drivers/gpu/drm/i915/gt/intel_gt_sysfs.c

   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 static struct intel_gt *kobj_to_gt(struct kobject *kobj)
  26 {
  27         return container_of(kobj, struct kobj_gt, base)->gt;
  28 }
  29
  30 struct intel_gt *intel_gt_sysfs_get_drvdata(struct device *dev,
  31                                             const char *name)
  32 {
  33         struct kobject *kobj = &dev->kobj;
  34
  35         /*
  36          * We are interested at knowing from where the interface
  37          * has been called, whether it's called from gt/ or from
  38          * the parent directory.
  39          * From the interface position it depends also the value of
  40          * the private data.
  41          * If the interface is called from gt/ then private data is
  42          * of the "struct intel_gt *" type, otherwise it's * a
  43          * "struct drm_i915_private *" type.
  44          */
  45         if (!is_object_gt(kobj)) {
  46                 struct drm_i915_private *i915 = kdev_minor_to_i915(dev);
  47
  48                 return to_gt(i915);
  49         }
  50
  51         return kobj_to_gt(kobj);
  52 }
  53
  54 static struct kobject *gt_get_parent_obj(struct intel_gt *gt)
  55 {
  56         return &gt->i915->drm.primary->kdev->kobj;
  57 }
  58
  59 static ssize_t id_show(struct device *dev,
  60                        struct device_attribute *attr,
  61                        char *buf)
  62 {
  63         struct intel_gt *gt = intel_gt_sysfs_get_drvdata(dev, attr->attr.name);
  64
  65         return sysfs_emit(buf, "%u\n", gt->info.id);
  66 }
  67 static DEVICE_ATTR_RO(id);
  68
  69 static struct attribute *id_attrs[] = {
  70         &dev_attr_id.attr,
  71         NULL,
  72 };
  73 ATTRIBUTE_GROUPS(id);
  74
  75 static void kobj_gt_release(struct kobject *kobj)
  76 {
  77         kfree(kobj);
  78 }
  79
  80 static struct kobj_type kobj_gt_type = {
  81         .release = kobj_gt_release,
  82         .sysfs_ops = &kobj_sysfs_ops,
  83         .default_groups = id_groups,
  84 };
  85
  86 void intel_gt_sysfs_register(struct intel_gt *gt)
  87 {
  88         struct kobj_gt *kg;
  89
  90         /*
  91          * We need to make things right with the
  92          * ABI compatibility. The files were originally
  93          * generated under the parent directory.
  94          *
  95          * We generate the files only for gt 0
  96          * to avoid duplicates.
  97          */
  98         if (gt_is_root(gt))
  99                 intel_gt_sysfs_pm_init(gt, gt_get_parent_obj(gt));
 100
 101         kg = kzalloc(sizeof(*kg), GFP_KERNEL);
 102         if (!kg)
 103                 goto exit_fail;
 104
 105         kobject_init(&kg->base, &kobj_gt_type);
 106         kg->gt = gt;
 107
 108         /* xfer ownership to sysfs tree */
 109         if (kobject_add(&kg->base, gt->i915->sysfs_gt, "gt%d", gt->info.id))
 110                 goto exit_kobj_put;
 111
 112         intel_gt_sysfs_pm_init(gt, &kg->base);
 113
 114         return;
 115
 116 exit_kobj_put:
 117         kobject_put(&kg->base);
 118
 119 exit_fail:
 120         drm_warn(&gt->i915->drm,
 121                  "failed to initialize gt%d sysfs root\n", gt->info.id);
 122 }