[PATCH v2 1/2] drm: call drm_gem_object_funcs.mmap with fake offset

[PATCH v2 1/2] drm: call drm_gem_object_funcs.mmap with fake offset

[Gerd Hoffmann]

The fake offset is going to stay, so change the calling convention for
drm_gem_object_funcs.mmap to include the fake offset.  Update all users
accordingly.

Note that this reverts 83b8a6f242ea ("drm/gem: Fix mmap fake offset
handling for drm_gem_object_funcs.mmap") and on top then adds the fake
offset to  drm_gem_prime_mmap to make sure all paths leading to
obj->funcs->mmap are consistent.

Fixes: 83b8a6f242ea ("drm/gem: Fix mmap fake offset handling for drm_gem_object_funcs.mmap")
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 include/drm/drm_gem.h                  | 4 +---
 drivers/gpu/drm/drm_gem.c              | 3 ---
 drivers/gpu/drm/drm_gem_shmem_helper.c | 3 +++
 drivers/gpu/drm/drm_prime.c            | 3 +++
 drivers/gpu/drm/ttm/ttm_bo_vm.c        | 7 -------
 5 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 97a48165642c..0b375069cd48 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -159,9 +159,7 @@ struct drm_gem_object_funcs {
 	 *
 	 * The callback is used by by both drm_gem_mmap_obj() and
 	 * drm_gem_prime_mmap().  When @mmap is present @vm_ops is not
-	 * used, the @mmap callback must set vma->vm_ops instead. The @mmap
-	 * callback is always called with a 0 offset. The caller will remove
-	 * the fake offset as necessary.
+	 * used, the @mmap callback must set vma->vm_ops instead.
 	 */
 	int (*mmap)(struct drm_gem_object *obj, struct vm_area_struct *vma);
 
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 2f2b889096b0..56f42e0f2584 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1106,9 +1106,6 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
 		return -EINVAL;
 
 	if (obj->funcs && obj->funcs->mmap) {
-		/* Remove the fake offset */
-		vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node);
-
 		ret = obj->funcs->mmap(obj, vma);
 		if (ret)
 			return ret;
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 0810d3ef6961..a421a2eed48a 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -528,6 +528,9 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 	struct drm_gem_shmem_object *shmem;
 	int ret;
 
+	/* Remove the fake offset */
+	vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node);
+
 	shmem = to_drm_gem_shmem_obj(obj);
 
 	ret = drm_gem_shmem_get_pages(shmem);
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 0814211b0f3f..a9633bd241bb 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -714,6 +714,9 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
 	int ret;
 
 	if (obj->funcs && obj->funcs->mmap) {
+		/* Add the fake offset */
+		vma->vm_pgoff += drm_vma_node_start(&obj->vma_node);
+
 		ret = obj->funcs->mmap(obj, vma);
 		if (ret)
 			return ret;
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index e6495ca2630b..3e8c3de91ae4 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -514,13 +514,6 @@ EXPORT_SYMBOL(ttm_bo_mmap);
 int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 {
 	ttm_bo_get(bo);
-
-	/*
-	 * FIXME: &drm_gem_object_funcs.mmap is called with the fake offset
-	 * removed. Add it back here until the rest of TTM works without it.
-	 */
-	vma->vm_pgoff += drm_vma_node_start(&bo->base.vma_node);
-
 	ttm_bo_mmap_vma_setup(bo, vma);
 	return 0;
 }
-- 
2.18.1

Re: [PATCH v2 1/2] drm: call drm_gem_object_funcs.mmap with fake offset

[Rob Herring]

On Fri, Nov 22, 2019 at 12:37 AM Gerd Hoffmann <kraxel@redhat.com> wrote:
>
> The fake offset is going to stay, so change the calling convention for
> drm_gem_object_funcs.mmap to include the fake offset.  Update all users
> accordingly.
>
> Note that this reverts 83b8a6f242ea ("drm/gem: Fix mmap fake offset
> handling for drm_gem_object_funcs.mmap") and on top then adds the fake
> offset to  drm_gem_prime_mmap to make sure all paths leading to
> obj->funcs->mmap are consistent.

IOW, v1 of my original fix. :) Though you did it a little differently:

> diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
> index 0814211b0f3f..a9633bd241bb 100644
> --- a/drivers/gpu/drm/drm_prime.c
> +++ b/drivers/gpu/drm/drm_prime.c
> @@ -714,6 +714,9 @@ int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
>         int ret;
>
>         if (obj->funcs && obj->funcs->mmap) {
> +               /* Add the fake offset */
> +               vma->vm_pgoff += drm_vma_node_start(&obj->vma_node);
> +

Can't this be moved out of the if and then the same thing later down
removed? Unless there's some requirement that drm_vma_node_allow() be
called before drm_vma_node_start() in that case. Doesn't look like it
to me, but I'm not really sure.

>                 ret = obj->funcs->mmap(obj, vma);
>                 if (ret)
>                         return ret;

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

[Gerd Hoffmann]

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>
---
 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

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

[Daniel Vetter]

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

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

[Alex Deucher]

On Fri, Nov 22, 2019 at 4:17 AM Daniel Vetter <daniel@ffwll.ch> wrote:
>
> 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

Looks correct to me.

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


> > ---
> >  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
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

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

[Christian König]

Am 22.11.19 um 19:21 schrieb Alex Deucher:
> On Fri, Nov 22, 2019 at 4:17 AM Daniel Vetter <daniel@ffwll.ch> wrote:
>> 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
> Looks correct to me.
>
> Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

>
>
>>> ---
>>>   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
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx