ata: libata-core: Reuse available ata_port print_ids

Currently, the ata_port print_ids are increased indefinitely, even when
there are lower ids available.

E.g. on first boot you will have ata1-ata6 assigned.
After a rmmod + modprobe, you will instead have ata7-ata12 assigned.

Move to use the ida_alloc() API, such that print_ids will get reused.
This means that even after a rmmod + modprobe, the ports will be assigned
print_ids ata1-ata6.

Reviewed-by: Damien Le Moal <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Reviewed-by: Martin K. Petersen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Niklas Cassel <[email protected]>

Author: floatious

drivers/ata/libata-core.c

@@ -86,7 +86,7 @@ static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
 static void ata_dev_xfermask(struct ata_device *dev);
 static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
 
-atomic_t ata_print_id = ATOMIC_INIT(0);
+static DEFINE_IDA(ata_ida);
 
 #ifdef CONFIG_ATA_FORCE
 struct ata_force_param {
@@ -5463,14 +5463,20 @@ int sata_link_init_spd(struct ata_link *link)
 struct ata_port *ata_port_alloc(struct ata_host *host)
 {
 	struct ata_port *ap;
+	int id;
 
 	ap = kzalloc(sizeof(*ap), GFP_KERNEL);
 	if (!ap)
 		return NULL;
 
 	ap->pflags |= ATA_PFLAG_INITIALIZING | ATA_PFLAG_FROZEN;
 	ap->lock = &host->lock;
-	ap->print_id = atomic_inc_return(&ata_print_id);
+	id = ida_alloc_min(&ata_ida, 1, GFP_KERNEL);
+	if (id < 0) {
+		kfree(ap);
+		return NULL;
+	}
+	ap->print_id = id;
 	ap->host = host;
 	ap->dev = host->dev;
 
@@ -5504,6 +5510,7 @@ void ata_port_free(struct ata_port *ap)
 	kfree(ap->pmp_link);
 	kfree(ap->slave_link);
 	kfree(ap->ncq_sense_buf);
+	ida_free(&ata_ida, ap->print_id);
 	kfree(ap);
 }
 EXPORT_SYMBOL_GPL(ata_port_free);