From b8eed8af94f9203e0cc39245ea335f4b8dc1ed31 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Mon, 14 Jan 2013 13:23:03 +0000 Subject: cpufreq: Simplify __cpufreq_remove_dev() __cpufreq_remove_dev() is called on multiple occasions: cpufreq_driver unregister and cpu removals. Current implementation of this routine is overly complex without much need. If the cpu to be removed is the policy->cpu, we remove the policy first and add all other cpus again from policy->cpus and then finally call __cpufreq_remove_dev() again to remove the cpu to be deleted. Haahhhh.. There exist a simple solution to removal of a cpu: - Simply use the old policy structure - update its fields like: policy->cpu, etc. - notify any users of cpufreq, which depend on changing policy->cpu Hence this patch, which tries to implement the above theory. It is tested well by myself on ARM big.LITTLE TC2 SoC, which has 5 cores (2 A15 and 3 A7). Both A15's share same struct policy and all A7's share same policy structure. Signed-off-by: Viresh Kumar Tested-by: Shawn Guo Signed-off-by: Rafael J. Wysocki --- include/linux/cpufreq.h | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) (limited to 'include/linux/cpufreq.h') diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index a55b88eaf96a..52be2d0c994a 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -93,7 +93,9 @@ struct cpufreq_policy { cpumask_var_t related_cpus; /* CPUs with any coordination */ unsigned int shared_type; /* ANY or ALL affected CPUs should set cpufreq */ - unsigned int cpu; /* cpu nr of registered CPU */ + unsigned int cpu; /* cpu nr of CPU managing this policy */ + unsigned int last_cpu; /* cpu nr of previous CPU that managed + * this policy */ struct cpufreq_cpuinfo cpuinfo;/* see above */ unsigned int min; /* in kHz */ @@ -112,10 +114,11 @@ struct cpufreq_policy { struct completion kobj_unregister; }; -#define CPUFREQ_ADJUST (0) -#define CPUFREQ_INCOMPATIBLE (1) -#define CPUFREQ_NOTIFY (2) -#define CPUFREQ_START (3) +#define CPUFREQ_ADJUST (0) +#define CPUFREQ_INCOMPATIBLE (1) +#define CPUFREQ_NOTIFY (2) +#define CPUFREQ_START (3) +#define CPUFREQ_UPDATE_POLICY_CPU (4) #define CPUFREQ_SHARED_TYPE_NONE (0) /* None */ #define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */ @@ -405,6 +408,7 @@ extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; void cpufreq_frequency_table_get_attr(struct cpufreq_frequency_table *table, unsigned int cpu); +void cpufreq_frequency_table_update_policy_cpu(struct cpufreq_policy *policy); void cpufreq_frequency_table_put_attr(unsigned int cpu); #endif /* _LINUX_CPUFREQ_H */ -- cgit v1.2.3