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 cpu = smp_processor_id();
  25         unsigned long eip = instruction_pointer(regs);
  26         int event = arg->pmd_eventid;
  27
  28         arg->ovfl_ctrl.bits.reset_ovfl_pmds = 1;
  29
  30         /* the owner of the oprofile event buffer may have exited
  31          * without perfmon being shutdown (e.g. SIGSEGV)
  32          */
  33         if (allow_ints)
  34                 oprofile_add_sample(eip, !user_mode(regs), event, cpu);
  35         return 0;
  36 }
  37
  38
  39 static int perfmon_start(void)
  40 {
  41         allow_ints = 1;
  42         return 0;
  43 }
  44
  45
  46 static void perfmon_stop(void)
  47 {
  48         allow_ints = 0;
  49 }
  50
  51
  52 #define OPROFILE_FMT_UUID { \
  53         0x77, 0x7a, 0x6e, 0x61, 0x20, 0x65, 0x73, 0x69, 0x74, 0x6e, 0x72, 0x20, 0x61, 0x65, 0x0a, 0x6c }
  54
  55 static pfm_buffer_fmt_t oprofile_fmt = {
  56         .fmt_name           = "oprofile_format",
  57         .fmt_uuid           = OPROFILE_FMT_UUID,
  58         .fmt_handler        = perfmon_handler,
  59 };
  60
  61
  62 static char * get_cpu_type(void)
  63 {
  64         __u8 family = local_cpu_data->family;
  65
  66         switch (family) {
  67                 case 0x07:
  68                         return "ia64/itanium";
  69                 case 0x1f:
  70                         return "ia64/itanium2";
  71                 default:
  72                         return "ia64/ia64";
  73         }
  74 }
  75
  76
  77 /* all the ops are handled via userspace for IA64 perfmon */
  78 static struct oprofile_operations perfmon_ops = {
  79         .start = perfmon_start,
  80         .stop = perfmon_stop,
  81 };
  82
  83 static int using_perfmon;
  84
  85 int perfmon_init(struct oprofile_operations ** ops)
  86 {
  87         int ret = pfm_register_buffer_fmt(&oprofile_fmt);
  88         if (ret)
  89                 return -ENODEV;
  90
  91         perfmon_ops.cpu_type = get_cpu_type();
  92         *ops = &perfmon_ops;
  93         using_perfmon = 1;
  94         printk(KERN_INFO "oprofile: using perfmon.\n");
  95         return 0;
  96 }
  97
  98
  99 void perfmon_exit(void)
 100 {
 101         if (!using_perfmon)
 102                 return;
 103
 104         pfm_unregister_buffer_fmt(oprofile_fmt.fmt_uuid);
 105 }