release/src-rt-6.x.4708/linux/linux-2.6.36/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/oprofile.h>
  12 #include <linux/sched.h>
  13 #include <asm/perfmon.h>
  14 #include <asm/ptrace.h>
  15 #include <asm/errno.h>
  16
  17 static int allow_ints;
  18
  19 static int
  20 perfmon_handler(struct task_struct *task, void *buf, pfm_ovfl_arg_t *arg,
  21                 struct pt_regs *regs, unsigned long stamp)
  22 {
  23         int event = arg->pmd_eventid;
  24
  25         arg->ovfl_ctrl.bits.reset_ovfl_pmds = 1;
  26
  27         /* the owner of the oprofile event buffer may have exited
  28          * without perfmon being shutdown (e.g. SIGSEGV)
  29          */
  30         if (allow_ints)
  31                 oprofile_add_sample(regs, event);
  32         return 0;
  33 }
  34
  35
  36 static int perfmon_start(void)
  37 {
  38         allow_ints = 1;
  39         return 0;
  40 }
  41
  42
  43 static void perfmon_stop(void)
  44 {
  45         allow_ints = 0;
  46 }
  47
  48
  49 #define OPROFILE_FMT_UUID { \
  50         0x77, 0x7a, 0x6e, 0x61, 0x20, 0x65, 0x73, 0x69, 0x74, 0x6e, 0x72, 0x20, 0x61, 0x65, 0x0a, 0x6c }
  51
  52 static pfm_buffer_fmt_t oprofile_fmt = {
  53         .fmt_name           = "oprofile_format",
  54         .fmt_uuid           = OPROFILE_FMT_UUID,
  55         .fmt_handler        = perfmon_handler,
  56 };
  57
  58
  59 static char *get_cpu_type(void)
  60 {
  61         __u8 family = local_cpu_data->family;
  62
  63         switch (family) {
  64                 case 0x07:
  65                         return "ia64/itanium";
  66                 case 0x1f:
  67                         return "ia64/itanium2";
  68                 default:
  69                         return "ia64/ia64";
  70         }
  71 }
  72
  73
  74 /* all the ops are handled via userspace for IA64 perfmon */
  75
  76 static int using_perfmon;
  77
  78 int perfmon_init(struct oprofile_operations *ops)
  79 {
  80         int ret = pfm_register_buffer_fmt(&oprofile_fmt);
  81         if (ret)
  82                 return -ENODEV;
  83
  84         ops->cpu_type = get_cpu_type();
  85         ops->start = perfmon_start;
  86         ops->stop = perfmon_stop;
  87         using_perfmon = 1;
  88         printk(KERN_INFO "oprofile: using perfmon.\n");
  89         return 0;
  90 }
  91
  92
  93 void perfmon_exit(void)
  94 {
  95         if (!using_perfmon)
  96                 return;
  97
  98         pfm_unregister_buffer_fmt(oprofile_fmt.fmt_uuid);
  99 }