On 2020-05-01 11:21 am, Brian Starkey wrote:
Hi John,
On Fri, May 01, 2020 at 07:39:48AM +0000, John Stultz wrote:
This patch reworks the cma_heap initialization so that
we expose both the default CMA region and any CMA regions
tagged with "linux,cma-heap" in the device-tree.
Cc: Rob Herring <robh...@kernel.org>
Cc: Sumit Semwal <sumit.sem...@linaro.org>
Cc: "Andrew F. Davis" <a...@ti.com>
Cc: Benjamin Gaignard <benjamin.gaign...@linaro.org>
Cc: Liam Mark <lm...@codeaurora.org>
Cc: Pratik Patel <prat...@codeaurora.org>
Cc: Laura Abbott <labb...@redhat.com>
Cc: Brian Starkey <brian.star...@arm.com>
Cc: Chenbo Feng <fe...@google.com>
Cc: Alistair Strachan <astrac...@google.com>
Cc: Sandeep Patil <sspa...@google.com>
Cc: Hridya Valsaraju <hri...@google.com>
Cc: Christoph Hellwig <h...@lst.de>
Cc: Marek Szyprowski <m.szyprow...@samsung.com>
Cc: Robin Murphy <robin.mur...@arm.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: devicet...@vger.kernel.org
Cc: dri-de...@lists.freedesktop.org
Cc: linux...@kvack.org
Signed-off-by: John Stultz <john.stu...@linaro.org>
---
drivers/dma-buf/heaps/cma_heap.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
index 626cf7fd033a..dd154e2db101 100644
--- a/drivers/dma-buf/heaps/cma_heap.c
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -141,6 +141,11 @@ static int __add_cma_heap(struct cma *cma, void *data)
{
struct cma_heap *cma_heap;
struct dma_heap_export_info exp_info;
+ struct cma *default_cma = dev_get_cma_area(NULL);
+
+ /* We only add the default heap and explicitly tagged heaps */
+ if (cma != default_cma && !cma_dma_heap_enabled(cma))
+ return 0;
Thinking about the pl111 thread[1], I'm wondering if we should also
let drivers call this directly to expose their CMA pools, even if they
aren't tagged for dma-heaps in DT. But perhaps that's too close to
policy.
That sounds much like what my first thoughts were - apologies if I'm
wildly off-base here, but as far as I understand:
- Device drivers know whether they have their own "memory-region" or not.
- Device drivers already have to do *something* to participate in dma-buf.
- Device drivers know best how they make use of both the above.
- Therefore couldn't it be left to drivers to choose whether to register
their CMA regions as heaps, without having to mess with DT at all?
Robin.
Cheers,
-Brian
[1] https://lists.freedesktop.org/archives/dri-devel/2020-April/264358.html
cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
if (!cma_heap)
@@ -162,16 +167,11 @@ static int __add_cma_heap(struct cma *cma, void *data)
return 0;
}
-static int add_default_cma_heap(void)
+static int cma_heaps_init(void)
{
- struct cma *default_cma = dev_get_cma_area(NULL);
- int ret = 0;
-
- if (default_cma)
- ret = __add_cma_heap(default_cma, NULL);
-
- return ret;
+ cma_for_each_area(__add_cma_heap, NULL);
+ return 0;
}
-module_init(add_default_cma_heap);
+module_init(cma_heaps_init);
MODULE_DESCRIPTION("DMA-BUF CMA Heap");
MODULE_LICENSE("GPL v2");
--
2.17.1
