arch/ia64/oprofile/perfmon.c

   1 /**
   2  * @file perfmon.c
   3  *
   4  * @remark Copyright 2003 OProfile authors
   5  * @remark Read the file COPYING
   6  *
   7  * @author John Levon <levon@movementarian.org>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/config.h>
  12 #include <linux/oprofile.h>
  13 #include <linux/sched.h>
  14 #include <asm/perfmon.h>
  15 #include <asm/ptrace.h>
  16 #include <asm/errno.h>
  17
  18 static int allow_ints;
  19
  20 static int
  21 perfmon_handler(struct task_struct *task, void *buf, pfm_ovfl_arg_t *arg,
  22                 struct pt_regs *regs, unsigned long stamp)
  23 {
  24         int event = arg->pmd_eventid;
  25
  26         arg->ovfl_ctrl.bits.reset_ovfl_pmds = 1;
  27
  28         /* the owner of the oprofile event buffer may have exited
  29          * without perfmon being shutdown (e.g. SIGSEGV)
  30          */
  31         if (allow_ints)
  32                 oprofile_add_sample(regs, event);
  33         return 0;
  34 }
  35
  36
  37 static int perfmon_start(void)
  38 {
  39         allow_ints = 1;
  40         return 0;
  41 }
  42
  43
  44 static void perfmon_stop(void)
  45 {
  46         allow_ints = 0;
  47 }
  48
  49
  50 #define OPROFILE_FMT_UUID { \
  51         0x77, 0x7a, 0x6e, 0x61, 0x20, 0x65, 0x73, 0x69, 0x74, 0x6e, 0x72, 0x20, 0x61, 0x65, 0x0a, 0x6c }
  52
  53 static pfm_buffer_fmt_t oprofile_fmt = {
  54         .fmt_name           = "oprofile_format",
  55         .fmt_uuid           = OPROFILE_FMT_UUID,
  56         .fmt_handler        = perfmon_handler,
  57 };
  58
  59
  60 static char * get_cpu_type(void)
  61 {
  62         __u8 family = local_cpu_data->family;
  63
  64         switch (family) {
  65                 case 0x07:
  66                         return "ia64/itanium";
  67                 case 0x1f:
  68                         return "ia64/itanium2";
  69                 default:
  70                         return "ia64/ia64";
  71         }
  72 }
  73
  74
  75 /* all the ops are handled via userspace for IA64 perfmon */
  76
  77 static int using_perfmon;
  78
  79 int perfmon_init(struct oprofile_operations * ops)
  80 {
  81         int ret = pfm_register_buffer_fmt(&oprofile_fmt);
  82         if (ret)
  83                 return -ENODEV;
  84
  85         ops->cpu_type = get_cpu_type();
  86         ops->start = perfmon_start;
  87         ops->stop = perfmon_stop;
  88         using_perfmon = 1;
  89         printk(KERN_INFO "oprofile: using perfmon.\n");
  90         return 0;
  91 }
  92
  93
  94 void perfmon_exit(void)
  95 {
  96         if (!using_perfmon)
  97                 return;
  98
  99         pfm_unregister_buffer_fmt(oprofile_fmt.fmt_uuid);
 100 }