From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 83E2C21C179; Tue, 8 Jul 2025 08:26:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751963186; cv=none; b=sMMDEYEHzE506eWsb/JPww7CraCl3p8UT6rn2rxmZOTSZQ7j3Sl7DUf0vd0KxqxTA9OM3MIxzijcehgVexTbktEZnYdkomVOwgheEVT6h5primeW/LD1o16MpdeC5Ub8J73+hUncJ8BNKIhrYqy/Z73pVFBgRJrnt8Re+9lDir0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751963186; c=relaxed/simple; bh=VzmkmgYoccWvFe3DcIW5WbhC0zuD/mh7N9zUr7ihIas=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=unfCBOyZ/Tiza8jVruG54+0fXpa9lVOgPapLBAcoySgChmLRZieKnxwnrw/XQBXl9SsURlrExRrDrX2PD6oUTi8Vr9q+iTSjR9l0Ac6deY573j4CFLjntocX9RqQ/OB4irFLTvttwZ2USdh/jTLx8s+nfEHBq/LBVkVBU1puZZM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4bbvLQ4KxZz6DB82; Tue, 8 Jul 2025 16:25:18 +0800 (CST) Received: from frapeml500008.china.huawei.com (unknown [7.182.85.71]) by mail.maildlp.com (Postfix) with ESMTPS id 4DA4B1404A9; Tue, 8 Jul 2025 16:26:22 +0800 (CST) Received: from localhost (10.203.177.66) by frapeml500008.china.huawei.com (7.182.85.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Tue, 8 Jul 2025 10:26:19 +0200 Date: Tue, 8 Jul 2025 09:26:18 +0100 From: Jonathan Cameron To: Alireza Sanaee CC: , , , , , , , , , , , , , , , Subject: Re: [PATCH 1/5] of: add infra for finding CPU id from phandle Message-ID: <20250708092618.000067d2@huawei.com> In-Reply-To: <20250707150414.620-2-alireza.sanaee@huawei.com> References: <20250707150414.620-1-alireza.sanaee@huawei.com> <20250707150414.620-2-alireza.sanaee@huawei.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500003.china.huawei.com (7.191.162.67) To frapeml500008.china.huawei.com (7.182.85.71) On Mon, 7 Jul 2025 16:04:10 +0100 Alireza Sanaee wrote: > Get CPU id from phandle. Many drivers get do this by getting hold of CPU > node first through a phandle and then find the CPU ID using the relevant > function. This commit encapsulates cpu node finding and improves > readability. > > The API interface requires two parameters, 1) node, 2) pointer to CPU > node. API sets the pointer to the CPU node and allows the driver to play > with the CPU itself, for logging purposes for instance. > > Signed-off-by: Alireza Sanaee > --- > drivers/of/cpu.c | 29 +++++++++++++++++++++++++++++ > include/linux/of.h | 9 +++++++++ > 2 files changed, 38 insertions(+) > > diff --git a/drivers/of/cpu.c b/drivers/of/cpu.c > index 5214dc3d05ae..fba17994fc20 100644 > --- a/drivers/of/cpu.c > +++ b/drivers/of/cpu.c > @@ -173,6 +173,35 @@ int of_cpu_node_to_id(struct device_node *cpu_node) > } > EXPORT_SYMBOL(of_cpu_node_to_id); > > +/** > + * of_cpu_phandle_to_id: Get the logical CPU number for a given device_node > + * > + * @node: Pointer to the device_node containing CPU phandle. > + * @cpu_np: Pointer to the device_node for CPU. > + * @cpu_idx: The index of the CPU in the list of CPUs. > + * > + * Return: The logical CPU number of the given CPU device_node or -ENODEV if > + * the CPU is not found, or if the node is NULL, it returns -1. On success, > + * cpu_np will always point to the retrieved CPU device_node with refcount > + * incremented, use of_node_put() on it when done. > + */ > +int of_cpu_phandle_to_id(const struct device_node *node, > + struct device_node **cpu_np, > + uint8_t cpu_idx) > +{ > + if (!node) > + return -1; > + > + *cpu_np = of_parse_phandle(node, "cpu", 0); Gut feeling is that it would be useful to allow a NULL cpu_np for case where they don't want the cpu device_node, just the ID. For that you'll need a local variable to hold the device_node then assign it or put it depending on whether cpu_np != NULL. Maybe there are no users for that pattern though. If that's the case then check !node || !cpu_np for that first check. > + if (!*cpu_np) > + *cpu_np = of_parse_phandle(node, "cpus", cpu_idx); > + if (!*cpu_np) > + return -ENODEV; > + > + return of_cpu_node_to_id(*cpu_np); > +} > +EXPORT_SYMBOL(of_cpu_phandle_to_id); > + > /** > * of_get_cpu_state_node - Get CPU's idle state node at the given index > * > diff --git a/include/linux/of.h b/include/linux/of.h > index eaf0e2a2b75c..194f1cb0f6c6 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -360,6 +360,8 @@ extern const void *of_get_property(const struct device_node *node, > extern struct device_node *of_get_cpu_node(int cpu, unsigned int *thread); > extern struct device_node *of_cpu_device_node_get(int cpu); > extern int of_cpu_node_to_id(struct device_node *np); > +extern int of_cpu_phandle_to_id(const struct device_node *np, > + struct device_node **cpu_np, uint8_t cpu_idx); > extern struct device_node *of_get_next_cpu_node(struct device_node *prev); > extern struct device_node *of_get_cpu_state_node(const struct device_node *cpu_node, > int index); > @@ -662,6 +664,13 @@ static inline int of_cpu_node_to_id(struct device_node *np) > return -ENODEV; > } > > +static inline int of_cpu_phandle_to_id(const struct device_node *np, > + struct device_node **cpu_np, > + uint8_t cpu_idx) > +{ > + return -ENODEV; > +} > + > static inline struct device_node *of_get_next_cpu_node(struct device_node *prev) > { > return NULL;