diff --git a/drivers/staging/vc04_services/vc-sm-cma/vc_sm.c b/drivers/staging/vc04_services/vc-sm-cma/vc_sm.c
index 03c30de5c2eb29..5015b694857ce1 100644
--- a/drivers/staging/vc04_services/vc-sm-cma/vc_sm.c
+++ b/drivers/staging/vc04_services/vc-sm-cma/vc_sm.c
@@ -91,7 +91,7 @@ struct sm_state_t {
 
 	struct sm_instance *sm_handle;	/* Handle for videocore service. */
 
-	spinlock_t kernelid_map_lock;	/* Spinlock protecting kernelid_map */
+	struct mutex kernelid_map_lock;	/* Mutex protecting kernelid_map */
 	struct idr kernelid_map;
 
 	struct mutex map_lock;          /* Global map lock. */
@@ -129,9 +129,9 @@ static int get_kernel_id(struct vc_sm_buffer *buffer)
 {
 	int handle;
 
-	spin_lock(&sm_state->kernelid_map_lock);
+	mutex_lock(&sm_state->kernelid_map_lock);
 	handle = idr_alloc(&sm_state->kernelid_map, buffer, 0, 0, GFP_KERNEL);
-	spin_unlock(&sm_state->kernelid_map_lock);
+	mutex_unlock(&sm_state->kernelid_map_lock);
 
 	return handle;
 }
@@ -143,9 +143,9 @@ static struct vc_sm_buffer *lookup_kernel_id(int handle)
 
 static void free_kernel_id(int handle)
 {
-	spin_lock(&sm_state->kernelid_map_lock);
+	mutex_lock(&sm_state->kernelid_map_lock);
 	idr_remove(&sm_state->kernelid_map, handle);
-	spin_unlock(&sm_state->kernelid_map_lock);
+	mutex_unlock(&sm_state->kernelid_map_lock);
 }
 
 static int vc_sm_cma_seq_file_show(struct seq_file *s, void *v)
@@ -249,9 +249,9 @@ static void vc_sm_clean_up_dmabuf(struct vc_sm_buffer *buffer)
 
 	/* Handle cleaning up imported dmabufs */
 	if (buffer->import.sgt) {
-		dma_buf_unmap_attachment(buffer->import.attach,
-					 buffer->import.sgt,
-					 DMA_BIDIRECTIONAL);
+		dma_buf_unmap_attachment_unlocked(buffer->import.attach,
+						  buffer->import.sgt,
+						  DMA_BIDIRECTIONAL);
 		buffer->import.sgt = NULL;
 	}
 	if (buffer->import.attach) {
@@ -735,7 +735,7 @@ vc_sm_cma_import_dmabuf_internal(struct vc_sm_privdata_t *private,
 		goto error;
 	}
 
-	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
+	sgt = dma_buf_map_attachment_unlocked(attach, DMA_BIDIRECTIONAL);
 	if (IS_ERR(sgt)) {
 		ret = PTR_ERR(sgt);
 		goto error;
@@ -845,7 +845,7 @@ vc_sm_cma_import_dmabuf_internal(struct vc_sm_privdata_t *private,
 	free_kernel_id(import.kernel_id);
 	kfree(buffer);
 	if (sgt)
-		dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
+		dma_buf_unmap_attachment_unlocked(attach, sgt, DMA_BIDIRECTIONAL);
 	if (attach)
 		dma_buf_detach(dma_buf, attach);
 	dma_buf_put(dma_buf);
@@ -1494,7 +1494,7 @@ static int bcm2835_vc_sm_cma_probe(struct vchiq_device *device)
 	sm_state->device = device;
 	mutex_init(&sm_state->map_lock);
 
-	spin_lock_init(&sm_state->kernelid_map_lock);
+	mutex_init(&sm_state->kernelid_map_lock);
 	idr_init_base(&sm_state->kernelid_map, 1);
 
 	device->dev.dma_parms = devm_kzalloc(&device->dev,