drm/i915: Cancel all ready but queued requests when wedging

When wedging the hw, we want to mark all in-flight requests as -EIO.
This is made slightly more complex by execlists who store the ready but
not yet submitted-to-hw requests on a private queue (an rbtree
priolist). Call into execlists to cancel not only the ELSP tracking for
the submitted requests, but also the queue of unsubmitted requests.

v2: Move the majority of engine_set_wedged to the backends (both legacy
ringbuffer and execlists handling their own lists).

Reported-by: Michał Winiarski <michal.winiarski@intel.com>
Testcase: igt/gem_eio/in-flight-contexts
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170915173100.26470-1-chris@chris-wilson.co.uk
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 22e5ea8516b6..85e64a45d0bf 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -782,6 +782,24 @@ static u32 *gen6_signal(struct drm_i915_gem_request *req, u32 *cs)
         return cs;
 }
 
+static void cancel_requests(struct intel_engine_cs *engine)
+{
+        struct drm_i915_gem_request *request;
+        unsigned long flags;
+
+        spin_lock_irqsave(&engine->timeline->lock, flags);
+
+        /* Mark all submitted requests as skipped. */
+        list_for_each_entry(request, &engine->timeline->requests, link) {
+                GEM_BUG_ON(!request->global_seqno);
+                if (!i915_gem_request_completed(request))
+                        dma_fence_set_error(&request->fence, -EIO);
+        }
+        /* Remaining _unready_ requests will be nop'ed when submitted */
+
+        spin_unlock_irqrestore(&engine->timeline->lock, flags);
+}
+
 static void i9xx_submit_request(struct drm_i915_gem_request *request)
 {
         struct drm_i915_private *dev_priv = request->i915;
@@ -1996,11 +2014,13 @@ static void intel_ring_init_irq(struct drm_i915_private *dev_priv,
 static void i9xx_set_default_submission(struct intel_engine_cs *engine)
 {
         engine->submit_request = i9xx_submit_request;
+        engine->cancel_requests = cancel_requests;
 }
 
 static void gen6_bsd_set_default_submission(struct intel_engine_cs *engine)
 {
         engine->submit_request = gen6_bsd_submit_request;
+        engine->cancel_requests = cancel_requests;
 }
 
 static void intel_ring_default_vfuncs(struct drm_i915_private *dev_priv,