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| author | Suzuki K Poulose <suzuki.poulose@arm.com> | 2018-01-02 14:25:27 +0300 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2018-01-02 19:43:12 +0300 |
| commit | a0e71cd9b1a0195f96500b2268759873ff8ff819 (patch) | |
| tree | 217c27009dd080b9b6e04a3a9829c13b3e25eb37 /drivers/of | |
| parent | 82975c46da8275a2a212cd94049bbef9bb961da2 (diff) | |
| download | linux-a0e71cd9b1a0195f96500b2268759873ff8ff819.tar.xz | |
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 <frowand.list@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/of')
| -rw-r--r-- | drivers/of/base.c | 26 |
1 files changed, 26 insertions, 0 deletions
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 |