arch/arm/kernel/perf_event_cpu.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License version 2 as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with this program; if not, write to the Free Software
  13  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  14  *
  15  * Copyright (C) 2012 ARM Limited
  16  *
  17  * Author: Will Deacon <will.deacon@arm.com>
  18  */
  19 #define pr_fmt(fmt) "CPU PMU: " fmt
  20
  21 #include <linux/bitmap.h>
  22 #include <linux/export.h>
  23 #include <linux/kernel.h>
  24 #include <linux/of.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/spinlock.h>
  27
  28 #include <asm/cputype.h>
  29 #include <asm/irq_regs.h>
  30 #include <asm/pmu.h>
  31
  32 /* Set at runtime when we know what CPU type we are. */
  33 static struct arm_pmu *cpu_pmu;
  34
  35 static DEFINE_PER_CPU(struct perf_event * [ARMPMU_MAX_HWEVENTS], hw_events);
  36 static DEFINE_PER_CPU(unsigned long [BITS_TO_LONGS(ARMPMU_MAX_HWEVENTS)], used_mask);
  37 static DEFINE_PER_CPU(struct pmu_hw_events, cpu_hw_events);
  38
  39 /*
  40  * Despite the names, these two functions are CPU-specific and are used
  41  * by the OProfile/perf code.
  42  */
  43 const char *perf_pmu_name(void)
  44 {
  45         if (!cpu_pmu)
  46                 return NULL;
  47
  48         return cpu_pmu->pmu.name;
  49 }
  50 EXPORT_SYMBOL_GPL(perf_pmu_name);
  51
  52 int perf_num_counters(void)
  53 {
  54         int max_events = 0;
  55
  56         if (cpu_pmu != NULL)
  57                 max_events = cpu_pmu->num_events;
  58
  59         return max_events;
  60 }
  61 EXPORT_SYMBOL_GPL(perf_num_counters);
  62
  63 /* Include the PMU-specific implementations. */
  64 #include "perf_event_xscale.c"
  65 #include "perf_event_v6.c"
  66 #include "perf_event_v7.c"
  67
  68 static struct pmu_hw_events *cpu_pmu_get_cpu_events(void)
  69 {
  70         return &__get_cpu_var(cpu_hw_events);
  71 }
  72
  73 static void __devinit cpu_pmu_init(struct arm_pmu *cpu_pmu)
  74 {
  75         int cpu;
  76         for_each_possible_cpu(cpu) {
  77                 struct pmu_hw_events *events = &per_cpu(cpu_hw_events, cpu);
  78                 events->events = per_cpu(hw_events, cpu);
  79                 events->used_mask = per_cpu(used_mask, cpu);
  80                 raw_spin_lock_init(&events->pmu_lock);
  81         }
  82         cpu_pmu->get_hw_events = cpu_pmu_get_cpu_events;
  83
  84         /* Ensure the PMU has sane values out of reset. */
  85         if (cpu_pmu && cpu_pmu->reset)
  86                 on_each_cpu(cpu_pmu->reset, NULL, 1);
  87 }
  88
  89 /*
  90  * PMU hardware loses all context when a CPU goes offline.
  91  * When a CPU is hotplugged back in, since some hardware registers are
  92  * UNKNOWN at reset, the PMU must be explicitly reset to avoid reading
  93  * junk values out of them.
  94  */
  95 static int __cpuinit cpu_pmu_notify(struct notifier_block *b,
  96                                     unsigned long action, void *hcpu)
  97 {
  98         if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING)
  99                 return NOTIFY_DONE;
 100
 101         if (cpu_pmu && cpu_pmu->reset)
 102                 cpu_pmu->reset(NULL);
 103
 104         return NOTIFY_OK;
 105 }
 106
 107 static struct notifier_block __cpuinitdata cpu_pmu_hotplug_notifier = {
 108         .notifier_call = cpu_pmu_notify,
 109 };
 110
 111 /*
 112  * PMU platform driver and devicetree bindings.
 113  */
 114 static struct of_device_id __devinitdata cpu_pmu_of_device_ids[] = {
 115         {.compatible = "arm,cortex-a15-pmu",    .data = armv7_a15_pmu_init},
 116         {.compatible = "arm,cortex-a9-pmu",     .data = armv7_a9_pmu_init},
 117         {.compatible = "arm,cortex-a8-pmu",     .data = armv7_a8_pmu_init},
 118         {.compatible = "arm,cortex-a7-pmu",     .data = armv7_a7_pmu_init},
 119         {.compatible = "arm,cortex-a5-pmu",     .data = armv7_a5_pmu_init},
 120         {.compatible = "arm,arm11mpcore-pmu",   .data = armv6mpcore_pmu_init},
 121         {.compatible = "arm,arm1176-pmu",       .data = armv6pmu_init},
 122         {.compatible = "arm,arm1136-pmu",       .data = armv6pmu_init},
 123         {},
 124 };
 125
 126 static struct platform_device_id __devinitdata cpu_pmu_plat_device_ids[] = {
 127         {.name = "arm-pmu"},
 128         {},
 129 };
 130
 131 /*
 132  * CPU PMU identification and probing.
 133  */
 134 static struct arm_pmu *__devinit probe_current_pmu(void)
 135 {
 136         struct arm_pmu *pmu = NULL;
 137         int cpu = get_cpu();
 138         unsigned long cpuid = read_cpuid_id();
 139         unsigned long implementor = (cpuid & 0xFF000000) >> 24;
 140         unsigned long part_number = (cpuid & 0xFFF0);
 141
 142         pr_info("probing PMU on CPU %d\n", cpu);
 143
 144         /* ARM Ltd CPUs. */
 145         if (0x41 == implementor) {
 146                 switch (part_number) {
 147                 case 0xB360:    /* ARM1136 */
 148                 case 0xB560:    /* ARM1156 */
 149                 case 0xB760:    /* ARM1176 */
 150                         pmu = armv6pmu_init();
 151                         break;
 152                 case 0xB020:    /* ARM11mpcore */
 153                         pmu = armv6mpcore_pmu_init();
 154                         break;
 155                 case 0xC080:    /* Cortex-A8 */
 156                         pmu = armv7_a8_pmu_init();
 157                         break;
 158                 case 0xC090:    /* Cortex-A9 */
 159                         pmu = armv7_a9_pmu_init();
 160                         break;
 161                 case 0xC050:    /* Cortex-A5 */
 162                         pmu = armv7_a5_pmu_init();
 163                         break;
 164                 case 0xC0F0:    /* Cortex-A15 */
 165                         pmu = armv7_a15_pmu_init();
 166                         break;
 167                 case 0xC070:    /* Cortex-A7 */
 168                         pmu = armv7_a7_pmu_init();
 169                         break;
 170                 }
 171         /* Intel CPUs [xscale]. */
 172         } else if (0x69 == implementor) {
 173                 part_number = (cpuid >> 13) & 0x7;
 174                 switch (part_number) {
 175                 case 1:
 176                         pmu = xscale1pmu_init();
 177                         break;
 178                 case 2:
 179                         pmu = xscale2pmu_init();
 180                         break;
 181                 }
 182         }
 183
 184         put_cpu();
 185         return pmu;
 186 }
 187
 188 static int __devinit cpu_pmu_device_probe(struct platform_device *pdev)
 189 {
 190         const struct of_device_id *of_id;
 191         struct arm_pmu *(*init_fn)(void);
 192         struct device_node *node = pdev->dev.of_node;
 193
 194         if (cpu_pmu) {
 195                 pr_info("attempt to register multiple PMU devices!");
 196                 return -ENOSPC;
 197         }
 198
 199         if (node && (of_id = of_match_node(cpu_pmu_of_device_ids, pdev->dev.of_node))) {
 200                 init_fn = of_id->data;
 201                 cpu_pmu = init_fn();
 202         } else {
 203                 cpu_pmu = probe_current_pmu();
 204         }
 205
 206         if (!cpu_pmu)
 207                 return -ENODEV;
 208
 209         cpu_pmu->plat_device = pdev;
 210         cpu_pmu_init(cpu_pmu);
 211         register_cpu_notifier(&cpu_pmu_hotplug_notifier);
 212         armpmu_register(cpu_pmu, cpu_pmu->name, PERF_TYPE_RAW);
 213
 214         return 0;
 215 }
 216
 217 static struct platform_driver cpu_pmu_driver = {
 218         .driver         = {
 219                 .name   = "arm-pmu",
 220                 .pm     = &armpmu_dev_pm_ops,
 221                 .of_match_table = cpu_pmu_of_device_ids,
 222         },
 223         .probe          = cpu_pmu_device_probe,
 224         .id_table       = cpu_pmu_plat_device_ids,
 225 };
 226
 227 static int __init register_pmu_driver(void)
 228 {
 229         return platform_driver_register(&cpu_pmu_driver);
 230 }
 231 device_initcall(register_pmu_driver);