From patchwork Wed Sep 6 09:41:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 720512 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 030B6EB8FAD for ; Wed, 6 Sep 2023 09:41:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229938AbjIFJlv (ORCPT ); Wed, 6 Sep 2023 05:41:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229937AbjIFJlu (ORCPT ); Wed, 6 Sep 2023 05:41:50 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 649D71BB; Wed, 6 Sep 2023 02:41:47 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B14B7C433C7; Wed, 6 Sep 2023 09:41:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1693993307; bh=oCKfqMVNrxKpZHzFqM4z491hl+uPYruxSgEUicAfYlI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IPfvt3V8gQEtfMQf2/0frKr6SedXyogmBexVdS1IpDWWUMYEtBEknaayZlXgNoWvd Q8BlxFe5JQJoT8K17x7MbfkCq2wFRMBErHwCI49t+jGx/+uptK69GngE/FFtpphSXD GCKMX9xRyvlGNfVP+0m7rxCjmtpP6aacMbVjbAJFB/F325KxDeCSDKfF7BQYkICXWG Omo2C+vDpTHmf0+BB0POnecJZQs9JgO/P15bXywSN0VuCrblZrEvy+ZMK8WR9APREi UfV2uOdH2NITAKYSIGnvLCJvOPP+mFfjf2nCx9Kf5bqLKj1YdimM/W/jZAGPQEXk5t Qgm8oCuAyvOgA== From: Lorenzo Pieralisi To: linux-kernel@vger.kernel.org Cc: Lorenzo Pieralisi , linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, Mark Rutland , Robin Murphy , Rob Herring , Fang Xiang , Marc Zyngier Subject: [PATCH v2 0/2] irqchip/gic-v3: Enable non-coherent GIC designs probing Date: Wed, 6 Sep 2023 11:41:37 +0200 Message-Id: <20230906094139.16032-1-lpieralisi@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230905104721.52199-1-lpieralisi@kernel.org> References: <20230905104721.52199-1-lpieralisi@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org This series is v2 of a previous version[1]. v1 -> v2: - Updated DT bindings as per feedback - Updated patch[2] to use GIC quirks infrastructure [1] https://lore.kernel.org/all/20230905104721.52199-1-lpieralisi@kernel.org Original cover letter --- The GICv3 architecture specifications provide a means for the system programmer to set the shareability and cacheability attributes the GIC components (redistributors and ITSes) use to drive memory transactions. Albeit the architecture give control over shareability/cacheability memory transactions attributes (and barriers), it is allowed to connect the GIC interconnect ports to non-coherent memory ports on the interconnect, basically tying off shareability/cacheability "wires" and de-facto making the redistributors and ITSes non-coherent memory observers. This series aims at starting a discussion over a possible solution to this problem, by adding to the GIC device tree bindings the standard dma-noncoherent property. The GIC driver uses the property to force the redistributors and ITSes shareability attributes to non-shareable, which consequently forces the driver to use CMOs on GIC memory tables. On ARM DT DMA is default non-coherent, so the GIC driver can't rely on the generic DT dma-coherent/non-coherent property management layer (of_dma_is_coherent()) which would default all GIC designs in the field as non-coherent; it has to rely on ad-hoc dma-noncoherent property handling. When a consistent approach is agreed upon for DT an equivalent binding will be put forward for ACPI based systems. Lorenzo Pieralisi (2): dt-bindings: interrupt-controller: arm,gic-v3: Add dma-noncoherent property irqchip/gic-v3: Enable non-coherent redistributors/ITSes probing .../interrupt-controller/arm,gic-v3.yaml | 12 +++++++++++ drivers/irqchip/irq-gic-common.h | 4 ++++ drivers/irqchip/irq-gic-v3-its.c | 21 +++++++++++++++---- drivers/irqchip/irq-gic-v3.c | 13 ++++++++++++ 4 files changed, 46 insertions(+), 4 deletions(-)