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 struct class *dca_class;
  17 static struct idr dca_idr;
  18 static spinlock_t dca_idr_lock;
  19
  20 int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot)
  21 {
  22         struct device *cd;
  23         static int req_count;
  24
  25         cd = device_create(dca_class, dca->cd, MKDEV(0, slot + 1), NULL,
  26                            "requester%d", req_count++);
  27         return PTR_ERR_OR_ZERO(cd);
  28 }
  29
  30 void dca_sysfs_remove_req(struct dca_provider *dca, int slot)
  31 {
  32         device_destroy(dca_class, MKDEV(0, slot + 1));
  33 }
  34
  35 int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev)
  36 {
  37         struct device *cd;
  38         int ret;
  39
  40         idr_preload(GFP_KERNEL);
  41         spin_lock(&dca_idr_lock);
  42
  43         ret = idr_alloc(&dca_idr, dca, 0, 0, GFP_NOWAIT);
  44         if (ret >= 0)
  45                 dca->id = ret;
  46
  47         spin_unlock(&dca_idr_lock);
  48         idr_preload_end();
  49         if (ret < 0)
  50                 return ret;
  51
  52         cd = device_create(dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id);
  53         if (IS_ERR(cd)) {
  54                 spin_lock(&dca_idr_lock);
  55                 idr_remove(&dca_idr, dca->id);
  56                 spin_unlock(&dca_idr_lock);
  57                 return PTR_ERR(cd);
  58         }
  59         dca->cd = cd;
  60         return 0;
  61 }
  62
  63 void dca_sysfs_remove_provider(struct dca_provider *dca)
  64 {
  65         device_unregister(dca->cd);
  66         dca->cd = NULL;
  67         spin_lock(&dca_idr_lock);
  68         idr_remove(&dca_idr, dca->id);
  69         spin_unlock(&dca_idr_lock);
  70 }
  71
  72 int __init dca_sysfs_init(void)
  73 {
  74         idr_init(&dca_idr);
  75         spin_lock_init(&dca_idr_lock);
  76
  77         dca_class = class_create(THIS_MODULE, "dca");
  78         if (IS_ERR(dca_class)) {
  79                 idr_destroy(&dca_idr);
  80                 return PTR_ERR(dca_class);
  81         }
  82         return 0;
  83 }
  84
  85 void __exit dca_sysfs_exit(void)
  86 {
  87         class_destroy(dca_class);
  88         idr_destroy(&dca_idr);
  89 }
  90