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