drivers/misc/mediatek/gpu/mt8127/mali/mali/platform/arm/arm_core_scaling.c

   1 /*
   2  * This confidential and proprietary software may be used only as
   3  * authorised by a licensing agreement from ARM Limited
   4  * (C) COPYRIGHT 2013-2015 ARM Limited
   5  * ALL RIGHTS RESERVED
   6  * The entire notice above must be reproduced on all authorised
   7  * copies and copies may only be made to the extent permitted
   8  * by a licensing agreement from ARM Limited.
   9  */
  10
  11 /**
  12  * @file arm_core_scaling.c
  13  * Example core scaling policy.
  14  */
  15
  16 #include "arm_core_scaling.h"
  17
  18 #include <linux/mali/mali_utgard.h>
  19 #include "mali_kernel_common.h"
  20
  21 #include <linux/workqueue.h>
  22
  23 static int num_cores_total;
  24 static int num_cores_enabled;
  25
  26 static struct work_struct wq_work;
  27
  28 static void set_num_cores(struct work_struct *work)
  29 {
  30         int err = mali_perf_set_num_pp_cores(num_cores_enabled);
  31         MALI_DEBUG_ASSERT(0 == err);
  32         MALI_IGNORE(err);
  33 }
  34
  35 static void enable_one_core(void)
  36 {
  37         if (num_cores_enabled < num_cores_total) {
  38                 ++num_cores_enabled;
  39                 schedule_work(&wq_work);
  40                 MALI_DEBUG_PRINT(3, ("Core scaling: Enabling one more core\n"));
  41         }
  42
  43         MALI_DEBUG_ASSERT(1 <= num_cores_enabled);
  44         MALI_DEBUG_ASSERT(num_cores_total >= num_cores_enabled);
  45 }
  46
  47 static void disable_one_core(void)
  48 {
  49         if (1 < num_cores_enabled) {
  50                 --num_cores_enabled;
  51                 schedule_work(&wq_work);
  52                 MALI_DEBUG_PRINT(3, ("Core scaling: Disabling one core\n"));
  53         }
  54
  55         MALI_DEBUG_ASSERT(1 <= num_cores_enabled);
  56         MALI_DEBUG_ASSERT(num_cores_total >= num_cores_enabled);
  57 }
  58
  59 static void enable_max_num_cores(void)
  60 {
  61         if (num_cores_enabled < num_cores_total) {
  62                 num_cores_enabled = num_cores_total;
  63                 schedule_work(&wq_work);
  64                 MALI_DEBUG_PRINT(3, ("Core scaling: Enabling maximum number of cores\n"));
  65         }
  66
  67         MALI_DEBUG_ASSERT(num_cores_total == num_cores_enabled);
  68 }
  69
  70 void mali_core_scaling_init(int num_pp_cores)
  71 {
  72         INIT_WORK(&wq_work, set_num_cores);
  73
  74         num_cores_total   = num_pp_cores;
  75         num_cores_enabled = num_pp_cores;
  76
  77         /* NOTE: Mali is not fully initialized at this point. */
  78 }
  79
  80 void mali_core_scaling_sync(int num_cores)
  81 {
  82         num_cores_enabled = num_cores;
  83 }
  84
  85 void mali_core_scaling_term(void)
  86 {
  87         flush_scheduled_work();
  88 }
  89
  90 #define PERCENT_OF(percent, max) ((int) ((percent)*(max)/100.0 + 0.5))
  91
  92 void mali_core_scaling_update(struct mali_gpu_utilization_data *data)
  93 {
  94         /*
  95          * This function implements a very trivial PP core scaling algorithm.
  96          *
  97          * It is _NOT_ of production quality.
  98          * The only intention behind this algorithm is to exercise and test the
  99          * core scaling functionality of the driver.
 100          * It is _NOT_ tuned for neither power saving nor performance!
 101          *
 102          * Other metrics than PP utilization need to be considered as well
 103          * in order to make a good core scaling algorithm.
 104          */
 105
 106         MALI_DEBUG_PRINT(3, ("Utilization: (%3d, %3d, %3d), cores enabled: %d/%d\n", data->utilization_gpu, data->utilization_gp, data->utilization_pp, num_cores_enabled, num_cores_total));
 107
 108         /* NOTE: this function is normally called directly from the utilization callback which is in
 109          * timer context. */
 110
 111         if (PERCENT_OF(90, 256) < data->utilization_pp) {
 112                 enable_max_num_cores();
 113         } else if (PERCENT_OF(50, 256) < data->utilization_pp) {
 114                 enable_one_core();
 115         } else if (PERCENT_OF(40, 256) < data->utilization_pp) {
 116                 /* do nothing */
 117         } else if (PERCENT_OF(0, 256) < data->utilization_pp) {
 118                 disable_one_core();
 119         } else {
 120                 /* do nothing */
 121         }
 122 }