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d91e657876
For controlling runtime pm of the GT and engines, we would like to have a callback to do extra work the first time we wake up and the last time we drop the wakeref. This first/last access needs serialisation and so we encompass a mutex with the regular intel_wakeref_t tracker. v2: Drop the _once naming and report the errors. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc; Tvrtko Ursulin <tvrtko.ursulin@intel.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190424200717.1686-1-chris@chris-wilson.co.uk
61 lines
1.3 KiB
C
61 lines
1.3 KiB
C
/*
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* SPDX-License-Identifier: MIT
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*
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* Copyright © 2019 Intel Corporation
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*/
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#include "intel_drv.h"
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#include "intel_wakeref.h"
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int __intel_wakeref_get_first(struct drm_i915_private *i915,
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struct intel_wakeref *wf,
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int (*fn)(struct intel_wakeref *wf))
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{
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/*
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* Treat get/put as different subclasses, as we may need to run
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* the put callback from under the shrinker and do not want to
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* cross-contanimate that callback with any extra work performed
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* upon acquiring the wakeref.
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*/
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mutex_lock_nested(&wf->mutex, SINGLE_DEPTH_NESTING);
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if (!atomic_read(&wf->count)) {
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int err;
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wf->wakeref = intel_runtime_pm_get(i915);
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err = fn(wf);
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if (unlikely(err)) {
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intel_runtime_pm_put(i915, wf->wakeref);
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mutex_unlock(&wf->mutex);
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return err;
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}
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smp_mb__before_atomic(); /* release wf->count */
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}
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atomic_inc(&wf->count);
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mutex_unlock(&wf->mutex);
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return 0;
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}
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int __intel_wakeref_put_last(struct drm_i915_private *i915,
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struct intel_wakeref *wf,
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int (*fn)(struct intel_wakeref *wf))
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{
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int err;
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err = fn(wf);
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if (likely(!err))
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intel_runtime_pm_put(i915, wf->wakeref);
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else
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atomic_inc(&wf->count);
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mutex_unlock(&wf->mutex);
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return err;
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}
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void __intel_wakeref_init(struct intel_wakeref *wf, struct lock_class_key *key)
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{
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__mutex_init(&wf->mutex, "wakeref", key);
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atomic_set(&wf->count, 0);
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}
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