rt2x00: Revise irqmask locking for PCI devices

The PCI device irqmask is locked by a spin_lock. Currently
spin_lock_irqsave is used everywhere. To reduce the locking overhead
replace spin_lock_irqsave in hard irq context with spin_lock and in
soft irq context with spin_lock_irq.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2400pci.c

@@ -1317,27 +1317,25 @@ static void rt2400pci_txdone(struct rt2x00_dev *rt2x00dev,
 static void rt2400pci_enable_interrupt(struct rt2x00_dev *rt2x00dev,
 				       struct rt2x00_field32 irq_field)
 {
-	unsigned long flags;
 	u32 reg;
 
 	/*
 	 * Enable a single interrupt. The interrupt mask register
 	 * access needs locking.
 	 */
-	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+	spin_lock_irq(&rt2x00dev->irqmask_lock);
 
 	rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
 	rt2x00_set_field32(&reg, irq_field, 0);
 	rt2x00pci_register_write(rt2x00dev, CSR8, reg);
 
-	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+	spin_unlock_irq(&rt2x00dev->irqmask_lock);
 }
 
 static void rt2400pci_txstatus_tasklet(unsigned long data)
 {
 	struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;
 	u32 reg;
-	unsigned long flags;
 
 	/*
 	 * Handle all tx queues.
@@ -1349,7 +1347,7 @@ static void rt2400pci_txstatus_tasklet(unsigned long data)
 	/*
 	 * Enable all TXDONE interrupts again.
 	 */
-	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+	spin_lock_irq(&rt2x00dev->irqmask_lock);
 
 	rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
 	rt2x00_set_field32(&reg, CSR8_TXDONE_TXRING, 0);
@@ -1357,7 +1355,7 @@ static void rt2400pci_txstatus_tasklet(unsigned long data)
 	rt2x00_set_field32(&reg, CSR8_TXDONE_PRIORING, 0);
 	rt2x00pci_register_write(rt2x00dev, CSR8, reg);
 
-	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+	spin_unlock_irq(&rt2x00dev->irqmask_lock);
 }
 
 static void rt2400pci_tbtt_tasklet(unsigned long data)
@@ -1378,7 +1376,6 @@ static irqreturn_t rt2400pci_interrupt(int irq, void *dev_instance)
 {
 	struct rt2x00_dev *rt2x00dev = dev_instance;
 	u32 reg, mask;
-	unsigned long flags;
 
 	/*
 	 * Get the interrupt sources & saved to local variable.
@@ -1420,13 +1417,13 @@ static irqreturn_t rt2400pci_interrupt(int irq, void *dev_instance)
 	 * Disable all interrupts for which a tasklet was scheduled right now,
 	 * the tasklet will reenable the appropriate interrupts.
 	 */
-	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+	spin_lock(&rt2x00dev->irqmask_lock);
 
 	rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
 	reg |= mask;
 	rt2x00pci_register_write(rt2x00dev, CSR8, reg);
 
-	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+	spin_unlock(&rt2x00dev->irqmask_lock);
 
 
 

drivers/net/wireless/rt2x00/rt2500pci.c

@@ -1449,27 +1449,25 @@ static void rt2500pci_txdone(struct rt2x00_dev *rt2x00dev,
 static void rt2500pci_enable_interrupt(struct rt2x00_dev *rt2x00dev,
 				       struct rt2x00_field32 irq_field)
 {
-	unsigned long flags;
 	u32 reg;
 
 	/*
 	 * Enable a single interrupt. The interrupt mask register
 	 * access needs locking.
 	 */
-	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+	spin_lock_irq(&rt2x00dev->irqmask_lock);
 
 	rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
 	rt2x00_set_field32(&reg, irq_field, 0);
 	rt2x00pci_register_write(rt2x00dev, CSR8, reg);
 
-	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+	spin_unlock_irq(&rt2x00dev->irqmask_lock);
 }
 
 static void rt2500pci_txstatus_tasklet(unsigned long data)
 {
 	struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;
 	u32 reg;
-	unsigned long flags;
 
 	/*
 	 * Handle all tx queues.
@@ -1481,7 +1479,7 @@ static void rt2500pci_txstatus_tasklet(unsigned long data)
 	/*
 	 * Enable all TXDONE interrupts again.
 	 */
-	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+	spin_lock_irq(&rt2x00dev->irqmask_lock);
 
 	rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
 	rt2x00_set_field32(&reg, CSR8_TXDONE_TXRING, 0);
@@ -1489,7 +1487,7 @@ static void rt2500pci_txstatus_tasklet(unsigned long data)
 	rt2x00_set_field32(&reg, CSR8_TXDONE_PRIORING, 0);
 	rt2x00pci_register_write(rt2x00dev, CSR8, reg);
 
-	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+	spin_unlock_irq(&rt2x00dev->irqmask_lock);
 }
 
 static void rt2500pci_tbtt_tasklet(unsigned long data)
@@ -1510,7 +1508,6 @@ static irqreturn_t rt2500pci_interrupt(int irq, void *dev_instance)
 {
 	struct rt2x00_dev *rt2x00dev = dev_instance;
 	u32 reg, mask;
-	unsigned long flags;
 
 	/*
 	 * Get the interrupt sources & saved to local variable.
@@ -1552,13 +1549,13 @@ static irqreturn_t rt2500pci_interrupt(int irq, void *dev_instance)
 	 * Disable all interrupts for which a tasklet was scheduled right now,
 	 * the tasklet will reenable the appropriate interrupts.
 	 */
-	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+	spin_lock(&rt2x00dev->irqmask_lock);
 
 	rt2x00pci_register_read(rt2x00dev, CSR8, &reg);
 	reg |= mask;
 	rt2x00pci_register_write(rt2x00dev, CSR8, reg);
 
-	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+	spin_unlock(&rt2x00dev->irqmask_lock);
 
 	return IRQ_HANDLED;
 }

drivers/net/wireless/rt2x00/rt2800pci.c

@@ -765,18 +765,17 @@ static void rt2800pci_txdone(struct rt2x00_dev *rt2x00dev)
 static void rt2800pci_enable_interrupt(struct rt2x00_dev *rt2x00dev,
 				       struct rt2x00_field32 irq_field)
 {
-	unsigned long flags;
 	u32 reg;
 
 	/*
 	 * Enable a single interrupt. The interrupt mask register
 	 * access needs locking.
 	 */
-	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+	spin_lock_irq(&rt2x00dev->irqmask_lock);
 	rt2800_register_read(rt2x00dev, INT_MASK_CSR, &reg);
 	rt2x00_set_field32(&reg, irq_field, 1);
 	rt2800_register_write(rt2x00dev, INT_MASK_CSR, reg);
-	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+	spin_unlock_irq(&rt2x00dev->irqmask_lock);
 }
 
 static void rt2800pci_txstatus_tasklet(unsigned long data)
@@ -862,7 +861,6 @@ static irqreturn_t rt2800pci_interrupt(int irq, void *dev_instance)
 {
 	struct rt2x00_dev *rt2x00dev = dev_instance;
 	u32 reg, mask;
-	unsigned long flags;
 
 	/* Read status and ACK all interrupts */
 	rt2800_register_read(rt2x00dev, INT_SOURCE_CSR, &reg);
@@ -905,11 +903,11 @@ static irqreturn_t rt2800pci_interrupt(int irq, void *dev_instance)
 	 * Disable all interrupts for which a tasklet was scheduled right now,
 	 * the tasklet will reenable the appropriate interrupts.
 	 */
-	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+	spin_lock(&rt2x00dev->irqmask_lock);
 	rt2800_register_read(rt2x00dev, INT_MASK_CSR, &reg);
 	reg &= mask;
 	rt2800_register_write(rt2x00dev, INT_MASK_CSR, reg);
-	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+	spin_unlock(&rt2x00dev->irqmask_lock);
 
 	return IRQ_HANDLED;
 }

drivers/net/wireless/rt2x00/rt61pci.c

@@ -2263,39 +2263,37 @@ static void rt61pci_wakeup(struct rt2x00_dev *rt2x00dev)
 static void rt61pci_enable_interrupt(struct rt2x00_dev *rt2x00dev,
 				     struct rt2x00_field32 irq_field)
 {
-	unsigned long flags;
 	u32 reg;
 
 	/*
 	 * Enable a single interrupt. The interrupt mask register
 	 * access needs locking.
 	 */
-	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+	spin_lock_irq(&rt2x00dev->irqmask_lock);
 
 	rt2x00pci_register_read(rt2x00dev, INT_MASK_CSR, &reg);
 	rt2x00_set_field32(&reg, irq_field, 0);
 	rt2x00pci_register_write(rt2x00dev, INT_MASK_CSR, reg);
 
-	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+	spin_unlock_irq(&rt2x00dev->irqmask_lock);
 }
 
 static void rt61pci_enable_mcu_interrupt(struct rt2x00_dev *rt2x00dev,
 					 struct rt2x00_field32 irq_field)
 {
-	unsigned long flags;
 	u32 reg;
 
 	/*
 	 * Enable a single MCU interrupt. The interrupt mask register
 	 * access needs locking.
 	 */
-	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+	spin_lock_irq(&rt2x00dev->irqmask_lock);
 
 	rt2x00pci_register_read(rt2x00dev, MCU_INT_MASK_CSR, &reg);
 	rt2x00_set_field32(&reg, irq_field, 0);
 	rt2x00pci_register_write(rt2x00dev, MCU_INT_MASK_CSR, reg);
 
-	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+	spin_unlock_irq(&rt2x00dev->irqmask_lock);
 }
 
 static void rt61pci_txstatus_tasklet(unsigned long data)
@@ -2333,7 +2331,6 @@ static irqreturn_t rt61pci_interrupt(int irq, void *dev_instance)
 	struct rt2x00_dev *rt2x00dev = dev_instance;
 	u32 reg_mcu, mask_mcu;
 	u32 reg, mask;
-	unsigned long flags;
 
 	/*
 	 * Get the interrupt sources & saved to local variable.
@@ -2378,7 +2375,7 @@ static irqreturn_t rt61pci_interrupt(int irq, void *dev_instance)
 	 * Disable all interrupts for which a tasklet was scheduled right now,
 	 * the tasklet will reenable the appropriate interrupts.
 	 */
-	spin_lock_irqsave(&rt2x00dev->irqmask_lock, flags);
+	spin_lock(&rt2x00dev->irqmask_lock);
 
 	rt2x00pci_register_read(rt2x00dev, INT_MASK_CSR, &reg);
 	reg |= mask;
@@ -2388,7 +2385,7 @@ static irqreturn_t rt61pci_interrupt(int irq, void *dev_instance)
 	reg |= mask_mcu;
 	rt2x00pci_register_write(rt2x00dev, MCU_INT_MASK_CSR, reg);
 
-	spin_unlock_irqrestore(&rt2x00dev->irqmask_lock, flags);
+	spin_unlock(&rt2x00dev->irqmask_lock);
 
 	return IRQ_HANDLED;
 }