cpufreq: CPPC: Add u64 casts to avoid overflowing

The fields of the _CPC object are unsigned 32-bits values.
To avoid overflows while using _CPC's values, add 'u64' casts.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 432dfb4..022e355 100644 (file)
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -487,7 +487,8 @@ static unsigned int get_perf_level_count(struct cpufreq_policy *policy)
        cpu_data = policy->driver_data;
        perf_caps = &cpu_data->perf_caps;
        max_cap = arch_scale_cpu_capacity(cpu);
-       min_cap = div_u64(max_cap * perf_caps->lowest_perf, perf_caps->highest_perf);
+       min_cap = div_u64((u64)max_cap * perf_caps->lowest_perf,
+                         perf_caps->highest_perf);
        if ((min_cap == 0) || (max_cap < min_cap))
                return 0;
        return 1 + max_cap / CPPC_EM_CAP_STEP - min_cap / CPPC_EM_CAP_STEP;
@@ -519,10 +520,10 @@ static int cppc_get_cpu_power(struct device *cpu_dev,
        cpu_data = policy->driver_data;
        perf_caps = &cpu_data->perf_caps;
        max_cap = arch_scale_cpu_capacity(cpu_dev->id);
-       min_cap = div_u64(max_cap * perf_caps->lowest_perf,
-                       perf_caps->highest_perf);
-
-       perf_step = CPPC_EM_CAP_STEP * perf_caps->highest_perf / max_cap;
+       min_cap = div_u64((u64)max_cap * perf_caps->lowest_perf,
+                         perf_caps->highest_perf);
+       perf_step = div_u64((u64)CPPC_EM_CAP_STEP * perf_caps->highest_perf,
+                           max_cap);
        min_step = min_cap / CPPC_EM_CAP_STEP;
        max_step = max_cap / CPPC_EM_CAP_STEP;