1/* SPDX-License-Identifier: MIT */
2/*
3 * Copyright © 2019 Intel Corporation
4 */
5
6#ifndef __INTEL_RESET_TYPES_H_
7#define __INTEL_RESET_TYPES_H_
8
9#include <linux/mutex.h>
10#include <linux/wait.h>
11#include <linux/srcu.h>
12
13struct intel_reset {
14 /**
15 * flags: Control various stages of the GPU reset
16 *
17 * #I915_RESET_BACKOFF - When we start a global reset, we need to
18 * serialise with any other users attempting to do the same, and
19 * any global resources that may be clobber by the reset (such as
20 * FENCE registers).
21 *
22 * #I915_RESET_ENGINE[num_engines] - Since the driver doesn't need to
23 * acquire a global lock to reset an engine, we need an explicit
24 * flag to prevent two concurrent reset attempts in the same engine.
25 * As the number of engines continues to grow, allocate the flags from
26 * the most significant bits.
27 *
28 * #I915_WEDGED - If reset fails and we can no longer use the GPU,
29 * we set the #I915_WEDGED bit. Prior to command submission, e.g.
30 * i915_request_alloc(), this bit is checked and the sequence
31 * aborted (with -EIO reported to userspace) if set.
32 *
33 * #I915_WEDGED_ON_INIT - If we fail to initialize the GPU we can no
34 * longer use the GPU - similar to #I915_WEDGED bit. The difference in
35 * the way we're handling "forced" unwedged (e.g. through debugfs),
36 * which is not allowed in case we failed to initialize.
37 *
38 * #I915_WEDGED_ON_FINI - Similar to #I915_WEDGED_ON_INIT, except we
39 * use it to mark that the GPU is no longer available (and prevent
40 * users from using it).
41 */
42 unsigned long flags;
43#define I915_RESET_BACKOFF 0
44#define I915_RESET_ENGINE 1
45#define I915_WEDGED_ON_INIT (BITS_PER_LONG - 3)
46#define I915_WEDGED_ON_FINI (BITS_PER_LONG - 2)
47#define I915_WEDGED (BITS_PER_LONG - 1)
48
49 struct mutex mutex; /* serialises wedging/unwedging */
50
51 /**
52 * Waitqueue to signal when the reset has completed. Used by clients
53 * that wait for i915->mm.wedged to settle.
54 */
55 wait_queue_head_t queue;
56
57 struct srcu_struct backoff_srcu;
58};
59
60#endif /* _INTEL_RESET_TYPES_H_ */
61

source code of linux/drivers/gpu/drm/i915/gt/intel_reset_types.h