arch/alpha/oprofile/op_model_ev6.c

   1 /**
   2  * @file arch/alpha/oprofile/op_model_ev6.c
   3  *
   4  * @remark Copyright 2002 OProfile authors
   5  * @remark Read the file COPYING
   6  *
   7  * @author Richard Henderson <rth@twiddle.net>
   8  */
   9
  10 #include <linux/oprofile.h>
  11 #include <linux/smp.h>
  12 #include <asm/ptrace.h>
  13
  14 #include "op_impl.h"
  15
  16
  17 /* Compute all of the registers in preparation for enabling profiling.  */
  18
  19 static void
  20 ev6_reg_setup(struct op_register_config *reg,
  21               struct op_counter_config *ctr,
  22               struct op_system_config *sys)
  23 {
  24         unsigned long ctl, reset, need_reset, i;
  25
  26         /* Select desired events.  We've mapped the event numbers
  27            such that they fit directly into the event selection fields.  */
  28         ctl = 0;
  29         if (ctr[0].enabled && ctr[0].event)
  30                 ctl |= (ctr[0].event & 1) << 4;
  31         if (ctr[1].enabled)
  32                 ctl |= (ctr[1].event - 2) & 15;
  33         reg->mux_select = ctl;
  34
  35         /* Select logging options.  */
  36         /* ??? Need to come up with some mechanism to trace only
  37            selected processes.  EV6 does not have a mechanism to
  38            select kernel or user mode only.  For now, enable always.  */
  39         reg->proc_mode = 0;
  40
  41         /* EV6 cannot change the width of the counters as with the
  42            other implementations.  But fortunately, we can write to
  43            the counters and set the value such that it will overflow
  44            at the right time.  */
  45         reset = need_reset = 0;
  46         for (i = 0; i < 2; ++i) {
  47                 unsigned long count = ctr[i].count;
  48                 if (!ctr[i].enabled)
  49                         continue;
  50
  51                 if (count > 0x100000)
  52                         count = 0x100000;
  53                 ctr[i].count = count;
  54                 reset |= (0x100000 - count) << (i ? 6 : 28);
  55                 if (count != 0x100000)
  56                         need_reset |= 1 << i;
  57         }
  58         reg->reset_values = reset;
  59         reg->need_reset = need_reset;
  60 }
  61
  62 /* Program all of the registers in preparation for enabling profiling.  */
  63
  64 static void
  65 ev6_cpu_setup (void *x)
  66 {
  67         struct op_register_config *reg = x;
  68
  69         wrperfmon(2, reg->mux_select);
  70         wrperfmon(3, reg->proc_mode);
  71         wrperfmon(6, reg->reset_values | 3);
  72 }
  73
  74 /* CTR is a counter for which the user has requested an interrupt count
  75    in between one of the widths selectable in hardware.  Reset the count
  76    for CTR to the value stored in REG->RESET_VALUES.  */
  77
  78 static void
  79 ev6_reset_ctr(struct op_register_config *reg, unsigned long ctr)
  80 {
  81         wrperfmon(6, reg->reset_values | (1 << ctr));
  82 }
  83
  84 static void
  85 ev6_handle_interrupt(unsigned long which, struct pt_regs *regs,
  86                      struct op_counter_config *ctr)
  87 {
  88         /* Record the sample.  */
  89         oprofile_add_sample(regs, which);
  90 }
  91
  92
  93 struct op_axp_model op_model_ev6 = {
  94         .reg_setup              = ev6_reg_setup,
  95         .cpu_setup              = ev6_cpu_setup,
  96         .reset_ctr              = ev6_reset_ctr,
  97         .handle_interrupt       = ev6_handle_interrupt,
  98         .cpu_type               = "alpha/ev6",
  99         .num_counters           = 2,
 100         .can_set_proc_mode      = 0,
 101 };