target/linux/xburst/patches-3.2/0010-cpufreq_stats-Support-runtime-changes-to-frequency-t.patch

   1 From ca40c7542f0cd0e0dfa074bd4ccefc04b8561427 Mon Sep 17 00:00:00 2001
   2 From: Maarten ter Huurne <maarten@treewalker.org>
   3 Date: Tue, 2 Aug 2011 10:26:09 +0200
   4 Subject: [PATCH 10/21] cpufreq_stats: Support runtime changes to frequency
   5  table.
   6
   7 ---
   8  drivers/cpufreq/cpufreq_stats.c |  161 ++++++++++++++++++++-------------------
   9  1 files changed, 83 insertions(+), 78 deletions(-)
  10
  11 --- a/drivers/cpufreq/cpufreq_stats.c
  12 +++ b/drivers/cpufreq/cpufreq_stats.c
  13 @@ -21,6 +21,7 @@
  14  #include <linux/kobject.h>
  15  #include <linux/spinlock.h>
  16  #include <linux/notifier.h>
  17 +#include <linux/string.h>
  18  #include <asm/cputime.h>
  19
  20  static spinlock_t cpufreq_stats_lock;
  21 @@ -37,7 +38,7 @@ struct cpufreq_stats {
  22         unsigned long long  last_time;
  23         unsigned int max_state;
  24         unsigned int state_num;
  25 -       unsigned int last_index;
  26 +       int last_index;
  27         cputime64_t *time_in_state;
  28         unsigned int *freq_table;
  29  #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
  30 @@ -60,7 +61,7 @@ static int cpufreq_stats_update(unsigned
  31         cur_time = get_jiffies_64();
  32         spin_lock(&cpufreq_stats_lock);
  33         stat = per_cpu(cpufreq_stats_table, cpu);
  34 -       if (stat->time_in_state)
  35 +       if (stat->time_in_state && stat->last_index != -1)
  36                 stat->time_in_state[stat->last_index] =
  37                         cputime64_add(stat->time_in_state[stat->last_index],
  38                                       cputime_sub(cur_time, stat->last_time));
  39 @@ -83,7 +84,7 @@ static ssize_t show_time_in_state(struct
  40         ssize_t len = 0;
  41         int i;
  42         struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
  43 -       if (!stat)
  44 +       if (!stat || !stat->time_in_state)
  45                 return 0;
  46         cpufreq_stats_update(stat->cpu);
  47         for (i = 0; i < stat->state_num; i++) {
  48 @@ -101,7 +102,7 @@ static ssize_t show_trans_table(struct c
  49         int i, j;
  50
  51         struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
  52 -       if (!stat)
  53 +       if (!stat || !stat->trans_table)
  54                 return 0;
  55         cpufreq_stats_update(stat->cpu);
  56         len += snprintf(buf + len, PAGE_SIZE - len, "   From  :    To\n");
  57 @@ -160,63 +161,35 @@ static struct attribute_group stats_attr
  58  static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
  59  {
  60         int index;
  61 -       for (index = 0; index < stat->max_state; index++)
  62 -               if (stat->freq_table[index] == freq)
  63 -                       return index;
  64 +       if (stat->freq_table)
  65 +               for (index = 0; index < stat->max_state; index++)
  66 +                       if (stat->freq_table[index] == freq)
  67 +                               return index;
  68         return -1;
  69  }
  70
  71 -/* should be called late in the CPU removal sequence so that the stats
  72 - * memory is still available in case someone tries to use it.
  73 - */
  74  static void cpufreq_stats_free_table(unsigned int cpu)
  75  {
  76         struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
  77 +       struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
  78 +       if (policy && policy->cpu == cpu)
  79 +               sysfs_remove_group(&policy->kobj, &stats_attr_group);
  80         if (stat) {
  81                 kfree(stat->time_in_state);
  82                 kfree(stat);
  83         }
  84         per_cpu(cpufreq_stats_table, cpu) = NULL;
  85 -}
  86 -
  87 -/* must be called early in the CPU removal sequence (before
  88 - * cpufreq_remove_dev) so that policy is still valid.
  89 - */
  90 -static void cpufreq_stats_free_sysfs(unsigned int cpu)
  91 -{
  92 -       struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
  93 -       if (policy && policy->cpu == cpu)
  94 -               sysfs_remove_group(&policy->kobj, &stats_attr_group);
  95         if (policy)
  96                 cpufreq_cpu_put(policy);
  97  }
  98
  99 -static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
 100 +static int cpufreq_stats_update_table(struct cpufreq_policy *policy,
 101                 struct cpufreq_frequency_table *table)
 102  {
 103 -       unsigned int i, j, count = 0, ret = 0;
 104 -       struct cpufreq_stats *stat;
 105 -       struct cpufreq_policy *data;
 106 +       unsigned int i, j, count = 0;
 107         unsigned int alloc_size;
 108         unsigned int cpu = policy->cpu;
 109 -       if (per_cpu(cpufreq_stats_table, cpu))
 110 -               return -EBUSY;
 111 -       stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
 112 -       if ((stat) == NULL)
 113 -               return -ENOMEM;
 114 -
 115 -       data = cpufreq_cpu_get(cpu);
 116 -       if (data == NULL) {
 117 -               ret = -EINVAL;
 118 -               goto error_get_fail;
 119 -       }
 120 -
 121 -       ret = sysfs_create_group(&data->kobj, &stats_attr_group);
 122 -       if (ret)
 123 -               goto error_out;
 124 -
 125 -       stat->cpu = cpu;
 126 -       per_cpu(cpufreq_stats_table, cpu) = stat;
 127 +       struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
 128
 129         for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
 130                 unsigned int freq = table[i].frequency;
 131 @@ -225,40 +198,73 @@ static int cpufreq_stats_create_table(st
 132                 count++;
 133         }
 134
 135 +       if (stat->max_state != count) {
 136 +               stat->max_state = count;
 137 +               kfree(stat->time_in_state);
 138 +               stat->time_in_state = NULL;
 139 +       }
 140         alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
 141 -
 142  #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
 143         alloc_size += count * count * sizeof(int);
 144  #endif
 145 -       stat->max_state = count;
 146 -       stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
 147 -       if (!stat->time_in_state) {
 148 -               ret = -ENOMEM;
 149 -               goto error_out;
 150 -       }
 151 -       stat->freq_table = (unsigned int *)(stat->time_in_state + count);
 152 -
 153 +       if (stat->time_in_state) {
 154 +               memset(stat->time_in_state, 0, alloc_size);
 155 +       } else {
 156 +               stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
 157 +               if (!stat->time_in_state)
 158 +                       return -ENOMEM;
 159 +               stat->freq_table = (unsigned int *)(
 160 +                               stat->time_in_state + count);
 161  #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
 162 -       stat->trans_table = stat->freq_table + count;
 163 +               stat->trans_table = stat->freq_table + count;
 164  #endif
 165 +       }
 166 +
 167         j = 0;
 168 -       for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
 169 -               unsigned int freq = table[i].frequency;
 170 -               if (freq == CPUFREQ_ENTRY_INVALID)
 171 -                       continue;
 172 -               if (freq_table_get_index(stat, freq) == -1)
 173 -                       stat->freq_table[j++] = freq;
 174 +       if (stat->freq_table) {
 175 +               for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
 176 +                       unsigned int freq = table[i].frequency;
 177 +                       if (freq == CPUFREQ_ENTRY_INVALID)
 178 +                               continue;
 179 +                       if (freq_table_get_index(stat, freq) == -1)
 180 +                               stat->freq_table[j++] = freq;
 181 +               }
 182         }
 183         stat->state_num = j;
 184         spin_lock(&cpufreq_stats_lock);
 185         stat->last_time = get_jiffies_64();
 186         stat->last_index = freq_table_get_index(stat, policy->cur);
 187         spin_unlock(&cpufreq_stats_lock);
 188 +       return 0;
 189 +}
 190 +
 191 +static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
 192 +               struct cpufreq_frequency_table *table)
 193 +{
 194 +       unsigned int ret = 0;
 195 +       struct cpufreq_stats *stat;
 196 +       struct cpufreq_policy *data;
 197 +       unsigned int cpu = policy->cpu;
 198 +
 199 +       stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL);
 200 +       if ((stat) == NULL)
 201 +               return -ENOMEM;
 202 +
 203 +       data = cpufreq_cpu_get(cpu);
 204 +       if (data == NULL) {
 205 +               ret = -EINVAL;
 206 +               goto error_out;
 207 +       }
 208 +       ret = sysfs_create_group(&data->kobj, &stats_attr_group);
 209         cpufreq_cpu_put(data);
 210 +       if (ret)
 211 +               goto error_out;
 212 +
 213 +       stat->cpu = cpu;
 214 +       per_cpu(cpufreq_stats_table, cpu) = stat;
 215 +
 216         return 0;
 217  error_out:
 218 -       cpufreq_cpu_put(data);
 219 -error_get_fail:
 220         kfree(stat);
 221         per_cpu(cpufreq_stats_table, cpu) = NULL;
 222         return ret;
 223 @@ -276,10 +282,12 @@ static int cpufreq_stat_notifier_policy(
 224         table = cpufreq_frequency_get_table(cpu);
 225         if (!table)
 226                 return 0;
 227 -       ret = cpufreq_stats_create_table(policy, table);
 228 -       if (ret)
 229 -               return ret;
 230 -       return 0;
 231 +       if (!per_cpu(cpufreq_stats_table, cpu)) {
 232 +               ret = cpufreq_stats_create_table(policy, table);
 233 +               if (ret)
 234 +                       return ret;
 235 +       }
 236 +       return cpufreq_stats_update_table(policy, table);
 237  }
 238
 239  static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
 240 @@ -299,21 +307,23 @@ static int cpufreq_stat_notifier_trans(s
 241         old_index = stat->last_index;
 242         new_index = freq_table_get_index(stat, freq->new);
 243
 244 -       /* We can't do stat->time_in_state[-1]= .. */
 245 -       if (old_index == -1 || new_index == -1)
 246 -               return 0;
 247 -
 248         cpufreq_stats_update(freq->cpu);
 249 -
 250         if (old_index == new_index)
 251                 return 0;
 252
 253 +       if (new_index == -1)
 254 +               return 0;
 255 +
 256         spin_lock(&cpufreq_stats_lock);
 257         stat->last_index = new_index;
 258 +       if (old_index != -1) {
 259  #ifdef CONFIG_CPU_FREQ_STAT_DETAILS
 260 -       stat->trans_table[old_index * stat->max_state + new_index]++;
 261 +               if (stat->trans_table)
 262 +                       stat->trans_table[old_index * stat->max_state +
 263 +                                         new_index]++;
 264  #endif
 265 -       stat->total_trans++;
 266 +               stat->total_trans++;
 267 +       }
 268         spin_unlock(&cpufreq_stats_lock);
 269         return 0;
 270  }
 271 @@ -329,9 +339,6 @@ static int __cpuinit cpufreq_stat_cpu_ca
 272         case CPU_ONLINE_FROZEN:
 273                 cpufreq_update_policy(cpu);
 274                 break;
 275 -       case CPU_DOWN_PREPARE:
 276 -               cpufreq_stats_free_sysfs(cpu);
 277 -               break;
 278         case CPU_DEAD:
 279         case CPU_DEAD_FROZEN:
 280                 cpufreq_stats_free_table(cpu);
 281 @@ -340,10 +347,9 @@ static int __cpuinit cpufreq_stat_cpu_ca
 282         return NOTIFY_OK;
 283  }
 284
 285 -/* priority=1 so this will get called before cpufreq_remove_dev */
 286 -static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
 287 +static struct notifier_block cpufreq_stat_cpu_notifier __refdata =
 288 +{
 289         .notifier_call = cpufreq_stat_cpu_callback,
 290 -       .priority = 1,
 291  };
 292
 293  static struct notifier_block notifier_policy_block = {
 294 @@ -390,7 +396,6 @@ static void __exit cpufreq_stats_exit(vo
 295         unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
 296         for_each_online_cpu(cpu) {
 297                 cpufreq_stats_free_table(cpu);
 298 -               cpufreq_stats_free_sysfs(cpu);
 299         }
 300  }
 301