drm/i915/guc: Don't enable scheduling on a banned context, guc_id invalid, not registered

When unblocking a context, do not enable scheduling if the context is
banned, guc_id invalid, or not registered.

v2:
 (Daniele)
  - Add helper for unblock

Fixes: 62eaf0ae ("drm/i915/guc: Support request cancellation")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210909164744.31249-10-matthew.brost@intel.com

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

@@ -148,6 +148,7 @@ static inline void clr_context_registered(struct intel_context *ce)
 #define SCHED_STATE_BLOCKED_SHIFT			4
 #define SCHED_STATE_BLOCKED		BIT(SCHED_STATE_BLOCKED_SHIFT)
 #define SCHED_STATE_BLOCKED_MASK	(0xfff << SCHED_STATE_BLOCKED_SHIFT)
+
 static inline void init_sched_state(struct intel_context *ce)
 {
 	/* Only should be called from guc_lrc_desc_pin() */
@@ -1563,6 +1564,23 @@ static struct i915_sw_fence *guc_context_block(struct intel_context *ce)
 	return &ce->guc_blocked;
 }
 
+#define SCHED_STATE_MULTI_BLOCKED_MASK \
+	(SCHED_STATE_BLOCKED_MASK & ~SCHED_STATE_BLOCKED)
+#define SCHED_STATE_NO_UNBLOCK \
+	(SCHED_STATE_MULTI_BLOCKED_MASK | \
+	 SCHED_STATE_PENDING_DISABLE | \
+	 SCHED_STATE_BANNED)
+
+static bool context_cant_unblock(struct intel_context *ce)
+{
+	lockdep_assert_held(&ce->guc_state.lock);
+
+	return (ce->guc_state.sched_state & SCHED_STATE_NO_UNBLOCK) ||
+		context_guc_id_invalid(ce) ||
+		!lrc_desc_registered(ce_to_guc(ce), ce->guc_id) ||
+		!intel_context_is_pinned(ce);
+}
+
 static void guc_context_unblock(struct intel_context *ce)
 {
 	struct intel_guc *guc = ce_to_guc(ce);
@@ -1577,9 +1595,7 @@ static void guc_context_unblock(struct intel_context *ce)
 	spin_lock_irqsave(&ce->guc_state.lock, flags);
 
 	if (unlikely(submission_disabled(guc) ||
-		     !intel_context_is_pinned(ce) ||
-		     context_pending_disable(ce) ||
-		     context_blocked(ce) > 1)) {
+		     context_cant_unblock(ce))) {
 		enable = false;
 	} else {
 		enable = true;