drivers/dca/dca-sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/spinlock.h>
   8 #include <linux/device.h>
   9 #include <linux/idr.h>
  10 #include <linux/kdev_t.h>
  11 #include <linux/err.h>
  12 #include <linux/dca.h>
  13 #include <linux/gfp.h>
  14 #include <linux/export.h>
  15
  16 static const struct class dca_class = {
  17         .name = "dca",
  18 };
  19 static struct idr dca_idr;
  20 static spinlock_t dca_idr_lock;
  21
  22 int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
  23 {
  24         struct device *cd;
  25         static int req_count;
  26
  27         cd = device_create(&dca_class, dca->cd, MKDEV(0, slot + 1), NULL,
  28                            "requester%d", req_count++);
  29         return PTR_ERR_OR_ZERO(cd);
  30 }
  31
  32 void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
  33 {
  34         device_destroy(&dca_class, MKDEV(0, slot + 1));
  35 }
  36
  37 int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
  38 {
  39         struct device *cd;
  40         int ret;
  41
  42         idr_preload(GFP_KERNEL);
  43         spin_lock(&dca_idr_lock);
  44
  45         ret = idr_alloc(&dca_idr, dca, 0, 0, GFP_NOWAIT);
  46         if (ret >= 0)
  47                 dca->id = ret;
  48
  49         spin_unlock(&dca_idr_lock);
  50         idr_preload_end();
  51         if (ret < 0)
  52                 return ret;
  53
  54         cd = device_create(&dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);
  55         if (IS_ERR(cd)) {
  56                 spin_lock(&dca_idr_lock);
  57                 idr_remove(&dca_idr, dca->id);
  58                 spin_unlock(&dca_idr_lock);
  59                 return PTR_ERR(cd);
  60         }
  61         dca->cd = cd;
  62         return 0;
  63 }
  64
  65 void dca_sysfs_remove_provider(struct dca_provider *dca)
  66 {
  67         device_unregister(dca->cd);
  68         dca->cd = NULL;
  69         spin_lock(&dca_idr_lock);
  70         idr_remove(&dca_idr, dca->id);
  71         spin_unlock(&dca_idr_lock);
  72 }
  73
  74 int __init dca_sysfs_init(void)
  75 {
  76         int err;
  77
  78         idr_init(&dca_idr);
  79         spin_lock_init(&dca_idr_lock);
  80
  81         err = class_register(&dca_class);
  82         if (err) {
  83                 idr_destroy(&dca_idr);
  84                 return err;
  85         }
  86         return 0;
  87 }
  88
  89 void __exit dca_sysfs_exit(void)
  90 {
  91         class_unregister(&dca_class);
  92         idr_destroy(&dca_idr);
  93 }
  94