From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 85B2CC982D6 for ; Thu, 17 Sep 2026 16:06:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=avuh6Og9p0aKaIBlcuzJBoKk7NCWagcKodZZuZcN8OE=; b=bBJ5cwC6Et/0f3pYXidY62+8pE Zgey5dWbL7V48YoqB2bf99kCFRz9s7sK4YFwZT3SdtOF/olzolxaSx8MwbleSOwyQVcf9l9DAv17v WcID5q6zPBRBCl3qqzAJ+jmlI6BjJVV4sXAOXEJ60hg98nufZeVyeTl16t0thihz0H4EvBkjclA0b KmA7gSsvjy4bCyAgVi/IfxGpM97J01NFIvmTVH9TcPOsAVE/mFFeU7Rk//o9r5w5WWkh1VGSMNXRe 7OPqJT/GdggKWCMBF1GJ7pd477/mmdnaiFgW67izqcgJc36mOdYfuc8Pw1uRfu/vjqkOvwOsvS1hb SwS7T8aA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x7Ecg-0000000BoNB-2bXu; Thu, 17 Sep 2026 16:06:06 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x7Ecb-0000000BoM1-40CW; Thu, 17 Sep 2026 16:06:04 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 723D01476; Thu, 17 Sep 2026 09:05:57 -0700 (PDT) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0930A3F86F; Thu, 17 Sep 2026 09:05:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789661161; bh=9mcxnDc8qxIpxmpk6T3Tp+BnQwg+ATLN/zS0rC02bj4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=iSTmFOj/SjkZUclQCqE4zTW0vk94VTD2VbErQFckNg1Hf9DqR+Wb+AcjT1kbXrZTY 9NCVL8hRLjredBc9QRerBZnnZDifRLrHjsitRjiaswGzll4lpHF3AB6KbXTdEHKJsU MLwoOZ4/t3+aNJhsyRfmX7PHIpukuOpzzytXFkiM= Date: Thu, 17 Sep 2026 17:05:53 +0100 From: Catalin Marinas To: "Aneesh Kumar K.V (Arm)" Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org, Robin Murphy , Marek Szyprowski , Will Deacon , Marc Zyngier , Steven Price , Suzuki K Poulose , Jiri Pirko , Jason Gunthorpe , Mostafa Saleh , Petr Tesarik , Alexey Kardashevskiy , Dan Williams , Xu Yilun , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , Russell King , Huacai Chen , Thomas Bogendoerfer , Jiaxun Yang , Paul Walmsley , Palmer Dabbelt , Albert Ou , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v4 4/5] dma: swiotlb: Add an overridable architecture pool opt-out Message-ID: References: <20260914070135.313337-1-aneesh.kumar@kernel.org> <20260914070135.313337-5-aneesh.kumar@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260914070135.313337-5-aneesh.kumar@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260917_090602_036011_65CDFBF4 X-CRM114-Status: GOOD ( 10.20 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Sep 14, 2026 at 12:31:33PM +0530, Aneesh Kumar K.V (Arm) wrote: > diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h > index be3962a33fc6..ef7a776ee508 100644 > --- a/include/linux/swiotlb.h > +++ b/include/linux/swiotlb.h > @@ -20,6 +20,8 @@ struct scatterlist; > #define SWIOTLB_INIT_ADDRESSING_LIMIT (1 << 2) > /* Initialize a default-sized pool that requires architecture remapping. */ > #define SWIOTLB_INIT_REMAP (1 << 3) > +/* Do not initialize a pool unless SWIOTLB is explicitly required. */ > +#define SWIOTLB_INIT_FORCE_DISABLE (1 << 4) Nit: maybe better as SWIOTLB_INIT_DEFAULT_OFF. "Force" sounds too drastic and it can be overridden on the command line to re-enable. Reviewed-by: Catalin Marinas