cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

lib_sw_fence.c (3372B)

      1/*
      2 * Copyright © 2017 Intel Corporation
      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 (including the next
     12 * paragraph) shall be included in all copies or substantial portions of the
     13 * Software.
     14 *
     15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
     20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
     21 * IN THE SOFTWARE.
     22 *
     23 */
     24
     25#include "lib_sw_fence.h"
     26
     27/* Small library of different fence types useful for writing tests */
     28
     29static int
     30nop_fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
     31{
     32	return NOTIFY_DONE;
     33}
     34
     35void __onstack_fence_init(struct i915_sw_fence *fence,
     36			  const char *name,
     37			  struct lock_class_key *key)
     38{
     39	debug_fence_init_onstack(fence);
     40
     41	__init_waitqueue_head(&fence->wait, name, key);
     42	atomic_set(&fence->pending, 1);
     43	fence->error = 0;
     44	fence->fn = nop_fence_notify;
     45}
     46
     47void onstack_fence_fini(struct i915_sw_fence *fence)
     48{
     49	if (!fence->fn)
     50		return;
     51
     52	i915_sw_fence_commit(fence);
     53	i915_sw_fence_fini(fence);
     54}
     55
     56static void timed_fence_wake(struct timer_list *t)
     57{
     58	struct timed_fence *tf = from_timer(tf, t, timer);
     59
     60	i915_sw_fence_commit(&tf->fence);
     61}
     62
     63void timed_fence_init(struct timed_fence *tf, unsigned long expires)
     64{
     65	onstack_fence_init(&tf->fence);
     66
     67	timer_setup_on_stack(&tf->timer, timed_fence_wake, 0);
     68
     69	if (time_after(expires, jiffies))
     70		mod_timer(&tf->timer, expires);
     71	else
     72		i915_sw_fence_commit(&tf->fence);
     73}
     74
     75void timed_fence_fini(struct timed_fence *tf)
     76{
     77	if (del_timer_sync(&tf->timer))
     78		i915_sw_fence_commit(&tf->fence);
     79
     80	destroy_timer_on_stack(&tf->timer);
     81	i915_sw_fence_fini(&tf->fence);
     82}
     83
     84struct heap_fence {
     85	struct i915_sw_fence fence;
     86	union {
     87		struct kref ref;
     88		struct rcu_head rcu;
     89	};
     90};
     91
     92static int
     93heap_fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
     94{
     95	struct heap_fence *h = container_of(fence, typeof(*h), fence);
     96
     97	switch (state) {
     98	case FENCE_COMPLETE:
     99		break;
    100
    101	case FENCE_FREE:
    102		heap_fence_put(&h->fence);
    103	}
    104
    105	return NOTIFY_DONE;
    106}
    107
    108struct i915_sw_fence *heap_fence_create(gfp_t gfp)
    109{
    110	struct heap_fence *h;
    111
    112	h = kmalloc(sizeof(*h), gfp);
    113	if (!h)
    114		return NULL;
    115
    116	i915_sw_fence_init(&h->fence, heap_fence_notify);
    117	refcount_set(&h->ref.refcount, 2);
    118
    119	return &h->fence;
    120}
    121
    122static void heap_fence_release(struct kref *ref)
    123{
    124	struct heap_fence *h = container_of(ref, typeof(*h), ref);
    125
    126	i915_sw_fence_fini(&h->fence);
    127
    128	kfree_rcu(h, rcu);
    129}
    130
    131void heap_fence_put(struct i915_sw_fence *fence)
    132{
    133	struct heap_fence *h = container_of(fence, typeof(*h), fence);
    134
    135	kref_put(&h->ref, heap_fence_release);
    136}