[PATCH 1/2] dim: make dim_calc_stats() inputs const pointers

[Caleb Sander Mateos <csander@purestorage.com>]

Make the start and end arguments to dim_calc_stats() const pointers
to clarify that the function does not modify their values.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 include/linux/dim.h | 3 ++-
 lib/dim/dim.c       | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/linux/dim.h b/include/linux/dim.h
index 1b581ff25a15..84579a50ae7f 100644
--- a/include/linux/dim.h
+++ b/include/linux/dim.h
@@ -349,11 +349,12 @@ void dim_park_tired(struct dim *dim);
  *
  * Calculate the delta between two samples (in data rates).
  * Takes into consideration counter wrap-around.
  * Returned boolean indicates whether curr_stats are reliable.
  */
-bool dim_calc_stats(struct dim_sample *start, struct dim_sample *end,
+bool dim_calc_stats(const struct dim_sample *start,
+		    const struct dim_sample *end,
 		    struct dim_stats *curr_stats);
 
 /**
  *	dim_update_sample - set a sample's fields with given values
  *	@event_ctr: number of events to set
diff --git a/lib/dim/dim.c b/lib/dim/dim.c
index 83b65ac74d73..97c3d084ebf0 100644
--- a/lib/dim/dim.c
+++ b/lib/dim/dim.c
@@ -52,11 +52,12 @@ void dim_park_tired(struct dim *dim)
 	dim->steps_left   = 0;
 	dim->tune_state   = DIM_PARKING_TIRED;
 }
 EXPORT_SYMBOL(dim_park_tired);
 
-bool dim_calc_stats(struct dim_sample *start, struct dim_sample *end,
+bool dim_calc_stats(const struct dim_sample *start,
+		    const struct dim_sample *end,
 		    struct dim_stats *curr_stats)
 {
 	/* u32 holds up to 71 minutes, should be enough */
 	u32 delta_us = ktime_us_delta(end->time, start->time);
 	u32 npkts = BIT_GAP(BITS_PER_TYPE(u32), end->pkt_ctr, start->pkt_ctr);
-- 
2.45.2