From: Maxime Ripard <mripard@kernel.org>
Date: Mon, 13 Oct 2025 08:35:18 +0000 (+0200)
Subject: dma: contiguous: Register reusable CMA regions at boot
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=84a593066a85e6fdfb7b71f74400ed6bb5e0c3fa;p=thirdparty%2Fkernel%2Flinux.git

dma: contiguous: Register reusable CMA regions at boot

In order to create a CMA dma-buf heap instance for each CMA heap region
in the system, we need to collect all of them during boot.

They are created from two main sources: the reserved-memory regions in
the device tree, and the default CMA region created from the
configuration or command line parameters, if no default region is
provided in the device tree.

Let's collect all the device-tree defined CMA regions flagged as
reusable.

Reviewed-by: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://lore.kernel.org/r/20251013-dma-buf-ecc-heap-v8-3-04ce150ea3d9@kernel.org
---

diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index d9b9dcba6ff7c..d67e95094749d 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -42,6 +42,7 @@
 #include <linux/memblock.h>
 #include <linux/err.h>
 #include <linux/sizes.h>
+#include <linux/dma-buf/heaps/cma.h>
 #include <linux/dma-map-ops.h>
 #include <linux/cma.h>
 #include <linux/nospec.h>
@@ -493,6 +494,10 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem)
 	pr_info("Reserved memory: created CMA memory pool at %pa, size %ld MiB\n",
 		&rmem->base, (unsigned long)rmem->size / SZ_1M);
 
+	err = dma_heap_cma_register_heap(cma);
+	if (err)
+		pr_warn("Couldn't register CMA heap.");
+
 	return 0;
 }
 RESERVEDMEM_OF_DECLARE(cma, "shared-dma-pool", rmem_cma_setup);