arch/powerpc/platforms/cell/spufs/sputrace.c

   1 /*
   2  * Copyright (C) 2007 IBM Deutschland Entwicklung GmbH
   3  *      Released under GPL v2.
   4  *
   5  * Partially based on net/ipv4/tcp_probe.c.
   6  *
   7  * Simple tracing facility for spu contexts.
   8  */
   9 #include <linux/sched.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/marker.h>
  13 #include <linux/proc_fs.h>
  14 #include <linux/wait.h>
  15 #include <asm/atomic.h>
  16 #include <asm/uaccess.h>
  17 #include "spufs.h"
  18
  19 struct spu_probe {
  20         const char *name;
  21         const char *format;
  22         marker_probe_func *probe_func;
  23 };
  24
  25 struct sputrace {
  26         ktime_t tstamp;
  27         int owner_tid; /* owner */
  28         int curr_tid;
  29         const char *name;
  30         int number;
  31 };
  32
  33 static int bufsize __read_mostly = 16384;
  34 MODULE_PARM_DESC(bufsize, "Log buffer size (number of records)");
  35 module_param(bufsize, int, 0);
  36
  37
  38 static DEFINE_SPINLOCK(sputrace_lock);
  39 static DECLARE_WAIT_QUEUE_HEAD(sputrace_wait);
  40 static ktime_t sputrace_start;
  41 static unsigned long sputrace_head, sputrace_tail;
  42 static struct sputrace *sputrace_log;
  43
  44 static int sputrace_used(void)
  45 {
  46         return (sputrace_head - sputrace_tail) % bufsize;
  47 }
  48
  49 static inline int sputrace_avail(void)
  50 {
  51         return bufsize - sputrace_used();
  52 }
  53
  54 static int sputrace_sprint(char *tbuf, int n)
  55 {
  56         const struct sputrace *t = sputrace_log + sputrace_tail % bufsize;
  57         struct timespec tv =
  58                 ktime_to_timespec(ktime_sub(t->tstamp, sputrace_start));
  59
  60         return snprintf(tbuf, n,
  61                 "[%lu.%09lu] %d: %s (ctxthread = %d, spu = %d)\n",
  62                 (unsigned long) tv.tv_sec,
  63                 (unsigned long) tv.tv_nsec,
  64                 t->curr_tid,
  65                 t->name,
  66                 t->owner_tid,
  67                 t->number);
  68 }
  69
  70 static ssize_t sputrace_read(struct file *file, char __user *buf,
  71                 size_t len, loff_t *ppos)
  72 {
  73         int error = 0, cnt = 0;
  74
  75         if (!buf || len < 0)
  76                 return -EINVAL;
  77
  78         while (cnt < len) {
  79                 char tbuf[128];
  80                 int width;
  81
  82                 error = wait_event_interruptible(sputrace_wait,
  83                                                  sputrace_used() > 0);
  84                 if (error)
  85                         break;
  86
  87                 spin_lock(&sputrace_lock);
  88                 if (sputrace_head == sputrace_tail) {
  89                         spin_unlock(&sputrace_lock);
  90                         continue;
  91                 }
  92
  93                 width = sputrace_sprint(tbuf, sizeof(tbuf));
  94                 if (width < len)
  95                         sputrace_tail = (sputrace_tail + 1) % bufsize;
  96                 spin_unlock(&sputrace_lock);
  97
  98                 if (width >= len)
  99                         break;
 100
 101                 error = copy_to_user(buf + cnt, tbuf, width);
 102                 if (error)
 103                         break;
 104                 cnt += width;
 105         }
 106
 107         return cnt == 0 ? error : cnt;
 108 }
 109
 110 static int sputrace_open(struct inode *inode, struct file *file)
 111 {
 112         spin_lock(&sputrace_lock);
 113         sputrace_head = sputrace_tail = 0;
 114         sputrace_start = ktime_get();
 115         spin_unlock(&sputrace_lock);
 116
 117         return 0;
 118 }
 119
 120 static const struct file_operations sputrace_fops = {
 121         .owner  = THIS_MODULE,
 122         .open   = sputrace_open,
 123         .read   = sputrace_read,
 124 };
 125
 126 static void sputrace_log_item(const char *name, struct spu_context *ctx,
 127                 struct spu *spu)
 128 {
 129         spin_lock(&sputrace_lock);
 130         if (sputrace_avail() > 1) {
 131                 struct sputrace *t = sputrace_log + sputrace_head;
 132
 133                 t->tstamp = ktime_get();
 134                 t->owner_tid = ctx->tid;
 135                 t->name = name;
 136                 t->curr_tid = current->pid;
 137                 t->number = spu ? spu->number : -1;
 138
 139                 sputrace_head = (sputrace_head + 1) % bufsize;
 140         } else {
 141                 printk(KERN_WARNING
 142                        "sputrace: lost samples due to full buffer.\n");
 143         }
 144         spin_unlock(&sputrace_lock);
 145
 146         wake_up(&sputrace_wait);
 147 }
 148
 149 static void spu_context_event(void *probe_private, void *call_data,
 150                 const char *format, va_list *args)
 151 {
 152         struct spu_probe *p = probe_private;
 153         struct spu_context *ctx;
 154         struct spu *spu;
 155
 156         ctx = va_arg(*args, struct spu_context *);
 157         spu = va_arg(*args, struct spu *);
 158
 159         sputrace_log_item(p->name, ctx, spu);
 160 }
 161
 162 static void spu_context_nospu_event(void *probe_private, void *call_data,
 163                 const char *format, va_list *args)
 164 {
 165         struct spu_probe *p = probe_private;
 166         struct spu_context *ctx;
 167
 168         ctx = va_arg(*args, struct spu_context *);
 169
 170         sputrace_log_item(p->name, ctx, NULL);
 171 }
 172
 173 struct spu_probe spu_probes[] = {
 174         { "spu_bind_context__enter", "%p %p", spu_context_event },
 175         { "spu_unbind_context__enter", "%p %p", spu_context_event },
 176         { "spu_get_idle__enter", "%p", spu_context_nospu_event },
 177         { "spu_get_idle__found", "%p %p", spu_context_event },
 178         { "spu_get_idle__not_found", "%p", spu_context_nospu_event },
 179         { "spu_find_victim__enter", "%p", spu_context_nospu_event },
 180         { "spusched_tick__preempt", "%p %p", spu_context_event },
 181         { "spusched_tick__newslice", "%p", spu_context_nospu_event },
 182         { "spu_yield__enter", "%p", spu_context_nospu_event },
 183         { "spu_deactivate__enter", "%p", spu_context_nospu_event },
 184         { "__spu_deactivate__unload", "%p %p", spu_context_event },
 185         { "spufs_ps_nopfn__enter", "%p", spu_context_nospu_event },
 186         { "spufs_ps_nopfn__sleep", "%p", spu_context_nospu_event },
 187         { "spufs_ps_nopfn__wake", "%p %p", spu_context_event },
 188         { "spufs_ps_nopfn__insert", "%p %p", spu_context_event },
 189         { "spu_acquire_saved__enter", "%p", spu_context_nospu_event },
 190         { "destroy_spu_context__enter", "%p", spu_context_nospu_event },
 191         { "spufs_stop_callback__enter", "%p %p", spu_context_event },
 192 };
 193
 194 static int __init sputrace_init(void)
 195 {
 196         struct proc_dir_entry *entry;
 197         int i, error = -ENOMEM;
 198
 199         sputrace_log = kcalloc(sizeof(struct sputrace),
 200                                 bufsize, GFP_KERNEL);
 201         if (!sputrace_log)
 202                 goto out;
 203
 204         entry = create_proc_entry("sputrace", S_IRUSR, NULL);
 205         if (!entry)
 206                 goto out_free_log;
 207         entry->proc_fops = &sputrace_fops;
 208
 209         for (i = 0; i < ARRAY_SIZE(spu_probes); i++) {
 210                 struct spu_probe *p = &spu_probes[i];
 211
 212                 error = marker_probe_register(p->name, p->format,
 213                                               p->probe_func, p);
 214                 if (error)
 215                         printk(KERN_INFO "Unable to register probe %s\n",
 216                                         p->name);
 217         }
 218
 219         return 0;
 220
 221 out_free_log:
 222         kfree(sputrace_log);
 223 out:
 224         return -ENOMEM;
 225 }
 226
 227 static void __exit sputrace_exit(void)
 228 {
 229         int i;
 230
 231         for (i = 0; i < ARRAY_SIZE(spu_probes); i++)
 232                 marker_probe_unregister(spu_probes[i].name,
 233                         spu_probes[i].probe_func, &spu_probes[i]);
 234
 235         remove_proc_entry("sputrace", NULL);
 236         kfree(sputrace_log);
 237 }
 238
 239 module_init(sputrace_init);
 240 module_exit(sputrace_exit);
 241
 242 MODULE_LICENSE("GPL");