linux-kernel - Re: [PATCH v8 4/5] dma: contiguous: Reserve default CMA heap

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] [day] [month] [year] [list]

Message-ID: <a321abc5-fba3-45a5-a99a-73a542fc35c9@samsung.com>
Date: Tue, 14 Oct 2025 09:55:20 +0200
From: Marek Szyprowski <m.szyprowski@...sung.com>
To: Maxime Ripard <mripard@...nel.org>, 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>, 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
Subject: Re: [PATCH v8 4/5] dma: contiguous: Reserve default CMA heap

On 13.10.2025 10:35, Maxime Ripard wrote:
> The CMA code, in addition to the reserved-memory regions in the device
> tree, will also register a default CMA region if the device tree doesn't
> provide any, with its size and position coming from either the kernel
> command-line or configuration.
>
> Let's register that one for use to create a heap for it.
>
> Reviewed-by: T.J. Mercier <tjmercier@...gle.com>
> Signed-off-by: Maxime Ripard <mripard@...nel.org>
Acked-by: Marek Szyprowski <m.szyprowski@...sung.com>
> ---
>   kernel/dma/contiguous.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
> index d67e95094749d45f43c1809c175e491a3f55b2e1..d8fd6f779f797f711b8e0fd628f868d644b8f784 100644
> --- a/kernel/dma/contiguous.c
> +++ b/kernel/dma/contiguous.c
> @@ -240,17 +240,23 @@ void __init dma_contiguous_reserve(phys_addr_t limit)
>   		selected_size = max(size_bytes, cma_early_percent_memory());
>   #endif
>   	}
>   
>   	if (selected_size && !dma_contiguous_default_area) {
> +		int ret;
> +
>   		pr_debug("%s: reserving %ld MiB for global area\n", __func__,
>   			 (unsigned long)selected_size / SZ_1M);
>   
>   		dma_contiguous_reserve_area(selected_size, selected_base,
>   					    selected_limit,
>   					    &dma_contiguous_default_area,
>   					    fixed);
> +
> +		ret = dma_heap_cma_register_heap(dma_contiguous_default_area);
> +		if (ret)
> +			pr_warn("Couldn't register default CMA heap.");
>   	}
>   }
>   
>   void __weak
>   dma_contiguous_early_fixup(phys_addr_t base, unsigned long size)
>
Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland