[PATCH v2 1/6] dma-buf: dma-heap: Keep track of the heap device struct

[Albert Esteve <aesteve@redhat.com>]

From: John Stultz <john.stultz@linaro.org>

Keep track of the heap device struct.

This will be useful for special DMA allocations
and actions.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Albert Esteve <aesteve@redhat.com>
---
 drivers/dma-buf/dma-heap.c | 34 ++++++++++++++++++++++++++--------
 include/linux/dma-heap.h   |  2 ++
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
index ac5f8685a6494..1124d63eb1398 100644
--- a/drivers/dma-buf/dma-heap.c
+++ b/drivers/dma-buf/dma-heap.c
@@ -31,6 +31,7 @@
  * @heap_devt:		heap device node
  * @list:		list head connecting to list of heaps
  * @heap_cdev:		heap char device
+ * @heap_dev:		heap device
  *
  * Represents a heap of memory from which buffers can be made.
  */
@@ -41,6 +42,7 @@ struct dma_heap {
 	dev_t heap_devt;
 	struct list_head list;
 	struct cdev heap_cdev;
+	struct device *heap_dev;
 };
 
 static LIST_HEAD(heap_list);
@@ -223,6 +225,19 @@ const char *dma_heap_get_name(struct dma_heap *heap)
 }
 EXPORT_SYMBOL_NS_GPL(dma_heap_get_name, "DMA_BUF_HEAP");
 
+/**
+ * dma_heap_get_dev() - get device struct for the heap
+ * @heap: DMA-Heap to retrieve device struct from
+ *
+ * Returns:
+ * The device struct for the heap.
+ */
+struct device *dma_heap_get_dev(struct dma_heap *heap)
+{
+	return heap->heap_dev;
+}
+EXPORT_SYMBOL_NS_GPL(dma_heap_get_dev, "DMA_BUF_HEAP");
+
 /**
  * dma_heap_add - adds a heap to dmabuf heaps
  * @exp_info: information needed to register this heap
@@ -230,7 +245,6 @@ EXPORT_SYMBOL_NS_GPL(dma_heap_get_name, "DMA_BUF_HEAP");
 struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
 {
 	struct dma_heap *heap, *h, *err_ret;
-	struct device *dev_ret;
 	unsigned int minor;
 	int ret;
 
@@ -272,14 +286,14 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
 		goto err1;
 	}
 
-	dev_ret = device_create(dma_heap_class,
-				NULL,
-				heap->heap_devt,
-				NULL,
-				heap->name);
-	if (IS_ERR(dev_ret)) {
+	heap->heap_dev = device_create(dma_heap_class,
+				       NULL,
+				       heap->heap_devt,
+				       NULL,
+				       heap->name);
+	if (IS_ERR(heap->heap_dev)) {
 		pr_err("dma_heap: Unable to create device\n");
-		err_ret = ERR_CAST(dev_ret);
+		err_ret = ERR_CAST(heap->heap_dev);
 		goto err2;
 	}
 
@@ -295,6 +309,10 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info)
 		}
 	}
 
+	/* Make sure it doesn't disappear on us */
+	heap->heap_dev = get_device(heap->heap_dev);
+
+
 	/* Add heap to the list */
 	list_add(&heap->list, &heap_list);
 	mutex_unlock(&heap_list_lock);
diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h
index 648328a64b27e..493085e69b70e 100644
--- a/include/linux/dma-heap.h
+++ b/include/linux/dma-heap.h
@@ -12,6 +12,7 @@
 #include <linux/types.h>
 
 struct dma_heap;
+struct device;
 
 /**
  * struct dma_heap_ops - ops to operate on a given heap
@@ -43,6 +44,7 @@ struct dma_heap_export_info {
 void *dma_heap_get_drvdata(struct dma_heap *heap);
 
 const char *dma_heap_get_name(struct dma_heap *heap);
+struct device *dma_heap_get_dev(struct dma_heap *heap);
 
 struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info);
 

-- 
2.52.0