1// SPDX-License-Identifier: MIT
2/*
3 * Copyright �� 2022 Intel Corporation
4 */
5
6#include <drm/drm_device.h>
7#include <linux/device.h>
8#include <linux/kobject.h>
9#include <linux/printk.h>
10#include <linux/sysfs.h>
11
12#include "i915_drv.h"
13#include "i915_sysfs.h"
14#include "intel_gt.h"
15#include "intel_gt_print.h"
16#include "intel_gt_sysfs.h"
17#include "intel_gt_sysfs_pm.h"
18#include "intel_gt_types.h"
19#include "intel_rc6.h"
20
21bool is_object_gt(struct kobject *kobj)
22{
23	return !strncmp(kobj->name, "gt", 2);
24}
25
26struct intel_gt *intel_gt_sysfs_get_drvdata(struct kobject *kobj,
27					    const char *name)
28{
29	/*
30	 * We are interested at knowing from where the interface
31	 * has been called, whether it's called from gt/ or from
32	 * the parent directory.
33	 * From the interface position it depends also the value of
34	 * the private data.
35	 * If the interface is called from gt/ then private data is
36	 * of the "struct intel_gt *" type, otherwise it's * a
37	 * "struct drm_i915_private *" type.
38	 */
39	if (!is_object_gt(kobj)) {
40		struct device *dev = kobj_to_dev(kobj);
41		struct drm_i915_private *i915 = kdev_minor_to_i915(dev);
42
43		return to_gt(i915);
44	}
45
46	return kobj_to_gt(kobj);
47}
48
49static struct kobject *gt_get_parent_obj(struct intel_gt *gt)
50{
51	return &gt->i915->drm.primary->kdev->kobj;
52}
53
54static ssize_t id_show(struct kobject *kobj,
55		       struct kobj_attribute *attr,
56		       char *buf)
57{
58	struct intel_gt *gt = intel_gt_sysfs_get_drvdata(kobj, attr->attr.name);
59
60	return sysfs_emit(buf, "%u\n", gt->info.id);
61}
62static struct kobj_attribute attr_id = __ATTR_RO(id);
63
64static struct attribute *id_attrs[] = {
65	&attr_id.attr,
66	NULL,
67};
68ATTRIBUTE_GROUPS(id);
69
70/* A kobject needs a release() method even if it does nothing */
71static void kobj_gt_release(struct kobject *kobj)
72{
73}
74
75static const struct kobj_type kobj_gt_type = {
76	.release = kobj_gt_release,
77	.sysfs_ops = &kobj_sysfs_ops,
78	.default_groups = id_groups,
79};
80
81void intel_gt_sysfs_register(struct intel_gt *gt)
82{
83	/*
84	 * We need to make things right with the
85	 * ABI compatibility. The files were originally
86	 * generated under the parent directory.
87	 *
88	 * We generate the files only for gt 0
89	 * to avoid duplicates.
90	 */
91	if (gt_is_root(gt))
92		intel_gt_sysfs_pm_init(gt, gt_get_parent_obj(gt));
93
94	/* init and xfer ownership to sysfs tree */
95	if (kobject_init_and_add(&gt->sysfs_gt, &kobj_gt_type,
96				 gt->i915->sysfs_gt, "gt%d", gt->info.id))
97		goto exit_fail;
98
99	gt->sysfs_defaults = kobject_create_and_add(".defaults", &gt->sysfs_gt);
100	if (!gt->sysfs_defaults)
101		goto exit_fail;
102
103	intel_gt_sysfs_pm_init(gt, &gt->sysfs_gt);
104
105	return;
106
107exit_fail:
108	kobject_put(&gt->sysfs_gt);
109	gt_warn(gt, "failed to initialize sysfs root\n");
110}
111
112void intel_gt_sysfs_unregister(struct intel_gt *gt)
113{
114	kobject_put(gt->sysfs_defaults);
115	kobject_put(&gt->sysfs_gt);
116}
117