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}