From patchwork Thu Jan 12 18:29:31 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 91208 Delivered-To: patch@linaro.org Received: by 10.140.20.99 with SMTP id 90csp1754963qgi; Thu, 12 Jan 2017 10:30:05 -0800 (PST) X-Received: by 10.98.3.7 with SMTP id 7mr18304318pfd.9.1484245805673; Thu, 12 Jan 2017 10:30:05 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id e1si10003336ple.244.2017.01.12.10.30.05; Thu, 12 Jan 2017 10:30:05 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751226AbdALSaD (ORCPT + 25 others); Thu, 12 Jan 2017 13:30:03 -0500 Received: from foss.arm.com ([217.140.101.70]:54244 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750981AbdALS3r (ORCPT ); Thu, 12 Jan 2017 13:29:47 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D5869AD7; Thu, 12 Jan 2017 10:29:46 -0800 (PST) Received: from e107155-lin.cambridge.arm.com (unknown [10.1.210.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 6D3813F24D; Thu, 12 Jan 2017 10:29:45 -0800 (PST) From: Sudeep Holla To: linux-arm-kernel@lists.infradead.org Cc: Sudeep Holla , Rob Herring , Catalin Marinas , Will Deacon , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Tan Xiaojun , Mark Rutland Subject: [PATCH v2 1/2] of: base: add support to find the level of the last cache Date: Thu, 12 Jan 2017 18:29:31 +0000 Message-Id: <1484245772-31511-1-git-send-email-sudeep.holla@arm.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It is useful to have helper function just to get the number of cache levels for a given logical cpu. We can obtain the same by just checking the level at which the last cache is present. This patch adds support to find the level of the last cache for a given cpu. It will be used on ARM64 platform where the device tree provides the information for the additional non-architected/transparent/external last level caches that are not integrated with the processors. Suggested-by: Rob Herring Cc: Rob Herring Cc: Mark Rutland Signed-off-by: Sudeep Holla --- drivers/of/base.c | 27 +++++++++++++++++++++++++++ include/linux/of.h | 1 + 2 files changed, 28 insertions(+) v1->v2: - Moved to using "cache-level" in the last level cache instead of counting through all the nodes as suggested by Rob -- 2.7.4 diff --git a/drivers/of/base.c b/drivers/of/base.c index d4bea3c797d6..c1128a077aea 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include @@ -2268,6 +2269,32 @@ 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 + * + * @cpu: cpu number(logical index) for which the last cache level is needed + * + * Returns 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. + */ +int of_find_last_cache_level(unsigned int cpu) +{ + int cache_level = 0; + struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu); + + while (np) { + prev = np; + of_node_put(np); + np = of_find_next_cache_node(np); + } + + if (prev) + of_property_read_u32(prev, "cache-level", &cache_level); + + return cache_level; +} + +/** * of_graph_parse_endpoint() - parse common endpoint node properties * @node: pointer to endpoint device_node * @endpoint: pointer to the OF endpoint data structure diff --git a/include/linux/of.h b/include/linux/of.h index d72f01009297..21e6323de0f3 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -280,6 +280,7 @@ 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 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);