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 95