From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oa0-x229.google.com (mail-oa0-x229.google.com [IPv6:2607:f8b0:4003:c02::229]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (not verified)) by ozlabs.org (Postfix) with ESMTPS id AB7A92C0152 for ; Mon, 19 Aug 2013 23:11:18 +1000 (EST) Received: by mail-oa0-f41.google.com with SMTP id j6so5969662oag.0 for ; Mon, 19 Aug 2013 06:11:16 -0700 (PDT) Message-ID: <5212196F.4060708@gmail.com> Date: Mon, 19 Aug 2013 08:11:11 -0500 From: Rob Herring MIME-Version: 1.0 To: Sudeep KarkadaNagesha Subject: Re: [RFC PATCH v2 4/4] of: move of_get_cpu_node implementation to DT core library References: <1376586580-5409-1-git-send-email-Sudeep.KarkadaNagesha@arm.com> <1376674791-28244-1-git-send-email-Sudeep.KarkadaNagesha@arm.com> <1376674791-28244-3-git-send-email-Sudeep.KarkadaNagesha@arm.com> In-Reply-To: <1376674791-28244-3-git-send-email-Sudeep.KarkadaNagesha@arm.com> Content-Type: text/plain; charset=ISO-8859-1 Cc: Jonas Bonn , devicetree@vger.kernel.org, Michal Simek , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Rob Herring , "Rafael J. Wysocki" , Grant Likely , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 08/16/2013 12:39 PM, Sudeep KarkadaNagesha wrote: > From: Sudeep KarkadaNagesha > > This patch moves the generalized implementation of of_get_cpu_node from > PowerPC to DT core library, thereby adding support for retrieving cpu > node for a given logical cpu index on any architecture. > > The CPU subsystem can now use this function to assign of_node in the > cpu device while registering CPUs. > > It is recommended to use these helper function only in pre-SMP/early > initialisation stages to retrieve CPU device node pointers in logical > ordering. Once the cpu devices are registered, it can be retrieved easily > from cpu device of_node which avoids unnecessary parsing and matching. > > Cc: Rob Herring > Cc: Grant Likely > Cc: Benjamin Herrenschmidt > Signed-off-by: Sudeep KarkadaNagesha [snip] > +/** > + * of_get_cpu_node - Get device node associated with the given logical CPU > + * > + * @cpu: CPU number(logical index) for which device node is required > + * @thread: if not NULL, local thread number within the physical core is > + * returned > + * > + * The main purpose of this function is to retrieve the device node for the > + * given logical CPU index. It should be used to initialize the of_node in > + * cpu device. Once of_node in cpu device is populated, all the further > + * references can use that instead. > + * > + * CPU logical to physical index mapping is architecture specific and is built > + * before booting secondary cores. This function uses arch_match_cpu_phys_id > + * which can be overridden by architecture specific implementation. > + * > + * Returns a node pointer for the logical cpu if found, else NULL. > + */ > +struct device_node *of_get_cpu_node(int cpu, unsigned int *thread) > +{ > + struct device_node *cpun, *cpus; > + > + cpus = of_find_node_by_path("/cpus"); > + if (!cpus) { > + pr_warn("Missing cpus node, bailing out\n"); > + return NULL; > + } > + > + for_each_child_of_node(cpus, cpun) { > + if (of_node_cmp(cpun->type, "cpu")) > + continue; > +#ifdef CONFIG_PPC You don't really need this ifdef as this function should never succeed on other arches. Alternatively, you can use "IS_ENABLED(CONFIG_PPC)" instead. Otherwise, Acked-by: Rob Herring Rob