xref: /linux/drivers/gpu/drm/i915/gt/intel_gt_sysfs.c (revision cf26e043c2a9213805d7ea9e8cf3e1d7166a62a4) 
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_sysfs.h"
16 #include "intel_gt_sysfs_pm.h"
17 #include "intel_gt_types.h"
18 #include "intel_rc6.h"
19 
20 bool is_object_gt(struct kobject *kobj)
21 {
22 	return !strncmp(kobj->name, "gt", 2);
23 }
24 
25 struct intel_gt *intel_gt_sysfs_get_drvdata(struct kobject *kobj,
26 					    const char *name)
27 {
28 	/*
29 	 * We are interested at knowing from where the interface
30 	 * has been called, whether it's called from gt/ or from
31 	 * the parent directory.
32 	 * From the interface position it depends also the value of
33 	 * the private data.
34 	 * If the interface is called from gt/ then private data is
35 	 * of the "struct intel_gt *" type, otherwise it's * a
36 	 * "struct drm_i915_private *" type.
37 	 */
38 	if (!is_object_gt(kobj)) {
39 		struct device *dev = kobj_to_dev(kobj);
40 		struct drm_i915_private *i915 = kdev_minor_to_i915(dev);
41 
42 		return to_gt(i915);
43 	}
44 
45 	return kobj_to_gt(kobj);
46 }
47 
48 static struct kobject *gt_get_parent_obj(struct intel_gt *gt)
49 {
50 	return &gt->i915->drm.primary->kdev->kobj;
51 }
52 
53 static ssize_t id_show(struct kobject *kobj,
54 		       struct kobj_attribute *attr,
55 		       char *buf)
56 {
57 	struct intel_gt *gt = intel_gt_sysfs_get_drvdata(kobj, attr->attr.name);
58 
59 	return sysfs_emit(buf, "%u\n", gt->info.id);
60 }
61 static struct kobj_attribute attr_id = __ATTR_RO(id);
62 
63 static struct attribute *id_attrs[] = {
64 	&attr_id.attr,
65 	NULL,
66 };
67 ATTRIBUTE_GROUPS(id);
68 
69 /* A kobject needs a release() method even if it does nothing */
70 static void kobj_gt_release(struct kobject *kobj)
71 {
72 }
73 
74 static struct kobj_type kobj_gt_type = {
75 	.release = kobj_gt_release,
76 	.sysfs_ops = &kobj_sysfs_ops,
77 	.default_groups = id_groups,
78 };
79 
80 void intel_gt_sysfs_register(struct intel_gt *gt)
81 {
82 	/*
83 	 * We need to make things right with the
84 	 * ABI compatibility. The files were originally
85 	 * generated under the parent directory.
86 	 *
87 	 * We generate the files only for gt 0
88 	 * to avoid duplicates.
89 	 */
90 	if (gt_is_root(gt))
91 		intel_gt_sysfs_pm_init(gt, gt_get_parent_obj(gt));
92 
93 	/* init and xfer ownership to sysfs tree */
94 	if (kobject_init_and_add(&gt->sysfs_gt, &kobj_gt_type,
95 				 gt->i915->sysfs_gt, "gt%d", gt->info.id))
96 		goto exit_fail;
97 
98 	gt->sysfs_defaults = kobject_create_and_add(".defaults", &gt->sysfs_gt);
99 	if (!gt->sysfs_defaults)
100 		goto exit_fail;
101 
102 	intel_gt_sysfs_pm_init(gt, &gt->sysfs_gt);
103 
104 	return;
105 
106 exit_fail:
107 	kobject_put(&gt->sysfs_gt);
108 	drm_warn(&gt->i915->drm,
109 		 "failed to initialize gt%d sysfs root\n", gt->info.id);
110 }
111 
112 void intel_gt_sysfs_unregister(struct intel_gt *gt)
113 {
114 	kobject_put(gt->sysfs_defaults);
115 	kobject_put(&gt->sysfs_gt);
116 }
117