NFC: Use IDR library to assing NFC devices IDs
As a consequence the NFC device IDs won't be increasing all the time,
as IDR provides the first available ID.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/net/nfc/core.c b/net/nfc/core.c
index f1c33f2..e94363d 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -40,6 +40,9 @@
int nfc_devlist_generation;
DEFINE_MUTEX(nfc_devlist_mutex);
+/* NFC device ID bitmap */
+static DEFINE_IDA(nfc_index_ida);
+
/**
* nfc_dev_up - turn on the NFC device
*
@@ -760,7 +763,6 @@
u32 supported_protocols,
int tx_headroom, int tx_tailroom)
{
- static atomic_t dev_no = ATOMIC_INIT(0);
struct nfc_dev *dev;
if (!ops->start_poll || !ops->stop_poll || !ops->activate_target ||
@@ -774,11 +776,6 @@
if (!dev)
return NULL;
- dev->dev.class = &nfc_class;
- dev->idx = atomic_inc_return(&dev_no) - 1;
- dev_set_name(&dev->dev, "nfc%d", dev->idx);
- device_initialize(&dev->dev);
-
dev->ops = ops;
dev->supported_protocols = supported_protocols;
dev->tx_headroom = tx_headroom;
@@ -814,6 +811,14 @@
pr_debug("dev_name=%s\n", dev_name(&dev->dev));
+ dev->idx = ida_simple_get(&nfc_index_ida, 0, 0, GFP_KERNEL);
+ if (dev->idx < 0)
+ return dev->idx;
+
+ dev->dev.class = &nfc_class;
+ dev_set_name(&dev->dev, "nfc%d", dev->idx);
+ device_initialize(&dev->dev);
+
mutex_lock(&nfc_devlist_mutex);
nfc_devlist_generation++;
rc = device_add(&dev->dev);
@@ -842,10 +847,12 @@
*/
void nfc_unregister_device(struct nfc_dev *dev)
{
- int rc;
+ int rc, id;
pr_debug("dev_name=%s\n", dev_name(&dev->dev));
+ id = dev->idx;
+
mutex_lock(&nfc_devlist_mutex);
nfc_devlist_generation++;
@@ -864,6 +871,8 @@
pr_debug("The userspace won't be notified that the device %s was removed\n",
dev_name(&dev->dev));
+ ida_simple_remove(&nfc_index_ida, id);
+
}
EXPORT_SYMBOL(nfc_unregister_device);