From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933682AbdKCRxf (ORCPT ); Fri, 3 Nov 2017 13:53:35 -0400 Received: from foss.arm.com ([217.140.101.70]:47836 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756263AbdKCRvX (ORCPT ); Fri, 3 Nov 2017 13:51:23 -0400 From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, marc.zyngier@arm.com, mark.rutland@arm.com, will.deacon@arm.com, catalin.marinas@arm.com, robh@kernel.org, sudeep.holla@arm.com, peterz@infradead.org, mathieu.poirier@linaro.org, leo.yan@linaro.org, frowand.list@gmail.com, Jonathan.Cameron@huawei.com, devicetree@vger.kernel.org, Suzuki K Poulose Subject: [PATCH v10 2/8] of: Add helper for mapping device node to logical CPU number Date: Fri, 3 Nov 2017 17:50:59 +0000 Message-Id: <20171103175105.23546-3-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20171103175105.23546-1-suzuki.poulose@arm.com> References: <20171103175105.23546-1-suzuki.poulose@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 63897531cd75..753c8160a092 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -418,6 +418,32 @@ 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 b240ed69dc96..13eb8bc92c10 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -538,6 +538,8 @@ 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) @@ -872,6 +874,11 @@ 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