Messages in this thread | | | Date | Thu, 19 Mar 2015 16:33:16 +0100 | From | Daniel Lezcano <> | Subject | Re: [PATCH V2 7/8] ARM: cpuidle: Register per cpuidle device |
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On 03/19/2015 04:31 PM, Lina Iyer wrote: > On Wed, Mar 18 2015 at 12:46 -0600, Daniel Lezcano wrote: >> Some architectures have some cpus which does not support idle states. >> >> Let the underlying low level code to return -ENOSYS when it is not >> possible to set an idle state. >> >> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> >> --- >> drivers/cpuidle/cpuidle-arm.c | 45 >> +++++++++++++++++++++++++++++++++++++++++-- >> 1 file changed, 43 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/cpuidle/cpuidle-arm.c >> b/drivers/cpuidle/cpuidle-arm.c >> index 1c94b88..0682ed0 100644 >> --- a/drivers/cpuidle/cpuidle-arm.c >> +++ b/drivers/cpuidle/cpuidle-arm.c >> @@ -17,11 +17,14 @@ >> #include <linux/kernel.h> >> #include <linux/module.h> >> #include <linux/of.h> >> +#include <linux/slab.h> >> >> #include <asm/cpuidle.h> >> >> #include "dt_idle_states.h" >> >> +static DEFINE_PER_CPU(struct cpuidle_device, *cpuidle_arm_dev); > > Is a per-cpu variable needed? There seems to be no per-cpu access, other > than at init.
:)
Actually it is the cpuidle framework which is using the per cpu variable.
>> + >> /* >> * arm_enter_idle_state - Programs CPU to enter the specified state >> * >> @@ -94,6 +97,7 @@ static int __init arm_idle_init(void) >> { >> int cpu, ret; >> struct cpuidle_driver *drv = &arm_idle_driver; >> + struct cpuidle_device *dev; >> >> /* >> * Initialize idle states data, starting at index 1. >> @@ -105,18 +109,55 @@ static int __init arm_idle_init(void) >> if (ret <= 0) >> return ret ? : -ENODEV; >> >> + ret = cpuidle_register_driver(drv); >> + if (ret) { >> + pr_err("Failed to register cpuidle driver\n"); >> + return ret; >> + } >> + >> /* >> * Call arch CPU operations in order to initialize >> * idle states suspend back-end specific data >> */ >> for_each_possible_cpu(cpu) { >> ret = arm_cpuidle_init(cpu); >> + >> + /* This cpu does not support any idle states */ >> + if (ret == -ENOSYS) >> + continue; >> + >> if (ret) { >> pr_err("CPU %d failed to init idle CPU ops\n", cpu); >> - return ret; >> + goto out_fail; >> + } >> + >> + dev = kzalloc(sizeof(*dev), GFP_KERNEL); >> + if (!dev) { >> + pr_err("Failed to allocate cpuidle device\n"); >> + goto out_fail; >> + } >> + >> + dev->cpu = cpu; >> + per_cpu(cpuidle_arm_dev, cpu) = dev; >> + >> + ret = cpuidle_register_device(dev); >> + if (ret) { >> + pr_err("Failed to register cpuidle device for CPU %d\n", >> + cpu); >> + kfree(dev); >> + goto out_fail; >> } >> } >> +out: >> + return ret; >> >> - return cpuidle_register(drv, NULL); >> +out_fail: >> + for (cpu--; cpu <= 0; cpu--) { >> + dev = per_cpu(cpuidle_arm_dev, cpu); >> + cpuidle_unregister_device(dev); >> + kfree(dev); >> + } >> + cpuidle_unregister_driver(drv); >> + goto out; >> } >> device_initcall(arm_idle_init); >> -- >> 1.9.1 >>
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