Re: [Intel-gfx] [PATCH 2/2] drm: share address space for dma bufs
On Thu, Nov 21, 2019 at 04:42:10PM +, Ruhl, Michael J wrote: > >-Original Message- > >From: Intel-gfx On Behalf Of Gerd > >Hoffmann > >Sent: Thursday, November 21, 2019 5:38 AM > >To: dri-devel@lists.freedesktop.org > >Cc: David Airlie ; intel-...@lists.freedesktop.org; open > >list > >; Maxime Ripard ; Gerd > >Hoffmann > >Subject: [Intel-gfx] [PATCH 2/2] drm: share address space for dma bufs > > > >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 > >unmaps not working properly. > > Hi Gerd, > > Just want to make sure I understand this... > > So unmaps will not work correctly for mappings when a driver does a > drm_vma_node_unamp()? Completely removing the mapping (aka munmap syscall) works fine. Zapping the pte's (using madvise(dontneed) for example) doesn't. > This is a day one bug? I guess so, but I'll leave that to others being active longer than me in drm hacking to answer ... cheers, Gerd ___ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
RE: [Intel-gfx] [PATCH 2/2] drm: share address space for dma bufs
>-Original Message-
>From: Intel-gfx On Behalf Of Gerd
>Hoffmann
>Sent: Thursday, November 21, 2019 5:38 AM
>To: dri-devel@lists.freedesktop.org
>Cc: David Airlie ; intel-...@lists.freedesktop.org; open list
>; Maxime Ripard ; Gerd
>Hoffmann
>Subject: [Intel-gfx] [PATCH 2/2] drm: share address space for dma bufs
>
>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
>unmaps not working properly.
Hi Gerd,
Just want to make sure I understand this...
So unmaps will not work correctly for mappings when a driver does a
drm_vma_node_unamp()?
I.e. the dmabuf mappings will not get cleaned up correctly?
This is a day one bug?
Thanks,
Mike
>Signed-off-by: Gerd Hoffmann
>---
> drivers/gpu/drm/drm_prime.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
>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
>
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Re: [PATCH 2/2] drm: share address space for dma bufs
On Thu, Nov 21, 2019 at 11:38:07AM +0100, Gerd Hoffmann 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
> unmaps not working properly.
>
> Signed-off-by: Gerd Hoffmann
> ---
> drivers/gpu/drm/drm_prime.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> 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;
Can you pls also throw the change to amdgpu_gem_prime_export on top here?
Imo makes a lot more sense that way. With that added I'm happy to r-b.
-Daniel
>
> return dma_buf;
> }
> --
> 2.18.1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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[PATCH 2/2] drm: share address space for dma bufs
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
unmaps not working properly.
Signed-off-by: Gerd Hoffmann
---
drivers/gpu/drm/drm_prime.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
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
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