drivers/staging/ozwpan/ozevent.c

   1 /* -----------------------------------------------------------------------------
   2  * Copyright (c) 2011 Ozmo Inc
   3  * Released under the GNU General Public License Version 2 (GPLv2).
   4  * -----------------------------------------------------------------------------
   5  */
   6 #include "ozconfig.h"
   7 #ifdef WANT_EVENT_TRACE
   8 #include <linux/jiffies.h>
   9 #include <linux/uaccess.h>
  10 #include "oztrace.h"
  11 #include "ozevent.h"
  12 /*------------------------------------------------------------------------------
  13  */
  14 unsigned long g_evt_mask = 0xffffffff;
  15 /*------------------------------------------------------------------------------
  16  */
  17 #define OZ_MAX_EVTS     2048    /* Must be power of 2 */
  18 DEFINE_SPINLOCK(g_eventlock);
  19 static int g_evt_in;
  20 static int g_evt_out;
  21 static int g_missed_events;
  22 static struct oz_event g_events[OZ_MAX_EVTS];
  23 /*------------------------------------------------------------------------------
  24  * Context: process
  25  */
  26 void oz_event_init(void)
  27 {
  28         oz_trace("Event tracing initialized\n");
  29         g_evt_in = g_evt_out = 0;
  30         g_missed_events = 0;
  31 }
  32 /*------------------------------------------------------------------------------
  33  * Context: process
  34  */
  35 void oz_event_term(void)
  36 {
  37         oz_trace("Event tracing terminated\n");
  38 }
  39 /*------------------------------------------------------------------------------
  40  * Context: any
  41  */
  42 void oz_event_log2(u8 evt, u8 ctx1, u16 ctx2, void *ctx3, unsigned ctx4)
  43 {
  44         unsigned long irqstate;
  45         int ix;
  46         spin_lock_irqsave(&g_eventlock, irqstate);
  47         ix = (g_evt_in + 1) & (OZ_MAX_EVTS - 1);
  48         if (ix != g_evt_out) {
  49                 struct oz_event *e = &g_events[g_evt_in];
  50                 e->jiffies = jiffies;
  51                 e->evt = evt;
  52                 e->ctx1 = ctx1;
  53                 e->ctx2 = ctx2;
  54                 e->ctx3 = ctx3;
  55                 e->ctx4 = ctx4;
  56                 g_evt_in = ix;
  57         } else {
  58                 g_missed_events++;
  59         }
  60         spin_unlock_irqrestore(&g_eventlock, irqstate);
  61 }
  62 /*------------------------------------------------------------------------------
  63  * Context: process
  64  */
  65 int oz_events_copy(struct oz_evtlist __user *lst)
  66 {
  67         int first;
  68         int ix;
  69         struct hdr {
  70                 int count;
  71                 int missed;
  72         } hdr;
  73         ix = g_evt_out;
  74         hdr.count = g_evt_in - ix;
  75         if (hdr.count < 0)
  76                 hdr.count += OZ_MAX_EVTS;
  77         if (hdr.count > OZ_EVT_LIST_SZ)
  78                 hdr.count = OZ_EVT_LIST_SZ;
  79         hdr.missed = g_missed_events;
  80         g_missed_events = 0;
  81         if (copy_to_user((void __user *)lst, &hdr, sizeof(hdr)))
  82                 return -EFAULT;
  83         first = OZ_MAX_EVTS - ix;
  84         if (first > hdr.count)
  85                 first = hdr.count;
  86         if (first) {
  87                 int sz = first*sizeof(struct oz_event);
  88                 void __user *p = (void __user *)lst->evts;
  89                 if (copy_to_user(p, &g_events[ix], sz))
  90                         return -EFAULT;
  91                 if (hdr.count > first) {
  92                         p = (void __user *)&lst->evts[first];
  93                         sz = (hdr.count-first)*sizeof(struct oz_event);
  94                         if (copy_to_user(p, g_events, sz))
  95                                 return -EFAULT;
  96                 }
  97         }
  98         ix += hdr.count;
  99         if (ix >= OZ_MAX_EVTS)
 100                 ix -= OZ_MAX_EVTS;
 101         g_evt_out = ix;
 102         return 0;
 103 }
 104 /*------------------------------------------------------------------------------
 105  * Context: process
 106  */
 107 void oz_events_clear(void)
 108 {
 109         unsigned long irqstate;
 110         spin_lock_irqsave(&g_eventlock, irqstate);
 111         g_evt_in = g_evt_out = 0;
 112         g_missed_events = 0;
 113         spin_unlock_irqrestore(&g_eventlock, irqstate);
 114 }
 115 #endif /* WANT_EVENT_TRACE */
 116