From 72eb16df010a436644c6515892ab8e2c428afe7f Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 8 Feb 2019 15:37:07 +0000 Subject: [PATCH] drm/i915: Serialise resets with wedging Prevent concurrent set-wedge with ongoing resets (and vice versa) by taking the same wedge_mutex around both operations. Signed-off-by: Chris Wilson Reviewed-by: Mika Kuoppala Link: https://patchwork.freedesktop.org/patch/msgid/20190208153708.20023-6-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_reset.c | 70 ++++++++++++++++++------------- 1 file changed, 41 insertions(+), 29 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_reset.c b/drivers/gpu/drm/i915/i915_reset.c index c4fcb450bd80..9494b015185a 100644 --- a/drivers/gpu/drm/i915/i915_reset.c +++ b/drivers/gpu/drm/i915/i915_reset.c @@ -794,17 +794,14 @@ static void nop_submit_request(struct i915_request *request) intel_engine_queue_breadcrumbs(engine); } -void i915_gem_set_wedged(struct drm_i915_private *i915) +static void __i915_gem_set_wedged(struct drm_i915_private *i915) { struct i915_gpu_error *error = &i915->gpu_error; struct intel_engine_cs *engine; enum intel_engine_id id; - mutex_lock(&error->wedge_mutex); - if (test_bit(I915_WEDGED, &error->flags)) { - mutex_unlock(&error->wedge_mutex); + if (test_bit(I915_WEDGED, &error->flags)) return; - } if (GEM_SHOW_DEBUG() && !intel_engines_are_idle(i915)) { struct drm_printer p = drm_debug_printer(__func__); @@ -853,12 +850,18 @@ void i915_gem_set_wedged(struct drm_i915_private *i915) set_bit(I915_WEDGED, &error->flags); GEM_TRACE("end\n"); - mutex_unlock(&error->wedge_mutex); - - wake_up_all(&error->reset_queue); } -bool i915_gem_unset_wedged(struct drm_i915_private *i915) +void i915_gem_set_wedged(struct drm_i915_private *i915) +{ + struct i915_gpu_error *error = &i915->gpu_error; + + mutex_lock(&error->wedge_mutex); + __i915_gem_set_wedged(i915); + mutex_unlock(&error->wedge_mutex); +} + +static bool __i915_gem_unset_wedged(struct drm_i915_private *i915) { struct i915_gpu_error *error = &i915->gpu_error; struct i915_timeline *tl; @@ -869,8 +872,6 @@ bool i915_gem_unset_wedged(struct drm_i915_private *i915) if (!i915->gt.scratch) /* Never full initialised, recovery impossible */ return false; - mutex_lock(&error->wedge_mutex); - GEM_TRACE("start\n"); /* @@ -921,11 +922,21 @@ bool i915_gem_unset_wedged(struct drm_i915_private *i915) smp_mb__before_atomic(); /* complete takeover before enabling execbuf */ clear_bit(I915_WEDGED, &i915->gpu_error.flags); - mutex_unlock(&i915->gpu_error.wedge_mutex); - return true; } +bool i915_gem_unset_wedged(struct drm_i915_private *i915) +{ + struct i915_gpu_error *error = &i915->gpu_error; + bool result; + + mutex_lock(&error->wedge_mutex); + result = __i915_gem_unset_wedged(i915); + mutex_unlock(&error->wedge_mutex); + + return result; +} + static int do_reset(struct drm_i915_private *i915, unsigned int stalled_mask) { int err, i; @@ -975,7 +986,7 @@ void i915_reset(struct drm_i915_private *i915, GEM_BUG_ON(!test_bit(I915_RESET_BACKOFF, &error->flags)); /* Clear any previous failed attempts at recovery. Time to try again. */ - if (!i915_gem_unset_wedged(i915)) + if (!__i915_gem_unset_wedged(i915)) return; if (reason) @@ -1037,7 +1048,7 @@ taint: */ add_taint(TAINT_WARN, LOCKDEP_STILL_OK); error: - i915_gem_set_wedged(i915); + __i915_gem_set_wedged(i915); goto finish; } @@ -1129,7 +1140,9 @@ static void i915_reset_device(struct drm_i915_private *i915, i915_wedge_on_timeout(&w, i915, 5 * HZ) { intel_prepare_reset(i915); + mutex_lock(&error->wedge_mutex); i915_reset(i915, engine_mask, reason); + mutex_unlock(&error->wedge_mutex); intel_finish_reset(i915); } @@ -1197,6 +1210,7 @@ void i915_handle_error(struct drm_i915_private *i915, unsigned long flags, const char *fmt, ...) { + struct i915_gpu_error *error = &i915->gpu_error; struct intel_engine_cs *engine; intel_wakeref_t wakeref; unsigned int tmp; @@ -1233,20 +1247,19 @@ void i915_handle_error(struct drm_i915_private *i915, * Try engine reset when available. We fall back to full reset if * single reset fails. */ - if (intel_has_reset_engine(i915) && - !i915_terminally_wedged(&i915->gpu_error)) { + if (intel_has_reset_engine(i915) && !i915_terminally_wedged(error)) { for_each_engine_masked(engine, i915, engine_mask, tmp) { BUILD_BUG_ON(I915_RESET_MODESET >= I915_RESET_ENGINE); if (test_and_set_bit(I915_RESET_ENGINE + engine->id, - &i915->gpu_error.flags)) + &error->flags)) continue; if (i915_reset_engine(engine, msg) == 0) engine_mask &= ~intel_engine_flag(engine); clear_bit(I915_RESET_ENGINE + engine->id, - &i915->gpu_error.flags); - wake_up_bit(&i915->gpu_error.flags, + &error->flags); + wake_up_bit(&error->flags, I915_RESET_ENGINE + engine->id); } } @@ -1255,10 +1268,9 @@ void i915_handle_error(struct drm_i915_private *i915, goto out; /* Full reset needs the mutex, stop any other user trying to do so. */ - if (test_and_set_bit(I915_RESET_BACKOFF, &i915->gpu_error.flags)) { - wait_event(i915->gpu_error.reset_queue, - !test_bit(I915_RESET_BACKOFF, - &i915->gpu_error.flags)); + if (test_and_set_bit(I915_RESET_BACKOFF, &error->flags)) { + wait_event(error->reset_queue, + !test_bit(I915_RESET_BACKOFF, &error->flags)); goto out; /* piggy-back on the other reset */ } @@ -1268,8 +1280,8 @@ void i915_handle_error(struct drm_i915_private *i915, /* Prevent any other reset-engine attempt. */ for_each_engine(engine, i915, tmp) { while (test_and_set_bit(I915_RESET_ENGINE + engine->id, - &i915->gpu_error.flags)) - wait_on_bit(&i915->gpu_error.flags, + &error->flags)) + wait_on_bit(&error->flags, I915_RESET_ENGINE + engine->id, TASK_UNINTERRUPTIBLE); } @@ -1278,11 +1290,11 @@ void i915_handle_error(struct drm_i915_private *i915, for_each_engine(engine, i915, tmp) { clear_bit(I915_RESET_ENGINE + engine->id, - &i915->gpu_error.flags); + &error->flags); } - clear_bit(I915_RESET_BACKOFF, &i915->gpu_error.flags); - wake_up_all(&i915->gpu_error.reset_queue); + clear_bit(I915_RESET_BACKOFF, &error->flags); + wake_up_all(&error->reset_queue); out: intel_runtime_pm_put(i915, wakeref);