From a0e71cd9b1a0195f96500b2268759873ff8ff819 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Tue, 2 Jan 2018 11:25:27 +0000 Subject: [PATCH] of: Add helper for mapping device node to logical CPU number 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 Signed-off-by: Will Deacon --- 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 @@ -315,6 +315,32 @@ 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 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 */ -- 2.30.2