xref: /linux/drivers/gpu/drm/i915/gt/intel_gt_sysfs.c (revision 50282fd57bcd3525c9d81eef58df8718e4337c6d) 
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 
21 bool is_object_gt(struct kobject *kobj)
22 {
23 	return !strncmp(kobj->name, "gt", 2);
24 }
25 
26 struct 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 
49 static struct kobject *gt_get_parent_obj(struct intel_gt *gt)
50 {
51 	return &gt->i915->drm.primary->kdev->kobj;
52 }
53 
54 static 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 }
62 static struct kobj_attribute attr_id = __ATTR_RO(id);
63 
64 static struct attribute *id_attrs[] = {
65 	&attr_id.attr,
66 	NULL,
67 };
68 ATTRIBUTE_GROUPS(id);
69 
70 /* A kobject needs a release() method even if it does nothing */
71 static void kobj_gt_release(struct kobject *kobj)
72 {
73 }
74 
75 static 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 
81 void 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 
107 exit_fail:
108 	kobject_put(&gt->sysfs_gt);
109 	gt_warn(gt, "failed to initialize sysfs root\n");
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