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 22FD6266581; Mon, 13 Apr 2026 06:08:42 +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=1776060523; cv=none; b=fbv3q30uyvciFdXoQhLdUtryXgrbqBALmj2Wus2dK0Z8EtDmz0EvFQkdrCnNandbV7haBzx4BkEqIg/t8BYltjYzuGG2wJzg82V9qJtbhByfqQoL+TJKI669Kw4Mqa+DDBW0Mjh3ARF5+IQ4+BwuIojl8EY3PF9zg4FWcMhWcT0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776060523; c=relaxed/simple; bh=ppNjTN17ZtNMJ9dO7yGf0/EnI3kOcrqsYNfdNJxlsuE=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=GrOIqJHCPCbl6f5gGe2deKktuzqOH3Fv0uRyF3YEIzlr+3/8T1h7Tf98aCQtGtT8X7d+CfJTxGOYQxkKqMbGTxBm7qIu+hJYcj57px0NWY6yubVKLb0f4sQ6Sw8TVYTFuaJ+bonsFrXZ/WQE6TCRu/JkvUfpKyvf+e8u73vsrjs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Sk6T2UVz; 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="Sk6T2UVz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 312AFC116C6; Mon, 13 Apr 2026 06:08:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776060522; bh=ppNjTN17ZtNMJ9dO7yGf0/EnI3kOcrqsYNfdNJxlsuE=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=Sk6T2UVzhH4mzCSjF1XvsGiUG0qPfwOuXGM6wumlTc8Wmb0Wk7YpbUSYEy/LyVrZW MKl67lkMNOp6hnvZbwmvmtjvbql8Qn4UlsDpLPEnGcYG8WfwXn1dfcaQFtzVN2cQX9 ITAEZ8zY/Ciu0p2LHyaNsRPVZfDob0hettgP3Z4U8bDAoa5P85Y31PMCZfRO90ew8J KOD0lerABRXieA58nPDF+K0ZAXI3lZBg8xnpZXmmywUxlBfhlbzSuJimd4s/OqT6Vy XCa3ULZYvYDOcos52YU0UUUE7UNZDj2I3052Da49K5HhJ9puNSM6mFpOiNRA6vr1iw kmic2crfXu88w== X-Mailer: emacs 30.2 (via feedmail 11-beta-1 I) From: Aneesh Kumar K.V To: Mostafa Saleh , iommu@lists.linux.dev, linux-kernel@vger.kernel.org Cc: robin.murphy@arm.com, m.szyprowski@samsung.com, will@kernel.org, maz@kernel.org, suzuki.poulose@arm.com, catalin.marinas@arm.com, jiri@resnulli.us, jgg@ziepe.ca, Mostafa Saleh Subject: Re: [RFC PATCH v2 2/5] dma-mapping: Use the correct phys_to_dma() for DMA_RESTRICTED_POOL In-Reply-To: <20260330145043.1586623-3-smostafa@google.com> References: <20260330145043.1586623-1-smostafa@google.com> <20260330145043.1586623-3-smostafa@google.com> Date: Mon, 13 Apr 2026 11:38:36 +0530 Message-ID: Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Mostafa Saleh writes: > As restricted dma pools are always decrypted, in swiotlb.c it uses > phys_to_dma_unencrypted() for address conversion. > > However, in DMA-direct, calls to phys_to_dma_direct() with > force_dma_unencrypted() returning false, will fallback to > phys_to_dma() which is inconsistent for memory allocated from > restricted dma pools. > > Fixes: f4111e39a52a ("swiotlb: Add restricted DMA alloc/free support") > Signed-off-by: Mostafa Saleh > --- > kernel/dma/direct.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > index 27d804f0473f..1a402bb956d9 100644 > --- a/kernel/dma/direct.c > +++ b/kernel/dma/direct.c > @@ -26,7 +26,7 @@ u64 zone_dma_limit __ro_after_init = DMA_BIT_MASK(24); > static inline dma_addr_t phys_to_dma_direct(struct device *dev, > phys_addr_t phys) > { > - if (force_dma_unencrypted(dev)) > + if (force_dma_unencrypted(dev) || is_swiotlb_for_alloc(dev)) > return phys_to_dma_unencrypted(dev, phys); > So what kind of device is this? Is it a trusted device that needs to use swiotlb in unencrypted form?(is that a valid use case?) Can we add additional comment explaining the type of device for which we are allocating the DMA buffer? > return phys_to_dma(dev, phys); > } > -- > 2.53.0.1185.g05d4b7b318-goog -aneesh