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Subject[PATCH 2/3] PM: EM: Make em_cpu_energy() able to return bigger values
Date
The Energy Model (EM) em_cpu_energy() is responsible for providing good
estimation regarding CPUs energy. It contains proper data structures which
are then used during calculation. The values stored in there are in
milli-Watts precision (or in abstract scale) smaller that 0xffff, which use
sufficient unsigned long even on 32-bit machines. There are scenarios where
we would like to provide calculated estimations in a better precision and
the values might be 1000 times bigger. This patch makes possible to use
quite big values for also 32-bit machines.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
---
include/linux/energy_model.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h
index 3f221dbf5f95..2016f5a706e0 100644
--- a/include/linux/energy_model.h
+++ b/include/linux/energy_model.h
@@ -101,7 +101,7 @@ void em_dev_unregister_perf_domain(struct device *dev);
* Return: the sum of the energy consumed by the CPUs of the domain assuming
* a capacity state satisfying the max utilization of the domain.
*/
-static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
+static inline u64 em_cpu_energy(struct em_perf_domain *pd,
unsigned long max_util, unsigned long sum_util,
unsigned long allowed_cpu_cap)
{
@@ -180,7 +180,7 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
* pd_nrg = ------------------------ (4)
* scale_cpu
*/
- return ps->cost * sum_util / scale_cpu;
+ return div_u64((u64)ps->cost * sum_util, scale_cpu);
}

/**
@@ -217,7 +217,7 @@ static inline struct em_perf_domain *em_pd_get(struct device *dev)
{
return NULL;
}
-static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
+static inline u64 em_cpu_energy(struct em_perf_domain *pd,
unsigned long max_util, unsigned long sum_util,
unsigned long allowed_cpu_cap)
{
--
2.17.1
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