diff mbox

[v2,1/1] drm: add kernel doc for exported gem dmabuf_ops

Message ID 1516311860-24949-1-git-send-email-Samuel.Li@amd.com (mailing list archive)
State New, archived
Headers show

Commit Message

Li, Samuel Jan. 18, 2018, 9:44 p.m. UTC
Signed-off-by: Samuel Li <Samuel.Li@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/drm_prime.c | 88 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)

Comments

Christian König Jan. 19, 2018, 8:51 a.m. UTC | #1
Am 18.01.2018 um 22:44 schrieb Samuel Li:
> Signed-off-by: Samuel Li <Samuel.Li@amd.com>
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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

> ---
>   drivers/gpu/drm/drm_prime.c | 88 +++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 88 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
> index ca09ce7..e82a976 100644
> --- a/drivers/gpu/drm/drm_prime.c
> +++ b/drivers/gpu/drm/drm_prime.c
> @@ -73,6 +73,9 @@
>    * Drivers should detect this situation and return back the gem object
>    * from the dma-buf private.  Prime will do this automatically for drivers that
>    * use the drm_gem_prime_{import,export} helpers.
> + *
> + * GEM struct &dma_buf_ops symbols are now exported. They can be resued by
> + * drivers which implement GEM interface.
>    */
>   
>   struct drm_prime_member {
> @@ -180,6 +183,18 @@ static int drm_prime_lookup_buf_handle(struct drm_prime_file_private *prime_fpri
>   	return -ENOENT;
>   }
>   
> +/**
> + * drm_gem_map_attach - dma_buf attach implementation for GEM
> + * @dma_buf: buffer to attach device to
> + * @target_dev: not used
> + * @attach: buffer attachment data
> + *
> + * Allocates &drm_prime_attachment and calls &drm_driver.gem_prime_pin for
> + * device specific attachment. This can be used as the &dma_buf_ops.attach
> + * callback.
> + *
> + * Returns 0 on success, negative error code on failure.
> + */
>   int drm_gem_map_attach(struct dma_buf *dma_buf, struct device *target_dev,
>   		       struct dma_buf_attachment *attach)
>   {
> @@ -201,6 +216,14 @@ int drm_gem_map_attach(struct dma_buf *dma_buf, struct device *target_dev,
>   }
>   EXPORT_SYMBOL(drm_gem_map_attach);
>   
> +/**
> + * drm_gem_map_detach - dma_buf detach implementation for GEM
> + * @dma_buf: buffer to detach from
> + * @attach: attachment to be detached
> + *
> + * Cleans up &dma_buf_attachment. This can be used as the &dma_buf_ops.detach
> + * callback.
> + */
>   void drm_gem_map_detach(struct dma_buf *dma_buf,
>   			struct dma_buf_attachment *attach)
>   {
> @@ -255,6 +278,18 @@ void drm_prime_remove_buf_handle_locked(struct drm_prime_file_private *prime_fpr
>   	}
>   }
>   
> +/**
> + * drm_gem_map_dma_buf - map_dma_buf implementation for GEM
> + * @attach: attachment whose scatterlist is to be returned
> + * @dir: direction of DMA transfer
> + *
> + * Calls &drm_driver.gem_prime_get_sg_table and then maps the scatterlist. This
> + * can be used as the &dma_buf_ops.map_dma_buf callback.
> + *
> + * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR
> + * on error. May return -EINTR if it is interrupted by a signal.
> + */
> +
>   struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
>   				     enum dma_data_direction dir)
>   {
> @@ -294,6 +329,12 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
>   }
>   EXPORT_SYMBOL(drm_gem_map_dma_buf);
>   
> +/**
> + * drm_gem_unmap_dma_buf - unmap_dma_buf implementation for GEM
> + *
> + * Not implemented. The unmap is done at drm_gem_map_detach().  This can be
> + * used as the &dma_buf_ops.unmap_dma_buf callback.
> + */
>   void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
>   			   struct sg_table *sgt,
>   			   enum dma_data_direction dir)
> @@ -351,6 +392,15 @@ void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
>   }
>   EXPORT_SYMBOL(drm_gem_dmabuf_release);
>   
> +/**
> + * drm_gem_dmabuf_vmap - dma_buf vmap implementation for GEM
> + * @dma_buf: buffer to be mapped
> + *
> + * Sets up a kernel virtual mapping. This can be used as the &dma_buf_ops.vmap
> + * callback.
> + *
> + * Returns the kernel virtual address.
> + */
>   void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
>   {
>   	struct drm_gem_object *obj = dma_buf->priv;
> @@ -360,6 +410,14 @@ void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
>   }
>   EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
>   
> +/**
> + * drm_gem_dmabuf_vunmap - dma_buf vunmap implementation for GEM
> + * @dma_buf: buffer to be unmapped
> + * @vaddr: the virtual address of the buffer
> + *
> + * Releases a kernel virtual mapping. This can be used as the
> + * &dma_buf_ops.vunmap callback.
> + */
>   void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
>   {
>   	struct drm_gem_object *obj = dma_buf->priv;
> @@ -369,6 +427,11 @@ void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
>   }
>   EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
>   
> +/**
> + * drm_gem_dmabuf_kmap_atomic - map_atomic implementation for GEM
> + *
> + * Not implemented. This can be used as the &dma_buf_ops.map_atomic callback.
> + */
>   void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
>   				 unsigned long page_num)
>   {
> @@ -376,6 +439,11 @@ void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
>   }
>   EXPORT_SYMBOL(drm_gem_dmabuf_kmap_atomic);
>   
> +/**
> + * drm_gem_dmabuf_kunmap_atomic - unmap_atomic implementation for GEM
> + *
> + * Not implemented. This can be used as the &dma_buf_ops.unmap_atomic callback.
> + */
>   void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
>   				  unsigned long page_num, void *addr)
>   {
> @@ -383,12 +451,22 @@ void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
>   }
>   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap_atomic);
>   
> +/**
> + * drm_gem_dmabuf_kmap - map implementation for GEM
> + *
> + * Not implemented. This can be used as the &dma_buf_ops.map callback.
> + */
>   void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
>   {
>   	return NULL;
>   }
>   EXPORT_SYMBOL(drm_gem_dmabuf_kmap);
>   
> +/**
> + * drm_gem_dmabuf_kunmap - unmap implementation for GEM
> + *
> + * Not implemented. This can be used as the &dma_buf_ops.unmap callback.
> + */
>   void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num,
>   			   void *addr)
>   {
> @@ -396,6 +474,16 @@ void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num,
>   }
>   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap);
>   
> +/**
> + * drm_gem_dmabuf_mmap - dma_buf mmap implementation for GEM
> + * @dma_buf: buffer to be mapped
> + * @vma: virtual address range
> + *
> + * Provides memory mapping for the buffer. This can be used as the
> + * &dma_buf_ops.mmap callback.
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
>   int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
>   {
>   	struct drm_gem_object *obj = dma_buf->priv;
Daniel Vetter Jan. 30, 2018, 9:32 a.m. UTC | #2
On Fri, Jan 19, 2018 at 09:51:20AM +0100, Christian König wrote:
> Am 18.01.2018 um 22:44 schrieb Samuel Li:
> > Signed-off-by: Samuel Li <Samuel.Li@amd.com>
> > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Thanks for updating the docs.
> 
> Reviewed-by: Christian König <christian.koenig@amd.com>

I'm assuming you'll als push this one.
-Daniel

> 
> > ---
> >   drivers/gpu/drm/drm_prime.c | 88 +++++++++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 88 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
> > index ca09ce7..e82a976 100644
> > --- a/drivers/gpu/drm/drm_prime.c
> > +++ b/drivers/gpu/drm/drm_prime.c
> > @@ -73,6 +73,9 @@
> >    * Drivers should detect this situation and return back the gem object
> >    * from the dma-buf private.  Prime will do this automatically for drivers that
> >    * use the drm_gem_prime_{import,export} helpers.
> > + *
> > + * GEM struct &dma_buf_ops symbols are now exported. They can be resued by
> > + * drivers which implement GEM interface.
> >    */
> >   struct drm_prime_member {
> > @@ -180,6 +183,18 @@ static int drm_prime_lookup_buf_handle(struct drm_prime_file_private *prime_fpri
> >   	return -ENOENT;
> >   }
> > +/**
> > + * drm_gem_map_attach - dma_buf attach implementation for GEM
> > + * @dma_buf: buffer to attach device to
> > + * @target_dev: not used
> > + * @attach: buffer attachment data
> > + *
> > + * Allocates &drm_prime_attachment and calls &drm_driver.gem_prime_pin for
> > + * device specific attachment. This can be used as the &dma_buf_ops.attach
> > + * callback.
> > + *
> > + * Returns 0 on success, negative error code on failure.
> > + */
> >   int drm_gem_map_attach(struct dma_buf *dma_buf, struct device *target_dev,
> >   		       struct dma_buf_attachment *attach)
> >   {
> > @@ -201,6 +216,14 @@ int drm_gem_map_attach(struct dma_buf *dma_buf, struct device *target_dev,
> >   }
> >   EXPORT_SYMBOL(drm_gem_map_attach);
> > +/**
> > + * drm_gem_map_detach - dma_buf detach implementation for GEM
> > + * @dma_buf: buffer to detach from
> > + * @attach: attachment to be detached
> > + *
> > + * Cleans up &dma_buf_attachment. This can be used as the &dma_buf_ops.detach
> > + * callback.
> > + */
> >   void drm_gem_map_detach(struct dma_buf *dma_buf,
> >   			struct dma_buf_attachment *attach)
> >   {
> > @@ -255,6 +278,18 @@ void drm_prime_remove_buf_handle_locked(struct drm_prime_file_private *prime_fpr
> >   	}
> >   }
> > +/**
> > + * drm_gem_map_dma_buf - map_dma_buf implementation for GEM
> > + * @attach: attachment whose scatterlist is to be returned
> > + * @dir: direction of DMA transfer
> > + *
> > + * Calls &drm_driver.gem_prime_get_sg_table and then maps the scatterlist. This
> > + * can be used as the &dma_buf_ops.map_dma_buf callback.
> > + *
> > + * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR
> > + * on error. May return -EINTR if it is interrupted by a signal.
> > + */
> > +
> >   struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
> >   				     enum dma_data_direction dir)
> >   {
> > @@ -294,6 +329,12 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
> >   }
> >   EXPORT_SYMBOL(drm_gem_map_dma_buf);
> > +/**
> > + * drm_gem_unmap_dma_buf - unmap_dma_buf implementation for GEM
> > + *
> > + * Not implemented. The unmap is done at drm_gem_map_detach().  This can be
> > + * used as the &dma_buf_ops.unmap_dma_buf callback.
> > + */
> >   void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
> >   			   struct sg_table *sgt,
> >   			   enum dma_data_direction dir)
> > @@ -351,6 +392,15 @@ void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
> >   }
> >   EXPORT_SYMBOL(drm_gem_dmabuf_release);
> > +/**
> > + * drm_gem_dmabuf_vmap - dma_buf vmap implementation for GEM
> > + * @dma_buf: buffer to be mapped
> > + *
> > + * Sets up a kernel virtual mapping. This can be used as the &dma_buf_ops.vmap
> > + * callback.
> > + *
> > + * Returns the kernel virtual address.
> > + */
> >   void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> >   {
> >   	struct drm_gem_object *obj = dma_buf->priv;
> > @@ -360,6 +410,14 @@ void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> >   }
> >   EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
> > +/**
> > + * drm_gem_dmabuf_vunmap - dma_buf vunmap implementation for GEM
> > + * @dma_buf: buffer to be unmapped
> > + * @vaddr: the virtual address of the buffer
> > + *
> > + * Releases a kernel virtual mapping. This can be used as the
> > + * &dma_buf_ops.vunmap callback.
> > + */
> >   void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
> >   {
> >   	struct drm_gem_object *obj = dma_buf->priv;
> > @@ -369,6 +427,11 @@ void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
> >   }
> >   EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
> > +/**
> > + * drm_gem_dmabuf_kmap_atomic - map_atomic implementation for GEM
> > + *
> > + * Not implemented. This can be used as the &dma_buf_ops.map_atomic callback.
> > + */
> >   void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
> >   				 unsigned long page_num)
> >   {
> > @@ -376,6 +439,11 @@ void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
> >   }
> >   EXPORT_SYMBOL(drm_gem_dmabuf_kmap_atomic);
> > +/**
> > + * drm_gem_dmabuf_kunmap_atomic - unmap_atomic implementation for GEM
> > + *
> > + * Not implemented. This can be used as the &dma_buf_ops.unmap_atomic callback.
> > + */
> >   void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
> >   				  unsigned long page_num, void *addr)
> >   {
> > @@ -383,12 +451,22 @@ void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
> >   }
> >   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap_atomic);
> > +/**
> > + * drm_gem_dmabuf_kmap - map implementation for GEM
> > + *
> > + * Not implemented. This can be used as the &dma_buf_ops.map callback.
> > + */
> >   void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
> >   {
> >   	return NULL;
> >   }
> >   EXPORT_SYMBOL(drm_gem_dmabuf_kmap);
> > +/**
> > + * drm_gem_dmabuf_kunmap - unmap implementation for GEM
> > + *
> > + * Not implemented. This can be used as the &dma_buf_ops.unmap callback.
> > + */
> >   void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num,
> >   			   void *addr)
> >   {
> > @@ -396,6 +474,16 @@ void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num,
> >   }
> >   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap);
> > +/**
> > + * drm_gem_dmabuf_mmap - dma_buf mmap implementation for GEM
> > + * @dma_buf: buffer to be mapped
> > + * @vma: virtual address range
> > + *
> > + * Provides memory mapping for the buffer. This can be used as the
> > + * &dma_buf_ops.mmap callback.
> > + *
> > + * Returns 0 on success or a negative error code on failure.
> > + */
> >   int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
> >   {
> >   	struct drm_gem_object *obj = dma_buf->priv;
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Li, Samuel Jan. 30, 2018, 4:01 p.m. UTC | #3
Alex helped push this into drm-tip,
https://cgit.freedesktop.org/drm/drm-tip/commit/drivers/gpu/drm?id=f7a71b0cf9e36c1b0edbfe89ce028a01164b864d

Thanks,
Samuel Li


> -----Original Message-----
> From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of Daniel
> Vetter
> Sent: Tuesday, January 30, 2018 4:33 AM
> To: Koenig, Christian <Christian.Koenig@amd.com>
> Cc: Li, Samuel <Samuel.Li@amd.com>; amd-gfx@lists.freedesktop.org; dri-
> devel@lists.freedesktop.org
> Subject: Re: [PATCH v2 1/1] drm: add kernel doc for exported gem
> dmabuf_ops
> 
> On Fri, Jan 19, 2018 at 09:51:20AM +0100, Christian König wrote:
> > Am 18.01.2018 um 22:44 schrieb Samuel Li:
> > > Signed-off-by: Samuel Li <Samuel.Li@amd.com>
> > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> 
> Thanks for updating the docs.
> >
> > Reviewed-by: Christian König <christian.koenig@amd.com>
> 
> I'm assuming you'll als push this one.
> -Daniel
> 
> >
> > > ---
> > >   drivers/gpu/drm/drm_prime.c | 88
> +++++++++++++++++++++++++++++++++++++++++++++
> > >   1 file changed, 88 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/drm_prime.c
> > > b/drivers/gpu/drm/drm_prime.c index ca09ce7..e82a976 100644
> > > --- a/drivers/gpu/drm/drm_prime.c
> > > +++ b/drivers/gpu/drm/drm_prime.c
> > > @@ -73,6 +73,9 @@
> > >    * Drivers should detect this situation and return back the gem object
> > >    * from the dma-buf private.  Prime will do this automatically for drivers
> that
> > >    * use the drm_gem_prime_{import,export} helpers.
> > > + *
> > > + * GEM struct &dma_buf_ops symbols are now exported. They can be
> > > + resued by
> > > + * drivers which implement GEM interface.
> > >    */
> > >   struct drm_prime_member {
> > > @@ -180,6 +183,18 @@ static int drm_prime_lookup_buf_handle(struct
> drm_prime_file_private *prime_fpri
> > >   	return -ENOENT;
> > >   }
> > > +/**
> > > + * drm_gem_map_attach - dma_buf attach implementation for GEM
> > > + * @dma_buf: buffer to attach device to
> > > + * @target_dev: not used
> > > + * @attach: buffer attachment data
> > > + *
> > > + * Allocates &drm_prime_attachment and calls
> > > +&drm_driver.gem_prime_pin for
> > > + * device specific attachment. This can be used as the
> > > +&dma_buf_ops.attach
> > > + * callback.
> > > + *
> > > + * Returns 0 on success, negative error code on failure.
> > > + */
> > >   int drm_gem_map_attach(struct dma_buf *dma_buf, struct device
> *target_dev,
> > >   		       struct dma_buf_attachment *attach)
> > >   {
> > > @@ -201,6 +216,14 @@ int drm_gem_map_attach(struct dma_buf
> *dma_buf, struct device *target_dev,
> > >   }
> > >   EXPORT_SYMBOL(drm_gem_map_attach);
> > > +/**
> > > + * drm_gem_map_detach - dma_buf detach implementation for GEM
> > > + * @dma_buf: buffer to detach from
> > > + * @attach: attachment to be detached
> > > + *
> > > + * Cleans up &dma_buf_attachment. This can be used as the
> > > +&dma_buf_ops.detach
> > > + * callback.
> > > + */
> > >   void drm_gem_map_detach(struct dma_buf *dma_buf,
> > >   			struct dma_buf_attachment *attach)
> > >   {
> > > @@ -255,6 +278,18 @@ void
> drm_prime_remove_buf_handle_locked(struct drm_prime_file_private
> *prime_fpr
> > >   	}
> > >   }
> > > +/**
> > > + * drm_gem_map_dma_buf - map_dma_buf implementation for GEM
> > > + * @attach: attachment whose scatterlist is to be returned
> > > + * @dir: direction of DMA transfer
> > > + *
> > > + * Calls &drm_driver.gem_prime_get_sg_table and then maps the
> > > +scatterlist. This
> > > + * can be used as the &dma_buf_ops.map_dma_buf callback.
> > > + *
> > > + * Returns sg_table containing the scatterlist to be returned;
> > > +returns ERR_PTR
> > > + * on error. May return -EINTR if it is interrupted by a signal.
> > > + */
> > > +
> > >   struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment
> *attach,
> > >   				     enum dma_data_direction dir)
> > >   {
> > > @@ -294,6 +329,12 @@ struct sg_table *drm_gem_map_dma_buf(struct
> dma_buf_attachment *attach,
> > >   }
> > >   EXPORT_SYMBOL(drm_gem_map_dma_buf);
> > > +/**
> > > + * drm_gem_unmap_dma_buf - unmap_dma_buf implementation for
> GEM
> > > + *
> > > + * Not implemented. The unmap is done at drm_gem_map_detach().
> > > +This can be
> > > + * used as the &dma_buf_ops.unmap_dma_buf callback.
> > > + */
> > >   void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
> > >   			   struct sg_table *sgt,
> > >   			   enum dma_data_direction dir) @@ -351,6 +392,15
> @@ void
> > > drm_gem_dmabuf_release(struct dma_buf *dma_buf)
> > >   }
> > >   EXPORT_SYMBOL(drm_gem_dmabuf_release);
> > > +/**
> > > + * drm_gem_dmabuf_vmap - dma_buf vmap implementation for GEM
> > > + * @dma_buf: buffer to be mapped
> > > + *
> > > + * Sets up a kernel virtual mapping. This can be used as the
> > > +&dma_buf_ops.vmap
> > > + * callback.
> > > + *
> > > + * Returns the kernel virtual address.
> > > + */
> > >   void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> > >   {
> > >   	struct drm_gem_object *obj = dma_buf->priv; @@ -360,6 +410,14
> @@
> > > void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> > >   }
> > >   EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
> > > +/**
> > > + * drm_gem_dmabuf_vunmap - dma_buf vunmap implementation for
> GEM
> > > + * @dma_buf: buffer to be unmapped
> > > + * @vaddr: the virtual address of the buffer
> > > + *
> > > + * Releases a kernel virtual mapping. This can be used as the
> > > + * &dma_buf_ops.vunmap callback.
> > > + */
> > >   void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void
> *vaddr)
> > >   {
> > >   	struct drm_gem_object *obj = dma_buf->priv; @@ -369,6 +427,11
> @@
> > > void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
> > >   }
> > >   EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
> > > +/**
> > > + * drm_gem_dmabuf_kmap_atomic - map_atomic implementation for
> GEM
> > > + *
> > > + * Not implemented. This can be used as the
> &dma_buf_ops.map_atomic callback.
> > > + */
> > >   void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
> > >   				 unsigned long page_num)
> > >   {
> > > @@ -376,6 +439,11 @@ void *drm_gem_dmabuf_kmap_atomic(struct
> dma_buf *dma_buf,
> > >   }
> > >   EXPORT_SYMBOL(drm_gem_dmabuf_kmap_atomic);
> > > +/**
> > > + * drm_gem_dmabuf_kunmap_atomic - unmap_atomic
> implementation for
> > > +GEM
> > > + *
> > > + * Not implemented. This can be used as the
> &dma_buf_ops.unmap_atomic callback.
> > > + */
> > >   void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
> > >   				  unsigned long page_num, void *addr)
> > >   {
> > > @@ -383,12 +451,22 @@ void drm_gem_dmabuf_kunmap_atomic(struct
> dma_buf *dma_buf,
> > >   }
> > >   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap_atomic);
> > > +/**
> > > + * drm_gem_dmabuf_kmap - map implementation for GEM
> > > + *
> > > + * Not implemented. This can be used as the &dma_buf_ops.map
> callback.
> > > + */
> > >   void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned
> long page_num)
> > >   {
> > >   	return NULL;
> > >   }
> > >   EXPORT_SYMBOL(drm_gem_dmabuf_kmap);
> > > +/**
> > > + * drm_gem_dmabuf_kunmap - unmap implementation for GEM
> > > + *
> > > + * Not implemented. This can be used as the &dma_buf_ops.unmap
> callback.
> > > + */
> > >   void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned
> long page_num,
> > >   			   void *addr)
> > >   {
> > > @@ -396,6 +474,16 @@ void drm_gem_dmabuf_kunmap(struct
> dma_buf *dma_buf, unsigned long page_num,
> > >   }
> > >   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap);
> > > +/**
> > > + * drm_gem_dmabuf_mmap - dma_buf mmap implementation for
> GEM
> > > + * @dma_buf: buffer to be mapped
> > > + * @vma: virtual address range
> > > + *
> > > + * Provides memory mapping for the buffer. This can be used as the
> > > + * &dma_buf_ops.mmap callback.
> > > + *
> > > + * Returns 0 on success or a negative error code on failure.
> > > + */
> > >   int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct
> vm_area_struct *vma)
> > >   {
> > >   	struct drm_gem_object *obj = dma_buf->priv;
> >
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
Daniel Vetter Feb. 20, 2018, 3:12 p.m. UTC | #4
On Tue, Jan 30, 2018 at 04:01:23PM +0000, Li, Samuel wrote:
> 
> Alex helped push this into drm-tip,
> https://cgit.freedesktop.org/drm/drm-tip/commit/drivers/gpu/drm?id=f7a71b0cf9e36c1b0edbfe89ce028a01164b864d
> 
> Thanks,
> Samuel Li
> 
> 
> > -----Original Message-----
> > From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of Daniel
> > Vetter
> > Sent: Tuesday, January 30, 2018 4:33 AM
> > To: Koenig, Christian <Christian.Koenig@amd.com>
> > Cc: Li, Samuel <Samuel.Li@amd.com>; amd-gfx@lists.freedesktop.org; dri-
> > devel@lists.freedesktop.org
> > Subject: Re: [PATCH v2 1/1] drm: add kernel doc for exported gem
> > dmabuf_ops
> > 
> > On Fri, Jan 19, 2018 at 09:51:20AM +0100, Christian König wrote:
> > > Am 18.01.2018 um 22:44 schrieb Samuel Li:
> > > > Signed-off-by: Samuel Li <Samuel.Li@amd.com>
> > > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > 
> > Thanks for updating the docs.
> > >
> > > Reviewed-by: Christian König <christian.koenig@amd.com>
> > 
> > I'm assuming you'll als push this one.

I just noticed that fairly obviously this wasn't tested when writing:

./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or member 'attach' not described in 'drm_gem_unmap_dma_buf'             
./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or member 'sgt' not described in 'drm_gem_unmap_dma_buf'
./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or member 'dir' not described in 'drm_gem_unmap_dma_buf'
./drivers/gpu/drm/drm_prime.c:438: warning: Function parameter or member 'dma_buf' not described in 'drm_gem_dmabuf_kmap_atomic'
./drivers/gpu/drm/drm_prime.c:438: warning: Function parameter or member 'page_num' not described in 'drm_gem_dmabuf_kmap_atomic'
./drivers/gpu/drm/drm_prime.c:450: warning: Function parameter or member 'dma_buf' not described in 'drm_gem_dmabuf_kunmap_atomic'
./drivers/gpu/drm/drm_prime.c:450: warning: Function parameter or member 'page_num' not described in 'drm_gem_dmabuf_kunmap_atomic'
./drivers/gpu/drm/drm_prime.c:450: warning: Function parameter or member 'addr' not described in 'drm_gem_dmabuf_kunmap_atomic'
./drivers/gpu/drm/drm_prime.c:461: warning: Function parameter or member 'dma_buf' not described in 'drm_gem_dmabuf_kmap'
./drivers/gpu/drm/drm_prime.c:461: warning: Function parameter or member 'page_num' not described in 'drm_gem_dmabuf_kmap'
./drivers/gpu/drm/drm_prime.c:473: warning: Function parameter or member 'dma_buf' not described in 'drm_gem_dmabuf_kunmap'
./drivers/gpu/drm/drm_prime.c:473: warning: Function parameter or member 'page_num' not described in 'drm_gem_dmabuf_kunmap'
./drivers/gpu/drm/drm_prime.c:473: warning: Function parameter or member 'addr' not described in 'drm_gem_dmabuf_kunmap'

Samuel, can you pls build docs using

$ make htmldocs

and fix up the fallout and submit a patch?

Thanks, Daniel

> > -Daniel
> > 
> > >
> > > > ---
> > > >   drivers/gpu/drm/drm_prime.c | 88
> > +++++++++++++++++++++++++++++++++++++++++++++
> > > >   1 file changed, 88 insertions(+)
> > > >
> > > > diff --git a/drivers/gpu/drm/drm_prime.c
> > > > b/drivers/gpu/drm/drm_prime.c index ca09ce7..e82a976 100644
> > > > --- a/drivers/gpu/drm/drm_prime.c
> > > > +++ b/drivers/gpu/drm/drm_prime.c
> > > > @@ -73,6 +73,9 @@
> > > >    * Drivers should detect this situation and return back the gem object
> > > >    * from the dma-buf private.  Prime will do this automatically for drivers
> > that
> > > >    * use the drm_gem_prime_{import,export} helpers.
> > > > + *
> > > > + * GEM struct &dma_buf_ops symbols are now exported. They can be
> > > > + resued by
> > > > + * drivers which implement GEM interface.
> > > >    */
> > > >   struct drm_prime_member {
> > > > @@ -180,6 +183,18 @@ static int drm_prime_lookup_buf_handle(struct
> > drm_prime_file_private *prime_fpri
> > > >   	return -ENOENT;
> > > >   }
> > > > +/**
> > > > + * drm_gem_map_attach - dma_buf attach implementation for GEM
> > > > + * @dma_buf: buffer to attach device to
> > > > + * @target_dev: not used
> > > > + * @attach: buffer attachment data
> > > > + *
> > > > + * Allocates &drm_prime_attachment and calls
> > > > +&drm_driver.gem_prime_pin for
> > > > + * device specific attachment. This can be used as the
> > > > +&dma_buf_ops.attach
> > > > + * callback.
> > > > + *
> > > > + * Returns 0 on success, negative error code on failure.
> > > > + */
> > > >   int drm_gem_map_attach(struct dma_buf *dma_buf, struct device
> > *target_dev,
> > > >   		       struct dma_buf_attachment *attach)
> > > >   {
> > > > @@ -201,6 +216,14 @@ int drm_gem_map_attach(struct dma_buf
> > *dma_buf, struct device *target_dev,
> > > >   }
> > > >   EXPORT_SYMBOL(drm_gem_map_attach);
> > > > +/**
> > > > + * drm_gem_map_detach - dma_buf detach implementation for GEM
> > > > + * @dma_buf: buffer to detach from
> > > > + * @attach: attachment to be detached
> > > > + *
> > > > + * Cleans up &dma_buf_attachment. This can be used as the
> > > > +&dma_buf_ops.detach
> > > > + * callback.
> > > > + */
> > > >   void drm_gem_map_detach(struct dma_buf *dma_buf,
> > > >   			struct dma_buf_attachment *attach)
> > > >   {
> > > > @@ -255,6 +278,18 @@ void
> > drm_prime_remove_buf_handle_locked(struct drm_prime_file_private
> > *prime_fpr
> > > >   	}
> > > >   }
> > > > +/**
> > > > + * drm_gem_map_dma_buf - map_dma_buf implementation for GEM
> > > > + * @attach: attachment whose scatterlist is to be returned
> > > > + * @dir: direction of DMA transfer
> > > > + *
> > > > + * Calls &drm_driver.gem_prime_get_sg_table and then maps the
> > > > +scatterlist. This
> > > > + * can be used as the &dma_buf_ops.map_dma_buf callback.
> > > > + *
> > > > + * Returns sg_table containing the scatterlist to be returned;
> > > > +returns ERR_PTR
> > > > + * on error. May return -EINTR if it is interrupted by a signal.
> > > > + */
> > > > +
> > > >   struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment
> > *attach,
> > > >   				     enum dma_data_direction dir)
> > > >   {
> > > > @@ -294,6 +329,12 @@ struct sg_table *drm_gem_map_dma_buf(struct
> > dma_buf_attachment *attach,
> > > >   }
> > > >   EXPORT_SYMBOL(drm_gem_map_dma_buf);
> > > > +/**
> > > > + * drm_gem_unmap_dma_buf - unmap_dma_buf implementation for
> > GEM
> > > > + *
> > > > + * Not implemented. The unmap is done at drm_gem_map_detach().
> > > > +This can be
> > > > + * used as the &dma_buf_ops.unmap_dma_buf callback.
> > > > + */
> > > >   void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
> > > >   			   struct sg_table *sgt,
> > > >   			   enum dma_data_direction dir) @@ -351,6 +392,15
> > @@ void
> > > > drm_gem_dmabuf_release(struct dma_buf *dma_buf)
> > > >   }
> > > >   EXPORT_SYMBOL(drm_gem_dmabuf_release);
> > > > +/**
> > > > + * drm_gem_dmabuf_vmap - dma_buf vmap implementation for GEM
> > > > + * @dma_buf: buffer to be mapped
> > > > + *
> > > > + * Sets up a kernel virtual mapping. This can be used as the
> > > > +&dma_buf_ops.vmap
> > > > + * callback.
> > > > + *
> > > > + * Returns the kernel virtual address.
> > > > + */
> > > >   void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> > > >   {
> > > >   	struct drm_gem_object *obj = dma_buf->priv; @@ -360,6 +410,14
> > @@
> > > > void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> > > >   }
> > > >   EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
> > > > +/**
> > > > + * drm_gem_dmabuf_vunmap - dma_buf vunmap implementation for
> > GEM
> > > > + * @dma_buf: buffer to be unmapped
> > > > + * @vaddr: the virtual address of the buffer
> > > > + *
> > > > + * Releases a kernel virtual mapping. This can be used as the
> > > > + * &dma_buf_ops.vunmap callback.
> > > > + */
> > > >   void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void
> > *vaddr)
> > > >   {
> > > >   	struct drm_gem_object *obj = dma_buf->priv; @@ -369,6 +427,11
> > @@
> > > > void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
> > > >   }
> > > >   EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
> > > > +/**
> > > > + * drm_gem_dmabuf_kmap_atomic - map_atomic implementation for
> > GEM
> > > > + *
> > > > + * Not implemented. This can be used as the
> > &dma_buf_ops.map_atomic callback.
> > > > + */
> > > >   void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
> > > >   				 unsigned long page_num)
> > > >   {
> > > > @@ -376,6 +439,11 @@ void *drm_gem_dmabuf_kmap_atomic(struct
> > dma_buf *dma_buf,
> > > >   }
> > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kmap_atomic);
> > > > +/**
> > > > + * drm_gem_dmabuf_kunmap_atomic - unmap_atomic
> > implementation for
> > > > +GEM
> > > > + *
> > > > + * Not implemented. This can be used as the
> > &dma_buf_ops.unmap_atomic callback.
> > > > + */
> > > >   void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
> > > >   				  unsigned long page_num, void *addr)
> > > >   {
> > > > @@ -383,12 +451,22 @@ void drm_gem_dmabuf_kunmap_atomic(struct
> > dma_buf *dma_buf,
> > > >   }
> > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap_atomic);
> > > > +/**
> > > > + * drm_gem_dmabuf_kmap - map implementation for GEM
> > > > + *
> > > > + * Not implemented. This can be used as the &dma_buf_ops.map
> > callback.
> > > > + */
> > > >   void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned
> > long page_num)
> > > >   {
> > > >   	return NULL;
> > > >   }
> > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kmap);
> > > > +/**
> > > > + * drm_gem_dmabuf_kunmap - unmap implementation for GEM
> > > > + *
> > > > + * Not implemented. This can be used as the &dma_buf_ops.unmap
> > callback.
> > > > + */
> > > >   void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned
> > long page_num,
> > > >   			   void *addr)
> > > >   {
> > > > @@ -396,6 +474,16 @@ void drm_gem_dmabuf_kunmap(struct
> > dma_buf *dma_buf, unsigned long page_num,
> > > >   }
> > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap);
> > > > +/**
> > > > + * drm_gem_dmabuf_mmap - dma_buf mmap implementation for
> > GEM
> > > > + * @dma_buf: buffer to be mapped
> > > > + * @vma: virtual address range
> > > > + *
> > > > + * Provides memory mapping for the buffer. This can be used as the
> > > > + * &dma_buf_ops.mmap callback.
> > > > + *
> > > > + * Returns 0 on success or a negative error code on failure.
> > > > + */
> > > >   int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct
> > vm_area_struct *vma)
> > > >   {
> > > >   	struct drm_gem_object *obj = dma_buf->priv;
> > >
> > > _______________________________________________
> > > dri-devel mailing list
> > > dri-devel@lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> > 
> > --
> > Daniel Vetter
> > Software Engineer, Intel Corporation
> > http://blog.ffwll.ch
Li, Samuel Feb. 20, 2018, 3:46 p.m. UTC | #5
> ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> member 'attach' not described in 'drm_gem_unmap_dma_buf'
> ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> member 'sgt' not described in 'drm_gem_unmap_dma_buf'
> ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> member 'dir' not described in 'drm_gem_unmap_dma_buf'
...

Actually I tested. Those parameters are left out on purpose since they are empty functions so far.

Regards,
Samuel Li

> -----Original Message-----
> From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of Daniel
> Vetter
> Sent: Tuesday, February 20, 2018 10:13 AM
> To: Li, Samuel <Samuel.Li@amd.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>; Koenig, Christian
> <Christian.Koenig@amd.com>; amd-gfx@lists.freedesktop.org; dri-
> devel@lists.freedesktop.org
> Subject: Re: [PATCH v2 1/1] drm: add kernel doc for exported gem
> dmabuf_ops
> 
> On Tue, Jan 30, 2018 at 04:01:23PM +0000, Li, Samuel wrote:
> >
> > Alex helped push this into drm-tip,
> > https://cgit.freedesktop.org/drm/drm-
> tip/commit/drivers/gpu/drm?id=f7a
> > 71b0cf9e36c1b0edbfe89ce028a01164b864d
> >
> > Thanks,
> > Samuel Li
> >
> >
> > > -----Original Message-----
> > > From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of
> > > Daniel Vetter
> > > Sent: Tuesday, January 30, 2018 4:33 AM
> > > To: Koenig, Christian <Christian.Koenig@amd.com>
> > > Cc: Li, Samuel <Samuel.Li@amd.com>; amd-gfx@lists.freedesktop.org;
> > > dri- devel@lists.freedesktop.org
> > > Subject: Re: [PATCH v2 1/1] drm: add kernel doc for exported gem
> > > dmabuf_ops
> > >
> > > On Fri, Jan 19, 2018 at 09:51:20AM +0100, Christian König wrote:
> > > > Am 18.01.2018 um 22:44 schrieb Samuel Li:
> > > > > Signed-off-by: Samuel Li <Samuel.Li@amd.com>
> > > > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > >
> > > Thanks for updating the docs.
> > > >
> > > > Reviewed-by: Christian König <christian.koenig@amd.com>
> > >
> > > I'm assuming you'll als push this one.
> 
> I just noticed that fairly obviously this wasn't tested when writing:
> 
> ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> member 'attach' not described in 'drm_gem_unmap_dma_buf'
> ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> member 'sgt' not described in 'drm_gem_unmap_dma_buf'
> ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> member 'dir' not described in 'drm_gem_unmap_dma_buf'
> ./drivers/gpu/drm/drm_prime.c:438: warning: Function parameter or
> member 'dma_buf' not described in 'drm_gem_dmabuf_kmap_atomic'
> ./drivers/gpu/drm/drm_prime.c:438: warning: Function parameter or
> member 'page_num' not described in 'drm_gem_dmabuf_kmap_atomic'
> ./drivers/gpu/drm/drm_prime.c:450: warning: Function parameter or
> member 'dma_buf' not described in 'drm_gem_dmabuf_kunmap_atomic'
> ./drivers/gpu/drm/drm_prime.c:450: warning: Function parameter or
> member 'page_num' not described in 'drm_gem_dmabuf_kunmap_atomic'
> ./drivers/gpu/drm/drm_prime.c:450: warning: Function parameter or
> member 'addr' not described in 'drm_gem_dmabuf_kunmap_atomic'
> ./drivers/gpu/drm/drm_prime.c:461: warning: Function parameter or
> member 'dma_buf' not described in 'drm_gem_dmabuf_kmap'
> ./drivers/gpu/drm/drm_prime.c:461: warning: Function parameter or
> member 'page_num' not described in 'drm_gem_dmabuf_kmap'
> ./drivers/gpu/drm/drm_prime.c:473: warning: Function parameter or
> member 'dma_buf' not described in 'drm_gem_dmabuf_kunmap'
> ./drivers/gpu/drm/drm_prime.c:473: warning: Function parameter or
> member 'page_num' not described in 'drm_gem_dmabuf_kunmap'
> ./drivers/gpu/drm/drm_prime.c:473: warning: Function parameter or
> member 'addr' not described in 'drm_gem_dmabuf_kunmap'
> 
> Samuel, can you pls build docs using
> 
> $ make htmldocs
> 
> and fix up the fallout and submit a patch?
> 
> Thanks, Daniel
> 
> > > -Daniel
> > >
> > > >
> > > > > ---
> > > > >   drivers/gpu/drm/drm_prime.c | 88
> > > +++++++++++++++++++++++++++++++++++++++++++++
> > > > >   1 file changed, 88 insertions(+)
> > > > >
> > > > > diff --git a/drivers/gpu/drm/drm_prime.c
> > > > > b/drivers/gpu/drm/drm_prime.c index ca09ce7..e82a976 100644
> > > > > --- a/drivers/gpu/drm/drm_prime.c
> > > > > +++ b/drivers/gpu/drm/drm_prime.c
> > > > > @@ -73,6 +73,9 @@
> > > > >    * Drivers should detect this situation and return back the gem object
> > > > >    * from the dma-buf private.  Prime will do this automatically
> > > > > for drivers
> > > that
> > > > >    * use the drm_gem_prime_{import,export} helpers.
> > > > > + *
> > > > > + * GEM struct &dma_buf_ops symbols are now exported. They can
> > > > > + be resued by
> > > > > + * drivers which implement GEM interface.
> > > > >    */
> > > > >   struct drm_prime_member {
> > > > > @@ -180,6 +183,18 @@ static int
> > > > > drm_prime_lookup_buf_handle(struct
> > > drm_prime_file_private *prime_fpri
> > > > >   	return -ENOENT;
> > > > >   }
> > > > > +/**
> > > > > + * drm_gem_map_attach - dma_buf attach implementation for GEM
> > > > > + * @dma_buf: buffer to attach device to
> > > > > + * @target_dev: not used
> > > > > + * @attach: buffer attachment data
> > > > > + *
> > > > > + * Allocates &drm_prime_attachment and calls
> > > > > +&drm_driver.gem_prime_pin for
> > > > > + * device specific attachment. This can be used as the
> > > > > +&dma_buf_ops.attach
> > > > > + * callback.
> > > > > + *
> > > > > + * Returns 0 on success, negative error code on failure.
> > > > > + */
> > > > >   int drm_gem_map_attach(struct dma_buf *dma_buf, struct device
> > > *target_dev,
> > > > >   		       struct dma_buf_attachment *attach)
> > > > >   {
> > > > > @@ -201,6 +216,14 @@ int drm_gem_map_attach(struct dma_buf
> > > *dma_buf, struct device *target_dev,
> > > > >   }
> > > > >   EXPORT_SYMBOL(drm_gem_map_attach);
> > > > > +/**
> > > > > + * drm_gem_map_detach - dma_buf detach implementation for
> GEM
> > > > > + * @dma_buf: buffer to detach from
> > > > > + * @attach: attachment to be detached
> > > > > + *
> > > > > + * Cleans up &dma_buf_attachment. This can be used as the
> > > > > +&dma_buf_ops.detach
> > > > > + * callback.
> > > > > + */
> > > > >   void drm_gem_map_detach(struct dma_buf *dma_buf,
> > > > >   			struct dma_buf_attachment *attach)
> > > > >   {
> > > > > @@ -255,6 +278,18 @@ void
> > > drm_prime_remove_buf_handle_locked(struct drm_prime_file_private
> > > *prime_fpr
> > > > >   	}
> > > > >   }
> > > > > +/**
> > > > > + * drm_gem_map_dma_buf - map_dma_buf implementation for
> GEM
> > > > > + * @attach: attachment whose scatterlist is to be returned
> > > > > + * @dir: direction of DMA transfer
> > > > > + *
> > > > > + * Calls &drm_driver.gem_prime_get_sg_table and then maps the
> > > > > +scatterlist. This
> > > > > + * can be used as the &dma_buf_ops.map_dma_buf callback.
> > > > > + *
> > > > > + * Returns sg_table containing the scatterlist to be returned;
> > > > > +returns ERR_PTR
> > > > > + * on error. May return -EINTR if it is interrupted by a signal.
> > > > > + */
> > > > > +
> > > > >   struct sg_table *drm_gem_map_dma_buf(struct
> dma_buf_attachment
> > > *attach,
> > > > >   				     enum dma_data_direction dir)
> > > > >   {
> > > > > @@ -294,6 +329,12 @@ struct sg_table
> *drm_gem_map_dma_buf(struct
> > > dma_buf_attachment *attach,
> > > > >   }
> > > > >   EXPORT_SYMBOL(drm_gem_map_dma_buf);
> > > > > +/**
> > > > > + * drm_gem_unmap_dma_buf - unmap_dma_buf implementation
> for
> > > GEM
> > > > > + *
> > > > > + * Not implemented. The unmap is done at
> drm_gem_map_detach().
> > > > > +This can be
> > > > > + * used as the &dma_buf_ops.unmap_dma_buf callback.
> > > > > + */
> > > > >   void drm_gem_unmap_dma_buf(struct dma_buf_attachment
> *attach,
> > > > >   			   struct sg_table *sgt,
> > > > >   			   enum dma_data_direction dir) @@ -351,6
> +392,15
> > > @@ void
> > > > > drm_gem_dmabuf_release(struct dma_buf *dma_buf)
> > > > >   }
> > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_release);
> > > > > +/**
> > > > > + * drm_gem_dmabuf_vmap - dma_buf vmap implementation for
> GEM
> > > > > + * @dma_buf: buffer to be mapped
> > > > > + *
> > > > > + * Sets up a kernel virtual mapping. This can be used as the
> > > > > +&dma_buf_ops.vmap
> > > > > + * callback.
> > > > > + *
> > > > > + * Returns the kernel virtual address.
> > > > > + */
> > > > >   void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> > > > >   {
> > > > >   	struct drm_gem_object *obj = dma_buf->priv; @@ -360,6
> +410,14
> > > @@
> > > > > void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> > > > >   }
> > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
> > > > > +/**
> > > > > + * drm_gem_dmabuf_vunmap - dma_buf vunmap implementation
> for
> > > GEM
> > > > > + * @dma_buf: buffer to be unmapped
> > > > > + * @vaddr: the virtual address of the buffer
> > > > > + *
> > > > > + * Releases a kernel virtual mapping. This can be used as the
> > > > > + * &dma_buf_ops.vunmap callback.
> > > > > + */
> > > > >   void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void
> > > *vaddr)
> > > > >   {
> > > > >   	struct drm_gem_object *obj = dma_buf->priv; @@ -369,6
> +427,11
> > > @@
> > > > > void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void
> *vaddr)
> > > > >   }
> > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
> > > > > +/**
> > > > > + * drm_gem_dmabuf_kmap_atomic - map_atomic implementation
> for
> > > GEM
> > > > > + *
> > > > > + * Not implemented. This can be used as the
> > > &dma_buf_ops.map_atomic callback.
> > > > > + */
> > > > >   void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
> > > > >   				 unsigned long page_num)
> > > > >   {
> > > > > @@ -376,6 +439,11 @@ void
> *drm_gem_dmabuf_kmap_atomic(struct
> > > dma_buf *dma_buf,
> > > > >   }
> > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kmap_atomic);
> > > > > +/**
> > > > > + * drm_gem_dmabuf_kunmap_atomic - unmap_atomic
> > > implementation for
> > > > > +GEM
> > > > > + *
> > > > > + * Not implemented. This can be used as the
> > > &dma_buf_ops.unmap_atomic callback.
> > > > > + */
> > > > >   void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
> > > > >   				  unsigned long page_num, void
> *addr)
> > > > >   {
> > > > > @@ -383,12 +451,22 @@ void
> drm_gem_dmabuf_kunmap_atomic(struct
> > > dma_buf *dma_buf,
> > > > >   }
> > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap_atomic);
> > > > > +/**
> > > > > + * drm_gem_dmabuf_kmap - map implementation for GEM
> > > > > + *
> > > > > + * Not implemented. This can be used as the &dma_buf_ops.map
> > > callback.
> > > > > + */
> > > > >   void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf,
> unsigned
> > > long page_num)
> > > > >   {
> > > > >   	return NULL;
> > > > >   }
> > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kmap);
> > > > > +/**
> > > > > + * drm_gem_dmabuf_kunmap - unmap implementation for GEM
> > > > > + *
> > > > > + * Not implemented. This can be used as the &dma_buf_ops.unmap
> > > callback.
> > > > > + */
> > > > >   void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
> unsigned
> > > long page_num,
> > > > >   			   void *addr)
> > > > >   {
> > > > > @@ -396,6 +474,16 @@ void drm_gem_dmabuf_kunmap(struct
> > > dma_buf *dma_buf, unsigned long page_num,
> > > > >   }
> > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap);
> > > > > +/**
> > > > > + * drm_gem_dmabuf_mmap - dma_buf mmap implementation for
> > > GEM
> > > > > + * @dma_buf: buffer to be mapped
> > > > > + * @vma: virtual address range
> > > > > + *
> > > > > + * Provides memory mapping for the buffer. This can be used as
> > > > > + the
> > > > > + * &dma_buf_ops.mmap callback.
> > > > > + *
> > > > > + * Returns 0 on success or a negative error code on failure.
> > > > > + */
> > > > >   int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct
> > > vm_area_struct *vma)
> > > > >   {
> > > > >   	struct drm_gem_object *obj = dma_buf->priv;
> > > >
> > > > _______________________________________________
> > > > dri-devel mailing list
> > > > dri-devel@lists.freedesktop.org
> > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> > >
> > > --
> > > Daniel Vetter
> > > Software Engineer, Intel Corporation http://blog.ffwll.ch
> 
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
Daniel Vetter Feb. 20, 2018, 4:23 p.m. UTC | #6
On Tue, Feb 20, 2018 at 03:46:51PM +0000, Li, Samuel wrote:
> > ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> > member 'attach' not described in 'drm_gem_unmap_dma_buf'
> > ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> > member 'sgt' not described in 'drm_gem_unmap_dma_buf'
> > ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> > member 'dir' not described in 'drm_gem_unmap_dma_buf'
> ...
> 
> Actually I tested. Those parameters are left out on purpose since they are empty functions so far.

Can you pls add dummy explanations? I know it's somewhat silly, but when
there's lots of warnings it's much harder to spot new ones. Docs are
sometimes just plain boring rote work :-/

Thanks, Daniel

> 
> Regards,
> Samuel Li
> 
> > -----Original Message-----
> > From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of Daniel
> > Vetter
> > Sent: Tuesday, February 20, 2018 10:13 AM
> > To: Li, Samuel <Samuel.Li@amd.com>
> > Cc: Daniel Vetter <daniel@ffwll.ch>; Koenig, Christian
> > <Christian.Koenig@amd.com>; amd-gfx@lists.freedesktop.org; dri-
> > devel@lists.freedesktop.org
> > Subject: Re: [PATCH v2 1/1] drm: add kernel doc for exported gem
> > dmabuf_ops
> > 
> > On Tue, Jan 30, 2018 at 04:01:23PM +0000, Li, Samuel wrote:
> > >
> > > Alex helped push this into drm-tip,
> > > https://cgit.freedesktop.org/drm/drm-
> > tip/commit/drivers/gpu/drm?id=f7a
> > > 71b0cf9e36c1b0edbfe89ce028a01164b864d
> > >
> > > Thanks,
> > > Samuel Li
> > >
> > >
> > > > -----Original Message-----
> > > > From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of
> > > > Daniel Vetter
> > > > Sent: Tuesday, January 30, 2018 4:33 AM
> > > > To: Koenig, Christian <Christian.Koenig@amd.com>
> > > > Cc: Li, Samuel <Samuel.Li@amd.com>; amd-gfx@lists.freedesktop.org;
> > > > dri- devel@lists.freedesktop.org
> > > > Subject: Re: [PATCH v2 1/1] drm: add kernel doc for exported gem
> > > > dmabuf_ops
> > > >
> > > > On Fri, Jan 19, 2018 at 09:51:20AM +0100, Christian König wrote:
> > > > > Am 18.01.2018 um 22:44 schrieb Samuel Li:
> > > > > > Signed-off-by: Samuel Li <Samuel.Li@amd.com>
> > > > > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > > >
> > > > Thanks for updating the docs.
> > > > >
> > > > > Reviewed-by: Christian König <christian.koenig@amd.com>
> > > >
> > > > I'm assuming you'll als push this one.
> > 
> > I just noticed that fairly obviously this wasn't tested when writing:
> > 
> > ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> > member 'attach' not described in 'drm_gem_unmap_dma_buf'
> > ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> > member 'sgt' not described in 'drm_gem_unmap_dma_buf'
> > ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> > member 'dir' not described in 'drm_gem_unmap_dma_buf'
> > ./drivers/gpu/drm/drm_prime.c:438: warning: Function parameter or
> > member 'dma_buf' not described in 'drm_gem_dmabuf_kmap_atomic'
> > ./drivers/gpu/drm/drm_prime.c:438: warning: Function parameter or
> > member 'page_num' not described in 'drm_gem_dmabuf_kmap_atomic'
> > ./drivers/gpu/drm/drm_prime.c:450: warning: Function parameter or
> > member 'dma_buf' not described in 'drm_gem_dmabuf_kunmap_atomic'
> > ./drivers/gpu/drm/drm_prime.c:450: warning: Function parameter or
> > member 'page_num' not described in 'drm_gem_dmabuf_kunmap_atomic'
> > ./drivers/gpu/drm/drm_prime.c:450: warning: Function parameter or
> > member 'addr' not described in 'drm_gem_dmabuf_kunmap_atomic'
> > ./drivers/gpu/drm/drm_prime.c:461: warning: Function parameter or
> > member 'dma_buf' not described in 'drm_gem_dmabuf_kmap'
> > ./drivers/gpu/drm/drm_prime.c:461: warning: Function parameter or
> > member 'page_num' not described in 'drm_gem_dmabuf_kmap'
> > ./drivers/gpu/drm/drm_prime.c:473: warning: Function parameter or
> > member 'dma_buf' not described in 'drm_gem_dmabuf_kunmap'
> > ./drivers/gpu/drm/drm_prime.c:473: warning: Function parameter or
> > member 'page_num' not described in 'drm_gem_dmabuf_kunmap'
> > ./drivers/gpu/drm/drm_prime.c:473: warning: Function parameter or
> > member 'addr' not described in 'drm_gem_dmabuf_kunmap'
> > 
> > Samuel, can you pls build docs using
> > 
> > $ make htmldocs
> > 
> > and fix up the fallout and submit a patch?
> > 
> > Thanks, Daniel
> > 
> > > > -Daniel
> > > >
> > > > >
> > > > > > ---
> > > > > >   drivers/gpu/drm/drm_prime.c | 88
> > > > +++++++++++++++++++++++++++++++++++++++++++++
> > > > > >   1 file changed, 88 insertions(+)
> > > > > >
> > > > > > diff --git a/drivers/gpu/drm/drm_prime.c
> > > > > > b/drivers/gpu/drm/drm_prime.c index ca09ce7..e82a976 100644
> > > > > > --- a/drivers/gpu/drm/drm_prime.c
> > > > > > +++ b/drivers/gpu/drm/drm_prime.c
> > > > > > @@ -73,6 +73,9 @@
> > > > > >    * Drivers should detect this situation and return back the gem object
> > > > > >    * from the dma-buf private.  Prime will do this automatically
> > > > > > for drivers
> > > > that
> > > > > >    * use the drm_gem_prime_{import,export} helpers.
> > > > > > + *
> > > > > > + * GEM struct &dma_buf_ops symbols are now exported. They can
> > > > > > + be resued by
> > > > > > + * drivers which implement GEM interface.
> > > > > >    */
> > > > > >   struct drm_prime_member {
> > > > > > @@ -180,6 +183,18 @@ static int
> > > > > > drm_prime_lookup_buf_handle(struct
> > > > drm_prime_file_private *prime_fpri
> > > > > >   	return -ENOENT;
> > > > > >   }
> > > > > > +/**
> > > > > > + * drm_gem_map_attach - dma_buf attach implementation for GEM
> > > > > > + * @dma_buf: buffer to attach device to
> > > > > > + * @target_dev: not used
> > > > > > + * @attach: buffer attachment data
> > > > > > + *
> > > > > > + * Allocates &drm_prime_attachment and calls
> > > > > > +&drm_driver.gem_prime_pin for
> > > > > > + * device specific attachment. This can be used as the
> > > > > > +&dma_buf_ops.attach
> > > > > > + * callback.
> > > > > > + *
> > > > > > + * Returns 0 on success, negative error code on failure.
> > > > > > + */
> > > > > >   int drm_gem_map_attach(struct dma_buf *dma_buf, struct device
> > > > *target_dev,
> > > > > >   		       struct dma_buf_attachment *attach)
> > > > > >   {
> > > > > > @@ -201,6 +216,14 @@ int drm_gem_map_attach(struct dma_buf
> > > > *dma_buf, struct device *target_dev,
> > > > > >   }
> > > > > >   EXPORT_SYMBOL(drm_gem_map_attach);
> > > > > > +/**
> > > > > > + * drm_gem_map_detach - dma_buf detach implementation for
> > GEM
> > > > > > + * @dma_buf: buffer to detach from
> > > > > > + * @attach: attachment to be detached
> > > > > > + *
> > > > > > + * Cleans up &dma_buf_attachment. This can be used as the
> > > > > > +&dma_buf_ops.detach
> > > > > > + * callback.
> > > > > > + */
> > > > > >   void drm_gem_map_detach(struct dma_buf *dma_buf,
> > > > > >   			struct dma_buf_attachment *attach)
> > > > > >   {
> > > > > > @@ -255,6 +278,18 @@ void
> > > > drm_prime_remove_buf_handle_locked(struct drm_prime_file_private
> > > > *prime_fpr
> > > > > >   	}
> > > > > >   }
> > > > > > +/**
> > > > > > + * drm_gem_map_dma_buf - map_dma_buf implementation for
> > GEM
> > > > > > + * @attach: attachment whose scatterlist is to be returned
> > > > > > + * @dir: direction of DMA transfer
> > > > > > + *
> > > > > > + * Calls &drm_driver.gem_prime_get_sg_table and then maps the
> > > > > > +scatterlist. This
> > > > > > + * can be used as the &dma_buf_ops.map_dma_buf callback.
> > > > > > + *
> > > > > > + * Returns sg_table containing the scatterlist to be returned;
> > > > > > +returns ERR_PTR
> > > > > > + * on error. May return -EINTR if it is interrupted by a signal.
> > > > > > + */
> > > > > > +
> > > > > >   struct sg_table *drm_gem_map_dma_buf(struct
> > dma_buf_attachment
> > > > *attach,
> > > > > >   				     enum dma_data_direction dir)
> > > > > >   {
> > > > > > @@ -294,6 +329,12 @@ struct sg_table
> > *drm_gem_map_dma_buf(struct
> > > > dma_buf_attachment *attach,
> > > > > >   }
> > > > > >   EXPORT_SYMBOL(drm_gem_map_dma_buf);
> > > > > > +/**
> > > > > > + * drm_gem_unmap_dma_buf - unmap_dma_buf implementation
> > for
> > > > GEM
> > > > > > + *
> > > > > > + * Not implemented. The unmap is done at
> > drm_gem_map_detach().
> > > > > > +This can be
> > > > > > + * used as the &dma_buf_ops.unmap_dma_buf callback.
> > > > > > + */
> > > > > >   void drm_gem_unmap_dma_buf(struct dma_buf_attachment
> > *attach,
> > > > > >   			   struct sg_table *sgt,
> > > > > >   			   enum dma_data_direction dir) @@ -351,6
> > +392,15
> > > > @@ void
> > > > > > drm_gem_dmabuf_release(struct dma_buf *dma_buf)
> > > > > >   }
> > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_release);
> > > > > > +/**
> > > > > > + * drm_gem_dmabuf_vmap - dma_buf vmap implementation for
> > GEM
> > > > > > + * @dma_buf: buffer to be mapped
> > > > > > + *
> > > > > > + * Sets up a kernel virtual mapping. This can be used as the
> > > > > > +&dma_buf_ops.vmap
> > > > > > + * callback.
> > > > > > + *
> > > > > > + * Returns the kernel virtual address.
> > > > > > + */
> > > > > >   void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> > > > > >   {
> > > > > >   	struct drm_gem_object *obj = dma_buf->priv; @@ -360,6
> > +410,14
> > > > @@
> > > > > > void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> > > > > >   }
> > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
> > > > > > +/**
> > > > > > + * drm_gem_dmabuf_vunmap - dma_buf vunmap implementation
> > for
> > > > GEM
> > > > > > + * @dma_buf: buffer to be unmapped
> > > > > > + * @vaddr: the virtual address of the buffer
> > > > > > + *
> > > > > > + * Releases a kernel virtual mapping. This can be used as the
> > > > > > + * &dma_buf_ops.vunmap callback.
> > > > > > + */
> > > > > >   void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void
> > > > *vaddr)
> > > > > >   {
> > > > > >   	struct drm_gem_object *obj = dma_buf->priv; @@ -369,6
> > +427,11
> > > > @@
> > > > > > void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void
> > *vaddr)
> > > > > >   }
> > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
> > > > > > +/**
> > > > > > + * drm_gem_dmabuf_kmap_atomic - map_atomic implementation
> > for
> > > > GEM
> > > > > > + *
> > > > > > + * Not implemented. This can be used as the
> > > > &dma_buf_ops.map_atomic callback.
> > > > > > + */
> > > > > >   void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
> > > > > >   				 unsigned long page_num)
> > > > > >   {
> > > > > > @@ -376,6 +439,11 @@ void
> > *drm_gem_dmabuf_kmap_atomic(struct
> > > > dma_buf *dma_buf,
> > > > > >   }
> > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kmap_atomic);
> > > > > > +/**
> > > > > > + * drm_gem_dmabuf_kunmap_atomic - unmap_atomic
> > > > implementation for
> > > > > > +GEM
> > > > > > + *
> > > > > > + * Not implemented. This can be used as the
> > > > &dma_buf_ops.unmap_atomic callback.
> > > > > > + */
> > > > > >   void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
> > > > > >   				  unsigned long page_num, void
> > *addr)
> > > > > >   {
> > > > > > @@ -383,12 +451,22 @@ void
> > drm_gem_dmabuf_kunmap_atomic(struct
> > > > dma_buf *dma_buf,
> > > > > >   }
> > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap_atomic);
> > > > > > +/**
> > > > > > + * drm_gem_dmabuf_kmap - map implementation for GEM
> > > > > > + *
> > > > > > + * Not implemented. This can be used as the &dma_buf_ops.map
> > > > callback.
> > > > > > + */
> > > > > >   void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf,
> > unsigned
> > > > long page_num)
> > > > > >   {
> > > > > >   	return NULL;
> > > > > >   }
> > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kmap);
> > > > > > +/**
> > > > > > + * drm_gem_dmabuf_kunmap - unmap implementation for GEM
> > > > > > + *
> > > > > > + * Not implemented. This can be used as the &dma_buf_ops.unmap
> > > > callback.
> > > > > > + */
> > > > > >   void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
> > unsigned
> > > > long page_num,
> > > > > >   			   void *addr)
> > > > > >   {
> > > > > > @@ -396,6 +474,16 @@ void drm_gem_dmabuf_kunmap(struct
> > > > dma_buf *dma_buf, unsigned long page_num,
> > > > > >   }
> > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap);
> > > > > > +/**
> > > > > > + * drm_gem_dmabuf_mmap - dma_buf mmap implementation for
> > > > GEM
> > > > > > + * @dma_buf: buffer to be mapped
> > > > > > + * @vma: virtual address range
> > > > > > + *
> > > > > > + * Provides memory mapping for the buffer. This can be used as
> > > > > > + the
> > > > > > + * &dma_buf_ops.mmap callback.
> > > > > > + *
> > > > > > + * Returns 0 on success or a negative error code on failure.
> > > > > > + */
> > > > > >   int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct
> > > > vm_area_struct *vma)
> > > > > >   {
> > > > > >   	struct drm_gem_object *obj = dma_buf->priv;
> > > > >
> > > > > _______________________________________________
> > > > > dri-devel mailing list
> > > > > dri-devel@lists.freedesktop.org
> > > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> > > >
> > > > --
> > > > Daniel Vetter
> > > > Software Engineer, Intel Corporation http://blog.ffwll.ch
> > 
> > --
> > Daniel Vetter
> > Software Engineer, Intel Corporation
> > http://blog.ffwll.ch
Li, Samuel Feb. 20, 2018, 4:25 p.m. UTC | #7
OK, I can do that.

Regards,
Samuel Li


> -----Original Message-----
> From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of Daniel
> Vetter
> Sent: Tuesday, February 20, 2018 11:23 AM
> To: Li, Samuel <Samuel.Li@amd.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>; Koenig, Christian
> <Christian.Koenig@amd.com>; amd-gfx@lists.freedesktop.org; dri-
> devel@lists.freedesktop.org
> Subject: Re: [PATCH v2 1/1] drm: add kernel doc for exported gem
> dmabuf_ops
> 
> On Tue, Feb 20, 2018 at 03:46:51PM +0000, Li, Samuel wrote:
> > > ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> > > member 'attach' not described in 'drm_gem_unmap_dma_buf'
> > > ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> > > member 'sgt' not described in 'drm_gem_unmap_dma_buf'
> > > ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> > > member 'dir' not described in 'drm_gem_unmap_dma_buf'
> > ...
> >
> > Actually I tested. Those parameters are left out on purpose since they are
> empty functions so far.
> 
> Can you pls add dummy explanations? I know it's somewhat silly, but when
> there's lots of warnings it's much harder to spot new ones. Docs are
> sometimes just plain boring rote work :-/
> 
> Thanks, Daniel
> 
> >
> > Regards,
> > Samuel Li
> >
> > > -----Original Message-----
> > > From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of
> > > Daniel Vetter
> > > Sent: Tuesday, February 20, 2018 10:13 AM
> > > To: Li, Samuel <Samuel.Li@amd.com>
> > > Cc: Daniel Vetter <daniel@ffwll.ch>; Koenig, Christian
> > > <Christian.Koenig@amd.com>; amd-gfx@lists.freedesktop.org; dri-
> > > devel@lists.freedesktop.org
> > > Subject: Re: [PATCH v2 1/1] drm: add kernel doc for exported gem
> > > dmabuf_ops
> > >
> > > On Tue, Jan 30, 2018 at 04:01:23PM +0000, Li, Samuel wrote:
> > > >
> > > > Alex helped push this into drm-tip,
> > > > https://cgit.freedesktop.org/drm/drm-
> > > tip/commit/drivers/gpu/drm?id=f7a
> > > > 71b0cf9e36c1b0edbfe89ce028a01164b864d
> > > >
> > > > Thanks,
> > > > Samuel Li
> > > >
> > > >
> > > > > -----Original Message-----
> > > > > From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of
> > > > > Daniel Vetter
> > > > > Sent: Tuesday, January 30, 2018 4:33 AM
> > > > > To: Koenig, Christian <Christian.Koenig@amd.com>
> > > > > Cc: Li, Samuel <Samuel.Li@amd.com>;
> > > > > amd-gfx@lists.freedesktop.org;
> > > > > dri- devel@lists.freedesktop.org
> > > > > Subject: Re: [PATCH v2 1/1] drm: add kernel doc for exported gem
> > > > > dmabuf_ops
> > > > >
> > > > > On Fri, Jan 19, 2018 at 09:51:20AM +0100, Christian König wrote:
> > > > > > Am 18.01.2018 um 22:44 schrieb Samuel Li:
> > > > > > > Signed-off-by: Samuel Li <Samuel.Li@amd.com>
> > > > > > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > > > >
> > > > > Thanks for updating the docs.
> > > > > >
> > > > > > Reviewed-by: Christian König <christian.koenig@amd.com>
> > > > >
> > > > > I'm assuming you'll als push this one.
> > >
> > > I just noticed that fairly obviously this wasn't tested when writing:
> > >
> > > ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> > > member 'attach' not described in 'drm_gem_unmap_dma_buf'
> > > ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> > > member 'sgt' not described in 'drm_gem_unmap_dma_buf'
> > > ./drivers/gpu/drm/drm_prime.c:342: warning: Function parameter or
> > > member 'dir' not described in 'drm_gem_unmap_dma_buf'
> > > ./drivers/gpu/drm/drm_prime.c:438: warning: Function parameter or
> > > member 'dma_buf' not described in 'drm_gem_dmabuf_kmap_atomic'
> > > ./drivers/gpu/drm/drm_prime.c:438: warning: Function parameter or
> > > member 'page_num' not described in 'drm_gem_dmabuf_kmap_atomic'
> > > ./drivers/gpu/drm/drm_prime.c:450: warning: Function parameter or
> > > member 'dma_buf' not described in
> 'drm_gem_dmabuf_kunmap_atomic'
> > > ./drivers/gpu/drm/drm_prime.c:450: warning: Function parameter or
> > > member 'page_num' not described in
> 'drm_gem_dmabuf_kunmap_atomic'
> > > ./drivers/gpu/drm/drm_prime.c:450: warning: Function parameter or
> > > member 'addr' not described in 'drm_gem_dmabuf_kunmap_atomic'
> > > ./drivers/gpu/drm/drm_prime.c:461: warning: Function parameter or
> > > member 'dma_buf' not described in 'drm_gem_dmabuf_kmap'
> > > ./drivers/gpu/drm/drm_prime.c:461: warning: Function parameter or
> > > member 'page_num' not described in 'drm_gem_dmabuf_kmap'
> > > ./drivers/gpu/drm/drm_prime.c:473: warning: Function parameter or
> > > member 'dma_buf' not described in 'drm_gem_dmabuf_kunmap'
> > > ./drivers/gpu/drm/drm_prime.c:473: warning: Function parameter or
> > > member 'page_num' not described in 'drm_gem_dmabuf_kunmap'
> > > ./drivers/gpu/drm/drm_prime.c:473: warning: Function parameter or
> > > member 'addr' not described in 'drm_gem_dmabuf_kunmap'
> > >
> > > Samuel, can you pls build docs using
> > >
> > > $ make htmldocs
> > >
> > > and fix up the fallout and submit a patch?
> > >
> > > Thanks, Daniel
> > >
> > > > > -Daniel
> > > > >
> > > > > >
> > > > > > > ---
> > > > > > >   drivers/gpu/drm/drm_prime.c | 88
> > > > > +++++++++++++++++++++++++++++++++++++++++++++
> > > > > > >   1 file changed, 88 insertions(+)
> > > > > > >
> > > > > > > diff --git a/drivers/gpu/drm/drm_prime.c
> > > > > > > b/drivers/gpu/drm/drm_prime.c index ca09ce7..e82a976 100644
> > > > > > > --- a/drivers/gpu/drm/drm_prime.c
> > > > > > > +++ b/drivers/gpu/drm/drm_prime.c
> > > > > > > @@ -73,6 +73,9 @@
> > > > > > >    * Drivers should detect this situation and return back the gem
> object
> > > > > > >    * from the dma-buf private.  Prime will do this
> > > > > > > automatically for drivers
> > > > > that
> > > > > > >    * use the drm_gem_prime_{import,export} helpers.
> > > > > > > + *
> > > > > > > + * GEM struct &dma_buf_ops symbols are now exported. They
> > > > > > > + can be resued by
> > > > > > > + * drivers which implement GEM interface.
> > > > > > >    */
> > > > > > >   struct drm_prime_member {
> > > > > > > @@ -180,6 +183,18 @@ static int
> > > > > > > drm_prime_lookup_buf_handle(struct
> > > > > drm_prime_file_private *prime_fpri
> > > > > > >   	return -ENOENT;
> > > > > > >   }
> > > > > > > +/**
> > > > > > > + * drm_gem_map_attach - dma_buf attach implementation for
> > > > > > > +GEM
> > > > > > > + * @dma_buf: buffer to attach device to
> > > > > > > + * @target_dev: not used
> > > > > > > + * @attach: buffer attachment data
> > > > > > > + *
> > > > > > > + * Allocates &drm_prime_attachment and calls
> > > > > > > +&drm_driver.gem_prime_pin for
> > > > > > > + * device specific attachment. This can be used as the
> > > > > > > +&dma_buf_ops.attach
> > > > > > > + * callback.
> > > > > > > + *
> > > > > > > + * Returns 0 on success, negative error code on failure.
> > > > > > > + */
> > > > > > >   int drm_gem_map_attach(struct dma_buf *dma_buf, struct
> > > > > > > device
> > > > > *target_dev,
> > > > > > >   		       struct dma_buf_attachment *attach)
> > > > > > >   {
> > > > > > > @@ -201,6 +216,14 @@ int drm_gem_map_attach(struct
> dma_buf
> > > > > *dma_buf, struct device *target_dev,
> > > > > > >   }
> > > > > > >   EXPORT_SYMBOL(drm_gem_map_attach);
> > > > > > > +/**
> > > > > > > + * drm_gem_map_detach - dma_buf detach implementation for
> > > GEM
> > > > > > > + * @dma_buf: buffer to detach from
> > > > > > > + * @attach: attachment to be detached
> > > > > > > + *
> > > > > > > + * Cleans up &dma_buf_attachment. This can be used as the
> > > > > > > +&dma_buf_ops.detach
> > > > > > > + * callback.
> > > > > > > + */
> > > > > > >   void drm_gem_map_detach(struct dma_buf *dma_buf,
> > > > > > >   			struct dma_buf_attachment *attach)
> > > > > > >   {
> > > > > > > @@ -255,6 +278,18 @@ void
> > > > > drm_prime_remove_buf_handle_locked(struct
> drm_prime_file_private
> > > > > *prime_fpr
> > > > > > >   	}
> > > > > > >   }
> > > > > > > +/**
> > > > > > > + * drm_gem_map_dma_buf - map_dma_buf implementation
> for
> > > GEM
> > > > > > > + * @attach: attachment whose scatterlist is to be returned
> > > > > > > + * @dir: direction of DMA transfer
> > > > > > > + *
> > > > > > > + * Calls &drm_driver.gem_prime_get_sg_table and then maps
> > > > > > > +the scatterlist. This
> > > > > > > + * can be used as the &dma_buf_ops.map_dma_buf callback.
> > > > > > > + *
> > > > > > > + * Returns sg_table containing the scatterlist to be
> > > > > > > +returned; returns ERR_PTR
> > > > > > > + * on error. May return -EINTR if it is interrupted by a signal.
> > > > > > > + */
> > > > > > > +
> > > > > > >   struct sg_table *drm_gem_map_dma_buf(struct
> > > dma_buf_attachment
> > > > > *attach,
> > > > > > >   				     enum dma_data_direction dir)
> > > > > > >   {
> > > > > > > @@ -294,6 +329,12 @@ struct sg_table
> > > *drm_gem_map_dma_buf(struct
> > > > > dma_buf_attachment *attach,
> > > > > > >   }
> > > > > > >   EXPORT_SYMBOL(drm_gem_map_dma_buf);
> > > > > > > +/**
> > > > > > > + * drm_gem_unmap_dma_buf - unmap_dma_buf
> implementation
> > > for
> > > > > GEM
> > > > > > > + *
> > > > > > > + * Not implemented. The unmap is done at
> > > drm_gem_map_detach().
> > > > > > > +This can be
> > > > > > > + * used as the &dma_buf_ops.unmap_dma_buf callback.
> > > > > > > + */
> > > > > > >   void drm_gem_unmap_dma_buf(struct dma_buf_attachment
> > > *attach,
> > > > > > >   			   struct sg_table *sgt,
> > > > > > >   			   enum dma_data_direction dir) @@ -351,6
> > > +392,15
> > > > > @@ void
> > > > > > > drm_gem_dmabuf_release(struct dma_buf *dma_buf)
> > > > > > >   }
> > > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_release);
> > > > > > > +/**
> > > > > > > + * drm_gem_dmabuf_vmap - dma_buf vmap implementation
> for
> > > GEM
> > > > > > > + * @dma_buf: buffer to be mapped
> > > > > > > + *
> > > > > > > + * Sets up a kernel virtual mapping. This can be used as
> > > > > > > +the &dma_buf_ops.vmap
> > > > > > > + * callback.
> > > > > > > + *
> > > > > > > + * Returns the kernel virtual address.
> > > > > > > + */
> > > > > > >   void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> > > > > > >   {
> > > > > > >   	struct drm_gem_object *obj = dma_buf->priv; @@ -360,6
> > > +410,14
> > > > > @@
> > > > > > > void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
> > > > > > >   }
> > > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
> > > > > > > +/**
> > > > > > > + * drm_gem_dmabuf_vunmap - dma_buf vunmap
> implementation
> > > for
> > > > > GEM
> > > > > > > + * @dma_buf: buffer to be unmapped
> > > > > > > + * @vaddr: the virtual address of the buffer
> > > > > > > + *
> > > > > > > + * Releases a kernel virtual mapping. This can be used as
> > > > > > > + the
> > > > > > > + * &dma_buf_ops.vunmap callback.
> > > > > > > + */
> > > > > > >   void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf,
> void
> > > > > *vaddr)
> > > > > > >   {
> > > > > > >   	struct drm_gem_object *obj = dma_buf->priv; @@ -369,6
> > > +427,11
> > > > > @@
> > > > > > > void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void
> > > *vaddr)
> > > > > > >   }
> > > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
> > > > > > > +/**
> > > > > > > + * drm_gem_dmabuf_kmap_atomic - map_atomic
> implementation
> > > for
> > > > > GEM
> > > > > > > + *
> > > > > > > + * Not implemented. This can be used as the
> > > > > &dma_buf_ops.map_atomic callback.
> > > > > > > + */
> > > > > > >   void *drm_gem_dmabuf_kmap_atomic(struct dma_buf
> *dma_buf,
> > > > > > >   				 unsigned long page_num)
> > > > > > >   {
> > > > > > > @@ -376,6 +439,11 @@ void
> > > *drm_gem_dmabuf_kmap_atomic(struct
> > > > > dma_buf *dma_buf,
> > > > > > >   }
> > > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kmap_atomic);
> > > > > > > +/**
> > > > > > > + * drm_gem_dmabuf_kunmap_atomic - unmap_atomic
> > > > > implementation for
> > > > > > > +GEM
> > > > > > > + *
> > > > > > > + * Not implemented. This can be used as the
> > > > > &dma_buf_ops.unmap_atomic callback.
> > > > > > > + */
> > > > > > >   void drm_gem_dmabuf_kunmap_atomic(struct dma_buf
> *dma_buf,
> > > > > > >   				  unsigned long page_num, void
> > > *addr)
> > > > > > >   {
> > > > > > > @@ -383,12 +451,22 @@ void
> > > drm_gem_dmabuf_kunmap_atomic(struct
> > > > > dma_buf *dma_buf,
> > > > > > >   }
> > > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap_atomic);
> > > > > > > +/**
> > > > > > > + * drm_gem_dmabuf_kmap - map implementation for GEM
> > > > > > > + *
> > > > > > > + * Not implemented. This can be used as the
> > > > > > > +&dma_buf_ops.map
> > > > > callback.
> > > > > > > + */
> > > > > > >   void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf,
> > > unsigned
> > > > > long page_num)
> > > > > > >   {
> > > > > > >   	return NULL;
> > > > > > >   }
> > > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kmap);
> > > > > > > +/**
> > > > > > > + * drm_gem_dmabuf_kunmap - unmap implementation for
> GEM
> > > > > > > + *
> > > > > > > + * Not implemented. This can be used as the
> > > > > > > +&dma_buf_ops.unmap
> > > > > callback.
> > > > > > > + */
> > > > > > >   void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
> > > unsigned
> > > > > long page_num,
> > > > > > >   			   void *addr)
> > > > > > >   {
> > > > > > > @@ -396,6 +474,16 @@ void drm_gem_dmabuf_kunmap(struct
> > > > > dma_buf *dma_buf, unsigned long page_num,
> > > > > > >   }
> > > > > > >   EXPORT_SYMBOL(drm_gem_dmabuf_kunmap);
> > > > > > > +/**
> > > > > > > + * drm_gem_dmabuf_mmap - dma_buf mmap implementation
> for
> > > > > GEM
> > > > > > > + * @dma_buf: buffer to be mapped
> > > > > > > + * @vma: virtual address range
> > > > > > > + *
> > > > > > > + * Provides memory mapping for the buffer. This can be used
> > > > > > > + as the
> > > > > > > + * &dma_buf_ops.mmap callback.
> > > > > > > + *
> > > > > > > + * Returns 0 on success or a negative error code on failure.
> > > > > > > + */
> > > > > > >   int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct
> > > > > vm_area_struct *vma)
> > > > > > >   {
> > > > > > >   	struct drm_gem_object *obj = dma_buf->priv;
> > > > > >
> > > > > > _______________________________________________
> > > > > > dri-devel mailing list
> > > > > > dri-devel@lists.freedesktop.org
> > > > > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> > > > >
> > > > > --
> > > > > Daniel Vetter
> > > > > Software Engineer, Intel Corporation http://blog.ffwll.ch
> > >
> > > --
> > > Daniel Vetter
> > > Software Engineer, Intel Corporation http://blog.ffwll.ch
> 
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
diff mbox

Patch

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index ca09ce7..e82a976 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -73,6 +73,9 @@ 
  * Drivers should detect this situation and return back the gem object
  * from the dma-buf private.  Prime will do this automatically for drivers that
  * use the drm_gem_prime_{import,export} helpers.
+ *
+ * GEM struct &dma_buf_ops symbols are now exported. They can be resued by
+ * drivers which implement GEM interface.
  */
 
 struct drm_prime_member {
@@ -180,6 +183,18 @@  static int drm_prime_lookup_buf_handle(struct drm_prime_file_private *prime_fpri
 	return -ENOENT;
 }
 
+/**
+ * drm_gem_map_attach - dma_buf attach implementation for GEM
+ * @dma_buf: buffer to attach device to
+ * @target_dev: not used
+ * @attach: buffer attachment data
+ *
+ * Allocates &drm_prime_attachment and calls &drm_driver.gem_prime_pin for
+ * device specific attachment. This can be used as the &dma_buf_ops.attach
+ * callback.
+ *
+ * Returns 0 on success, negative error code on failure.
+ */
 int drm_gem_map_attach(struct dma_buf *dma_buf, struct device *target_dev,
 		       struct dma_buf_attachment *attach)
 {
@@ -201,6 +216,14 @@  int drm_gem_map_attach(struct dma_buf *dma_buf, struct device *target_dev,
 }
 EXPORT_SYMBOL(drm_gem_map_attach);
 
+/**
+ * drm_gem_map_detach - dma_buf detach implementation for GEM
+ * @dma_buf: buffer to detach from
+ * @attach: attachment to be detached
+ *
+ * Cleans up &dma_buf_attachment. This can be used as the &dma_buf_ops.detach
+ * callback.
+ */
 void drm_gem_map_detach(struct dma_buf *dma_buf,
 			struct dma_buf_attachment *attach)
 {
@@ -255,6 +278,18 @@  void drm_prime_remove_buf_handle_locked(struct drm_prime_file_private *prime_fpr
 	}
 }
 
+/**
+ * drm_gem_map_dma_buf - map_dma_buf implementation for GEM
+ * @attach: attachment whose scatterlist is to be returned
+ * @dir: direction of DMA transfer
+ *
+ * Calls &drm_driver.gem_prime_get_sg_table and then maps the scatterlist. This
+ * can be used as the &dma_buf_ops.map_dma_buf callback.
+ *
+ * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR
+ * on error. May return -EINTR if it is interrupted by a signal.
+ */
+
 struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 				     enum dma_data_direction dir)
 {
@@ -294,6 +329,12 @@  struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
 }
 EXPORT_SYMBOL(drm_gem_map_dma_buf);
 
+/**
+ * drm_gem_unmap_dma_buf - unmap_dma_buf implementation for GEM
+ *
+ * Not implemented. The unmap is done at drm_gem_map_detach().  This can be
+ * used as the &dma_buf_ops.unmap_dma_buf callback.
+ */
 void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 			   struct sg_table *sgt,
 			   enum dma_data_direction dir)
@@ -351,6 +392,15 @@  void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_release);
 
+/**
+ * drm_gem_dmabuf_vmap - dma_buf vmap implementation for GEM
+ * @dma_buf: buffer to be mapped
+ *
+ * Sets up a kernel virtual mapping. This can be used as the &dma_buf_ops.vmap
+ * callback.
+ *
+ * Returns the kernel virtual address.
+ */
 void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 {
 	struct drm_gem_object *obj = dma_buf->priv;
@@ -360,6 +410,14 @@  void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
 
+/**
+ * drm_gem_dmabuf_vunmap - dma_buf vunmap implementation for GEM
+ * @dma_buf: buffer to be unmapped
+ * @vaddr: the virtual address of the buffer
+ *
+ * Releases a kernel virtual mapping. This can be used as the
+ * &dma_buf_ops.vunmap callback.
+ */
 void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 {
 	struct drm_gem_object *obj = dma_buf->priv;
@@ -369,6 +427,11 @@  void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_vunmap);
 
+/**
+ * drm_gem_dmabuf_kmap_atomic - map_atomic implementation for GEM
+ *
+ * Not implemented. This can be used as the &dma_buf_ops.map_atomic callback.
+ */
 void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
 				 unsigned long page_num)
 {
@@ -376,6 +439,11 @@  void *drm_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_kmap_atomic);
 
+/**
+ * drm_gem_dmabuf_kunmap_atomic - unmap_atomic implementation for GEM
+ *
+ * Not implemented. This can be used as the &dma_buf_ops.unmap_atomic callback.
+ */
 void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
 				  unsigned long page_num, void *addr)
 {
@@ -383,12 +451,22 @@  void drm_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_kunmap_atomic);
 
+/**
+ * drm_gem_dmabuf_kmap - map implementation for GEM
+ *
+ * Not implemented. This can be used as the &dma_buf_ops.map callback.
+ */
 void *drm_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
 {
 	return NULL;
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_kmap);
 
+/**
+ * drm_gem_dmabuf_kunmap - unmap implementation for GEM
+ *
+ * Not implemented. This can be used as the &dma_buf_ops.unmap callback.
+ */
 void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num,
 			   void *addr)
 {
@@ -396,6 +474,16 @@  void drm_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num,
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_kunmap);
 
+/**
+ * drm_gem_dmabuf_mmap - dma_buf mmap implementation for GEM
+ * @dma_buf: buffer to be mapped
+ * @vma: virtual address range
+ *
+ * Provides memory mapping for the buffer. This can be used as the
+ * &dma_buf_ops.mmap callback.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
 int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 {
 	struct drm_gem_object *obj = dma_buf->priv;