From 0a10d3fe3e5c601031676e81b41fb2977650b4d4 Mon Sep 17 00:00:00 2001 From: Ionela Voinescu Date: Tue, 1 Sep 2020 21:55:45 +0100 Subject: arch_topology: validate input frequencies to arch_set_freq_scale() The current frequency passed to arch_set_freq_scale() could end up being 0, signaling an error in setting a new frequency. Also, if the maximum frequency in 0, this will result in a division by 0 error. Therefore, validate these input values before using them for the setting of the frequency scale factor. Signed-off-by: Ionela Voinescu Acked-by: Viresh Kumar Reviewed-by: Sudeep Holla Signed-off-by: Rafael J. Wysocki --- drivers/base/arch_topology.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/base') diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 75f72d684294..42a08ef693ae 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -33,6 +33,9 @@ void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, unsigned long scale; int i; + if (WARN_ON_ONCE(!cur_freq || !max_freq)) + return; + /* * If the use of counters for FIE is enabled, just return as we don't * want to update the scale factor with information from CPUFREQ. -- cgit v1.2.3 From ecddc3a0d5d752071c627aa1a1d4d7b529ddae67 Mon Sep 17 00:00:00 2001 From: Valentin Schneider Date: Tue, 1 Sep 2020 21:55:48 +0100 Subject: arch_topology, cpufreq: constify arch_* cpumasks The passed cpumask arguments to arch_set_freq_scale() and arch_freq_counters_available() are only iterated over, so reflect this in the prototype. This also allows to pass system cpumasks like cpu_online_mask without getting a warning. Signed-off-by: Valentin Schneider Signed-off-by: Ionela Voinescu Acked-by: Catalin Marinas Acked-by: Viresh Kumar Reviewed-by: Sudeep Holla Signed-off-by: Rafael J. Wysocki --- arch/arm64/kernel/topology.c | 2 +- drivers/base/arch_topology.c | 4 ++-- drivers/cpufreq/cpufreq.c | 5 +++-- include/linux/arch_topology.h | 2 +- include/linux/cpufreq.h | 3 ++- 5 files changed, 9 insertions(+), 7 deletions(-) (limited to 'drivers/base') diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 0801a0f3c156..9a9f2b8dedf5 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -253,7 +253,7 @@ free_valid_mask: } late_initcall_sync(init_amu_fie); -bool arch_freq_counters_available(struct cpumask *cpus) +bool arch_freq_counters_available(const struct cpumask *cpus) { return amu_freq_invariant() && cpumask_subset(cpus, amu_fie_cpus); diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 42a08ef693ae..91de5331ac8a 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -21,13 +21,13 @@ #include #include -__weak bool arch_freq_counters_available(struct cpumask *cpus) +__weak bool arch_freq_counters_available(const struct cpumask *cpus) { return false; } DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE; -void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, +void arch_set_freq_scale(const struct cpumask *cpus, unsigned long cur_freq, unsigned long max_freq) { unsigned long scale; diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 570bf2ebe9d4..2ea245a6c0c0 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -160,8 +160,9 @@ u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) } EXPORT_SYMBOL_GPL(get_cpu_idle_time); -__weak void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, - unsigned long max_freq) +__weak void arch_set_freq_scale(const struct cpumask *cpus, + unsigned long cur_freq, + unsigned long max_freq) { } EXPORT_SYMBOL_GPL(arch_set_freq_scale); diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h index 69b1dabe39dc..810c83336257 100644 --- a/include/linux/arch_topology.h +++ b/include/linux/arch_topology.h @@ -30,7 +30,7 @@ static inline unsigned long topology_get_freq_scale(int cpu) return per_cpu(freq_scale, cpu); } -bool arch_freq_counters_available(struct cpumask *cpus); +bool arch_freq_counters_available(const struct cpumask *cpus); DECLARE_PER_CPU(unsigned long, thermal_pressure); diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index e54767e2a68a..9f779fbdbe7b 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -1011,7 +1011,8 @@ static inline void sched_cpufreq_governor_change(struct cpufreq_policy *policy, extern void arch_freq_prepare_all(void); extern unsigned int arch_freq_get_on_cpu(int cpu); -extern void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, +extern void arch_set_freq_scale(const struct cpumask *cpus, + unsigned long cur_freq, unsigned long max_freq); /* the following are really really optional */ -- cgit v1.2.3 From 15e5d5b45b2b7072214af519357a1c0af078c50b Mon Sep 17 00:00:00 2001 From: Valentin Schneider Date: Tue, 1 Sep 2020 21:55:49 +0100 Subject: arch_topology, arm, arm64: define arch_scale_freq_invariant() arch_scale_freq_invariant() is used by schedutil to determine whether the scheduler's load-tracking signals are frequency invariant. Its definition is overridable, though by default it is hardcoded to 'true' if arch_scale_freq_capacity() is defined ('false' otherwise). This behaviour is not overridden on arm, arm64 and other users of the generic arch topology driver, which is somewhat precarious: arch_scale_freq_capacity() will always be defined, yet not all cpufreq drivers are guaranteed to drive the frequency invariance scale factor setting. In other words, the load-tracking signals may very well *not* be frequency invariant. Now that cpufreq can be queried on whether the current driver is driving the Frequency Invariance (FI) scale setting, the current situation can be improved. This combines the query of whether cpufreq supports the setting of the frequency scale factor, with whether all online CPUs are counter-based FI enabled. While cpufreq FI enablement applies at system level, for all CPUs, counter-based FI support could also be used for only a subset of CPUs to set the invariance scale factor. Therefore, if cpufreq-based FI support is present, we consider the system to be invariant. If missing, we require all online CPUs to be counter-based FI enabled in order for the full system to be considered invariant. If the system ends up not being invariant, a new condition is needed in the counter initialization code that disables all scale factor setting based on counters. Precedence of counters over cpufreq use is not important here. The invariant status is only given to the system if all CPUs have at least one method of setting the frequency scale factor. Signed-off-by: Valentin Schneider Signed-off-by: Ionela Voinescu Acked-by: Catalin Marinas Acked-by: Viresh Kumar Reviewed-by: Sudeep Holla Signed-off-by: Rafael J. Wysocki --- arch/arm/include/asm/topology.h | 1 + arch/arm64/include/asm/topology.h | 1 + arch/arm64/kernel/topology.c | 7 +++++++ drivers/base/arch_topology.c | 6 ++++++ include/linux/arch_topology.h | 2 ++ 5 files changed, 17 insertions(+) (limited to 'drivers/base') diff --git a/arch/arm/include/asm/topology.h b/arch/arm/include/asm/topology.h index e0593cf095d0..9219e67befbe 100644 --- a/arch/arm/include/asm/topology.h +++ b/arch/arm/include/asm/topology.h @@ -9,6 +9,7 @@ /* Replace task scheduler's default frequency-invariant accounting */ #define arch_scale_freq_capacity topology_get_freq_scale +#define arch_scale_freq_invariant topology_scale_freq_invariant /* Replace task scheduler's default cpu-invariant accounting */ #define arch_scale_cpu_capacity topology_get_cpu_scale diff --git a/arch/arm64/include/asm/topology.h b/arch/arm64/include/asm/topology.h index e042f6527981..7cb519473fbd 100644 --- a/arch/arm64/include/asm/topology.h +++ b/arch/arm64/include/asm/topology.h @@ -27,6 +27,7 @@ void topology_scale_freq_tick(void); /* Replace task scheduler's default frequency-invariant accounting */ #define arch_scale_freq_capacity topology_get_freq_scale +#define arch_scale_freq_invariant topology_scale_freq_invariant /* Replace task scheduler's default cpu-invariant accounting */ #define arch_scale_cpu_capacity topology_get_cpu_scale diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 9a9f2b8dedf5..4064d39bb66d 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -246,6 +246,13 @@ static int __init init_amu_fie(void) static_branch_enable(&amu_fie_key); } + /* + * If the system is not fully invariant after AMU init, disable + * partial use of counters for frequency invariance. + */ + if (!topology_scale_freq_invariant()) + static_branch_disable(&amu_fie_key); + free_valid_mask: free_cpumask_var(valid_cpus); diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 91de5331ac8a..89cae168b076 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -21,6 +21,12 @@ #include #include +bool topology_scale_freq_invariant(void) +{ + return cpufreq_supports_freq_invariance() || + arch_freq_counters_available(cpu_online_mask); +} + __weak bool arch_freq_counters_available(const struct cpumask *cpus) { return false; diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h index 810c83336257..083df331a3c9 100644 --- a/include/linux/arch_topology.h +++ b/include/linux/arch_topology.h @@ -30,6 +30,8 @@ static inline unsigned long topology_get_freq_scale(int cpu) return per_cpu(freq_scale, cpu); } +bool topology_scale_freq_invariant(void); + bool arch_freq_counters_available(const struct cpumask *cpus); DECLARE_PER_CPU(unsigned long, thermal_pressure); -- cgit v1.2.3