arch/i386/oprofile/op_model_ppro.c

   1 /**
   2  * @file op_model_ppro.h
   3  * pentium pro / P6 model-specific MSR operations
   4  *
   5  * @remark Copyright 2002 OProfile authors
   6  * @remark Read the file COPYING
   7  *
   8  * @author John Levon
   9  * @author Philippe Elie
  10  * @author Graydon Hoare
  11  */
  12
  13 #include <linux/oprofile.h>
  14 #include <asm/ptrace.h>
  15 #include <asm/msr.h>
  16 #include <asm/apic.h>
  17 #include <asm/nmi.h>
  18
  19 #include "op_x86_model.h"
  20 #include "op_counter.h"
  21
  22 #define NUM_COUNTERS 2
  23 #define NUM_CONTROLS 2
  24
  25 #define CTR_IS_RESERVED(msrs,c) (msrs->counters[(c)].addr ? 1 : 0)
  26 #define CTR_READ(l,h,msrs,c) do {rdmsr(msrs->counters[(c)].addr, (l), (h));} while (0)
  27 #define CTR_WRITE(l,msrs,c) do {wrmsr(msrs->counters[(c)].addr, -(u32)(l), -1);} while (0)
  28 #define CTR_OVERFLOWED(n) (!((n) & (1U<<31)))
  29
  30 #define CTRL_IS_RESERVED(msrs,c) (msrs->controls[(c)].addr ? 1 : 0)
  31 #define CTRL_READ(l,h,msrs,c) do {rdmsr((msrs->controls[(c)].addr), (l), (h));} while (0)
  32 #define CTRL_WRITE(l,h,msrs,c) do {wrmsr((msrs->controls[(c)].addr), (l), (h));} while (0)
  33 #define CTRL_SET_ACTIVE(n) (n |= (1<<22))
  34 #define CTRL_SET_INACTIVE(n) (n &= ~(1<<22))
  35 #define CTRL_CLEAR(x) (x &= (1<<21))
  36 #define CTRL_SET_ENABLE(val) (val |= 1<<20)
  37 #define CTRL_SET_USR(val,u) (val |= ((u & 1) << 16))
  38 #define CTRL_SET_KERN(val,k) (val |= ((k & 1) << 17))
  39 #define CTRL_SET_UM(val, m) (val |= (m << 8))
  40 #define CTRL_SET_EVENT(val, e) (val |= e)
  41
  42 static unsigned long reset_value[NUM_COUNTERS];
  43
  44 static void ppro_fill_in_addresses(struct op_msrs * const msrs)
  45 {
  46         int i;
  47
  48         for (i=0; i < NUM_COUNTERS; i++) {
  49                 if (reserve_perfctr_nmi(MSR_P6_PERFCTR0 + i))
  50                         msrs->counters[i].addr = MSR_P6_PERFCTR0 + i;
  51                 else
  52                         msrs->counters[i].addr = 0;
  53         }
  54
  55         for (i=0; i < NUM_CONTROLS; i++) {
  56                 if (reserve_evntsel_nmi(MSR_P6_EVNTSEL0 + i))
  57                         msrs->controls[i].addr = MSR_P6_EVNTSEL0 + i;
  58                 else
  59                         msrs->controls[i].addr = 0;
  60         }
  61 }
  62
  63
  64 static void ppro_setup_ctrs(struct op_msrs const * const msrs)
  65 {
  66         unsigned int low, high;
  67         int i;
  68
  69         /* clear all counters */
  70         for (i = 0 ; i < NUM_CONTROLS; ++i) {
  71                 if (unlikely(!CTRL_IS_RESERVED(msrs,i)))
  72                         continue;
  73                 CTRL_READ(low, high, msrs, i);
  74                 CTRL_CLEAR(low);
  75                 CTRL_WRITE(low, high, msrs, i);
  76         }
  77
  78         /* avoid a false detection of ctr overflows in NMI handler */
  79         for (i = 0; i < NUM_COUNTERS; ++i) {
  80                 if (unlikely(!CTR_IS_RESERVED(msrs,i)))
  81                         continue;
  82                 CTR_WRITE(1, msrs, i);
  83         }
  84
  85         /* enable active counters */
  86         for (i = 0; i < NUM_COUNTERS; ++i) {
  87                 if ((counter_config[i].enabled) && (CTR_IS_RESERVED(msrs,i))) {
  88                         reset_value[i] = counter_config[i].count;
  89
  90                         CTR_WRITE(counter_config[i].count, msrs, i);
  91
  92                         CTRL_READ(low, high, msrs, i);
  93                         CTRL_CLEAR(low);
  94                         CTRL_SET_ENABLE(low);
  95                         CTRL_SET_USR(low, counter_config[i].user);
  96                         CTRL_SET_KERN(low, counter_config[i].kernel);
  97                         CTRL_SET_UM(low, counter_config[i].unit_mask);
  98                         CTRL_SET_EVENT(low, counter_config[i].event);
  99                         CTRL_WRITE(low, high, msrs, i);
 100                 } else {
 101                         reset_value[i] = 0;
 102                 }
 103         }
 104 }
 105
 106
 107 static int ppro_check_ctrs(struct pt_regs * const regs,
 108                            struct op_msrs const * const msrs)
 109 {
 110         unsigned int low, high;
 111         int i;
 112
 113         for (i = 0 ; i < NUM_COUNTERS; ++i) {
 114                 if (!reset_value[i])
 115                         continue;
 116                 CTR_READ(low, high, msrs, i);
 117                 if (CTR_OVERFLOWED(low)) {
 118                         oprofile_add_sample(regs, i);
 119                         CTR_WRITE(reset_value[i], msrs, i);
 120                 }
 121         }
 122
 123         /* Only P6 based Pentium M need to re-unmask the apic vector but it
 124          * doesn't hurt other P6 variant */
 125         apic_write(APIC_LVTPC, apic_read(APIC_LVTPC) & ~APIC_LVT_MASKED);
 126
 127         /* We can't work out if we really handled an interrupt. We
 128          * might have caught a *second* counter just after overflowing
 129          * the interrupt for this counter then arrives
 130          * and we don't find a counter that's overflowed, so we
 131          * would return 0 and get dazed + confused. Instead we always
 132          * assume we found an overflow. This sucks.
 133          */
 134         return 1;
 135 }
 136
 137
 138 static void ppro_start(struct op_msrs const * const msrs)
 139 {
 140         unsigned int low,high;
 141         int i;
 142
 143         for (i = 0; i < NUM_COUNTERS; ++i) {
 144                 if (reset_value[i]) {
 145                         CTRL_READ(low, high, msrs, i);
 146                         CTRL_SET_ACTIVE(low);
 147                         CTRL_WRITE(low, high, msrs, i);
 148                 }
 149         }
 150 }
 151
 152
 153 static void ppro_stop(struct op_msrs const * const msrs)
 154 {
 155         unsigned int low,high;
 156         int i;
 157
 158         for (i = 0; i < NUM_COUNTERS; ++i) {
 159                 if (!reset_value[i])
 160                         continue;
 161                 CTRL_READ(low, high, msrs, i);
 162                 CTRL_SET_INACTIVE(low);
 163                 CTRL_WRITE(low, high, msrs, i);
 164         }
 165 }
 166
 167 static void ppro_shutdown(struct op_msrs const * const msrs)
 168 {
 169         int i;
 170
 171         for (i = 0 ; i < NUM_COUNTERS ; ++i) {
 172                 if (CTR_IS_RESERVED(msrs,i))
 173                         release_perfctr_nmi(MSR_P6_PERFCTR0 + i);
 174         }
 175         for (i = 0 ; i < NUM_CONTROLS ; ++i) {
 176                 if (CTRL_IS_RESERVED(msrs,i))
 177                         release_evntsel_nmi(MSR_P6_EVNTSEL0 + i);
 178         }
 179 }
 180
 181
 182 struct op_x86_model_spec const op_ppro_spec = {
 183         .num_counters = NUM_COUNTERS,
 184         .num_controls = NUM_CONTROLS,
 185         .fill_in_addresses = &ppro_fill_in_addresses,
 186         .setup_ctrs = &ppro_setup_ctrs,
 187         .check_ctrs = &ppro_check_ctrs,
 188         .start = &ppro_start,
 189         .stop = &ppro_stop,
 190         .shutdown = &ppro_shutdown
 191 };