summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/xe/xe_preempt_fence.c
blob: 7d50c6e89d8e7dc0ba718b9439ef86858e1f3992 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
// SPDX-License-Identifier: MIT
/*
 * Copyright © 2022 Intel Corporation
 */

#include "xe_preempt_fence.h"

#include <linux/slab.h>

#include "xe_exec_queue.h"
#include "xe_vm.h"

static void preempt_fence_work_func(struct work_struct *w)
{
	bool cookie = dma_fence_begin_signalling();
	struct xe_preempt_fence *pfence =
		container_of(w, typeof(*pfence), preempt_work);
	struct xe_exec_queue *q = pfence->q;

	if (pfence->error)
		dma_fence_set_error(&pfence->base, pfence->error);
	else
		q->ops->suspend_wait(q);

	dma_fence_signal(&pfence->base);
	dma_fence_end_signalling(cookie);

	xe_vm_queue_rebind_worker(q->vm);

	xe_exec_queue_put(q);
}

static const char *
preempt_fence_get_driver_name(struct dma_fence *fence)
{
	return "xe";
}

static const char *
preempt_fence_get_timeline_name(struct dma_fence *fence)
{
	return "preempt";
}

static bool preempt_fence_enable_signaling(struct dma_fence *fence)
{
	struct xe_preempt_fence *pfence =
		container_of(fence, typeof(*pfence), base);
	struct xe_exec_queue *q = pfence->q;

	pfence->error = q->ops->suspend(q);
	queue_work(q->vm->xe->preempt_fence_wq, &pfence->preempt_work);
	return true;
}

static const struct dma_fence_ops preempt_fence_ops = {
	.get_driver_name = preempt_fence_get_driver_name,
	.get_timeline_name = preempt_fence_get_timeline_name,
	.enable_signaling = preempt_fence_enable_signaling,
};

/**
 * xe_preempt_fence_alloc() - Allocate a preempt fence with minimal
 * initialization
 *
 * Allocate a preempt fence, and initialize its list head.
 * If the preempt_fence allocated has been armed with
 * xe_preempt_fence_arm(), it must be freed using dma_fence_put(). If not,
 * it must be freed using xe_preempt_fence_free().
 *
 * Return: A struct xe_preempt_fence pointer used for calling into
 * xe_preempt_fence_arm() or xe_preempt_fence_free().
 * An error pointer on error.
 */
struct xe_preempt_fence *xe_preempt_fence_alloc(void)
{
	struct xe_preempt_fence *pfence;

	pfence = kmalloc(sizeof(*pfence), GFP_KERNEL);
	if (!pfence)
		return ERR_PTR(-ENOMEM);

	INIT_LIST_HEAD(&pfence->link);
	INIT_WORK(&pfence->preempt_work, preempt_fence_work_func);

	return pfence;
}

/**
 * xe_preempt_fence_free() - Free a preempt fence allocated using
 * xe_preempt_fence_alloc().
 * @pfence: pointer obtained from xe_preempt_fence_alloc();
 *
 * Free a preempt fence that has not yet been armed.
 */
void xe_preempt_fence_free(struct xe_preempt_fence *pfence)
{
	list_del(&pfence->link);
	kfree(pfence);
}

/**
 * xe_preempt_fence_arm() - Arm a preempt fence allocated using
 * xe_preempt_fence_alloc().
 * @pfence: The struct xe_preempt_fence pointer returned from
 *          xe_preempt_fence_alloc().
 * @q: The struct xe_exec_queue used for arming.
 * @context: The dma-fence context used for arming.
 * @seqno: The dma-fence seqno used for arming.
 *
 * Inserts the preempt fence into @context's timeline, takes @link off any
 * list, and registers the struct xe_exec_queue as the xe_engine to be preempted.
 *
 * Return: A pointer to a struct dma_fence embedded into the preempt fence.
 * This function doesn't error.
 */
struct dma_fence *
xe_preempt_fence_arm(struct xe_preempt_fence *pfence, struct xe_exec_queue *q,
		     u64 context, u32 seqno)
{
	list_del_init(&pfence->link);
	pfence->q = xe_exec_queue_get(q);
	dma_fence_init(&pfence->base, &preempt_fence_ops,
		      &q->compute.lock, context, seqno);

	return &pfence->base;
}

/**
 * xe_preempt_fence_create() - Helper to create and arm a preempt fence.
 * @q: The struct xe_exec_queue used for arming.
 * @context: The dma-fence context used for arming.
 * @seqno: The dma-fence seqno used for arming.
 *
 * Allocates and inserts the preempt fence into @context's timeline,
 * and registers @e as the struct xe_exec_queue to be preempted.
 *
 * Return: A pointer to the resulting struct dma_fence on success. An error
 * pointer on error. In particular if allocation fails it returns
 * ERR_PTR(-ENOMEM);
 */
struct dma_fence *
xe_preempt_fence_create(struct xe_exec_queue *q,
			u64 context, u32 seqno)
{
	struct xe_preempt_fence *pfence;

	pfence = xe_preempt_fence_alloc();
	if (IS_ERR(pfence))
		return ERR_CAST(pfence);

	return xe_preempt_fence_arm(pfence, q, context, seqno);
}

bool xe_fence_is_xe_preempt(const struct dma_fence *fence)
{
	return fence->ops == &preempt_fence_ops;
}