linux-kernel - [PATCH v8 3/5] dma: contiguous: Register reusable CMA regions at boot

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20251013-dma-buf-ecc-heap-v8-3-04ce150ea3d9@kernel.org>
Date: Mon, 13 Oct 2025 10:35:18 +0200
From: Maxime Ripard <mripard@...nel.org>
To: Sumit Semwal <sumit.semwal@...aro.org>, 
 Benjamin Gaignard <benjamin.gaignard@...labora.com>, 
 Brian Starkey <Brian.Starkey@....com>, John Stultz <jstultz@...gle.com>, 
 "T.J. Mercier" <tjmercier@...gle.com>, Jonathan Corbet <corbet@....net>, 
 Christian König <christian.koenig@....com>, 
 Marek Szyprowski <m.szyprowski@...sung.com>, 
 Robin Murphy <robin.murphy@....com>
Cc: Andrew Davis <afd@...com>, Jared Kangas <jkangas@...hat.com>, 
 Mattijs Korpershoek <mkorpershoek@...nel.org>, linux-media@...r.kernel.org, 
 dri-devel@...ts.freedesktop.org, linaro-mm-sig@...ts.linaro.org, 
 linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org, 
 iommu@...ts.linux.dev, Maxime Ripard <mripard@...nel.org>
Subject: [PATCH v8 3/5] 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@...gle.com>
Signed-off-by: Maxime Ripard <mripard@...nel.org>
---
 kernel/dma/contiguous.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index d9b9dcba6ff7cf5904ac93b72c061fd59072c41b..d67e95094749d45f43c1809c175e491a3f55b2e1 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -40,10 +40,11 @@
 #include <asm/page.h>

 #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>

 #ifdef CONFIG_CMA_SIZE_MBYTES
@@ -491,9 +492,13 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem)
 	rmem->priv = cma;

 	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);
 #endif

-- 
2.51.0