Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752646AbeABL1g (ORCPT + 1 other); Tue, 2 Jan 2018 06:27:36 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:37188 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751809AbeABLZu (ORCPT ); Tue, 2 Jan 2018 06:25:50 -0500 From: Suzuki K Poulose To: will.deacon@arm.com Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, robh@kernel.org, mathieu.poirier@linaro.org, leo.yan@linaro.org, peterz@infradead.org, mark.rutland@arm.com, frowand.list@gmail.com, marc.zyngier@arm.com, jonathan.cameron@huawei.com, sudeep.holla@arm.com, Suzuki K Poulose , devicetree@vger.kernel.org Subject: [PATCH v11 2/8] of: Add helper for mapping device node to logical CPU number Date: Tue, 2 Jan 2018 11:25:27 +0000 Message-Id: <20180102112533.13640-3-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180102112533.13640-1-suzuki.poulose@arm.com> References: <20180102112533.13640-1-suzuki.poulose@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: Add a helper to map a device node to a logical CPU number to avoid duplication. Currently this is open coded in different places (e.g gic-v3, coresight). The helper tries to map device node to a "possible" logical CPU id, which may not be online yet. It is the responsibility of the user to make sure that the CPU is online. The helper uses of_cpu_device_node_get() to retrieve the device node for a given CPU (which uses per_cpu data if available else falls back to slower of_get_cpu_node()). Cc: devicetree@vger.kernel.org Cc: Frank Rowand Cc: Mark Rutland Cc: Sudeep Holla Reviewed-by: Marc Zyngier Reviewed-by: Rob Herring Signed-off-by: Suzuki K Poulose --- Changes since V6: - Use faster of_cpu_device_node_get instead of of_get_cpu_node(), which now falls back to latter if called in early. Changes since V3: - Renamed the helper to of_cpu_node_to_id(), suggested by Rob - Return -ENODEV on failure than nr_cpus_id --- drivers/of/base.c | 26 ++++++++++++++++++++++++++ include/linux/of.h | 7 +++++++ 2 files changed, 33 insertions(+) diff --git a/drivers/of/base.c b/drivers/of/base.c index 26618ba8f92a..a9d6fe86585b 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -316,6 +316,32 @@ struct device_node *of_get_cpu_node(int cpu, unsigned int *thread) EXPORT_SYMBOL(of_get_cpu_node); /** + * of_cpu_node_to_id: Get the logical CPU number for a given device_node + * + * @cpu_node: Pointer to the device_node for CPU. + * + * Returns the logical CPU number of the given CPU device_node. + * Returns -ENODEV if the CPU is not found. + */ +int of_cpu_node_to_id(struct device_node *cpu_node) +{ + int cpu; + bool found = false; + struct device_node *np; + + for_each_possible_cpu(cpu) { + np = of_cpu_device_node_get(cpu); + found = (cpu_node == np); + of_node_put(np); + if (found) + return cpu; + } + + return -ENODEV; +} +EXPORT_SYMBOL(of_cpu_node_to_id); + +/** * __of_device_is_compatible() - Check if the node matches given constraints * @device: pointer to node * @compat: required compatible string, NULL or "" for any match diff --git a/include/linux/of.h b/include/linux/of.h index d3dea1d1e3a9..173102dafb07 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -544,6 +544,8 @@ const char *of_prop_next_string(struct property *prop, const char *cur); bool of_console_check(struct device_node *dn, char *name, int index); +extern int of_cpu_node_to_id(struct device_node *np); + #else /* CONFIG_OF */ static inline void of_core_init(void) @@ -916,6 +918,11 @@ static inline void of_property_clear_flag(struct property *p, unsigned long flag { } +static inline int of_cpu_node_to_id(struct device_node *np) +{ + return -ENODEV; +} + #define of_match_ptr(_ptr) NULL #define of_match_node(_matches, _node) NULL #endif /* CONFIG_OF */ -- 2.13.6