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/slab.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/irq.h>
  29 #include <linux/irqdesc.h>
  30
  31 #include <asm/cputype.h>
  32 #include <asm/irq_regs.h>
  33 #include <asm/pmu.h>
  34
  35 /* Set at runtime when we know what CPU type we are. */
  36 static struct arm_pmu *cpu_pmu;
  37
  38 /*
  39  * Despite the names, these two functions are CPU-specific and are used
  40  * by the OProfile/perf code.
  41  */
  42 const char *perf_pmu_name(void)
  43 {
  44         if (!cpu_pmu)
  45                 return NULL;
  46
  47         return cpu_pmu->name;
  48 }
  49 EXPORT_SYMBOL_GPL(perf_pmu_name);
  50
  51 int perf_num_counters(void)
  52 {
  53         int max_events = 0;
  54
  55         if (cpu_pmu != NULL)
  56                 max_events = cpu_pmu->num_events;
  57
  58         return max_events;
  59 }
  60 EXPORT_SYMBOL_GPL(perf_num_counters);
  61
  62 /* Include the PMU-specific implementations. */
  63 #include "perf_event_xscale.c"
  64 #include "perf_event_v6.c"
  65 #include "perf_event_v7.c"
  66
  67 static void cpu_pmu_enable_percpu_irq(void *data)
  68 {
  69         int irq = *(int *)data;
  70
  71         enable_percpu_irq(irq, IRQ_TYPE_NONE);
  72 }
  73
  74 static void cpu_pmu_disable_percpu_irq(void *data)
  75 {
  76         int irq = *(int *)data;
  77
  78         disable_percpu_irq(irq);
  79 }
  80
  81 static void cpu_pmu_free_irq(struct arm_pmu *cpu_pmu)
  82 {
  83         int i, irq, irqs;
  84         struct platform_device *pmu_device = cpu_pmu->plat_device;
  85         struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events;
  86
  87         irqs = min(pmu_device->num_resources, num_possible_cpus());
  88
  89         irq = platform_get_irq(pmu_device, 0);
  90         if (irq >= 0 && irq_is_percpu(irq)) {
  91                 on_each_cpu(cpu_pmu_disable_percpu_irq, &irq, 1);
  92                 free_percpu_irq(irq, &hw_events->percpu_pmu);
  93         } else {
  94                 for (i = 0; i < irqs; ++i) {
  95                         if (!cpumask_test_and_clear_cpu(i, &cpu_pmu->active_irqs))
  96                                 continue;
  97                         irq = platform_get_irq(pmu_device, i);
  98                         if (irq >= 0)
  99                                 free_irq(irq, per_cpu_ptr(&hw_events->percpu_pmu, i));
 100                 }
 101         }
 102 }
 103
 104 static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
 105 {
 106         int i, err, irq, irqs;
 107         struct platform_device *pmu_device = cpu_pmu->plat_device;
 108         struct pmu_hw_events __percpu *hw_events = cpu_pmu->hw_events;
 109
 110         if (!pmu_device)
 111                 return -ENODEV;
 112
 113         irqs = min(pmu_device->num_resources, num_possible_cpus());
 114         if (irqs < 1) {
 115                 pr_warn_once("perf/ARM: No irqs for PMU defined, sampling events not supported\n");
 116                 return 0;
 117         }
 118
 119         irq = platform_get_irq(pmu_device, 0);
 120         if (irq >= 0 && irq_is_percpu(irq)) {
 121                 err = request_percpu_irq(irq, handler, "arm-pmu",
 122                                          &hw_events->percpu_pmu);
 123                 if (err) {
 124                         pr_err("unable to request IRQ%d for ARM PMU counters\n",
 125                                 irq);
 126                         return err;
 127                 }
 128                 on_each_cpu(cpu_pmu_enable_percpu_irq, &irq, 1);
 129         } else {
 130                 for (i = 0; i < irqs; ++i) {
 131                         err = 0;
 132                         irq = platform_get_irq(pmu_device, i);
 133                         if (irq < 0)
 134                                 continue;
 135
 136                         /*
 137                          * If we have a single PMU interrupt that we can't shift,
 138                          * assume that we're running on a uniprocessor machine and
 139                          * continue. Otherwise, continue without this interrupt.
 140                          */
 141                         if (irq_set_affinity(irq, cpumask_of(i)) && irqs > 1) {
 142                                 pr_warn("unable to set irq affinity (irq=%d, cpu=%u)\n",
 143                                         irq, i);
 144                                 continue;
 145                         }
 146
 147                         err = request_irq(irq, handler,
 148                                           IRQF_NOBALANCING | IRQF_NO_THREAD, "arm-pmu",
 149                                           per_cpu_ptr(&hw_events->percpu_pmu, i));
 150                         if (err) {
 151                                 pr_err("unable to request IRQ%d for ARM PMU counters\n",
 152                                         irq);
 153                                 return err;
 154                         }
 155
 156                         cpumask_set_cpu(i, &cpu_pmu->active_irqs);
 157                 }
 158         }
 159
 160         return 0;
 161 }
 162
 163 /*
 164  * PMU hardware loses all context when a CPU goes offline.
 165  * When a CPU is hotplugged back in, since some hardware registers are
 166  * UNKNOWN at reset, the PMU must be explicitly reset to avoid reading
 167  * junk values out of them.
 168  */
 169 static int cpu_pmu_notify(struct notifier_block *b, unsigned long action,
 170                           void *hcpu)
 171 {
 172         struct arm_pmu *pmu = container_of(b, struct arm_pmu, hotplug_nb);
 173
 174         if ((action & ~CPU_TASKS_FROZEN) != CPU_STARTING)
 175                 return NOTIFY_DONE;
 176
 177         if (pmu->reset)
 178                 pmu->reset(pmu);
 179         else
 180                 return NOTIFY_DONE;
 181
 182         return NOTIFY_OK;
 183 }
 184
 185 static int cpu_pmu_init(struct arm_pmu *cpu_pmu)
 186 {
 187         int err;
 188         int cpu;
 189         struct pmu_hw_events __percpu *cpu_hw_events;
 190
 191         cpu_hw_events = alloc_percpu(struct pmu_hw_events);
 192         if (!cpu_hw_events)
 193                 return -ENOMEM;
 194
 195         cpu_pmu->hotplug_nb.notifier_call = cpu_pmu_notify;
 196         err = register_cpu_notifier(&cpu_pmu->hotplug_nb);
 197         if (err)
 198                 goto out_hw_events;
 199
 200         for_each_possible_cpu(cpu) {
 201                 struct pmu_hw_events *events = per_cpu_ptr(cpu_hw_events, cpu);
 202                 raw_spin_lock_init(&events->pmu_lock);
 203                 events->percpu_pmu = cpu_pmu;
 204         }
 205
 206         cpu_pmu->hw_events      = cpu_hw_events;
 207         cpu_pmu->request_irq    = cpu_pmu_request_irq;
 208         cpu_pmu->free_irq       = cpu_pmu_free_irq;
 209
 210         /* Ensure the PMU has sane values out of reset. */
 211         if (cpu_pmu->reset)
 212                 on_each_cpu(cpu_pmu->reset, cpu_pmu, 1);
 213
 214         /* If no interrupts available, set the corresponding capability flag */
 215         if (!platform_get_irq(cpu_pmu->plat_device, 0))
 216                 cpu_pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
 217
 218         return 0;
 219
 220 out_hw_events:
 221         free_percpu(cpu_hw_events);
 222         return err;
 223 }
 224
 225 static void cpu_pmu_destroy(struct arm_pmu *cpu_pmu)
 226 {
 227         unregister_cpu_notifier(&cpu_pmu->hotplug_nb);
 228         free_percpu(cpu_pmu->hw_events);
 229 }
 230
 231 /*
 232  * PMU platform driver and devicetree bindings.
 233  */
 234 static struct of_device_id cpu_pmu_of_device_ids[] = {
 235         {.compatible = "arm,cortex-a17-pmu",    .data = armv7_a17_pmu_init},
 236         {.compatible = "arm,cortex-a15-pmu",    .data = armv7_a15_pmu_init},
 237         {.compatible = "arm,cortex-a12-pmu",    .data = armv7_a12_pmu_init},
 238         {.compatible = "arm,cortex-a9-pmu",     .data = armv7_a9_pmu_init},
 239         {.compatible = "arm,cortex-a8-pmu",     .data = armv7_a8_pmu_init},
 240         {.compatible = "arm,cortex-a7-pmu",     .data = armv7_a7_pmu_init},
 241         {.compatible = "arm,cortex-a5-pmu",     .data = armv7_a5_pmu_init},
 242         {.compatible = "arm,arm11mpcore-pmu",   .data = armv6mpcore_pmu_init},
 243         {.compatible = "arm,arm1176-pmu",       .data = armv6_1176_pmu_init},
 244         {.compatible = "arm,arm1136-pmu",       .data = armv6_1136_pmu_init},
 245         {.compatible = "qcom,krait-pmu",        .data = krait_pmu_init},
 246         {},
 247 };
 248
 249 static struct platform_device_id cpu_pmu_plat_device_ids[] = {
 250         {.name = "arm-pmu"},
 251         {.name = "armv6-pmu"},
 252         {.name = "armv7-pmu"},
 253         {.name = "xscale-pmu"},
 254         {},
 255 };
 256
 257 static const struct pmu_probe_info pmu_probe_table[] = {
 258         ARM_PMU_PROBE(ARM_CPU_PART_ARM1136, armv6_1136_pmu_init),
 259         ARM_PMU_PROBE(ARM_CPU_PART_ARM1156, armv6_1156_pmu_init),
 260         ARM_PMU_PROBE(ARM_CPU_PART_ARM1176, armv6_1176_pmu_init),
 261         ARM_PMU_PROBE(ARM_CPU_PART_ARM11MPCORE, armv6mpcore_pmu_init),
 262         ARM_PMU_PROBE(ARM_CPU_PART_CORTEX_A8, armv7_a8_pmu_init),
 263         ARM_PMU_PROBE(ARM_CPU_PART_CORTEX_A9, armv7_a9_pmu_init),
 264         XSCALE_PMU_PROBE(ARM_CPU_XSCALE_ARCH_V1, xscale1pmu_init),
 265         XSCALE_PMU_PROBE(ARM_CPU_XSCALE_ARCH_V2, xscale2pmu_init),
 266         { /* sentinel value */ }
 267 };
 268
 269 /*
 270  * CPU PMU identification and probing.
 271  */
 272 static int probe_current_pmu(struct arm_pmu *pmu)
 273 {
 274         int cpu = get_cpu();
 275         unsigned int cpuid = read_cpuid_id();
 276         int ret = -ENODEV;
 277         const struct pmu_probe_info *info;
 278
 279         pr_info("probing PMU on CPU %d\n", cpu);
 280
 281         for (info = pmu_probe_table; info->init != NULL; info++) {
 282                 if ((cpuid & info->mask) != info->cpuid)
 283                         continue;
 284                 ret = info->init(pmu);
 285                 break;
 286         }
 287
 288         put_cpu();
 289         return ret;
 290 }
 291
 292 static int cpu_pmu_device_probe(struct platform_device *pdev)
 293 {
 294         const struct of_device_id *of_id;
 295         const int (*init_fn)(struct arm_pmu *);
 296         struct device_node *node = pdev->dev.of_node;
 297         struct arm_pmu *pmu;
 298         int ret = -ENODEV;
 299
 300         if (cpu_pmu) {
 301                 pr_info("attempt to register multiple PMU devices!\n");
 302                 return -ENOSPC;
 303         }
 304
 305         pmu = kzalloc(sizeof(struct arm_pmu), GFP_KERNEL);
 306         if (!pmu) {
 307                 pr_info("failed to allocate PMU device!\n");
 308                 return -ENOMEM;
 309         }
 310
 311         cpu_pmu = pmu;
 312         cpu_pmu->plat_device = pdev;
 313
 314         if (node && (of_id = of_match_node(cpu_pmu_of_device_ids, pdev->dev.of_node))) {
 315                 init_fn = of_id->data;
 316                 ret = init_fn(pmu);
 317         } else {
 318                 ret = probe_current_pmu(pmu);
 319         }
 320
 321         if (ret) {
 322                 pr_info("failed to probe PMU!\n");
 323                 goto out_free;
 324         }
 325
 326         ret = cpu_pmu_init(cpu_pmu);
 327         if (ret)
 328                 goto out_free;
 329
 330         ret = armpmu_register(cpu_pmu, -1);
 331         if (ret)
 332                 goto out_destroy;
 333
 334         return 0;
 335
 336 out_destroy:
 337         cpu_pmu_destroy(cpu_pmu);
 338 out_free:
 339         pr_info("failed to register PMU devices!\n");
 340         kfree(pmu);
 341         return ret;
 342 }
 343
 344 static struct platform_driver cpu_pmu_driver = {
 345         .driver         = {
 346                 .name   = "arm-pmu",
 347                 .pm     = &armpmu_dev_pm_ops,
 348                 .of_match_table = cpu_pmu_of_device_ids,
 349         },
 350         .probe          = cpu_pmu_device_probe,
 351         .id_table       = cpu_pmu_plat_device_ids,
 352 };
 353
 354 static int __init register_pmu_driver(void)
 355 {
 356         return platform_driver_register(&cpu_pmu_driver);
 357 }
 358 device_initcall(register_pmu_driver);