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Date: Tue, 22 Sep 2026 17:39:04 +0100
From: Catalin Marinas <catalin.marinas@arm.com>
To: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>
Cc: linux-coco@lists.linux.dev, kvmarm@lists.linux.dev,
	linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
	iommu@lists.linux.dev, Andrew Morton <akpm@linux-foundation.org>,
	christian.koenig@amd.com, Jason Gunthorpe <jgg@ziepe.ca>,
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	Robin Murphy <robin.murphy@arm.com>,
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	Sumit Semwal <sumit.semwal@linaro.org>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
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	dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org,
	linux-media@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC PATCH v7 12/13] dma-buf: system_heap: Allocate shared
 buffers using CoCo shared memory allocator
Message-ID: <arKvKME-_wNeW7ea@arm.com>
References: <20260921144847.501151-1-aneesh.kumar@kernel.org>
 <20260921144847.501151-13-aneesh.kumar@kernel.org>
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In-Reply-To: <20260921144847.501151-13-aneesh.kumar@kernel.org>

On Mon, Sep 21, 2026 at 08:18:46PM +0530, Aneesh Kumar K.V (Arm) wrote:
> @@ -405,6 +396,7 @@ static struct dma_buf *system_heap_allocate(struct dma_heap *heap,
>  {
>  	struct system_heap_buffer *buffer;
>  	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
> +	struct cc_shared_layout layout;
>  	unsigned long size_remaining = len;
>  	unsigned long sg_remaining = len;
>  	unsigned int max_order = orders[0];
> @@ -417,6 +409,14 @@ static struct dma_buf *system_heap_allocate(struct dma_heap *heap,
>  	struct page *page, *tmp_page;
>  	int i, ret = -ENOMEM;
>  
> +	if (cc_shared) {
> +		ret = cc_shared_calc_layout(len, &layout);

You should not override 'ret' here, it was set to -ENOMEM for a reason.
cc_shared_calc_layout() succeeds resetting 'ret' and some further down
allocation failure, goto free will return ERR_PTR(0).

-- 
Catalin