From 4e90a6e222720dd0ec529f87eca990c736ba8ede Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Sun, 26 Nov 2017 22:09:01 +0000
Subject: [PATCH] drm/i915: Record default HW state in the GPU error state
Git-commit: 4e90a6e222720dd0ec529f87eca990c736ba8ede
Patch-mainline: v4.16-rc1
References: FATE#322643 bsc#1055900

It may be of interest to both compare the active HW context against the
default (aka NULL) context, to see what has been changed and if either are
corrupt.

V2: Rename the fake vma as fake.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171126220901.14735-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/i915_drv.h       |    1 +
 drivers/gpu/drm/i915/i915_gpu_error.c |   23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1009,6 +1009,7 @@ struct i915_gpu_state {
 		long user_bo_count;
 
 		struct drm_i915_error_object *wa_ctx;
+		struct drm_i915_error_object *default_state;
 
 		struct drm_i915_error_request {
 			long jiffies;
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -791,6 +791,9 @@ int i915_error_state_to_str(struct drm_i
 
 		print_error_obj(m, dev_priv->engine[i],
 				"WA batchbuffer", ee->wa_batchbuffer);
+
+		print_error_obj(m, dev_priv->engine[i],
+				"NULL context", ee->default_state);
 	}
 
 	if (error->overlay)
@@ -1414,6 +1417,23 @@ static void request_record_user_bo(struc
 	ee->user_bo_count = count;
 }
 
+static struct drm_i915_error_object *
+capture_object(struct drm_i915_private *dev_priv,
+	       struct drm_i915_gem_object *obj)
+{
+	if (obj && i915_gem_object_has_pages(obj)) {
+		struct i915_vma fake = {
+			.node = { .start = U64_MAX, .size = obj->base.size },
+			.pages = obj->mm.pages,
+			.obj = obj,
+		};
+
+		return i915_error_object_create(dev_priv, &fake);
+	} else {
+		return NULL;
+	}
+}
+
 static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
 				  struct i915_gpu_state *error)
 {
@@ -1485,6 +1505,9 @@ static void i915_gem_record_rings(struct
 
 		ee->wa_ctx =
 			i915_error_object_create(dev_priv, engine->wa_ctx.vma);
+
+		ee->default_state =
+			capture_object(dev_priv, engine->default_state);
 	}
 }