drm/i915/gvt: Add basic debugfs infrastructure

We need debugfs entry to expose some debug information of gvt and vGPUs.
The first tool will be added is mmio-diff, which help to find the
difference values of host and vGPU mmio. It's useful for platform
enabling.

This patch just add a basic debugfs infrastructure, each vGPU has its own
sub-folder. Two simple attributes are created as a template.
.
├── num_tracked_mmio
├── vgpu1
|   └── active
└── vgpu2
    └── active

Signed-off-by: Changbin Du <changbin.du@intel.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>

1 files changed, 97 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gvt/debugfs.c b/drivers/gpu/drm/i915/gvt/debugfs.c
new file mode 100644
index 000000000000..02acd5842605
--- /dev/null
+++ b/drivers/gpu/drm/i915/gvt/debugfs.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright(c) 2011-2017 Intel Corporation. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include <linux/debugfs.h>
+#include "i915_drv.h"
+#include "gvt.h"
+
+
+/**
+ * intel_gvt_debugfs_add_vgpu - register debugfs entries for a vGPU
+ * @vgpu: a vGPU
+ *
+ * Returns:
+ * Zero on success, negative error code if failed.
+ */
+int intel_gvt_debugfs_add_vgpu(struct intel_vgpu *vgpu)
+{
+	struct dentry *ent;
+	char name[10] = "";
+
+	sprintf(name, "vgpu%d", vgpu->id);
+	vgpu->debugfs = debugfs_create_dir(name, vgpu->gvt->debugfs_root);
+	if (!vgpu->debugfs)
+		return -ENOMEM;
+
+	ent = debugfs_create_bool("active", 0444, vgpu->debugfs,
+				  &vgpu->active);
+	if (!ent)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/**
+ * intel_gvt_debugfs_remove_vgpu - remove debugfs entries of a vGPU
+ * @vgpu: a vGPU
+ */
+void intel_gvt_debugfs_remove_vgpu(struct intel_vgpu *vgpu)
+{
+	debugfs_remove_recursive(vgpu->debugfs);
+	vgpu->debugfs = NULL;
+}
+
+/**
+ * intel_gvt_debugfs_init - register gvt debugfs root entry
+ * @gvt: GVT device
+ *
+ * Returns:
+ * zero on success, negative if failed.
+ */
+int intel_gvt_debugfs_init(struct intel_gvt *gvt)
+{
+	struct drm_minor *minor = gvt->dev_priv->drm.primary;
+	struct dentry *ent;
+
+	gvt->debugfs_root = debugfs_create_dir("gvt", minor->debugfs_root);
+	if (!gvt->debugfs_root) {
+		gvt_err("Cannot create debugfs dir\n");
+		return -ENOMEM;
+	}
+
+	ent = debugfs_create_ulong("num_tracked_mmio", 0444, gvt->debugfs_root,
+				   &gvt->mmio.num_tracked_mmio);
+	if (!ent)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/**
+ * intel_gvt_debugfs_clean - remove debugfs entries
+ * @gvt: GVT device
+ */
+void intel_gvt_debugfs_clean(struct intel_gvt *gvt)
+{
+	debugfs_remove_recursive(gvt->debugfs_root);
+	gvt->debugfs_root = NULL;
+}