[PATCH v2,02/21] v4l2: handle secure memory flags in queue setup

[Yunfei Dong <yunfei.dong@mediatek.com>]

From: Jeffrey Kardatzke <jkardatzke@google.com>

Validates the secure 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   | 25 ++++++++++++++
 .../media/common/videobuf2/videobuf2-v4l2.c   | 33 ++++++++++++-------
 2 files changed, 47 insertions(+), 11 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 27aee92f3eea..7ee68f5533ba 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -744,12 +744,22 @@ static bool verify_coherency_flags(struct vb2_queue *q, bool non_coherent_mem)
 	return true;
 }
 
+static bool verify_secure_mem_flags(struct vb2_queue *q, bool secure_mem)
+{
+	if (secure_mem != q->secure_mem) {
+		dprintk(q, 1, "secure memory model mismatch\n");
+		return false;
+	}
+	return true;
+}
+
 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 		     unsigned int flags, unsigned int *count)
 {
 	unsigned int num_buffers, allocated_buffers, num_planes = 0;
 	unsigned plane_sizes[VB2_MAX_PLANES] = { };
 	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
+	bool secure_mem = flags & V4L2_MEMORY_FLAG_SECURE;
 	unsigned int i;
 	int ret;
 
@@ -766,6 +776,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 	if (*count == 0 || q->num_buffers != 0 ||
 	    (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory) ||
 	    !verify_coherency_flags(q, non_coherent_mem)) {
+		bool no_previous_buffers = !q->num_buffers;
+
 		/*
 		 * We already have buffers allocated, so first check if they
 		 * are not in use and can be freed.
@@ -784,6 +796,14 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 		__vb2_queue_free(q, q->num_buffers);
 		mutex_unlock(&q->mmap_lock);
 
+		/*
+		 * Do not allow switching secure buffer mode.
+		 */
+		if (!no_previous_buffers &&
+		    !verify_secure_mem_flags(q, secure_mem)) {
+			return -EINVAL;
+		}
+
 		/*
 		 * In case of REQBUFS(0) return immediately without calling
 		 * driver's queue_setup() callback and allocating resources.
@@ -807,6 +827,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
 	q->memory = memory;
 	mutex_unlock(&q->mmap_lock);
 	set_queue_coherency(q, non_coherent_mem);
+	q->secure_mem = secure_mem;
 
 	/*
 	 * Ask the driver how many buffers and planes per buffer it requires.
@@ -910,6 +931,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 	unsigned int num_planes = 0, num_buffers, allocated_buffers;
 	unsigned plane_sizes[VB2_MAX_PLANES] = { };
 	bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT;
+	bool secure_mem = flags & V4L2_MEMORY_FLAG_SECURE;
 	bool no_previous_buffers = !q->num_buffers;
 	int ret;
 
@@ -933,6 +955,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
 		mutex_unlock(&q->mmap_lock);
 		q->waiting_for_buffers = !q->is_output;
 		set_queue_coherency(q, non_coherent_mem);
+		q->secure_mem = secure_mem;
 	} else {
 		if (q->memory != memory) {
 			dprintk(q, 1, "memory model mismatch\n");
@@ -940,6 +963,8 @@ 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_secure_mem_flags(q, secure_mem))
+			return -EINVAL;
 	}
 
 	num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index c7a54d82a55e..966ce74e26b3 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -685,26 +685,33 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
 		*caps |= V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF;
 	if (q->allow_cache_hints && q->io_modes & VB2_MMAP)
 		*caps |= V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS;
+	if (q->allow_secure_mem && q->io_modes & VB2_DMABUF)
+		*caps |= V4L2_BUF_CAP_SUPPORTS_SECURE_MEM;
 #ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API
 	if (q->supports_requests)
 		*caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
 #endif
 }
 
-static void validate_memory_flags(struct vb2_queue *q,
+static bool validate_memory_flags(struct vb2_queue *q,
 				  int memory,
 				  u32 *flags)
 {
+	if (*flags & V4L2_MEMORY_FLAG_SECURE &&
+	    (!q->allow_secure_mem || memory != V4L2_MEMORY_DMABUF)) {
+		return false;
+	}
 	if (!q->allow_cache_hints || memory != V4L2_MEMORY_MMAP) {
 		/*
-		 * This needs to clear V4L2_MEMORY_FLAG_NON_COHERENT only,
-		 * but in order to avoid bugs we zero out all bits.
+		 * This needs to clear V4L2_MEMORY_FLAG_NON_COHERENT only.
 		 */
-		*flags = 0;
-	} else {
-		/* Clear all unknown flags. */
-		*flags &= V4L2_MEMORY_FLAG_NON_COHERENT;
+		*flags &= ~V4L2_MEMORY_FLAG_NON_COHERENT;
 	}
+
+	/* Clear all unknown flags. */
+	*flags &= V4L2_MEMORY_FLAG_NON_COHERENT | V4L2_MEMORY_FLAG_SECURE;
+
+	return true;
 }
 
 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
@@ -713,7 +720,8 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
 	u32 flags = req->flags;
 
 	fill_buf_caps(q, &req->capabilities);
-	validate_memory_flags(q, req->memory, &flags);
+	if (!validate_memory_flags(q, req->memory, &flags))
+		return -EINVAL;
 	req->flags = flags;
 	return ret ? ret : vb2_core_reqbufs(q, req->memory,
 					    req->flags, &req->count);
@@ -748,7 +756,8 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
 	unsigned i;
 
 	fill_buf_caps(q, &create->capabilities);
-	validate_memory_flags(q, create->memory, &create->flags);
+	if (!validate_memory_flags(q, create->memory, &create->flags))
+		return -EINVAL;
 	create->index = q->num_buffers;
 	if (create->count == 0)
 		return ret != -EBUSY ? ret : 0;
@@ -986,7 +995,8 @@ int vb2_ioctl_reqbufs(struct file *file, void *priv,
 	u32 flags = p->flags;
 
 	fill_buf_caps(vdev->queue, &p->capabilities);
-	validate_memory_flags(vdev->queue, p->memory, &flags);
+	if (!validate_memory_flags(vdev->queue, p->memory, &flags))
+		return -EINVAL;
 	p->flags = flags;
 	if (res)
 		return res;
@@ -1010,7 +1020,8 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
 
 	p->index = vdev->queue->num_buffers;
 	fill_buf_caps(vdev->queue, &p->capabilities);
-	validate_memory_flags(vdev->queue, p->memory, &p->flags);
+	if (!validate_memory_flags(vdev->queue, p->memory, &p->flags))
+		return -EINVAL;
 	/*
 	 * If count == 0, then just check if memory and type are valid.
 	 * Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
-- 
2.18.0