drm/i915: use mock device info for creating mock device

Instead of modifying the device info on the fly, use static const mock
device info.

It's not okay to modify device info at runtime; we've added separate
runtime info for info that needs to be modified at runtime. We've added
safeguards to device info to prevent it from being modified, but commit
5e352e32 ("drm/i915: preparation for using PAT index") just cast the
const away and modified it anyway. This prevents device info from being
moved to rodata.

Fixes: 5e352e32 ("drm/i915: preparation for using PAT index")
Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Fei Yang <fei.yang@intel.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Andrzej Hajda <andrzej.hajda@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/b0db62045a96a3fd4cf123685da88cc777f9b485.1687878757.git.jani.nikula@intel.com
(cherry picked from commit ecc7a3ce)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

drivers/gpu/drm/i915/selftests/mock_gem_device.c

@@ -118,15 +118,31 @@ static void mock_gt_probe(struct drm_i915_private *i915)
 	i915->gt[0]->name = "Mock GT";
 }
 
+static const struct intel_device_info mock_info = {
+	.__runtime.graphics.ip.ver = -1,
+	.__runtime.page_sizes = (I915_GTT_PAGE_SIZE_4K |
+				 I915_GTT_PAGE_SIZE_64K |
+				 I915_GTT_PAGE_SIZE_2M),
+	.__runtime.memory_regions = REGION_SMEM,
+	.__runtime.platform_engine_mask = BIT(0),
+
+	/* simply use legacy cache level for mock device */
+	.max_pat_index = 3,
+	.cachelevel_to_pat = {
+		[I915_CACHE_NONE]   = 0,
+		[I915_CACHE_LLC]    = 1,
+		[I915_CACHE_L3_LLC] = 2,
+		[I915_CACHE_WT]     = 3,
+	},
+};
+
 struct drm_i915_private *mock_gem_device(void)
 {
 #if IS_ENABLED(CONFIG_IOMMU_API) && defined(CONFIG_INTEL_IOMMU)
 	static struct dev_iommu fake_iommu = { .priv = (void *)-1 };
 #endif
 	struct drm_i915_private *i915;
-	struct intel_device_info *i915_info;
 	struct pci_dev *pdev;
-	unsigned int i;
 	int ret;
 
 	pdev = kzalloc(sizeof(*pdev), GFP_KERNEL);
@@ -159,15 +175,18 @@ struct drm_i915_private *mock_gem_device(void)
 
 	pci_set_drvdata(pdev, i915);
 
+	/* Device parameters start as a copy of module parameters. */
+	i915_params_copy(&i915->params, &i915_modparams);
+
+	/* Set up device info and initial runtime info. */
+	intel_device_info_driver_create(i915, pdev->device, &mock_info);
+
 	dev_pm_domain_set(&pdev->dev, &pm_domain);
 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	if (pm_runtime_enabled(&pdev->dev))
 		WARN_ON(pm_runtime_get_sync(&pdev->dev));
 
-
-	i915_params_copy(&i915->params, &i915_modparams);
-
 	intel_runtime_pm_init_early(&i915->runtime_pm);
 	/* wakeref tracking has significant overhead */
 	i915->runtime_pm.no_wakeref_tracking = true;
@@ -175,21 +194,6 @@ struct drm_i915_private *mock_gem_device(void)
 	/* Using the global GTT may ask questions about KMS users, so prepare */
 	drm_mode_config_init(&i915->drm);
 
-	RUNTIME_INFO(i915)->graphics.ip.ver = -1;
-
-	RUNTIME_INFO(i915)->page_sizes =
-		I915_GTT_PAGE_SIZE_4K |
-		I915_GTT_PAGE_SIZE_64K |
-		I915_GTT_PAGE_SIZE_2M;
-
-	RUNTIME_INFO(i915)->memory_regions = REGION_SMEM;
-
-	/* simply use legacy cache level for mock device */
-	i915_info = (struct intel_device_info *)INTEL_INFO(i915);
-	i915_info->max_pat_index = 3;
-	for (i = 0; i < I915_MAX_CACHE_LEVEL; i++)
-		i915_info->cachelevel_to_pat[i] = i;
-
 	intel_memory_regions_hw_probe(i915);
 
 	spin_lock_init(&i915->gpu_error.lock);
@@ -223,7 +227,6 @@ struct drm_i915_private *mock_gem_device(void)
 	mock_init_ggtt(to_gt(i915));
 	to_gt(i915)->vm = i915_vm_get(&to_gt(i915)->ggtt->vm);
 
-	RUNTIME_INFO(i915)->platform_engine_mask = BIT(0);
 	to_gt(i915)->info.engine_mask = BIT(0);
 
 	to_gt(i915)->engine[RCS0] = mock_engine(i915, "mock", RCS0);