cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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notify.c (4759B)

      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
     27static inline void
     28nvkm_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
     34void
     35nvkm_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
     49static inline void
     50nvkm_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
     56void
     57nvkm_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
     69static inline void
     70nvkm_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
     83static void
     84nvkm_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
     90void
     91nvkm_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
    117void
    118nvkm_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
    131int
    132nvkm_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}