kernel/drivers/gpu/drm/nouveau/nvkm/core/notify.c

   1 /*
   2  * Copyright 2014 Red Hat Inc.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20  * OTHER DEALINGS IN THE SOFTWARE.
  21  *
  22  * Authors: Ben Skeggs <bskeggs@redhat.com>
  23  */
  24 #include <core/notify.h>
  25 #include <core/event.h>
  26
  27 static inline void
  28 nvkm_notify_put_locked(struct nvkm_notify *notify)
  29 {
  30         if (notify->block++ == 0)
  31                 nvkm_event_put(notify->event, notify->types, notify->index);
  32 }
  33
  34 void
  35 nvkm_notify_put(struct nvkm_notify *notify)
  36 {
  37         struct nvkm_event *event = notify->event;
  38         unsigned long flags;
  39         if (likely(event) &&
  40             test_and_clear_bit(NVKM_NOTIFY_USER, &notify->flags)) {
  41                 spin_lock_irqsave(&event->refs_lock, flags);
  42                 nvkm_notify_put_locked(notify);
  43                 spin_unlock_irqrestore(&event->refs_lock, flags);
  44                 if (test_bit(NVKM_NOTIFY_WORK, &notify->flags))
  45                         flush_work(&notify->work);
  46         }
  47 }
  48
  49 static inline void
  50 nvkm_notify_get_locked(struct nvkm_notify *notify)
  51 {
  52         if (--notify->block == 0)
  53                 nvkm_event_get(notify->event, notify->types, notify->index);
  54 }
  55
  56 void
  57 nvkm_notify_get(struct nvkm_notify *notify)
  58 {
  59         struct nvkm_event *event = notify->event;
  60         unsigned long flags;
  61         if (likely(event) &&
  62             !test_and_set_bit(NVKM_NOTIFY_USER, &notify->flags)) {
  63                 spin_lock_irqsave(&event->refs_lock, flags);
  64                 nvkm_notify_get_locked(notify);
  65                 spin_unlock_irqrestore(&event->refs_lock, flags);
  66         }
  67 }
  68
  69 static inline void
  70 nvkm_notify_func(struct nvkm_notify *notify)
  71 {
  72         struct nvkm_event *event = notify->event;
  73         int ret = notify->func(notify);
  74         unsigned long flags;
  75         if ((ret == NVKM_NOTIFY_KEEP) ||
  76             !test_and_clear_bit(NVKM_NOTIFY_USER, &notify->flags)) {
  77                 spin_lock_irqsave(&event->refs_lock, flags);
  78                 nvkm_notify_get_locked(notify);
  79                 spin_unlock_irqrestore(&event->refs_lock, flags);
  80         }
  81 }
  82
  83 static void
  84 nvkm_notify_work(struct work_struct *work)
  85 {
  86         struct nvkm_notify *notify = container_of(work, typeof(*notify), work);
  87         nvkm_notify_func(notify);
  88 }
  89
  90 void
  91 nvkm_notify_send(struct nvkm_notify *notify, void *data, u32 size)
  92 {
  93         struct nvkm_event *event = notify->event;
  94         unsigned long flags;
  95
  96         assert_spin_locked(&event->list_lock);
  97         BUG_ON(size != notify->size);
  98
  99         spin_lock_irqsave(&event->refs_lock, flags);
 100         if (notify->block) {
 101                 spin_unlock_irqrestore(&event->refs_lock, flags);
 102                 return;
 103         }
 104         nvkm_notify_put_locked(notify);
 105         spin_unlock_irqrestore(&event->refs_lock, flags);
 106
 107         if (test_bit(NVKM_NOTIFY_WORK, &notify->flags)) {
 108                 memcpy((void *)notify->data, data, size);
 109                 schedule_work(&notify->work);
 110         } else {
 111                 notify->data = data;
 112                 nvkm_notify_func(notify);
 113                 notify->data = NULL;
 114         }
 115 }
 116
 117 void
 118 nvkm_notify_fini(struct nvkm_notify *notify)
 119 {
 120         unsigned long flags;
 121         if (notify->event) {
 122                 nvkm_notify_put(notify);
 123                 spin_lock_irqsave(&notify->event->list_lock, flags);
 124                 list_del(&notify->head);
 125                 spin_unlock_irqrestore(&notify->event->list_lock, flags);
 126                 kfree((void *)notify->data);
 127                 notify->event = NULL;
 128         }
 129 }
 130
 131 int
 132 nvkm_notify_init(struct nvkm_object *object, struct nvkm_event *event,
 133                  int (*func)(struct nvkm_notify *), bool work,
 134                  void *data, u32 size, u32 reply,
 135                  struct nvkm_notify *notify)
 136 {
 137         unsigned long flags;
 138         int ret = -ENODEV;
 139         if ((notify->event = event), event->refs) {
 140                 ret = event->func->ctor(object, data, size, notify);
 141                 if (ret == 0 && (ret = -EINVAL, notify->size == reply)) {
 142                         notify->flags = 0;
 143                         notify->block = 1;
 144                         notify->func = func;
 145                         notify->data = NULL;
 146                         if (ret = 0, work) {
 147                                 INIT_WORK(&notify->work, nvkm_notify_work);
 148                                 set_bit(NVKM_NOTIFY_WORK, &notify->flags);
 149                                 notify->data = kmalloc(reply, GFP_KERNEL);
 150                                 if (!notify->data)
 151                                         ret = -ENOMEM;
 152                         }
 153                 }
 154                 if (ret == 0) {
 155                         spin_lock_irqsave(&event->list_lock, flags);
 156                         list_add_tail(&notify->head, &event->list);
 157                         spin_unlock_irqrestore(&event->list_lock, flags);
 158                 }
 159         }
 160         if (ret)
 161                 notify->event = NULL;
 162         return ret;
 163 }