From 3c00660db18371c632adae4836ed2b2d3d78ecb6 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 14 Oct 2019 13:13:36 +0100 Subject: drm/i915/execlists: Assert tasklet is locked for process_csb() We rely on only the tasklet being allowed to call into process_csb(), so assert that is locked when we do. As the tasklet uses a simple bitlock, there is no strong lockdep checking so we must make do with a plain assertion that the tasklet is running and assume that we are the tasklet! v2: Fixup intel_gt_sanitize() to prepare each engine for the reset so that the locks are marked as held during the reset v3: Check for existent function pointers for very early sanitisation. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20191014121336.30137-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/intel_gt_pm.c | 13 ++++++++++--- drivers/gpu/drm/i915/gt/intel_lrc.c | 7 +++++++ drivers/gpu/drm/i915/i915_gem.h | 5 +++++ 3 files changed, 22 insertions(+), 3 deletions(-) (limited to 'drivers/gpu/drm/i915') diff --git a/drivers/gpu/drm/i915/gt/intel_gt_pm.c b/drivers/gpu/drm/i915/gt/intel_gt_pm.c index 87e34e0b6427..bd1bd3e00a94 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_pm.c +++ b/drivers/gpu/drm/i915/gt/intel_gt_pm.c @@ -136,11 +136,18 @@ void intel_gt_sanitize(struct intel_gt *gt, bool force) intel_uc_sanitize(>->uc); - if (!reset_engines(gt) && !force) - return; + for_each_engine(engine, gt->i915, id) + if (engine->reset.prepare) + engine->reset.prepare(engine); + + if (reset_engines(gt) || force) { + for_each_engine(engine, gt->i915, id) + __intel_engine_reset(engine, false); + } for_each_engine(engine, gt->i915, id) - __intel_engine_reset(engine, false); + if (engine->reset.finish) + engine->reset.finish(engine); } void intel_gt_pm_disable(struct intel_gt *gt) diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index ee21307ab5fe..26b6b699193b 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -1842,6 +1842,13 @@ static void process_csb(struct intel_engine_cs *engine) const u8 num_entries = execlists->csb_size; u8 head, tail; + /* + * As we modify our execlists state tracking we require exclusive + * access. Either we are inside the tasklet, or the tasklet is disabled + * and we assume that is only inside the reset paths and so serialised. + */ + GEM_BUG_ON(!tasklet_is_locked(&execlists->tasklet) && + !reset_in_progress(execlists)); GEM_BUG_ON(USES_GUC_SUBMISSION(engine->i915)); /* diff --git a/drivers/gpu/drm/i915/i915_gem.h b/drivers/gpu/drm/i915/i915_gem.h index db20d2b0842b..f6f9675848b8 100644 --- a/drivers/gpu/drm/i915/i915_gem.h +++ b/drivers/gpu/drm/i915/i915_gem.h @@ -86,6 +86,11 @@ static inline void tasklet_lock(struct tasklet_struct *t) cpu_relax(); } +static inline bool tasklet_is_locked(const struct tasklet_struct *t) +{ + return test_bit(TASKLET_STATE_RUN, &t->state); +} + static inline void __tasklet_disable_sync_once(struct tasklet_struct *t) { if (!atomic_fetch_inc(&t->count)) -- cgit v1.2.3