drm/i915/gt: Trace placement of timeline HWSP

Track the position of the HWSP for each timeline.

References: https://gitlab.freedesktop.org/drm/intel/-/issues/2169
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200714135002.17508-1-chris@chris-wilson.co.uk

Author: ickle

drivers/gpu/drm/i915/gt/intel_timeline.c

@@ -73,6 +73,8 @@ hwsp_alloc(struct intel_timeline *timeline, unsigned int *cacheline)
 			return vma;
 		}
 
+		GT_TRACE(timeline->gt, "new HWSP allocated\n");
+
 		vma->private = hwsp;
 		hwsp->gt = timeline->gt;
 		hwsp->vma = vma;
@@ -327,6 +329,8 @@ int intel_timeline_pin(struct intel_timeline *tl)
 	tl->hwsp_offset =
 		i915_ggtt_offset(tl->hwsp_ggtt) +
 		offset_in_page(tl->hwsp_offset);
+	GT_TRACE(tl->gt, "timeline:%llx using HWSP offset:%x\n",
+		 tl->fence_context, tl->hwsp_offset);
 
 	cacheline_acquire(tl->hwsp_cacheline);
 	if (atomic_fetch_inc(&tl->pin_count)) {
@@ -434,6 +438,7 @@ __intel_timeline_get_seqno(struct intel_timeline *tl,
 	int err;
 
 	might_lock(&tl->gt->ggtt->vm.mutex);
+	GT_TRACE(tl->gt, "timeline:%llx wrapped\n", tl->fence_context);
 
 	/*
 	 * If there is an outstanding GPU reference to this cacheline,
@@ -497,6 +502,8 @@ __intel_timeline_get_seqno(struct intel_timeline *tl,
 		memset(vaddr + tl->hwsp_offset, 0, CACHELINE_BYTES);
 
 	tl->hwsp_offset += i915_ggtt_offset(vma);
+	GT_TRACE(tl->gt, "timeline:%llx using HWSP offset:%x\n",
+		 tl->fence_context, tl->hwsp_offset);
 
 	cacheline_acquire(cl);
 	tl->hwsp_cacheline = cl;

drivers/gpu/drm/i915/gt/selftest_timeline.c

@@ -562,8 +562,9 @@ static int live_hwsp_engine(void *arg)
 		struct intel_timeline *tl = timelines[n];
 
 		if (!err && *tl->hwsp_seqno != n) {
-			pr_err("Invalid seqno stored in timeline %lu, found 0x%x\n",
-			       n, *tl->hwsp_seqno);
+			pr_err("Invalid seqno stored in timeline %lu @ %x, found 0x%x\n",
+			       n, tl->hwsp_offset, *tl->hwsp_seqno);
+			GEM_TRACE_DUMP();
 			err = -EINVAL;
 		}
 		intel_timeline_put(tl);
@@ -633,8 +634,9 @@ static int live_hwsp_alternate(void *arg)
 		struct intel_timeline *tl = timelines[n];
 
 		if (!err && *tl->hwsp_seqno != n) {
-			pr_err("Invalid seqno stored in timeline %lu, found 0x%x\n",
-			       n, *tl->hwsp_seqno);
+			pr_err("Invalid seqno stored in timeline %lu @ %x, found 0x%x\n",
+			       n, tl->hwsp_offset, *tl->hwsp_seqno);
+			GEM_TRACE_DUMP();
 			err = -EINVAL;
 		}
 		intel_timeline_put(tl);
@@ -965,8 +967,9 @@ static int live_hwsp_recycle(void *arg)
 			}
 
 			if (*tl->hwsp_seqno != count) {
-				pr_err("Invalid seqno stored in timeline %lu, found 0x%x\n",
+				pr_err("Invalid seqno stored in timeline %lu @ tl->hwsp_offset, found 0x%x\n",
 				       count, *tl->hwsp_seqno);
+				GEM_TRACE_DUMP();
 				err = -EINVAL;
 			}