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 <ionela.voinescu@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 75f72d6..42a08ef 100644 (file)
--- 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.