@linux.ie>,
	"Maarten Lankhorst" <maarten.lankhorst@linux.intel.com>,
	"Maxime Ripard" <mripard@kernel.org>,
	"open list:RADEON and AMDGPU DRM DRIVERS"
	<amd-gfx@lists.freedesktop.org>,
	"open list" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 2/2] drm: share address space for dma bufs
Date: Fri, 22 Nov 2019 10:17:27 +0100	[thread overview]
Message-ID: <CAKMK7uFz3hmPT3OE8UtUQwmv+tXsjazUWT2RVHLxAq47X+EaXA@mail.gmail.com> (raw)
In-Reply-To: <20191122063749.27113-3-kraxel@redhat.com>

On Fri, Nov 22, 2019 at 7:37 AM Gerd Hoffmann <kraxel@redhat.com> wrote:
>
> Use the shared address space of the drm device (see drm_open() in
> drm_file.c) for dma-bufs too.  That removes a difference betweem drm
> device mmap vmas and dma-buf mmap vmas and fixes corner cases like
> dropping ptes (using madvise(DONTNEED) for example) not working
> properly.
>
> Also remove amdgpu driver's private dmabuf update.  It is not needed
> any more now that we are doing this for everybody.
>
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

But I think you want at least an ack from amd guys for double checking here.
-Daniel
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 4 +---
>  drivers/gpu/drm/drm_prime.c                 | 4 +++-
>  2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> index d5bcdfefbad6..586db4fb46bd 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> @@ -361,10 +361,8 @@ struct dma_buf *amdgpu_gem_prime_export(struct drm_gem_object *gobj,
>                 return ERR_PTR(-EPERM);
>
>         buf = drm_gem_prime_export(gobj, flags);
> -       if (!IS_ERR(buf)) {
> -               buf->file->f_mapping = gobj->dev->anon_inode->i_mapping;
> +       if (!IS_ERR(buf))
>                 buf->ops = &amdgpu_dmabuf_ops;
> -       }
>
>         return buf;
>  }
> diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
> index a9633bd241bb..c3fc341453c0 100644
> --- a/drivers/gpu/drm/drm_prime.c
> +++ b/drivers/gpu/drm/drm_prime.c
> @@ -240,6 +240,7 @@ void drm_prime_destroy_file_private(struct drm_prime_file_private *prime_fpriv)
>  struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev,
>                                       struct dma_buf_export_info *exp_info)
>  {
> +       struct drm_gem_object *obj = exp_info->priv;
>         struct dma_buf *dma_buf;
>
>         dma_buf = dma_buf_export(exp_info);
> @@ -247,7 +248,8 @@ struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev,
>                 return dma_buf;
>
>         drm_dev_get(dev);
> -       drm_gem_object_get(exp_info->priv);
> +       drm_gem_object_get(obj);
> +       dma_buf->file->f_mapping = obj->dev->anon_inode->i_mapping;
>
>         return dma_buf;
>  }
> --
> 2.18.1
>


-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch