From 921f3a60e54e751ce1393deef6218c5900558b3d Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 13 Dec 2018 09:15:20 +0000 Subject: [PATCH] drm/i915/selftests: Verify we can perform resets from atomic context We currently require that our per-engine reset can be called from any context, even hardirq, and in the future wish to perform the device reset without holding struct_mutex (which requires some lockless shenanigans that demand the lowlevel intel_reset_gpu() be able to be used in atomic context). Test that we meet the current requirements by calling i915_reset_engine() from under various atomic contexts. Signed-off-by: Chris Wilson Cc: Mika Kuoppala Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20181213091522.2926-2-chris@chris-wilson.co.uk --- .../gpu/drm/i915/selftests/intel_hangcheck.c | 172 ++++++++++++++++++ 1 file changed, 172 insertions(+) diff --git a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c index 9e6c9c171ed5..797cf5e6d6d4 100644 --- a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c +++ b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c @@ -1472,6 +1472,177 @@ static int igt_handle_error(void *arg) return err; } +static void __preempt_begin(void) +{ + preempt_disable(); +} + +static void __preempt_end(void) +{ + preempt_enable(); +} + +static void __softirq_begin(void) +{ + local_bh_disable(); +} + +static void __softirq_end(void) +{ + local_bh_enable(); +} + +static void __hardirq_begin(void) +{ + local_irq_disable(); +} + +static void __hardirq_end(void) +{ + local_irq_enable(); +} + +struct atomic_section { + const char *name; + void (*critical_section_begin)(void); + void (*critical_section_end)(void); +}; + +static int __igt_atomic_reset_engine(struct intel_engine_cs *engine, + const struct atomic_section *p, + const char *mode) +{ + struct tasklet_struct * const t = &engine->execlists.tasklet; + int err; + + GEM_TRACE("i915_reset_engine(%s:%s) under %s\n", + engine->name, mode, p->name); + + tasklet_disable_nosync(t); + p->critical_section_begin(); + + err = i915_reset_engine(engine, NULL); + + p->critical_section_end(); + tasklet_enable(t); + + if (err) + pr_err("i915_reset_engine(%s:%s) failed under %s\n", + engine->name, mode, p->name); + + return err; +} + +static int igt_atomic_reset_engine(struct intel_engine_cs *engine, + const struct atomic_section *p) +{ + struct drm_i915_private *i915 = engine->i915; + struct i915_request *rq; + struct hang h; + int err; + + err = __igt_atomic_reset_engine(engine, p, "idle"); + if (err) + return err; + + err = hang_init(&h, i915); + if (err) + return err; + + rq = hang_create_request(&h, engine); + if (IS_ERR(rq)) { + err = PTR_ERR(rq); + goto out; + } + + i915_request_get(rq); + i915_request_add(rq); + + if (wait_until_running(&h, rq)) { + err = __igt_atomic_reset_engine(engine, p, "active"); + } else { + pr_err("%s(%s): Failed to start request %llx, at %x\n", + __func__, engine->name, + rq->fence.seqno, hws_seqno(&h, rq)); + err = -EIO; + } + + if (err == 0) { + struct igt_wedge_me w; + + igt_wedge_on_timeout(&w, i915, HZ / 20 /* 50ms timeout*/) + i915_request_wait(rq, + I915_WAIT_LOCKED, + MAX_SCHEDULE_TIMEOUT); + if (i915_terminally_wedged(&i915->gpu_error)) + err = -EIO; + } + + i915_request_put(rq); +out: + hang_fini(&h); + return err; +} + +static void force_reset(struct drm_i915_private *i915) +{ + i915_gem_set_wedged(i915); + set_bit(I915_RESET_HANDOFF, &i915->gpu_error.flags); + i915_reset(i915, 0, NULL); +} + +static int igt_atomic_reset(void *arg) +{ + static const struct atomic_section phases[] = { + { "preempt", __preempt_begin, __preempt_end }, + { "softirq", __softirq_begin, __softirq_end }, + { "hardirq", __hardirq_begin, __hardirq_end }, + { } + }; + struct drm_i915_private *i915 = arg; + int err = 0; + + /* Check that the resets are usable from atomic context */ + + if (USES_GUC_SUBMISSION(i915)) + return 0; /* guc is dead; long live the guc */ + + igt_global_reset_lock(i915); + mutex_lock(&i915->drm.struct_mutex); + intel_runtime_pm_get(i915); + + /* Flush any requests before we get started and check basics */ + force_reset(i915); + if (i915_terminally_wedged(&i915->gpu_error)) + goto unlock; + + if (intel_has_reset_engine(i915)) { + struct intel_engine_cs *engine; + enum intel_engine_id id; + + for_each_engine(engine, i915, id) { + const typeof(*phases) *p; + + for (p = phases; p->name; p++) { + err = igt_atomic_reset_engine(engine, p); + if (err) + goto out; + } + } + } + +out: + /* As we poke around the guts, do a full reset before continuing. */ + force_reset(i915); + +unlock: + intel_runtime_pm_put(i915); + mutex_unlock(&i915->drm.struct_mutex); + igt_global_reset_unlock(i915); + + return err; +} + int intel_hangcheck_live_selftests(struct drm_i915_private *i915) { static const struct i915_subtest tests[] = { @@ -1487,6 +1658,7 @@ int intel_hangcheck_live_selftests(struct drm_i915_private *i915) SUBTEST(igt_reset_evict_ppgtt), SUBTEST(igt_reset_evict_fence), SUBTEST(igt_handle_error), + SUBTEST(igt_atomic_reset), }; bool saved_hangcheck; int err; -- 2.45.2