Re: [PATCH v6,02/24] v4l2: handle restricted memory flags in queue setup

["Yunfei Dong (董云飞)" <Yunfei.Dong@mediatek.com>]

Hi Andrzej,

Thanks for your help to review this patch.

Your suggestion is very reasonable, I will change it later.

Best Regards,
Yunfei Dong
On Wed, 2024-05-22 at 14:20 +0200, Andrzej Pietrasiewicz wrote:
> Hi Yunfei & Jeffrey,
> 
> W dniu 16.05.2024 o 14:20, Yunfei Dong pisze:
> > From: Jeffrey Kardatzke <jkardatzke@google.com>
> > 
> > Validates the restricted memory flags when setting up a queue and
> > ensures the queue has the proper capability.
> > 
> > Signed-off-by: Jeffrey Kardatzke <jkardatzke@google.com>
> > Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
> > ---
> >   .../media/common/videobuf2/videobuf2-core.c   | 21
> > +++++++++++++++++++
> >   .../media/common/videobuf2/videobuf2-v4l2.c   |  4 +++-
> >   2 files changed, 24 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/media/common/videobuf2/videobuf2-core.c
> > b/drivers/media/common/videobuf2/videobuf2-core.c
> > index 358f1fe42975..fe4c0594ab81 100644
> > --- a/drivers/media/common/videobuf2/videobuf2-core.c
> > +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> > @@ -831,6 +831,15 @@ static bool verify_coherency_flags(struct
> > vb2_queue *q, bool non_coherent_mem)
> >   	return true;
> >   }
> >   
> > +static bool verify_restricted_mem_flags(struct vb2_queue *q, bool
> > restricted_mem)
> > +{
> > +	if (restricted_mem != q->restricted_mem) {
> > +		dprintk(q, 1, "restricted memory model mismatch\n");
> > +		return false;
> > +	}
> > +	return true;
> > +}
> > +
> >   static int vb2_core_allocated_buffers_storage(struct vb2_queue
> > *q)
> >   {
> >   	if (!q->bufs)
> > @@ -864,6 +873,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum
> > vb2_memory memory,
> >   	unsigned int q_num_bufs = vb2_get_num_buffers(q);
> >   	unsigned plane_sizes[VB2_MAX_PLANES] = { };
> >   	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
> > +	bool restricted_mem = flags & V4L2_MEMORY_FLAG_RESTRICTED;
> >   	unsigned int i, first_index;
> >   	int ret = 0;
> >   
> > @@ -907,6 +917,9 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum
> > vb2_memory memory,
> >   			return 0;
> >   	}
> >   
> > +	if (restricted_mem && (!q->allow_restricted_mem || memory !=
> > VB2_MEMORY_DMABUF))
> > +		return -EINVAL;
> > +
> >   	/*
> >   	 * Make sure the requested values and current defaults are
> > sane.
> >   	 */
> > @@ -924,6 +937,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum
> > vb2_memory memory,
> >   	if (ret)
> >   		return ret;
> >   	set_queue_coherency(q, non_coherent_mem);
> > +	q->restricted_mem = restricted_mem;
> >   
> >   	/*
> >   	 * Ask the driver how many buffers and planes per buffer it
> > requires.
> > @@ -1032,6 +1046,7 @@ int vb2_core_create_bufs(struct vb2_queue *q,
> > enum vb2_memory memory,
> >   	unsigned plane_sizes[VB2_MAX_PLANES] = { };
> >   	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
> >   	unsigned int q_num_bufs = vb2_get_num_buffers(q);
> > +	bool restricted_mem = flags & V4L2_MEMORY_FLAG_RESTRICTED;
> >   	bool no_previous_buffers = !q_num_bufs;
> >   	int ret = 0;
> >   
> > @@ -1040,6 +1055,9 @@ int vb2_core_create_bufs(struct vb2_queue *q,
> > enum vb2_memory memory,
> >   		return -ENOBUFS;
> >   	}
> >   
> > +	if (restricted_mem && (!q->allow_restricted_mem || memory !=
> > VB2_MEMORY_DMABUF))
> > +		return -EINVAL;
> > +
> 
> This condition is repeated in another place. If it is ever to be
> changed, the person changing it must remember to look at both
> places. Maybe:
> 
> static inline int restricted_mem_mismatch(bool restricted_mem,
> 				struct vb2_queue *q, enum vb2_memory
> memory)
> {
> 	return restricted_mem &&
> 		(!q->allow_restricted_mem || memory !=
> VB2_MEMORY_DMABUF) ?
> 		-1 : 0;
> }
> 
> (you probably want to clean up line breaks)
> 
> and:
> 
> 	if (restricted_mem_mismatch(restricted_mem, q, memory))
> 		return -EINVAL;
> 
> Regards,
> 
> Andrzej
> 
> >   	if (no_previous_buffers) {
> >   		if (q->waiting_in_dqbuf && *count) {
> >   			dprintk(q, 1, "another dup()ped fd is waiting
> > for a buffer\n");
> > @@ -1058,6 +1076,7 @@ int vb2_core_create_bufs(struct vb2_queue *q,
> > enum vb2_memory memory,
> >   			return ret;
> >   		q->waiting_for_buffers = !q->is_output;
> >   		set_queue_coherency(q, non_coherent_mem);
> > +		q->restricted_mem = restricted_mem;
> >   	} else {
> >   		if (q->memory != memory) {
> >   			dprintk(q, 1, "memory model mismatch\n");
> > @@ -1065,6 +1084,8 @@ int vb2_core_create_bufs(struct vb2_queue *q,
> > enum vb2_memory memory,
> >   		}
> >   		if (!verify_coherency_flags(q, non_coherent_mem))
> >   			return -EINVAL;
> > +		if (!verify_restricted_mem_flags(q, restricted_mem))
> > +			return -EINVAL;
> >   	}
> >   
> >   	num_buffers = min(*count, q->max_num_buffers - q_num_bufs);
> > diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> > b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> > index 293f3d5f1c4e..9ee24e537e0c 100644
> > --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> > +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> > @@ -682,7 +682,7 @@ static void vb2_set_flags_and_caps(struct
> > vb2_queue *q, u32 memory,
> >   		*flags = 0;
> >   	} else {
> >   		/* Clear all unknown flags. */
> > -		*flags &= V4L2_MEMORY_FLAG_NON_COHERENT;
> > +		*flags &= V4L2_MEMORY_FLAG_NON_COHERENT |
> > V4L2_MEMORY_FLAG_RESTRICTED;
> >   	}
> >   
> >   	*caps |= V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS;
> > @@ -698,6 +698,8 @@ static void vb2_set_flags_and_caps(struct
> > vb2_queue *q, u32 memory,
> >   		*caps |= V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS;
> >   	if (q->supports_requests)
> >   		*caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
> > +	if (q->allow_restricted_mem && q->io_modes & VB2_DMABUF)
> > +		*caps |= V4L2_BUF_CAP_SUPPORTS_RESTRICTED_MEM;
> >   	if (max_num_bufs) {
> >   		*max_num_bufs = q->max_num_buffers;
> >   		*caps |= V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS;
> 
>