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(kdev: 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, name: attr->attr.name);
59
60 return sysfs_emit(buf, fmt: "%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, kobj: gt_get_parent_obj(gt));
93
94 /* init and xfer ownership to sysfs tree */
95 if (kobject_init_and_add(kobj: &gt->sysfs_gt, ktype: &kobj_gt_type,
96 parent: gt->i915->sysfs_gt, fmt: "gt%d", gt->info.id))
97 goto exit_fail;
98
99 gt->sysfs_defaults = kobject_create_and_add(name: ".defaults", parent: &gt->sysfs_gt);
100 if (!gt->sysfs_defaults)
101 goto exit_fail;
102
103 intel_gt_sysfs_pm_init(gt, kobj: &gt->sysfs_gt);
104
105 return;
106
107exit_fail:
108 kobject_put(kobj: &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(kobj: gt->sysfs_defaults);
115 kobject_put(kobj: &gt->sysfs_gt);
116}
117

source code of linux/drivers/gpu/drm/i915/gt/intel_gt_sysfs.c