[PATCH 1/2] sample/mdev/mbochs: remove mbochs_kmap_atomic_dmabuf

[PATCH 1/2] sample/mdev/mbochs: remove mbochs_kmap_atomic_dmabuf

[Gerd Hoffmann]

Atomic mapping interface for dmabufs will be removed.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 samples/vfio-mdev/mbochs.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index 2960e26c6e..aa25cda21d 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -803,15 +803,6 @@ static void mbochs_release_dmabuf(struct dma_buf *buf)
 	mutex_unlock(&mdev_state->ops_lock);
 }
 
-static void *mbochs_kmap_atomic_dmabuf(struct dma_buf *buf,
-				       unsigned long page_num)
-{
-	struct mbochs_dmabuf *dmabuf = buf->priv;
-	struct page *page = dmabuf->pages[page_num];
-
-	return kmap_atomic(page);
-}
-
 static void *mbochs_kmap_dmabuf(struct dma_buf *buf, unsigned long page_num)
 {
 	struct mbochs_dmabuf *dmabuf = buf->priv;
@@ -824,7 +815,6 @@ static struct dma_buf_ops mbochs_dmabuf_ops = {
 	.map_dma_buf	  = mbochs_map_dmabuf,
 	.unmap_dma_buf	  = mbochs_unmap_dmabuf,
 	.release	  = mbochs_release_dmabuf,
-	.map_atomic	  = mbochs_kmap_atomic_dmabuf,
 	.map		  = mbochs_kmap_dmabuf,
 	.mmap		  = mbochs_mmap_dmabuf,
 };
-- 
2.9.3

[PATCH 2/2] sample/mdev/mbochs: add mbochs_kunmap_dmabuf

[Gerd Hoffmann]

There is no default implementation for dma_buf_ops->unmap.
So add a function unmapping the page, otherwise we'll leak them.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 samples/vfio-mdev/mbochs.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index aa25cda21d..85ac603769 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -811,11 +811,18 @@ static void *mbochs_kmap_dmabuf(struct dma_buf *buf, unsigned long page_num)
 	return kmap(page);
 }
 
+static void mbochs_kunmap_dmabuf(struct dma_buf *buf, unsigned long page_num,
+				 void *vaddr)
+{
+	kunmap(vaddr);
+}
+
 static struct dma_buf_ops mbochs_dmabuf_ops = {
 	.map_dma_buf	  = mbochs_map_dmabuf,
 	.unmap_dma_buf	  = mbochs_unmap_dmabuf,
 	.release	  = mbochs_release_dmabuf,
 	.map		  = mbochs_kmap_dmabuf,
+	.unmap		  = mbochs_kunmap_dmabuf,
 	.mmap		  = mbochs_mmap_dmabuf,
 };
 
-- 
2.9.3

Re: [PATCH 2/2] sample/mdev/mbochs: add mbochs_kunmap_dmabuf

[Alex Williamson]

On Mon, 25 Jun 2018 08:44:52 +0200
Gerd Hoffmann <kraxel@redhat.com> wrote:

> There is no default implementation for dma_buf_ops->unmap.
> So add a function unmapping the page, otherwise we'll leak them.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  samples/vfio-mdev/mbochs.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
> index aa25cda21d..85ac603769 100644
> --- a/samples/vfio-mdev/mbochs.c
> +++ b/samples/vfio-mdev/mbochs.c
> @@ -811,11 +811,18 @@ static void *mbochs_kmap_dmabuf(struct dma_buf *buf, unsigned long page_num)
>  	return kmap(page);
>  }
>  
> +static void mbochs_kunmap_dmabuf(struct dma_buf *buf, unsigned long page_num,
> +				 void *vaddr)
> +{
> +	kunmap(vaddr);
> +}
> +
>  static struct dma_buf_ops mbochs_dmabuf_ops = {
>  	.map_dma_buf	  = mbochs_map_dmabuf,
>  	.unmap_dma_buf	  = mbochs_unmap_dmabuf,
>  	.release	  = mbochs_release_dmabuf,
>  	.map		  = mbochs_kmap_dmabuf,
> +	.unmap		  = mbochs_kunmap_dmabuf,
>  	.mmap		  = mbochs_mmap_dmabuf,
>  };
>  

Is this a fix for v4.18?  AFAICT, the kmap_atomic removal is only in
next, not yet upstream and hopefully includes this sample driver before
hitting mainline.  Should we therefore have a v4.18-rc based patch for
this to include before v4.18 to resolve this?  Thanks,

Alex

Re: [PATCH 2/2] sample/mdev/mbochs: add mbochs_kunmap_dmabuf

[Gerd Hoffmann]

> >  	.map		  = mbochs_kmap_dmabuf,
> > +	.unmap		  = mbochs_kunmap_dmabuf,
> >  	.mmap		  = mbochs_mmap_dmabuf,
> >  };
> >  
> 
> Is this a fix for v4.18?

Yes.

> AFAICT, the kmap_atomic removal is only in
> next, not yet upstream and hopefully includes this sample driver before
> hitting mainline.  Should we therefore have a v4.18-rc based patch for
> this to include before v4.18 to resolve this?

The kmap_atomic interface will be removed in 4.19 because nobody uses
it, so dropping the mbochs implementation already in 4.18 should not
cause any issues.

So just queue both for 4.18 would be the easiest way do deal with the
dependency I think.

cheers,
  Gerd

Re: [PATCH 2/2] sample/mdev/mbochs: add mbochs_kunmap_dmabuf

[Alex Williamson]

On Tue, 26 Jun 2018 09:32:33 +0200
Gerd Hoffmann <kraxel@redhat.com> wrote:

> > >  	.map		  = mbochs_kmap_dmabuf,
> > > +	.unmap		  = mbochs_kunmap_dmabuf,
> > >  	.mmap		  = mbochs_mmap_dmabuf,
> > >  };
> > >    
> > 
> > Is this a fix for v4.18?  
> 
> Yes.
> 
> > AFAICT, the kmap_atomic removal is only in
> > next, not yet upstream and hopefully includes this sample driver before
> > hitting mainline.  Should we therefore have a v4.18-rc based patch for
> > this to include before v4.18 to resolve this?  
> 
> The kmap_atomic interface will be removed in 4.19 because nobody uses
> it, so dropping the mbochs implementation already in 4.18 should not
> cause any issues.
> 
> So just queue both for 4.18 would be the easiest way do deal with the
> dependency I think.

Ok, so I'll drop the fixes tag and apply both to my for-linus branch
for v4.18 and then Christian won't need to include it for the v4.19
patch.  Thanks,

Alex

Re: [PATCH 1/2] sample/mdev/mbochs: remove mbochs_kmap_atomic_dmabuf

[Alex Williamson]

On Mon, 25 Jun 2018 08:44:51 +0200
Gerd Hoffmann <kraxel@redhat.com> wrote:

> Atomic mapping interface for dmabufs will be removed.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Fixes: f664a5269542 ("dma-buf: remove kmap_atomic interface")

Though really the above commit needs to be updated to include this fix
to preserve bisection since the mbochs sample driver is already
upstream, suggests we only compile tested removing kmap_atomic without
looking for other users.  drm folks, please update.  Thanks,

Alex

> ---
>  samples/vfio-mdev/mbochs.c | 10 ----------
>  1 file changed, 10 deletions(-)
> 
> diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
> index 2960e26c6e..aa25cda21d 100644
> --- a/samples/vfio-mdev/mbochs.c
> +++ b/samples/vfio-mdev/mbochs.c
> @@ -803,15 +803,6 @@ static void mbochs_release_dmabuf(struct dma_buf *buf)
>  	mutex_unlock(&mdev_state->ops_lock);
>  }
>  
> -static void *mbochs_kmap_atomic_dmabuf(struct dma_buf *buf,
> -				       unsigned long page_num)
> -{
> -	struct mbochs_dmabuf *dmabuf = buf->priv;
> -	struct page *page = dmabuf->pages[page_num];
> -
> -	return kmap_atomic(page);
> -}
> -
>  static void *mbochs_kmap_dmabuf(struct dma_buf *buf, unsigned long page_num)
>  {
>  	struct mbochs_dmabuf *dmabuf = buf->priv;
> @@ -824,7 +815,6 @@ static struct dma_buf_ops mbochs_dmabuf_ops = {
>  	.map_dma_buf	  = mbochs_map_dmabuf,
>  	.unmap_dma_buf	  = mbochs_unmap_dmabuf,
>  	.release	  = mbochs_release_dmabuf,
> -	.map_atomic	  = mbochs_kmap_atomic_dmabuf,
>  	.map		  = mbochs_kmap_dmabuf,
>  	.mmap		  = mbochs_mmap_dmabuf,
>  };