firewire: clean up fw_card reference counting
This is a functionally equivalent replacement of the current reference
counting of struct fw_card instances. It only converts it to common
idioms as suggested by Kristian Høgsberg:
- struct kref replaces atomic_t as the counter.
- wait_for_completion is used to wait for all card users to complete.
BTW, it may make sense to count card->flush_timer and card->work as
card users too.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-transaction.h b/drivers/firewire/fw-transaction.h
index 219094e..2ae1b0d 100644
--- a/drivers/firewire/fw-transaction.h
+++ b/drivers/firewire/fw-transaction.h
@@ -19,14 +19,15 @@
#ifndef __fw_transaction_h
#define __fw_transaction_h
+#include <linux/completion.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/firewire-constants.h>
+#include <linux/kref.h>
#include <linux/list.h>
#include <linux/spinlock_types.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
-#include <asm/atomic.h>
#define TCODE_IS_READ_REQUEST(tcode) (((tcode) & ~1) == 4)
#define TCODE_IS_BLOCK_PACKET(tcode) (((tcode) & 1) != 0)
@@ -219,7 +220,8 @@
struct fw_card {
const struct fw_card_driver *driver;
struct device *device;
- atomic_t device_count;
+ struct kref kref;
+ struct completion done;
int node_id;
int generation;
@@ -260,6 +262,20 @@
int bm_generation;
};
+static inline struct fw_card *fw_card_get(struct fw_card *card)
+{
+ kref_get(&card->kref);
+
+ return card;
+}
+
+void fw_card_release(struct kref *kref);
+
+static inline void fw_card_put(struct fw_card *card)
+{
+ kref_put(&card->kref, fw_card_release);
+}
+
/*
* The iso packet format allows for an immediate header/payload part
* stored in 'header' immediately after the packet info plus an