diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_wakeref.c')
-rw-r--r-- | drivers/gpu/drm/i915/intel_wakeref.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_wakeref.c b/drivers/gpu/drm/i915/intel_wakeref.c new file mode 100644 index 000000000000..91196d9612bb --- /dev/null +++ b/drivers/gpu/drm/i915/intel_wakeref.c @@ -0,0 +1,75 @@ +/* + * SPDX-License-Identifier: MIT + * + * Copyright © 2019 Intel Corporation + */ + +#include "intel_drv.h" +#include "intel_wakeref.h" + +static void rpm_get(struct drm_i915_private *i915, struct intel_wakeref *wf) +{ + wf->wakeref = intel_runtime_pm_get(i915); +} + +static void rpm_put(struct drm_i915_private *i915, struct intel_wakeref *wf) +{ + intel_wakeref_t wakeref = fetch_and_zero(&wf->wakeref); + + intel_runtime_pm_put(i915, wakeref); + GEM_BUG_ON(!wakeref); +} + +int __intel_wakeref_get_first(struct drm_i915_private *i915, + struct intel_wakeref *wf, + int (*fn)(struct intel_wakeref *wf)) +{ + /* + * Treat get/put as different subclasses, as we may need to run + * the put callback from under the shrinker and do not want to + * cross-contanimate that callback with any extra work performed + * upon acquiring the wakeref. + */ + mutex_lock_nested(&wf->mutex, SINGLE_DEPTH_NESTING); + if (!atomic_read(&wf->count)) { + int err; + + rpm_get(i915, wf); + + err = fn(wf); + if (unlikely(err)) { + rpm_put(i915, wf); + mutex_unlock(&wf->mutex); + return err; + } + + smp_mb__before_atomic(); /* release wf->count */ + } + atomic_inc(&wf->count); + mutex_unlock(&wf->mutex); + + return 0; +} + +int __intel_wakeref_put_last(struct drm_i915_private *i915, + struct intel_wakeref *wf, + int (*fn)(struct intel_wakeref *wf)) +{ + int err; + + err = fn(wf); + if (likely(!err)) + rpm_put(i915, wf); + else + atomic_inc(&wf->count); + mutex_unlock(&wf->mutex); + + return err; +} + +void __intel_wakeref_init(struct intel_wakeref *wf, struct lock_class_key *key) +{ + __mutex_init(&wf->mutex, "wakeref", key); + atomic_set(&wf->count, 0); + wf->wakeref = 0; +} |