1 #include <linux/kernel.h> 2 #include <linux/spinlock.h> 3 #include <linux/device.h> 4 #include <linux/idr.h> 5 #include <linux/kdev_t.h> 6 #include <linux/err.h> 7 #include <linux/dca.h> 8 9 static struct class *dca_class; 10 static struct idr dca_idr; 11 static spinlock_t dca_idr_lock; 12 13 int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot) 14 { 15 struct device *cd; 16 static int req_count; 17 18 cd = device_create(dca_class, dca->cd, MKDEV(0, slot + 1), NULL, 19 "requester%d", req_count++); 20 if (IS_ERR(cd)) 21 return PTR_ERR(cd); 22 return 0; 23 } 24 25 void dca_sysfs_remove_req(struct dca_provider *dca, int slot) 26 { 27 device_destroy(dca_class, MKDEV(0, slot + 1)); 28 } 29 30 int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev) 31 { 32 struct device *cd; 33 int err = 0; 34 35 idr_try_again: 36 if (!idr_pre_get(&dca_idr, GFP_KERNEL)) 37 return -ENOMEM; 38 spin_lock(&dca_idr_lock); 39 err = idr_get_new(&dca_idr, dca, &dca->id); 40 spin_unlock(&dca_idr_lock); 41 switch (err) { 42 case 0: 43 break; 44 case -EAGAIN: 45 goto idr_try_again; 46 default: 47 return err; 48 } 49 50 cd = device_create(dca_class, dev, MKDEV(0, 0), NULL, "dca%d", dca->id); 51 if (IS_ERR(cd)) { 52 spin_lock(&dca_idr_lock); 53 idr_remove(&dca_idr, dca->id); 54 spin_unlock(&dca_idr_lock); 55 return PTR_ERR(cd); 56 } 57 dca->cd = cd; 58 return 0; 59 } 60 61 void dca_sysfs_remove_provider(struct dca_provider *dca) 62 { 63 device_unregister(dca->cd); 64 dca->cd = NULL; 65 spin_lock(&dca_idr_lock); 66 idr_remove(&dca_idr, dca->id); 67 spin_unlock(&dca_idr_lock); 68 } 69 70 int __init dca_sysfs_init(void) 71 { 72 idr_init(&dca_idr); 73 spin_lock_init(&dca_idr_lock); 74 75 dca_class = class_create(THIS_MODULE, "dca"); 76 if (IS_ERR(dca_class)) { 77 idr_destroy(&dca_idr); 78 return PTR_ERR(dca_class); 79 } 80 return 0; 81 } 82 83 void __exit dca_sysfs_exit(void) 84 { 85 class_destroy(dca_class); 86 idr_destroy(&dca_idr); 87 } 88 89