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 X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B4BBC67790 for ; Wed, 25 Jul 2018 09:37:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B273D20671 for ; Wed, 25 Jul 2018 09:37:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="bPSK/ieK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B273D20671 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728868AbeGYKsB (ORCPT ); Wed, 25 Jul 2018 06:48:01 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:42882 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728844AbeGYKsA (ORCPT ); Wed, 25 Jul 2018 06:48:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=tIXrVvq9OSoPk2KsHRsT/SmHJfZnosDj8UGX6gqpiOs=; b=bPSK/ieKzG6PryrnoXjwRwdrY 720EloLSbs5fQToJO9I19CGJ9uRT3A47ugV01LmWqLGM6cYdGfTDbawsQ2sRPRXWiM5l4KVDuTcTc M0FnsTAVk0oS6wpa0vxg6AVh7No6LHWirfz2izDE6coZhPFmp5XN1Vdc830Xjb/NOWGeBRZ/QWFJU B9xFAdsYb+W2e51ZlfOovchC5LxDB/AYKWVNvzuLqpsWFMdi4Zgr3U0EzCRp5rQ2rL1+WX8pHGfXR Ce0PMIP/m6eS7CDEMtJl4OOYlV2M3t/9234f6Arvdop5wSmeQdTs6NGNi+KkfgUYMFsoLgYRR4+bs /tWRkIhIw==; Received: from [91.112.108.175] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fiGED-0005IV-R8; Wed, 25 Jul 2018 09:37:06 +0000 From: Christoph Hellwig To: tglx@linutronix.de, palmer@sifive.com, jason@lakedaemon.net, marc.zyngier@arm.com, robh+dt@kernel.org, mark.rutland@arm.com Cc: devicetree@vger.kernel.org, aou@eecs.berkeley.edu, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, shorne@gmail.com, Palmer Dabbelt Subject: [PATCH 4/6] dt-bindings: interrupt-controller: RISC-V local interrupt controller docs Date: Wed, 25 Jul 2018 11:36:47 +0200 Message-Id: <20180725093649.32332-5-hch@lst.de> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180725093649.32332-1-hch@lst.de> References: <20180725093649.32332-1-hch@lst.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Palmer Dabbelt This patch adds documentation on the RISC-V local interrupt controller, which is a per-hart interrupt controller that manages all interrupts entering a RISC-V hart. This interrupt controller is present on all RISC-V systems. Signed-off-by: Palmer Dabbelt --- .../interrupt-controller/riscv,cpu-intc.txt | 41 +++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt diff --git a/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt new file mode 100644 index 000000000000..61900e2e3868 --- /dev/null +++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt @@ -0,0 +1,41 @@ +RISC-V Hart-Level Interrupt Controller (HLIC) +--------------------------------------------- + +RISC-V cores include Control Status Registers (CSRs) which are local to each +hart and can be read or written by software. Some of these CSRs are used to +control local interrupts connected to the core. Every interrupt is ultimately +routed through a hart's HLIC before it interrupts that hart. + +The RISC-V supervisor ISA manual specifies three interrupt sources that are +attached to every HLIC: software interrupts, the timer interrupt, and external +interrupts. Software interrupts are used to send IPIs between cores. The +timer interrupt comes from an architecturally mandated real-time timer that is +controller via SBI calls and CSR reads. External interrupts connect all other +device interrupts to the HLIC, which are routed via the platform-level +interrupt controller (PLIC). + +All RISC-V systems that conform to the supervisor ISA specification are +required to have a HLIC with these three interrupt sources present. Since the +interrupt map is defined by the ISA it's not listed in the HLIC's device tree +entry, though external interrupt controllers (like the PLIC, for example) will +need to define how their interrupts map to the relevant HLICs. + +Required properties: +- compatible : "riscv,cpu-intc" +- #interrupt-cells : should be <1> +- interrupt-controller : Identifies the node as an interrupt controller + +Furthermore, this interrupt-controller MUST be embedded inside the cpu +definition of the hart whose CSRs control these local interrupts. + +An example device tree entry for a HLIC is show below. + + cpu1: cpu@1 { + compatible = "riscv"; + ... + cpu1-intc: interrupt-controller { + #interrupt-cells = <1>; + compatible = "riscv,cpu-intc"; + interrupt-controller; + }; + }; -- 2.18.0