7 files changed, 151 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 61b078bd1b32..f68d62d2bbea 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -105,6 +105,7 @@ gt-y += \
 	gt/intel_gt_pm_debugfs.o \
 	gt/intel_gt_pm_irq.o \
 	gt/intel_gt_requests.o \
+	gt/intel_gt_sysfs.o \
 	gt/intel_gtt.o \
 	gt/intel_llc.o \
 	gt/intel_lrc.o \
diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index cfac4a913642..5001a6168d56 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -26,6 +26,7 @@
 #include "intel_rc6.h"
 #include "intel_renderstate.h"
 #include "intel_rps.h"
+#include "intel_gt_sysfs.h"
 #include "intel_uncore.h"
 #include "shmem_utils.h"
 
@@ -458,6 +459,7 @@ void intel_gt_driver_register(struct intel_gt *gt)
 	intel_rps_driver_register(&gt->rps);
 
 	intel_gt_debugfs_register(gt);
+	intel_gt_sysfs_register(gt);
 }
 
 static int intel_gt_init_scratch(struct intel_gt *gt, unsigned int size)
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_sysfs.c b/drivers/gpu/drm/i915/gt/intel_gt_sysfs.c
new file mode 100644
index 000000000000..d50831961294
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_gt_sysfs.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include <drm/drm_device.h>
+#include <linux/device.h>
+#include <linux/kobject.h>
+#include <linux/printk.h>
+#include <linux/sysfs.h>
+
+#include "i915_drv.h"
+#include "i915_sysfs.h"
+#include "intel_gt.h"
+#include "intel_gt_sysfs.h"
+#include "intel_gt_types.h"
+#include "intel_rc6.h"
+
+bool is_object_gt(struct kobject *kobj)
+{
+	return !strncmp(kobj->name, "gt", 2);
+}
+
+static struct intel_gt *kobj_to_gt(struct kobject *kobj)
+{
+	return container_of(kobj, struct kobj_gt, base)->gt;
+}
+
+struct intel_gt *intel_gt_sysfs_get_drvdata(struct device *dev,
+					    const char *name)
+{
+	struct kobject *kobj = &dev->kobj;
+
+	/*
+	 * We are interested at knowing from where the interface
+	 * has been called, whether it's called from gt/ or from
+	 * the parent directory.
+	 * From the interface position it depends also the value of
+	 * the private data.
+	 * If the interface is called from gt/ then private data is
+	 * of the "struct intel_gt *" type, otherwise it's * a
+	 * "struct drm_i915_private *" type.
+	 */
+	if (!is_object_gt(kobj)) {
+		struct drm_i915_private *i915 = kdev_minor_to_i915(dev);
+
+		return to_gt(i915);
+	}
+
+	return kobj_to_gt(kobj);
+}
+
+static ssize_t id_show(struct device *dev,
+		       struct device_attribute *attr,
+		       char *buf)
+{
+	struct intel_gt *gt = intel_gt_sysfs_get_drvdata(dev, attr->attr.name);
+
+	return sysfs_emit(buf, "%u\n", gt->info.id);
+}
+static DEVICE_ATTR_RO(id);
+
+static struct attribute *id_attrs[] = {
+	&dev_attr_id.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(id);
+
+static void kobj_gt_release(struct kobject *kobj)
+{
+	kfree(kobj);
+}
+
+static struct kobj_type kobj_gt_type = {
+	.release = kobj_gt_release,
+	.sysfs_ops = &kobj_sysfs_ops,
+	.default_groups = id_groups,
+};
+
+void intel_gt_sysfs_register(struct intel_gt *gt)
+{
+	struct kobj_gt *kg;
+
+	kg = kzalloc(sizeof(*kg), GFP_KERNEL);
+	if (!kg)
+		goto exit_fail;
+
+	kobject_init(&kg->base, &kobj_gt_type);
+	kg->gt = gt;
+
+	/* xfer ownership to sysfs tree */
+	if (kobject_add(&kg->base, gt->i915->sysfs_gt, "gt%d", gt->info.id))
+		goto exit_kobj_put;
+
+	return;
+
+exit_kobj_put:
+	kobject_put(&kg->base);
+
+exit_fail:
+	drm_warn(&gt->i915->drm,
+		 "failed to initialize gt%d sysfs root\n", gt->info.id);
+}
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_sysfs.h b/drivers/gpu/drm/i915/gt/intel_gt_sysfs.h
new file mode 100644
index 000000000000..9471b26752cf
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_gt_sysfs.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#ifndef __SYSFS_GT_H__
+#define __SYSFS_GT_H__
+
+#include <linux/ctype.h>
+#include <linux/kobject.h>
+
+#include "i915_gem.h" /* GEM_BUG_ON() */
+
+struct intel_gt;
+
+struct kobj_gt {
+	struct kobject base;
+	struct intel_gt *gt;
+};
+
+bool is_object_gt(struct kobject *kobj);
+
+struct drm_i915_private *kobj_to_i915(struct kobject *kobj);
+
+struct kobject *
+intel_gt_create_kobj(struct intel_gt *gt,
+		     struct kobject *dir,
+		     const char *name);
+
+void intel_gt_sysfs_register(struct intel_gt *gt);
+struct intel_gt *intel_gt_sysfs_get_drvdata(struct device *dev,
+					    const char *name);
+
+#endif /* SYSFS_GT_H */
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 64977f0833b0..8c99a3c58a5a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -814,6 +814,8 @@ struct drm_i915_private {
 #define I915_MAX_GT 4
 	struct intel_gt *gt[I915_MAX_GT];
 
+	struct kobject *sysfs_gt;
+
 	struct {
 		struct i915_gem_contexts {
 			spinlock_t lock; /* locks list */
diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index a4d1759375b9..5ff915b93c21 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -39,7 +39,7 @@
 #include "i915_sysfs.h"
 #include "intel_pm.h"
 
-static inline struct drm_i915_private *kdev_minor_to_i915(struct device *kdev)
+struct drm_i915_private *kdev_minor_to_i915(struct device *kdev)
 {
 	struct drm_minor *minor = dev_get_drvdata(kdev);
 	return to_i915(minor->dev);
@@ -538,6 +538,11 @@ void i915_setup_sysfs(struct drm_i915_private *dev_priv)
 	if (ret)
 		drm_err(&dev_priv->drm, "RPS sysfs setup failed\n");
 
+	dev_priv->sysfs_gt = kobject_create_and_add("gt", &kdev->kobj);
+	if (!dev_priv->sysfs_gt)
+		drm_warn(&dev_priv->drm,
+			 "failed to register GT sysfs directory\n");
+
 	i915_setup_error_capture(kdev);
 
 	intel_engines_add_sysfs(dev_priv);
diff --git a/drivers/gpu/drm/i915/i915_sysfs.h b/drivers/gpu/drm/i915/i915_sysfs.h
index 41afd4366416..243a17741e3f 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.h
+++ b/drivers/gpu/drm/i915/i915_sysfs.h
@@ -6,8 +6,11 @@
 #ifndef __I915_SYSFS_H__
 #define __I915_SYSFS_H__
 
+struct device;
 struct drm_i915_private;
 
+struct drm_i915_private *kdev_minor_to_i915(struct device *kdev);
+
 void i915_setup_sysfs(struct drm_i915_private *i915);
 void i915_teardown_sysfs(struct drm_i915_private *i915);