From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BA41130EF63; Thu, 26 Feb 2026 10:49:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772102987; cv=none; b=pMjBkCrHALqikvv2NYzi1yAk/8rI5u4UCdbqQvxFdspkJTDf5Y4H6AKUATZV+d6sHN9XQJJtsG3XWKZzzbilc5qRgRcZX8jA8EhxJ3yh6nhv9Lw9DEmzVdLfIOwZY1z/1864YsTJaFkkOeQVCRW4PWdON98Fa+GOQw+1On6HfNY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772102987; c=relaxed/simple; bh=w+0V20EBJh5qECvkc2OQ44zCAneRat/noqNIUiosghY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ebWlKOvuuMqFJpZuNs+xpjb0r2WWIrcdfEzFZvjs4Iz+w5gO9eT8BFkfUyocRG6K9Q6zWWk1A78UYPHW3HJgH4W5O6D5e49SVMdTPATej4PQCAlDnwk6eP8h538nbKHe5duv9wg7p6O1OJaXOXWpTdz7+JUOe5fM8Pl+zP8cKEA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=exhUTgtL; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="exhUTgtL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 655E3C116C6; Thu, 26 Feb 2026 10:49:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772102987; bh=w+0V20EBJh5qECvkc2OQ44zCAneRat/noqNIUiosghY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=exhUTgtLyFPrajFWfC8pgQCO2UoCD8uLPLhnqXImqCgZaJNT6nv/0iY1krin8/HQD YIQerDYd3Z2xGKbU0IaZYtLKP0djcJGyl52lTOAdexsZq55hqw4rbMUWXBcyMISSZ2 +/HpDXO8hiT6NVVjRpzXSadZRJ0Y5HndqH+bjAo3YDlCK8EAkEiGNK7qus4iY7WHzy qt+dIWNTGHqM+8T/UCDGBfULdMOwG9jcYAzkHslmmNTOd4SD0MTWbOBXAMDMUKfFLA GbMyUOyvg9LmyfhVzWU5I4gdRS4NdekSsW9+U6DifVjLyVnq7nKjUJtbtvx3WVGk72 3GyBkbOh5iXSQ== Message-ID: Date: Thu, 26 Feb 2026 11:49:41 +0100 Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/7] mm: cma: Export cma_alloc and cma_release To: Maxime Ripard Cc: Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T.J. Mercier" , =?UTF-8?Q?Christian_K=C3=B6nig?= , Marek Szyprowski , Robin Murphy , Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, iommu@lists.linux.dev, linux-mm@kvack.org References: <20260225-dma-buf-heaps-as-modules-v1-0-2109225a090d@kernel.org> <20260225-dma-buf-heaps-as-modules-v1-2-2109225a090d@kernel.org> <60ecebf2-a708-4797-bedd-588c3e9931ff@kernel.org> <20260226-impetuous-analytic-jellyfish-d4a86d@penduick> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20260226-impetuous-analytic-jellyfish-d4a86d@penduick> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/26/26 11:38, Maxime Ripard wrote: > Hi David, > > On Thu, Feb 26, 2026 at 11:25:24AM +0100, David Hildenbrand (Arm) wrote: >> On 2/25/26 17:41, Maxime Ripard wrote: >>> The CMA dma-buf heap uses cma_alloc() and cma_release() to allocate and >>> free, respectively, its CMA buffers. >>> >>> However, these functions are not exported. Since we want to turn the CMA >>> heap into a module, let's export them both. >>> >>> Signed-off-by: Maxime Ripard >>> --- >>> mm/cma.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/mm/cma.c b/mm/cma.c >>> index 94b5da468a7d719e5144d33b06bcc7619c0fbcc9..be142b473f3bd41b9c7d8ba4397f018f6993d962 100644 >>> --- a/mm/cma.c >>> +++ b/mm/cma.c >>> @@ -949,10 +949,11 @@ struct page *cma_alloc(struct cma *cma, unsigned long count, >>> if (page) >>> set_pages_refcounted(page, count); >>> >>> return page; >>> } >>> +EXPORT_SYMBOL_GPL(cma_alloc); >>> >>> static struct cma_memrange *find_cma_memrange(struct cma *cma, >>> const struct page *pages, unsigned long count) >>> { >>> struct cma_memrange *cmr = NULL; >>> @@ -1025,10 +1026,11 @@ bool cma_release(struct cma *cma, const struct page *pages, >>> >>> __cma_release_frozen(cma, cmr, pages, count); >>> >>> return true; >>> } >>> +EXPORT_SYMBOL_GPL(cma_release); >>> >>> bool cma_release_frozen(struct cma *cma, const struct page *pages, >>> unsigned long count) >>> { >>> struct cma_memrange *cmr; >>> >> >> I'm wondering whether we want to restrict all these exports to the >> dma-buf module only using EXPORT_SYMBOL_FOR_MODULES(). > > TIL about EXPORT_SYMBOL_FOR_MODULES, thanks. > >> Especially dma_contiguous_default_area() (patch #4), I am not sure >> whether we want arbitrary modules to mess with that. > > Yeah, I wasn't too fond about that one either. Alternatively, I guess we > could turn dev_get_cma_area into a non-inlined function and export that > instead? That would be one option, yes. -- Cheers, David