[PATCH v4 6/7] dma-buf: dma-heap: Keep track of the heap device struct

From: John Stultz
Date: Sat Oct 17 2020 - 02:02:42 EST


Keep track of the heap device struct.

This will be useful for special DMA allocations
and actions.

Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Cc: Liam Mark <lmark@xxxxxxxxxxxxxx>
Cc: Laura Abbott <labbott@xxxxxxxxxx>
Cc: Brian Starkey <Brian.Starkey@xxxxxxx>
Cc: Hridya Valsaraju <hridya@xxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Sandeep Patil <sspatil@xxxxxxxxxx>
Cc: Daniel Mentz <danielmentz@xxxxxxxxxx>
Cc: Chris Goldsworthy <cgoldswo@xxxxxxxxxxxxxx>
Cc: Ørjan Eide <orjan.eide@xxxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Cc: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
Cc: Simon Ser <contact@xxxxxxxxxxx>
Cc: James Jones <jajones@xxxxxxxxxx>
Cc: linux-media@xxxxxxxxxxxxxxx
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
drivers/dma-buf/dma-heap.c | 33 +++++++++++++++++++++++++--------
include/linux/dma-heap.h | 9 +++++++++
2 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
index afd22c9dbdcf..72c746755d89 100644
--- a/drivers/dma-buf/dma-heap.c
+++ b/drivers/dma-buf/dma-heap.c
@@ -30,6 +30,7 @@
* @heap_devt heap device node
* @list list head connecting to list of heaps
* @heap_cdev heap char device
+ * @heap_dev heap device struct
*
* Represents a heap of memory from which buffers can be made.
*/
@@ -40,6 +41,7 @@ struct dma_heap {
dev_t heap_devt;
struct list_head list;
struct cdev heap_cdev;
+ struct device *heap_dev;
};

static LIST_HEAD(heap_list);
@@ -190,10 +192,21 @@ void *dma_heap_get_drvdata(struct dma_heap *heap)
return heap->priv;
}

+/**
+ * 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;
+}
+
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;

@@ -247,16 +260,20 @@ 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;
}
+
+ /* Make sure it doesn't disappear on us */
+ heap->heap_dev = get_device(heap->heap_dev);
+
/* Add heap to the list */
mutex_lock(&heap_list_lock);
list_add(&heap->list, &heap_list);
diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h
index 454e354d1ffb..82857e096910 100644
--- a/include/linux/dma-heap.h
+++ b/include/linux/dma-heap.h
@@ -50,6 +50,15 @@ struct dma_heap_export_info {
*/
void *dma_heap_get_drvdata(struct dma_heap *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);
+
/**
* dma_heap_add - adds a heap to dmabuf heaps
* @exp_info: information needed to register this heap
--
2.17.1