07779a76ee
Previously, we assumed we could use mutex_trylock() within an atomic context, falling back to a worker if contended. However, such trickery is illegal inside interrupt context, and so we need to always use a worker under such circumstances. As we normally are in process context, we can typically use a plain mutex, and only defer to a work when we know we are being called from an interrupt path. Fixes:51fbd8de87("drm/i915/pmu: Atomically acquire the gt_pm wakeref") References:a0855d24fc("locking/mutex: Complain upon mutex API misuse in IRQ contexts") References: https://bugs.freedesktop.org/show_bug.cgi?id=111626 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/20191120125433.3767149-1-chris@chris-wilson.co.uk
85 lines
2.1 KiB
C
85 lines
2.1 KiB
C
/*
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* SPDX-License-Identifier: GPL-2.0
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*
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* Copyright © 2018 Intel Corporation
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*/
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#include "i915_selftest.h"
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#include "selftest_engine.h"
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#include "selftests/igt_atomic.h"
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static int live_engine_pm(void *arg)
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{
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struct intel_gt *gt = arg;
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struct intel_engine_cs *engine;
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enum intel_engine_id id;
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/*
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* Check we can call intel_engine_pm_put from any context. No
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* failures are reported directly, but if we mess up lockdep should
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* tell us.
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*/
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if (intel_gt_pm_wait_for_idle(gt)) {
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pr_err("Unable to flush GT pm before test\n");
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return -EBUSY;
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}
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GEM_BUG_ON(intel_gt_pm_is_awake(gt));
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for_each_engine(engine, gt, id) {
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const typeof(*igt_atomic_phases) *p;
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for (p = igt_atomic_phases; p->name; p++) {
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/*
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* Acquisition is always synchronous, except if we
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* know that the engine is already awake, in which
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* case we should use intel_engine_pm_get_if_awake()
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* to atomically grab the wakeref.
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*
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* In practice,
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* intel_engine_pm_get();
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* intel_engine_pm_put();
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* occurs in one thread, while simultaneously
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* intel_engine_pm_get_if_awake();
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* intel_engine_pm_put();
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* occurs from atomic context in another.
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*/
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GEM_BUG_ON(intel_engine_pm_is_awake(engine));
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intel_engine_pm_get(engine);
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p->critical_section_begin();
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if (!intel_engine_pm_get_if_awake(engine))
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pr_err("intel_engine_pm_get_if_awake(%s) failed under %s\n",
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engine->name, p->name);
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else
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intel_engine_pm_put_async(engine);
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intel_engine_pm_put_async(engine);
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p->critical_section_end();
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intel_engine_pm_flush(engine);
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if (intel_engine_pm_is_awake(engine)) {
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pr_err("%s is still awake after flushing pm\n",
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engine->name);
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return -EINVAL;
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}
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/* gt wakeref is async (deferred to workqueue) */
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if (intel_gt_pm_wait_for_idle(gt)) {
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pr_err("GT failed to idle\n");
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return -EINVAL;
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}
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}
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}
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return 0;
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}
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int live_engine_pm_selftests(struct intel_gt *gt)
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{
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static const struct i915_subtest tests[] = {
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SUBTEST(live_engine_pm),
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};
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return intel_gt_live_subtests(tests, gt);
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}
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