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 40654C433EF for ; Fri, 17 Jun 2022 08:31:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=C3BQ7LEaqYgE5uXg8vFVwb5tiaa8F+vbbVu1xDhy92Q=; b=vv1f/XNejO409p m8iTdWFQELo7+MTlOWYFf4yMBDk/BozSm/Xljoua03QNQwudvD24hJNcu/0mbOuzKBMYIBn4mdJS4 2lj5pdgygi5C5BiRcz4N7g6RerUa9P4eNMinx+e5CEp0KaTFyxRvYR/mMveazt+euz4GMvQz6/rmw yS4W8f8LZXpAXx+xpBgYnFF3CYXaURx21pNGJO1s242TOEKIUG+x0BpHxAj6enTiujcohqdepaK8X ocZuNBlTyZ1pkvl8HPEvLtpVPLnNqfqlT566haodJM9syI3PoJZ6gmnrMHt1yzbZF0p9mhv/sLKPV +jVigUwfGEASxYtiynEA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o27Nc-006K7D-P7; Fri, 17 Jun 2022 08:31:00 +0000 Received: from gloria.sntech.de ([185.11.138.130]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o27Na-006K4e-Gk for linux-riscv@lists.infradead.org; Fri, 17 Jun 2022 08:30:59 +0000 Received: from ip5b412258.dynamic.kabel-deutschland.de ([91.65.34.88] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1o27NU-0003My-Jd; Fri, 17 Jun 2022 10:30:52 +0200 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Christoph Hellwig Cc: Christoph Hellwig , palmer@dabbelt.com, paul.walmsley@sifive.com, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, wefu@redhat.com, guoren@kernel.org, cmuellner@linux.com, philipp.tomsich@vrull.eu, samuel@sholland.org, atishp@atishpatra.org, anup@brainfault.org, mick@ics.forth.gr, robh+dt@kernel.org, krzk+dt@kernel.org, devicetree@vger.kernel.org, drew@beagleboard.org, Atish Patra Subject: Re: [PATCH 2/3] riscv: Implement Zicbom-based cache management operations Date: Fri, 17 Jun 2022 10:30:51 +0200 Message-ID: <16237654.geO5KgaWL5@diego> In-Reply-To: <20220616121157.GA11657@lst.de> References: <20220610004308.1903626-1-heiko@sntech.de> <2041345.KlZ2vcFHjT@diego> <20220616121157.GA11657@lst.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220617_013058_599157_B562EC91 X-CRM114-Status: UNSURE ( 9.26 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Am Donnerstag, 16. Juni 2022, 14:11:57 CEST schrieb Christoph Hellwig: > On Thu, Jun 16, 2022 at 02:09:47PM +0200, Heiko St=FCbner wrote: > > My guess was that new platforms implementing cache-management will want > > to be non-coherent by default? > = > No. Cache incoherent DMA is absolutely horrible and almost impossible > to get right for the corner cases. It is a cost cutting measure seen on > cheap SOCs and mostly avoided for more enterprise grade products. ok, then we'll do it the other way around as suggested :-) . Coherent by default and marking the non-coherent parts. DT people on IRC yesterday were also open to adding a dma-noncoherent property for that case. Heiko _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv