Messages in this thread | | | Subject | Re: [PATCH v3 2/6] of: Add helper for mapping device node to logical CPU number | From | Suzuki K Poulose <> | Date | Thu, 27 Jul 2017 17:27:19 +0100 |
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On 27/07/17 16:48, Rob Herring wrote: > Please use get_maintainers and cc the right people/lists. >
Sorry about that, will fix it.
> +Frank, DT list > > On Thu, Jul 27, 2017 at 10:10 AM, Suzuki K Poulose > <suzuki.poulose@arm.com> wrote: >> 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_get_cpu_node() which uses arch specific backends to match the phyiscal >> ids. >> >> Cc: Rob Herring <robh+dt@kernel.org> >> Cc: Mark Rutland <mark.rutland@arm.com> >> Cc: Sudeep Holla <sudeep.holla@arm.com> >> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> >> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> >> --- >> drivers/of/base.c | 26 ++++++++++++++++++++++++++ >> include/linux/of_device.h | 7 +++++++ >> 2 files changed, 33 insertions(+) >> >> diff --git a/drivers/of/base.c b/drivers/of/base.c >> index 686628d..0b01515 100644 >> --- a/drivers/of/base.c >> +++ b/drivers/of/base.c >> @@ -420,6 +420,32 @@ struct device_node *of_get_cpu_node(int cpu, unsigned int *thread) >> EXPORT_SYMBOL(of_get_cpu_node); >> >> /** >> + * of_device_node_get_cpu: 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 >= nr_cpu_ids if CPU is not found. > > Wouldn't negative be easier to test for? Then the caller doesn't need > to know nr_cpu_ids.
I followed the conventions used by cpu_mask upon error here. But, we could return -ENODEV upon failure here. > >> + */ >> +int of_device_node_get_cpu(struct device_node *cpu_node) > > of_device_* is for functions operating on struct device. So find > another name. of_cpu_node_to_id perhaps. > > _get functions generally imply incrementing ref counts which you are > not doing here. >
OK, I can switch to of_cpu_node_to_id().
>> +{ >> + int cpu; >> + bool found = false; >> + struct device_node *np; >> + >> + for_each_possible_cpu(cpu) { >> + np = of_get_cpu_node(cpu, NULL); >> + found = (cpu_node == np); >> + of_node_put(np); >> + if (found) >> + break; >> + } >> + >> + return cpu; >> +} >> +EXPORT_SYMBOL(of_device_node_get_cpu); >> + >> +/** >> * __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_device.h b/include/linux/of_device.h >> index b4ad8b4..00a4ba9 100644 >> --- a/include/linux/of_device.h >> +++ b/include/linux/of_device.h >> @@ -40,6 +40,8 @@ extern int of_device_request_module(struct device *dev); >> extern void of_device_uevent(struct device *dev, struct kobj_uevent_env *env); >> extern int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env); >> >> +extern int of_device_node_get_cpu(struct device_node *np); >> + > > Wrong place for this. >
How about include/linux/of.h ?
Suzuki
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