drm/i915/gen8: Add dynamic page trace events

The dynamic page allocation patch series added it for GEN6, this patch
adds them for GEN8.

v2: Consolidate pagetable/page_directory events
v3: Multiple rebases.
v4: Rebase after s/page_tables/page_table/.
v5: Rebase after Mika's ppgtt cleanup / scratch merge patch series.
v6: Rebase after gen8_map_pagetable_range removal.
v7: Use generic page name (px) in DECLARE_EVENT_CLASS (Akash)
v8: Defer define of i915_page_directory_pointer_entry_alloc (Akash)

Cc: Akash Goel <akash.goel@intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Michel Thierry <michel.thierry@intel.com> (v3+)
Reviewed-by: Akash Goel <akash.goel@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index fc58f54..72f4777f 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -847,6 +847,7 @@
 		gen8_initialize_pt(vm, pt);
 		pd->page_table[pde] = pt;
 		__set_bit(pde, new_pts);
+		trace_i915_page_table_entry_alloc(vm, pde, start, GEN8_PDE_SHIFT);
 	}
 
 	return 0;
@@ -907,6 +908,7 @@
 		gen8_initialize_pd(vm, pd);
 		pdp->page_directory[pdpe] = pd;
 		__set_bit(pdpe, new_pds);
+		trace_i915_page_directory_entry_alloc(vm, pdpe, start, GEN8_PDPE_SHIFT);
 	}
 
 	return 0;
@@ -1056,6 +1058,10 @@
 			/* Map the PDE to the page table */
 			page_directory[pde] = gen8_pde_encode(px_dma(pt),
 							      I915_CACHE_LLC);
+			trace_i915_page_table_entry_map(&ppgtt->base, pde, pt,
+							gen8_pte_index(start),
+							gen8_pte_count(start, length),
+							GEN8_PTES);
 
 			/* NB: We haven't yet mapped ptes to pages. At this
 			 * point we're still relying on insert_entries() */