LXR linux/drivers/gpu/drm/i915/gt/intel_reset

   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 the struct_mutex 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_MODESET      1
  45#define I915_RESET_ENGINE       2
  46#define I915_WEDGED_ON_INIT     (BITS_PER_LONG - 3)
  47#define I915_WEDGED_ON_FINI     (BITS_PER_LONG - 2)
  48#define I915_WEDGED             (BITS_PER_LONG - 1)
  49
  50        struct mutex mutex; /* serialises wedging/unwedging */
  51
  52        /**
  53         * Waitqueue to signal when the reset has completed. Used by clients
  54         * that wait for dev_priv->mm.wedged to settle.
  55         */
  56        wait_queue_head_t queue;
  57
  58        struct srcu_struct backoff_srcu;
  59};
  60
  61#endif /* _INTEL_RESET_TYPES_H_ */
  62