arch/x86/oprofile/op_model_ppro.c

   1 /*
   2  * @file op_model_ppro.h
   3  * Family 6 perfmon and architectural perfmon MSR operations
   4  *
   5  * @remark Copyright 2002 OProfile authors
   6  * @remark Copyright 2008 Intel Corporation
   7  * @remark Read the file COPYING
   8  *
   9  * @author John Levon
  10  * @author Philippe Elie
  11  * @author Graydon Hoare
  12  * @author Andi Kleen
  13  */
  14
  15 #include <linux/oprofile.h>
  16 #include <linux/slab.h>
  17 #include <asm/ptrace.h>
  18 #include <asm/msr.h>
  19 #include <asm/apic.h>
  20 #include <asm/nmi.h>
  21 #include <asm/perf_counter.h>
  22
  23 #include "op_x86_model.h"
  24 #include "op_counter.h"
  25
  26 static int num_counters = 2;
  27 static int counter_width = 32;
  28
  29 #define CTR_IS_RESERVED(msrs, c) (msrs->counters[(c)].addr ? 1 : 0)
  30 #define CTR_OVERFLOWED(n) (!((n) & (1ULL<<(counter_width-1))))
  31
  32 #define CTRL_IS_RESERVED(msrs, c) (msrs->controls[(c)].addr ? 1 : 0)
  33 #define CTRL_READ(l, h, msrs, c) do {rdmsr((msrs->controls[(c)].addr), (l), (h)); } while (0)
  34 #define CTRL_WRITE(l, h, msrs, c) do {wrmsr((msrs->controls[(c)].addr), (l), (h)); } while (0)
  35 #define CTRL_SET_ACTIVE(n) (n |= (1<<22))
  36 #define CTRL_SET_INACTIVE(n) (n &= ~(1<<22))
  37 #define CTRL_CLEAR(x) (x &= (1<<21))
  38 #define CTRL_SET_ENABLE(val) (val |= 1<<20)
  39 #define CTRL_SET_USR(val, u) (val |= ((u & 1) << 16))
  40 #define CTRL_SET_KERN(val, k) (val |= ((k & 1) << 17))
  41 #define CTRL_SET_UM(val, m) (val |= (m << 8))
  42 #define CTRL_SET_EVENT(val, e) (val |= e)
  43
  44 static u64 *reset_value;
  45
  46 static void ppro_fill_in_addresses(struct op_msrs * const msrs)
  47 {
  48         int i;
  49
  50         for (i = 0; i < num_counters; i++) {
  51                 if (reserve_perfctr_nmi(MSR_P6_PERFCTR0 + i))
  52                         msrs->counters[i].addr = MSR_P6_PERFCTR0 + i;
  53                 else
  54                         msrs->counters[i].addr = 0;
  55         }
  56
  57         for (i = 0; i < num_counters; i++) {
  58                 if (reserve_evntsel_nmi(MSR_P6_EVNTSEL0 + i))
  59                         msrs->controls[i].addr = MSR_P6_EVNTSEL0 + i;
  60                 else
  61                         msrs->controls[i].addr = 0;
  62         }
  63 }
  64
  65
  66 static void ppro_setup_ctrs(struct op_msrs const * const msrs)
  67 {
  68         unsigned int low, high;
  69         int i;
  70
  71         if (!reset_value) {
  72                 reset_value = kmalloc(sizeof(reset_value[0]) * num_counters,
  73                                         GFP_ATOMIC);
  74                 if (!reset_value)
  75                         return;
  76         }
  77
  78         if (cpu_has_arch_perfmon) {
  79                 union cpuid10_eax eax;
  80                 eax.full = cpuid_eax(0xa);
  81
  82                 /*
  83                  * For Core2 (family 6, model 15), don't reset the
  84                  * counter width:
  85                  */
  86                 if (!(eax.split.version_id == 0 &&
  87                         current_cpu_data.x86 == 6 &&
  88                                 current_cpu_data.x86_model == 15)) {
  89
  90                         if (counter_width < eax.split.bit_width)
  91                                 counter_width = eax.split.bit_width;
  92                 }
  93         }
  94
  95         /* clear all counters */
  96         for (i = 0 ; i < num_counters; ++i) {
  97                 if (unlikely(!CTRL_IS_RESERVED(msrs, i)))
  98                         continue;
  99                 CTRL_READ(low, high, msrs, i);
 100                 CTRL_CLEAR(low);
 101                 CTRL_WRITE(low, high, msrs, i);
 102         }
 103
 104         /* avoid a false detection of ctr overflows in NMI handler */
 105         for (i = 0; i < num_counters; ++i) {
 106                 if (unlikely(!CTR_IS_RESERVED(msrs, i)))
 107                         continue;
 108                 wrmsrl(msrs->counters[i].addr, -1LL);
 109         }
 110
 111         /* enable active counters */
 112         for (i = 0; i < num_counters; ++i) {
 113                 if ((counter_config[i].enabled) && (CTR_IS_RESERVED(msrs, i))) {
 114                         reset_value[i] = counter_config[i].count;
 115
 116                         wrmsrl(msrs->counters[i].addr, -reset_value[i]);
 117
 118                         CTRL_READ(low, high, msrs, i);
 119                         CTRL_CLEAR(low);
 120                         CTRL_SET_ENABLE(low);
 121                         CTRL_SET_USR(low, counter_config[i].user);
 122                         CTRL_SET_KERN(low, counter_config[i].kernel);
 123                         CTRL_SET_UM(low, counter_config[i].unit_mask);
 124                         CTRL_SET_EVENT(low, counter_config[i].event);
 125                         CTRL_WRITE(low, high, msrs, i);
 126                 } else {
 127                         reset_value[i] = 0;
 128                 }
 129         }
 130 }
 131
 132
 133 static int ppro_check_ctrs(struct pt_regs * const regs,
 134                            struct op_msrs const * const msrs)
 135 {
 136         u64 val;
 137         int i;
 138
 139         /*
 140          * This can happen if perf counters are in use when
 141          * we steal the die notifier NMI.
 142          */
 143         if (unlikely(!reset_value))
 144                 goto out;
 145
 146         for (i = 0 ; i < num_counters; ++i) {
 147                 if (!reset_value[i])
 148                         continue;
 149                 rdmsrl(msrs->counters[i].addr, val);
 150                 if (CTR_OVERFLOWED(val)) {
 151                         oprofile_add_sample(regs, i);
 152                         wrmsrl(msrs->counters[i].addr, -reset_value[i]);
 153                 }
 154         }
 155
 156 out:
 157         /* Only P6 based Pentium M need to re-unmask the apic vector but it
 158          * doesn't hurt other P6 variant */
 159         apic_write(APIC_LVTPC, apic_read(APIC_LVTPC) & ~APIC_LVT_MASKED);
 160
 161         /* We can't work out if we really handled an interrupt. We
 162          * might have caught a *second* counter just after overflowing
 163          * the interrupt for this counter then arrives
 164          * and we don't find a counter that's overflowed, so we
 165          * would return 0 and get dazed + confused. Instead we always
 166          * assume we found an overflow. This sucks.
 167          */
 168         return 1;
 169 }
 170
 171
 172 static void ppro_start(struct op_msrs const * const msrs)
 173 {
 174         unsigned int low, high;
 175         int i;
 176
 177         if (!reset_value)
 178                 return;
 179         for (i = 0; i < num_counters; ++i) {
 180                 if (reset_value[i]) {
 181                         CTRL_READ(low, high, msrs, i);
 182                         CTRL_SET_ACTIVE(low);
 183                         CTRL_WRITE(low, high, msrs, i);
 184                 }
 185         }
 186 }
 187
 188
 189 static void ppro_stop(struct op_msrs const * const msrs)
 190 {
 191         unsigned int low, high;
 192         int i;
 193
 194         if (!reset_value)
 195                 return;
 196         for (i = 0; i < num_counters; ++i) {
 197                 if (!reset_value[i])
 198                         continue;
 199                 CTRL_READ(low, high, msrs, i);
 200                 CTRL_SET_INACTIVE(low);
 201                 CTRL_WRITE(low, high, msrs, i);
 202         }
 203 }
 204
 205 static void ppro_shutdown(struct op_msrs const * const msrs)
 206 {
 207         int i;
 208
 209         for (i = 0 ; i < num_counters ; ++i) {
 210                 if (CTR_IS_RESERVED(msrs, i))
 211                         release_perfctr_nmi(MSR_P6_PERFCTR0 + i);
 212         }
 213         for (i = 0 ; i < num_counters ; ++i) {
 214                 if (CTRL_IS_RESERVED(msrs, i))
 215                         release_evntsel_nmi(MSR_P6_EVNTSEL0 + i);
 216         }
 217         if (reset_value) {
 218                 kfree(reset_value);
 219                 reset_value = NULL;
 220         }
 221 }
 222
 223
 224 struct op_x86_model_spec op_ppro_spec = {
 225         .num_counters           = 2,    /* can be overriden */
 226         .num_controls           = 2,    /* dito */
 227         .fill_in_addresses      = &ppro_fill_in_addresses,
 228         .setup_ctrs             = &ppro_setup_ctrs,
 229         .check_ctrs             = &ppro_check_ctrs,
 230         .start                  = &ppro_start,
 231         .stop                   = &ppro_stop,
 232         .shutdown               = &ppro_shutdown
 233 };
 234
 235 /*
 236  * Architectural performance monitoring.
 237  *
 238  * Newer Intel CPUs (Core1+) have support for architectural
 239  * events described in CPUID 0xA. See the IA32 SDM Vol3b.18 for details.
 240  * The advantage of this is that it can be done without knowing about
 241  * the specific CPU.
 242  */
 243
 244 void arch_perfmon_setup_counters(void)
 245 {
 246         union cpuid10_eax eax;
 247
 248         eax.full = cpuid_eax(0xa);
 249
 250         /* Workaround for BIOS bugs in 6/15. Taken from perfmon2 */
 251         if (eax.split.version_id == 0 && current_cpu_data.x86 == 6 &&
 252                 current_cpu_data.x86_model == 15) {
 253                 eax.split.version_id = 2;
 254                 eax.split.num_counters = 2;
 255                 eax.split.bit_width = 40;
 256         }
 257
 258         num_counters = eax.split.num_counters;
 259
 260         op_arch_perfmon_spec.num_counters = num_counters;
 261         op_arch_perfmon_spec.num_controls = num_counters;
 262         op_ppro_spec.num_counters = num_counters;
 263         op_ppro_spec.num_controls = num_counters;
 264 }
 265
 266 struct op_x86_model_spec op_arch_perfmon_spec = {
 267         /* num_counters/num_controls filled in at runtime */
 268         .fill_in_addresses      = &ppro_fill_in_addresses,
 269         /* user space does the cpuid check for available events */
 270         .setup_ctrs             = &ppro_setup_ctrs,
 271         .check_ctrs             = &ppro_check_ctrs,
 272         .start                  = &ppro_start,
 273         .stop                   = &ppro_stop,
 274         .shutdown               = &ppro_shutdown
 275 };