arch/ia64/kernel/perfmon_default_smpl.c

   1 /*
   2  * Copyright (C) 2002-2003 Hewlett-Packard Co
   3  *               Stephane Eranian <eranian@hpl.hp.com>
   4  *
   5  * This file implements the default sampling buffer format
   6  * for the Linux/ia64 perfmon-2 subsystem.
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/types.h>
  10 #include <linux/module.h>
  11 #include <linux/config.h>
  12 #include <linux/init.h>
  13 #include <asm/delay.h>
  14 #include <linux/smp.h>
  15
  16 #include <asm/perfmon.h>
  17 #include <asm/perfmon_default_smpl.h>
  18
  19 MODULE_AUTHOR("Stephane Eranian <eranian@hpl.hp.com>");
  20 MODULE_DESCRIPTION("perfmon default sampling format");
  21 MODULE_LICENSE("GPL");
  22
  23 MODULE_PARM(debug, "i");
  24 MODULE_PARM_DESC(debug, "debug");
  25
  26 MODULE_PARM(debug_ovfl, "i");
  27 MODULE_PARM_DESC(debug_ovfl, "debug ovfl");
  28
  29
  30 #define DEFAULT_DEBUG 1
  31
  32 #ifdef DEFAULT_DEBUG
  33 #define DPRINT(a) \
  34         do { \
  35                 if (unlikely(debug >0)) { printk("%s.%d: CPU%d ", __FUNCTION__, __LINE__, smp_processor_id()); printk a; } \
  36         } while (0)
  37
  38 #define DPRINT_ovfl(a) \
  39         do { \
  40                 if (unlikely(debug_ovfl >0)) { printk("%s.%d: CPU%d ", __FUNCTION__, __LINE__, smp_processor_id()); printk a; } \
  41         } while (0)
  42
  43 #else
  44 #define DPRINT(a)
  45 #define DPRINT_ovfl(a)
  46 #endif
  47
  48 static int debug, debug_ovfl;
  49
  50 static int
  51 default_validate(struct task_struct *task, unsigned int flags, int cpu, void *data)
  52 {
  53         pfm_default_smpl_arg_t *arg = (pfm_default_smpl_arg_t*)data;
  54         int ret = 0;
  55
  56         if (data == NULL) {
  57                 DPRINT(("[%d] no argument passed\n", task->pid));
  58                 return -EINVAL;
  59         }
  60
  61         DPRINT(("[%d] validate flags=0x%x CPU%d\n", task->pid, flags, cpu));
  62
  63         /*
  64          * must hold at least the buffer header + one minimally sized entry
  65          */
  66         if (arg->buf_size < PFM_DEFAULT_SMPL_MIN_BUF_SIZE) return -EINVAL;
  67
  68         DPRINT(("buf_size=%lu\n", arg->buf_size));
  69
  70         return ret;
  71 }
  72
  73 static int
  74 default_get_size(struct task_struct *task, unsigned int flags, int cpu, void *data, unsigned long *size)
  75 {
  76         pfm_default_smpl_arg_t *arg = (pfm_default_smpl_arg_t *)data;
  77
  78         /*
  79          * size has been validated in default_validate
  80          */
  81         *size = arg->buf_size;
  82
  83         return 0;
  84 }
  85
  86 static int
  87 default_init(struct task_struct *task, void *buf, unsigned int flags, int cpu, void *data)
  88 {
  89         pfm_default_smpl_hdr_t *hdr;
  90         pfm_default_smpl_arg_t *arg = (pfm_default_smpl_arg_t *)data;
  91
  92         hdr = (pfm_default_smpl_hdr_t *)buf;
  93
  94         hdr->hdr_version      = PFM_DEFAULT_SMPL_VERSION;
  95         hdr->hdr_buf_size     = arg->buf_size;
  96         hdr->hdr_cur_offs     = sizeof(*hdr);
  97         hdr->hdr_overflows    = 0UL;
  98         hdr->hdr_count        = 0UL;
  99
 100         DPRINT(("[%d] buffer=%p buf_size=%lu hdr_size=%lu hdr_version=%u cur_offs=%lu\n",
 101                 task->pid,
 102                 buf,
 103                 hdr->hdr_buf_size,
 104                 sizeof(*hdr),
 105                 hdr->hdr_version,
 106                 hdr->hdr_cur_offs));
 107
 108         return 0;
 109 }
 110
 111 static int
 112 default_handler(struct task_struct *task, void *buf, pfm_ovfl_arg_t *arg, struct pt_regs *regs, unsigned long stamp)
 113 {
 114         pfm_default_smpl_hdr_t *hdr;
 115         pfm_default_smpl_entry_t *ent;
 116         void *cur, *last;
 117         unsigned long *e, entry_size;
 118         unsigned int npmds, i;
 119         unsigned char ovfl_pmd;
 120         unsigned char ovfl_notify;
 121
 122         if (unlikely(buf == NULL || arg == NULL|| regs == NULL || task == NULL)) {
 123                 DPRINT(("[%d] invalid arguments buf=%p arg=%p\n", task->pid, buf, arg));
 124                 return -EINVAL;
 125         }
 126
 127         hdr         = (pfm_default_smpl_hdr_t *)buf;
 128         cur         = buf+hdr->hdr_cur_offs;
 129         last        = buf+hdr->hdr_buf_size;
 130         ovfl_pmd    = arg->ovfl_pmd;
 131         ovfl_notify = arg->ovfl_notify;
 132
 133         /*
 134          * precheck for sanity
 135          */
 136         if ((last - cur) < PFM_DEFAULT_MAX_ENTRY_SIZE) goto full;
 137
 138         npmds = hweight64(arg->smpl_pmds[0]);
 139
 140         ent = (pfm_default_smpl_entry_t *)cur;
 141
 142         prefetch(arg->smpl_pmds_values);
 143
 144         entry_size = sizeof(*ent) + (npmds << 3);
 145
 146         /* position for first pmd */
 147         e = (unsigned long *)(ent+1);
 148
 149         hdr->hdr_count++;
 150
 151         DPRINT_ovfl(("[%d] count=%lu cur=%p last=%p free_bytes=%lu ovfl_pmd=%d ovfl_notify=%d npmds=%u\n",
 152                         task->pid,
 153                         hdr->hdr_count,
 154                         cur, last,
 155                         last-cur,
 156                         ovfl_pmd,
 157                         ovfl_notify, npmds));
 158
 159         /*
 160          * current = task running at the time of the overflow.
 161          *
 162          * per-task mode:
 163          *      - this is ususally the task being monitored.
 164          *        Under certain conditions, it might be a different task
 165          *
 166          * system-wide:
 167          *      - this is not necessarily the task controlling the session
 168          */
 169         ent->pid            = current->pid;
 170         ent->ovfl_pmd       = ovfl_pmd;
 171         ent->last_reset_val = arg->pmd_last_reset; //pmd[0].reg_last_reset_val;
 172
 173         /*
 174          * where did the fault happen (includes slot number)
 175          */
 176         ent->ip = regs->cr_iip | ((regs->cr_ipsr >> 41) & 0x3);
 177
 178         ent->tstamp    = stamp;
 179         ent->cpu       = smp_processor_id();
 180         ent->set       = arg->active_set;
 181         ent->tgid      = current->tgid;
 182
 183         /*
 184          * selectively store PMDs in increasing index number
 185          */
 186         if (npmds) {
 187                 unsigned long *val = arg->smpl_pmds_values;
 188                 for(i=0; i < npmds; i++) {
 189                         *e++ = *val++;
 190                 }
 191         }
 192
 193         /*
 194          * update position for next entry
 195          */
 196         hdr->hdr_cur_offs += entry_size;
 197         cur               += entry_size;
 198
 199         /*
 200          * post check to avoid losing the last sample
 201          */
 202         if ((last - cur) < PFM_DEFAULT_MAX_ENTRY_SIZE) goto full;
 203
 204         /*
 205          * keep same ovfl_pmds, ovfl_notify
 206          */
 207         arg->ovfl_ctrl.bits.notify_user     = 0;
 208         arg->ovfl_ctrl.bits.block_task      = 0;
 209         arg->ovfl_ctrl.bits.mask_monitoring = 0;
 210         arg->ovfl_ctrl.bits.reset_ovfl_pmds = 1; /* reset before returning from interrupt handler */
 211
 212         return 0;
 213 full:
 214         DPRINT_ovfl(("sampling buffer full free=%lu, count=%lu, ovfl_notify=%d\n", last-cur, hdr->hdr_count, ovfl_notify));
 215
 216         /*
 217          * increment number of buffer overflow.
 218          * important to detect duplicate set of samples.
 219          */
 220         hdr->hdr_overflows++;
 221
 222         /*
 223          * if no notification requested, then we saturate the buffer
 224          */
 225         if (ovfl_notify == 0) {
 226                 arg->ovfl_ctrl.bits.notify_user     = 0;
 227                 arg->ovfl_ctrl.bits.block_task      = 0;
 228                 arg->ovfl_ctrl.bits.mask_monitoring = 1;
 229                 arg->ovfl_ctrl.bits.reset_ovfl_pmds = 0;
 230         } else {
 231                 arg->ovfl_ctrl.bits.notify_user     = 1;
 232                 arg->ovfl_ctrl.bits.block_task      = 1; /* ignored for non-blocking context */
 233                 arg->ovfl_ctrl.bits.mask_monitoring = 1;
 234                 arg->ovfl_ctrl.bits.reset_ovfl_pmds = 0; /* no reset now */
 235         }
 236         return -1; /* we are full, sorry */
 237 }
 238
 239 static int
 240 default_restart(struct task_struct *task, pfm_ovfl_ctrl_t *ctrl, void *buf, struct pt_regs *regs)
 241 {
 242         pfm_default_smpl_hdr_t *hdr;
 243
 244         hdr = (pfm_default_smpl_hdr_t *)buf;
 245
 246         hdr->hdr_count    = 0UL;
 247         hdr->hdr_cur_offs = sizeof(*hdr);
 248
 249         ctrl->bits.mask_monitoring = 0;
 250         ctrl->bits.reset_ovfl_pmds = 1; /* uses long-reset values */
 251
 252         return 0;
 253 }
 254
 255 static int
 256 default_exit(struct task_struct *task, void *buf, struct pt_regs *regs)
 257 {
 258         DPRINT(("[%d] exit(%p)\n", task->pid, buf));
 259         return 0;
 260 }
 261
 262 static pfm_buffer_fmt_t default_fmt={
 263         .fmt_name           = "default_format",
 264         .fmt_uuid           = PFM_DEFAULT_SMPL_UUID,
 265         .fmt_arg_size       = sizeof(pfm_default_smpl_arg_t),
 266         .fmt_validate       = default_validate,
 267         .fmt_getsize        = default_get_size,
 268         .fmt_init           = default_init,
 269         .fmt_handler        = default_handler,
 270         .fmt_restart        = default_restart,
 271         .fmt_restart_active = default_restart,
 272         .fmt_exit           = default_exit,
 273 };
 274
 275 static int __init
 276 pfm_default_smpl_init_module(void)
 277 {
 278         int ret;
 279
 280         ret = pfm_register_buffer_fmt(&default_fmt);
 281         if (ret == 0) {
 282                 printk("perfmon_default_smpl: %s v%u.%u registered\n",
 283                         default_fmt.fmt_name,
 284                         PFM_DEFAULT_SMPL_VERSION_MAJ,
 285                         PFM_DEFAULT_SMPL_VERSION_MIN);
 286         } else {
 287                 printk("perfmon_default_smpl: %s cannot register ret=%d\n",
 288                         default_fmt.fmt_name,
 289                         ret);
 290         }
 291
 292         return ret;
 293 }
 294
 295 static void __exit
 296 pfm_default_smpl_cleanup_module(void)
 297 {
 298         int ret;
 299         ret = pfm_unregister_buffer_fmt(default_fmt.fmt_uuid);
 300
 301         printk("perfmon_default_smpl: unregister %s=%d\n", default_fmt.fmt_name, ret);
 302 }
 303
 304 module_init(pfm_default_smpl_init_module);
 305 module_exit(pfm_default_smpl_cleanup_module);
 306