[PATCH] bcm43xx: Abstract the locking mechanism.
This is the starting point to make the driver out-of-order-MMIO-stores safe.
There are more mmiowb() needed.
Signed-off-by: Michael Buesch <mbuesch@freenet.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/bcm43xx/bcm43xx.h b/drivers/net/wireless/bcm43xx/bcm43xx.h
index fd9754b..5f8c63f 100644
--- a/drivers/net/wireless/bcm43xx/bcm43xx.h
+++ b/drivers/net/wireless/bcm43xx/bcm43xx.h
@@ -619,7 +619,9 @@
void __iomem *mmio_addr;
unsigned int mmio_len;
- spinlock_t lock;
+ /* Do not use the lock directly. Use the bcm43xx_lock* helper
+ * functions, to be MMIO-safe. */
+ spinlock_t _lock;
/* Driver status flags. */
u32 initialized:1, /* init_board() succeed */
@@ -721,6 +723,22 @@
#endif
};
+/* bcm43xx_(un)lock() protect struct bcm43xx_private.
+ * Note that _NO_ MMIO writes are allowed. If you want to
+ * write to the device through MMIO in the critical section, use
+ * the *_mmio lock functions.
+ * MMIO read-access is allowed, though.
+ */
+#define bcm43xx_lock(bcm, flags) spin_lock_irqsave(&(bcm)->_lock, flags)
+#define bcm43xx_unlock(bcm, flags) spin_unlock_irqrestore(&(bcm)->_lock, flags)
+/* bcm43xx_(un)lock_mmio() protect struct bcm43xx_private and MMIO.
+ * MMIO write-access to the device is allowed.
+ * All MMIO writes are flushed on unlock, so it is guaranteed to not
+ * interfere with other threads writing MMIO registers.
+ */
+#define bcm43xx_lock_mmio(bcm, flags) bcm43xx_lock(bcm, flags)
+#define bcm43xx_unlock_mmio(bcm, flags) do { mmiowb(); bcm43xx_unlock(bcm, flags); } while (0)
+
static inline
struct bcm43xx_private * bcm43xx_priv(struct net_device *dev)
{