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Diffstat (limited to 'drivers/gpu/drm/i915/gt/intel_engine_pm.c')
-rw-r--r--drivers/gpu/drm/i915/gt/intel_engine_pm.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
new file mode 100644
index 000000000000..ccf034764741
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
@@ -0,0 +1,164 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2019 Intel Corporation
+ */
+
+#include "i915_drv.h"
+
+#include "intel_engine.h"
+#include "intel_engine_pm.h"
+#include "intel_gt_pm.h"
+
+static int __engine_unpark(struct intel_wakeref *wf)
+{
+ struct intel_engine_cs *engine =
+ container_of(wf, typeof(*engine), wakeref);
+ void *map;
+
+ GEM_TRACE("%s\n", engine->name);
+
+ intel_gt_pm_get(engine->i915);
+
+ /* Pin the default state for fast resets from atomic context. */
+ map = NULL;
+ if (engine->default_state)
+ map = i915_gem_object_pin_map(engine->default_state,
+ I915_MAP_WB);
+ if (!IS_ERR_OR_NULL(map))
+ engine->pinned_default_state = map;
+
+ if (engine->unpark)
+ engine->unpark(engine);
+
+ intel_engine_init_hangcheck(engine);
+ return 0;
+}
+
+void intel_engine_pm_get(struct intel_engine_cs *engine)
+{
+ intel_wakeref_get(engine->i915, &engine->wakeref, __engine_unpark);
+}
+
+void intel_engine_park(struct intel_engine_cs *engine)
+{
+ /*
+ * We are committed now to parking this engine, make sure there
+ * will be no more interrupts arriving later and the engine
+ * is truly idle.
+ */
+ if (wait_for(intel_engine_is_idle(engine), 10)) {
+ struct drm_printer p = drm_debug_printer(__func__);
+
+ dev_err(engine->i915->drm.dev,
+ "%s is not idle before parking\n",
+ engine->name);
+ intel_engine_dump(engine, &p, NULL);
+ }
+}
+
+static bool switch_to_kernel_context(struct intel_engine_cs *engine)
+{
+ struct i915_request *rq;
+
+ /* Already inside the kernel context, safe to power down. */
+ if (engine->wakeref_serial == engine->serial)
+ return true;
+
+ /* GPU is pointing to the void, as good as in the kernel context. */
+ if (i915_reset_failed(engine->i915))
+ return true;
+
+ /*
+ * Note, we do this without taking the timeline->mutex. We cannot
+ * as we may be called while retiring the kernel context and so
+ * already underneath the timeline->mutex. Instead we rely on the
+ * exclusive property of the __engine_park that prevents anyone
+ * else from creating a request on this engine. This also requires
+ * that the ring is empty and we avoid any waits while constructing
+ * the context, as they assume protection by the timeline->mutex.
+ * This should hold true as we can only park the engine after
+ * retiring the last request, thus all rings should be empty and
+ * all timelines idle.
+ */
+ rq = __i915_request_create(engine->kernel_context, GFP_NOWAIT);
+ if (IS_ERR(rq))
+ /* Context switch failed, hope for the best! Maybe reset? */
+ return true;
+
+ /* Check again on the next retirement. */
+ engine->wakeref_serial = engine->serial + 1;
+ __i915_request_commit(rq);
+
+ return false;
+}
+
+static int __engine_park(struct intel_wakeref *wf)
+{
+ struct intel_engine_cs *engine =
+ container_of(wf, typeof(*engine), wakeref);
+
+ /*
+ * If one and only one request is completed between pm events,
+ * we know that we are inside the kernel context and it is
+ * safe to power down. (We are paranoid in case that runtime
+ * suspend causes corruption to the active context image, and
+ * want to avoid that impacting userspace.)
+ */
+ if (!switch_to_kernel_context(engine))
+ return -EBUSY;
+
+ GEM_TRACE("%s\n", engine->name);
+
+ intel_engine_disarm_breadcrumbs(engine);
+
+ /* Must be reset upon idling, or we may miss the busy wakeup. */
+ GEM_BUG_ON(engine->execlists.queue_priority_hint != INT_MIN);
+
+ if (engine->park)
+ engine->park(engine);
+
+ if (engine->pinned_default_state) {
+ i915_gem_object_unpin_map(engine->default_state);
+ engine->pinned_default_state = NULL;
+ }
+
+ engine->execlists.no_priolist = false;
+
+ intel_gt_pm_put(engine->i915);
+ return 0;
+}
+
+void intel_engine_pm_put(struct intel_engine_cs *engine)
+{
+ intel_wakeref_put(engine->i915, &engine->wakeref, __engine_park);
+}
+
+void intel_engine_init__pm(struct intel_engine_cs *engine)
+{
+ intel_wakeref_init(&engine->wakeref);
+}
+
+int intel_engines_resume(struct drm_i915_private *i915)
+{
+ struct intel_engine_cs *engine;
+ enum intel_engine_id id;
+ int err = 0;
+
+ intel_gt_pm_get(i915);
+ for_each_engine(engine, i915, id) {
+ intel_engine_pm_get(engine);
+ engine->serial++; /* kernel context lost */
+ err = engine->resume(engine);
+ intel_engine_pm_put(engine);
+ if (err) {
+ dev_err(i915->drm.dev,
+ "Failed to restart %s (%d)\n",
+ engine->name, err);
+ break;
+ }
+ }
+ intel_gt_pm_put(i915);
+
+ return err;
+}