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| author |   Viresh Kumar <viresh.kumar@linaro.org> | 2013-01-31 02:03:53 +0000 |
|---|---|---|
| committer |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-02-02 00:01:16 +0100 |
| commit | 951fc5f45836988c7df1d05c7f4658f331e7a920 (patch) | |
| tree | 196083ffadd033233faf66e0883c4662409ad569 | |
| parent | cpufreq: instantiate cpufreq-cpu0 as a platform_driver (diff) | |
| download | linux-dev-951fc5f45836988c7df1d05c7f4658f331e7a920.tar.xz linux-dev-951fc5f45836988c7df1d05c7f4658f331e7a920.zip | |
cpufreq: Update Documentation for cpus and related_cpus
Documentation related to cpus and related_cpus is confusing and not very clear.
Over that CPUFreq core has seen much changes recently. Lets update documentation
and comments for cpus and related_cpus.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | Documentation/cpu-freq/cpu-drivers.txt | 6 | ||||
| -rw-r--r-- | Documentation/cpu-freq/user-guide.txt | 8 | ||||
| -rw-r--r-- | include/linux/cpufreq.h | 6 |
3 files changed, 14 insertions, 6 deletions
diff --git a/Documentation/cpu-freq/cpu-drivers.txt b/Documentation/cpu-freq/cpu-drivers.txt index c436096351f8..72f70b16d299 100644 --- a/Documentation/cpu-freq/cpu-drivers.txt +++ b/Documentation/cpu-freq/cpu-drivers.txt @@ -111,6 +111,12 @@ policy->governor must contain the "default policy" for For setting some of these values, the frequency table helpers might be helpful. See the section 2 for more information on them. +SMP systems normally have same clock source for a group of cpus. For these the +.init() would be called only once for the first online cpu. Here the .init() +routine must initialize policy->cpus with mask of all possible cpus (Online + +Offline) that share the clock. Then the core would copy this mask onto +policy->related_cpus and will reset policy->cpus to carry only online cpus. + 1.3 verify ------------ diff --git a/Documentation/cpu-freq/user-guide.txt b/Documentation/cpu-freq/user-guide.txt index 04f6b32993e6..ff2f28332cc4 100644 --- a/Documentation/cpu-freq/user-guide.txt +++ b/Documentation/cpu-freq/user-guide.txt @@ -190,11 +190,11 @@ scaling_max_freq show the current "policy limits" (in first set scaling_max_freq, then scaling_min_freq. -affected_cpus : List of CPUs that require software coordination - of frequency. +affected_cpus : List of Online CPUs that require software + coordination of frequency. -related_cpus : List of CPUs that need some sort of frequency - coordination, whether software or hardware. +related_cpus : List of Online + Offline CPUs that need software + coordination of frequency. scaling_driver : Hardware driver for cpufreq. diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 5fdc6c6e3f8a..753b198750cf 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -89,8 +89,10 @@ struct cpufreq_real_policy { }; struct cpufreq_policy { - cpumask_var_t cpus; /* CPUs requiring sw coordination */ - cpumask_var_t related_cpus; /* CPUs with any coordination */ + /* CPUs sharing clock, require sw coordination */ + cpumask_var_t cpus; /* Online CPUs only */ + cpumask_var_t related_cpus; /* Online + Offline CPUs */ + unsigned int shared_type; /* ANY or ALL affected CPUs should set cpufreq */ unsigned int cpu; /* cpu nr of CPU managing this policy */ |