Re: [PATCH] CMA: Don't return a valid cma for non-cma dev

[Feng Tang <feng.tang@intel.com>]

On Wed, Aug 05, 2015 at 12:28:03PM +0200, Michal Nazarewicz wrote:
> On Wed, Aug 05 2015, Feng Tang wrote:
> > that for a system which needs multiple cma heaps (like for security
> > reason), they may have to share one struct device *dev, as in
> > ion_cma_heap_create()
> 
> If you need several CMA areas to allocate from, create multiple struct
> devices.

I've made a quick patch, which works ok on our multiple cma heap cases.

Thanks,
Feng

---
diff --git a/drivers/staging/android/ion/ion_cma_heap.c b/drivers/staging/android/ion/ion_cma_heap.c
index f4211f1..ee9c5d1 100644
--- a/drivers/staging/android/ion/ion_cma_heap.c
+++ b/drivers/staging/android/ion/ion_cma_heap.c
@@ -29,6 +29,7 @@
 struct ion_cma_heap {
 	struct ion_heap heap;
 	struct device *dev;
+	struct device default_dma_dev;
 };
 
 #define to_cma_heap(x) container_of(x, struct ion_cma_heap, heap)
@@ -180,9 +181,14 @@ struct ion_heap *ion_cma_heap_create(struct ion_platform_heap *data)
 		return ERR_PTR(-ENOMEM);
 
 	cma_heap->heap.ops = &ion_cma_ops;
-	/* get device from private heaps data, later it will be
-	 * used to make the link with reserved CMA memory */
-	cma_heap->dev = data->priv;
+
+	cma_heap->dev = &cma_heap->default_dma_dev;
+	cma_heap->dev->coherent_dma_mask = DMA_BIT_MASK(32);
+	cma_heap->dev->dma_mask = &dev->coherent_dma_mask;
+
+	/* data->priv contains a pointer to struct cma */
+	dev_set_cma_area(cma_heap->dev, data->priv);
+
 	cma_heap->heap.type = ION_HEAP_TYPE_DMA;
 	return &cma_heap->heap;
 }


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