git.openwrt.org Git - openwrt/openwrt.git/blob

   1 From 26984d9d581e5049bd75091d2e789b9cc3ea12e0 Mon Sep 17 00:00:00 2001
   2 From: Chanwoo Choi <cw00.choi@samsung.com>
   3 Date: Wed, 27 Apr 2022 03:49:19 +0900
   4 Subject: [PATCH 4/5] PM / devfreq: passive: Keep cpufreq_policy for possible
   5  cpus
   6
   7 The passive governor requires the cpu data to get the next target frequency
   8 of devfreq device if depending on cpu. In order to reduce the unnecessary
   9 memory data, keep cpufreq_policy data for possible cpus instead of NR_CPU.
  10
  11 Tested-by: Chen-Yu Tsai <wenst@chromium.org>
  12 Tested-by: Johnson Wang <johnson.wang@mediatek.com>
  13 Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
  14 ---
  15  drivers/devfreq/governor.h         |  3 ++
  16  drivers/devfreq/governor_passive.c | 75 +++++++++++++++++++++++-------
  17  include/linux/devfreq.h            |  4 +-
  18  3 files changed, 64 insertions(+), 18 deletions(-)
  19
  20 --- a/drivers/devfreq/governor.h
  21 +++ b/drivers/devfreq/governor.h
  22 @@ -49,6 +49,7 @@
  23
  24  /**
  25   * struct devfreq_cpu_data - Hold the per-cpu data
  26 + * @node:      list node
  27   * @dev:       reference to cpu device.
  28   * @first_cpu: the cpumask of the first cpu of a policy.
  29   * @opp_table: reference to cpu opp table.
  30 @@ -60,6 +61,8 @@
  31   * This is auto-populated by the governor.
  32   */
  33  struct devfreq_cpu_data {
  34 +       struct list_head node;
  35 +
  36         struct device *dev;
  37         unsigned int first_cpu;
  38
  39 --- a/drivers/devfreq/governor_passive.c
  40 +++ b/drivers/devfreq/governor_passive.c
  41 @@ -1,4 +1,4 @@
  42 -// SPDX-License-Identifier: GPL-2.0-only
  43 +       // SPDX-License-Identifier: GPL-2.0-only
  44  /*
  45   * linux/drivers/devfreq/governor_passive.c
  46   *
  47 @@ -18,6 +18,22 @@
  48
  49  #define HZ_PER_KHZ     1000
  50
  51 +static struct devfreq_cpu_data *
  52 +get_parent_cpu_data(struct devfreq_passive_data *p_data,
  53 +                   struct cpufreq_policy *policy)
  54 +{
  55 +       struct devfreq_cpu_data *parent_cpu_data;
  56 +
  57 +       if (!p_data || !policy)
  58 +               return NULL;
  59 +
  60 +       list_for_each_entry(parent_cpu_data, &p_data->cpu_data_list, node)
  61 +               if (parent_cpu_data->first_cpu == cpumask_first(policy->related_cpus))
  62 +                       return parent_cpu_data;
  63 +
  64 +       return NULL;
  65 +}
  66 +
  67  static unsigned long get_target_freq_by_required_opp(struct device *p_dev,
  68                                                 struct opp_table *p_opp_table,
  69                                                 struct opp_table *opp_table,
  70 @@ -51,14 +67,24 @@ static int get_target_freq_with_cpufreq(
  71         struct devfreq_passive_data *p_data =
  72                                 (struct devfreq_passive_data *)devfreq->data;
  73         struct devfreq_cpu_data *parent_cpu_data;
  74 +       struct cpufreq_policy *policy;
  75         unsigned long cpu, cpu_cur, cpu_min, cpu_max, cpu_percent;
  76         unsigned long dev_min, dev_max;
  77         unsigned long freq = 0;
  78 +       int ret = 0;
  79
  80         for_each_online_cpu(cpu) {
  81 -               parent_cpu_data = p_data->parent_cpu_data[cpu];
  82 -               if (!parent_cpu_data || parent_cpu_data->first_cpu != cpu)
  83 +               policy = cpufreq_cpu_get(cpu);
  84 +               if (!policy) {
  85 +                       ret = -EINVAL;
  86 +                       continue;
  87 +               }
  88 +
  89 +               parent_cpu_data = get_parent_cpu_data(p_data, policy);
  90 +               if (!parent_cpu_data) {
  91 +                       cpufreq_cpu_put(policy);
  92                         continue;
  93 +               }
  94
  95                 /* Get target freq via required opps */
  96                 cpu_cur = parent_cpu_data->cur_freq * HZ_PER_KHZ;
  97 @@ -67,6 +93,7 @@ static int get_target_freq_with_cpufreq(
  98                                         devfreq->opp_table, &cpu_cur);
  99                 if (freq) {
 100                         *target_freq = max(freq, *target_freq);
 101 +                       cpufreq_cpu_put(policy);
 102                         continue;
 103                 }
 104
 105 @@ -81,9 +108,10 @@ static int get_target_freq_with_cpufreq(
 106                 freq = dev_min + mult_frac(dev_max - dev_min, cpu_percent, 100);
 107
 108                 *target_freq = max(freq, *target_freq);
 109 +               cpufreq_cpu_put(policy);
 110         }
 111
 112 -       return 0;
 113 +       return ret;
 114  }
 115
 116  static int get_target_freq_with_devfreq(struct devfreq *devfreq,
 117 @@ -168,12 +196,11 @@ static int cpufreq_passive_notifier_call
 118         unsigned int cur_freq;
 119         int ret;
 120
 121 -       if (event != CPUFREQ_POSTCHANGE || !freqs ||
 122 -               !p_data->parent_cpu_data[freqs->policy->cpu])
 123 +       if (event != CPUFREQ_POSTCHANGE || !freqs)
 124                 return 0;
 125
 126 -       parent_cpu_data = p_data->parent_cpu_data[freqs->policy->cpu];
 127 -       if (parent_cpu_data->cur_freq == freqs->new)
 128 +       parent_cpu_data = get_parent_cpu_data(p_data, freqs->policy);
 129 +       if (!parent_cpu_data || parent_cpu_data->cur_freq == freqs->new)
 130                 return 0;
 131
 132         cur_freq = parent_cpu_data->cur_freq;
 133 @@ -196,7 +223,7 @@ static int cpufreq_passive_unregister_no
 134         struct devfreq_passive_data *p_data
 135                         = (struct devfreq_passive_data *)devfreq->data;
 136         struct devfreq_cpu_data *parent_cpu_data;
 137 -       int cpu, ret;
 138 +       int cpu, ret = 0;
 139
 140         if (p_data->nb.notifier_call) {
 141                 ret = cpufreq_unregister_notifier(&p_data->nb,
 142 @@ -206,16 +233,26 @@ static int cpufreq_passive_unregister_no
 143         }
 144
 145         for_each_possible_cpu(cpu) {
 146 -               parent_cpu_data = p_data->parent_cpu_data[cpu];
 147 -               if (!parent_cpu_data)
 148 +               struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
 149 +               if (!policy) {
 150 +                       ret = -EINVAL;
 151 +                       continue;
 152 +               }
 153 +
 154 +               parent_cpu_data = get_parent_cpu_data(p_data, policy);
 155 +               if (!parent_cpu_data) {
 156 +                       cpufreq_cpu_put(policy);
 157                         continue;
 158 +               }
 159
 160 +               list_del(&parent_cpu_data->node);
 161                 if (parent_cpu_data->opp_table)
 162                         dev_pm_opp_put_opp_table(parent_cpu_data->opp_table);
 163                 kfree(parent_cpu_data);
 164 +               cpufreq_cpu_put(policy);
 165         }
 166
 167 -       return 0;
 168 +       return ret;
 169  }
 170
 171  static int cpufreq_passive_register_notifier(struct devfreq *devfreq)
 172 @@ -230,6 +267,9 @@ static int cpufreq_passive_register_noti
 173         unsigned int cpu;
 174         int ret;
 175
 176 +       p_data->cpu_data_list
 177 +               = (struct list_head)LIST_HEAD_INIT(p_data->cpu_data_list);
 178 +
 179         p_data->nb.notifier_call = cpufreq_passive_notifier_call;
 180         ret = cpufreq_register_notifier(&p_data->nb, CPUFREQ_TRANSITION_NOTIFIER);
 181         if (ret) {
 182 @@ -239,15 +279,18 @@ static int cpufreq_passive_register_noti
 183         }
 184
 185         for_each_possible_cpu(cpu) {
 186 -               if (p_data->parent_cpu_data[cpu])
 187 -                       continue;
 188 -
 189                 policy = cpufreq_cpu_get(cpu);
 190                 if (!policy) {
 191                         ret = -EPROBE_DEFER;
 192                         goto err;
 193                 }
 194
 195 +               parent_cpu_data = get_parent_cpu_data(p_data, policy);
 196 +               if (parent_cpu_data) {
 197 +                       cpufreq_cpu_put(policy);
 198 +                       continue;
 199 +               }
 200 +
 201                 parent_cpu_data = kzalloc(sizeof(*parent_cpu_data),
 202                                                 GFP_KERNEL);
 203                 if (!parent_cpu_data) {
 204 @@ -276,7 +319,7 @@ static int cpufreq_passive_register_noti
 205                 parent_cpu_data->min_freq = policy->cpuinfo.min_freq;
 206                 parent_cpu_data->max_freq = policy->cpuinfo.max_freq;
 207
 208 -               p_data->parent_cpu_data[cpu] = parent_cpu_data;
 209 +               list_add_tail(&parent_cpu_data->node, &p_data->cpu_data_list);
 210                 cpufreq_cpu_put(policy);
 211         }
 212
 213 --- a/include/linux/devfreq.h
 214 +++ b/include/linux/devfreq.h
 215 @@ -310,7 +310,7 @@ enum devfreq_parent_dev_type {
 216   * @this:              the devfreq instance of own device.
 217   * @nb:                        the notifier block for DEVFREQ_TRANSITION_NOTIFIER or
 218   *                     CPUFREQ_TRANSITION_NOTIFIER list.
 219 - * @parent_cpu_data:   the state min/max/current frequency of all online cpu's.
 220 + * @cpu_data_list:     the list of cpu frequency data for all cpufreq_policy.
 221   *
 222   * The devfreq_passive_data have to set the devfreq instance of parent
 223   * device with governors except for the passive governor. But, don't need to
 224 @@ -330,7 +330,7 @@ struct devfreq_passive_data {
 225         /* For passive governor's internal use. Don't need to set them */
 226         struct devfreq *this;
 227         struct notifier_block nb;
 228 -       struct devfreq_cpu_data *parent_cpu_data[NR_CPUS];
 229 +       struct list_head cpu_data_list;
 230  };
 231  #endif
 232