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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DAB95C433F5 for ; Wed, 18 May 2022 09:34:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234423AbiERJej (ORCPT ); Wed, 18 May 2022 05:34:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234357AbiERJeL (ORCPT ); Wed, 18 May 2022 05:34:11 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0AF5CB042C for ; Wed, 18 May 2022 02:34:06 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 90D0C1063; Wed, 18 May 2022 02:34:06 -0700 (PDT) Received: from usa.arm.com (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DDDBB3F66F; Wed, 18 May 2022 02:34:04 -0700 (PDT) From: Sudeep Holla To: Atish Patra , linux-kernel@vger.kernel.org Cc: Sudeep Holla , Atish Patra , Vincent Guittot , Morten Rasmussen , Dietmar Eggemann , Qing Wang , linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, Rob Herring Subject: [PATCH v2 7/8] of: base: add support to get the device node for the CPU's last level cache Date: Wed, 18 May 2022 10:33:24 +0100 Message-Id: <20220518093325.2070336-8-sudeep.holla@arm.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220518093325.2070336-1-sudeep.holla@arm.com> References: <20220518093325.2070336-1-sudeep.holla@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is useful to have helper function just to get the pointer to the device node of the last level cache for a given logical cpu. It can be used as unique firmware identifier for the last level cache. This is useful to obtain the cpumask/cpumap of all the CPUs sharing the last level cache using the device node pointer as unique identifier for the last level cache. Cc: Rob Herring Signed-off-by: Sudeep Holla --- drivers/of/base.c | 33 +++++++++++++++++++++++++-------- include/linux/of.h | 1 + 2 files changed, 26 insertions(+), 8 deletions(-) diff --git a/drivers/of/base.c b/drivers/of/base.c index d4f98c8469ed..0b6a8c3f9a85 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -2072,17 +2072,17 @@ struct device_node *of_find_next_cache_node(const struct device_node *np) } /** - * of_find_last_cache_level - Find the level at which the last cache is - * present for the given logical cpu + * of_find_last_level_cache_node - Find the device node at which the last + * cache is present for the given logical cpu * - * @cpu: cpu number(logical index) for which the last cache level is needed + * @cpu: cpu number(logical index) for which the last cache level's device + * node is needed * - * Return: The the level at which the last cache is present. It is exactly - * same as the total number of cache levels for the given logical cpu. + * Return: The device node corresponding to the last cache for the given + * logical cpu */ -int of_find_last_cache_level(unsigned int cpu) +struct device_node *of_find_last_level_cache_node(unsigned int cpu) { - u32 cache_level = 0; struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu); while (np) { @@ -2091,7 +2091,24 @@ int of_find_last_cache_level(unsigned int cpu) np = of_find_next_cache_node(np); } - of_property_read_u32(prev, "cache-level", &cache_level); + return prev; +} + +/** + * of_find_last_cache_level - Find the level at which the last cache is + * present for the given logical cpu + * + * @cpu: cpu number(logical index) for which the last cache level is needed + * + * Return: The level at which the last cache is present. It is exactly + * same as the total number of cache levels for the given logical cpu. + */ +int of_find_last_cache_level(unsigned int cpu) +{ + u32 cache_level = 0; + struct device_node *np = of_find_last_level_cache_node(cpu); + + of_property_read_u32(np, "cache-level", &cache_level); return cache_level; } diff --git a/include/linux/of.h b/include/linux/of.h index 04971e85fbc9..ca0384cf08a3 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -297,6 +297,7 @@ extern struct device_node *of_get_child_by_name(const struct device_node *node, /* cache lookup */ extern struct device_node *of_find_next_cache_node(const struct device_node *); +extern struct device_node *of_find_last_level_cache_node(unsigned int cpu); extern int of_find_last_cache_level(unsigned int cpu); extern struct device_node *of_find_node_with_property( struct device_node *from, const char *prop_name); -- 2.36.1