bcm43xx-d80211: opencoded locking

Index: wireless-dev-dscapeports/drivers/net/wireless/d80211/bcm43xx/bcm43xx.h
===================================================================
@@ -660,6 +660,19 @@
 #define bcm43xx_status(bcm)		atomic_read(&(bcm)->init_status)
 #define bcm43xx_set_status(bcm, stat)	atomic_set(&(bcm)->init_status, (stat))
 
+/*    *** THEORY OF LOCKING ***
+ *
+ * We have two different locks in the bcm43xx driver.
+ * => bcm->mutex:    General sleeping mutex. Protects struct bcm43xx_private
+ *                   and the device registers. This mutex does _not_ protect
+ *                   against concurrency from the IRQ handler.
+ * => bcm->irq_lock: IRQ spinlock. Protects against IRQ handler concurrency.
+ *
+ * Please note that, if you only take the irq_lock, you are not protected
+ * against concurrency from the periodic work handlers.
+ * Most times you want to take _both_ locks.
+ */
+
 struct bcm43xx_private {
 	struct ieee80211_hw *ieee;
 	struct ieee80211_low_level_stats ieee_stats;

@@ -670,7 +683,6 @@
 
 	void __iomem *mmio_addr;
 
-	/* Locking, see "theory of locking" text below. */
 	spinlock_t irq_lock;
 	struct mutex mutex;
 

@@ -710,6 +722,7 @@
 	struct bcm43xx_sprominfo sprom;
 #define BCM43xx_NR_LEDS		4
 	struct bcm43xx_led leds[BCM43xx_NR_LEDS];
+	spinlock_t leds_lock;
 
 	/* The currently active core. */
 	struct bcm43xx_coreinfo *current_core;

@@ -779,55 +792,6 @@
 };
 
 
-/*    *** THEORY OF LOCKING ***
- *
- * We have two different locks in the bcm43xx driver.
- * => bcm->mutex:    General sleeping mutex. Protects struct bcm43xx_private
- *                   and the device registers.
- * => bcm->irq_lock: IRQ spinlock. Protects against IRQ handler concurrency.
- *
- * We have three types of helper function pairs to utilize these locks.
- *     (Always use the helper functions.)
- * 1) bcm43xx_{un}lock_noirq():
- *     Takes bcm->mutex. Does _not_ protect against IRQ concurrency,
- *     so it is almost always unsafe, if device IRQs are enabled.
- *     So only use this, if device IRQs are masked.
- *     Locking may sleep.
- *     You can sleep within the critical section.
- * 2) bcm43xx_{un}lock_irqonly():
- *     Takes bcm->irq_lock. Does _not_ protect against
- *     bcm43xx_lock_noirq() critical sections.
- *     Does only protect against the IRQ handler path and other
- *     irqonly() critical sections.
- *     Locking does not sleep.
- *     You must not sleep within the critical section.
- * 3) bcm43xx_{un}lock_irqsafe():
- *     This is the cummulative lock and takes both, mutex and irq_lock.
- *     Protects against noirq() and irqonly() critical sections (and
- *     the IRQ handler path).
- *     Locking may sleep.
- *     You must not sleep within the critical section.
- */
-
-/* Lock type 1 */
-#define bcm43xx_lock_noirq(bcm)		mutex_lock(&(bcm)->mutex)
-#define bcm43xx_unlock_noirq(bcm)	mutex_unlock(&(bcm)->mutex)
-/* Lock type 2 */
-#define bcm43xx_lock_irqonly(bcm, flags)	\
-	spin_lock_irqsave(&(bcm)->irq_lock, flags)
-#define bcm43xx_unlock_irqonly(bcm, flags)	\
-	spin_unlock_irqrestore(&(bcm)->irq_lock, flags)
-/* Lock type 3 */
-#define bcm43xx_lock_irqsafe(bcm, flags) do {	\
-	bcm43xx_lock_noirq(bcm);		\
-	bcm43xx_lock_irqonly(bcm, flags);	\
-		} while (0)
-#define bcm43xx_unlock_irqsafe(bcm, flags) do {	\
-	bcm43xx_unlock_irqonly(bcm, flags);	\
-	bcm43xx_unlock_noirq(bcm);		\
-		} while (0)
-
-
 static inline
 struct bcm43xx_private * bcm43xx_priv(struct net_device *dev)
 {

Index: wireless-dev-dscapeports/drivers/net/wireless/d80211/bcm43xx/bcm43xx_debugfs.c
===================================================================
@@ -77,7 +77,8 @@
 
 	down(&big_buffer_sem);
 
-	bcm43xx_lock_irqsafe(bcm, flags);
+	mutex_lock(&bcm->mutex);
+	spin_lock_irqsave(&bcm->irq_lock, flags);
 	if (bcm43xx_status(bcm) != BCM43xx_STAT_INITIALIZED) {
 		fappend("Board not initialized.\n");
 		goto out;

@@ -121,7 +122,8 @@
 	fappend("\n");
 
 out:
-	bcm43xx_unlock_irqsafe(bcm, flags);
+	spin_unlock_irqrestore(&bcm->irq_lock, flags);
+	mutex_unlock(&bcm->mutex);
 	res = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
 	up(&big_buffer_sem);
 	return res;

@@ -159,7 +161,8 @@
 	unsigned long flags;
 
 	down(&big_buffer_sem);
-	bcm43xx_lock_irqsafe(bcm, flags);
+	mutex_lock(&bcm->mutex);
+	spin_lock_irqsave(&bcm->irq_lock, flags);
 	if (bcm43xx_status(bcm) != BCM43xx_STAT_INITIALIZED) {
 		fappend("Board not initialized.\n");
 		goto out;

@@ -169,7 +172,8 @@
 	fappend("boardflags: 0x%04x\n", bcm->sprom.boardflags);
 
 out:
-	bcm43xx_unlock_irqsafe(bcm, flags);
+	spin_unlock_irqrestore(&bcm->irq_lock, flags);
+	mutex_unlock(&bcm->mutex);
 	res = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
 	up(&big_buffer_sem);
 	return res;

@@ -188,7 +192,8 @@
 	u64 tsf;
 
 	down(&big_buffer_sem);
-	bcm43xx_lock_irqsafe(bcm, flags);
+	mutex_lock(&bcm->mutex);
+	spin_lock_irqsave(&bcm->irq_lock, flags);
 	if (bcm43xx_status(bcm) != BCM43xx_STAT_INITIALIZED) {
 		fappend("Board not initialized.\n");
 		goto out;

@@ -199,7 +204,8 @@
 		(unsigned int)(tsf & 0xFFFFFFFFULL));
 
 out:
-	bcm43xx_unlock_irqsafe(bcm, flags);
+	spin_unlock_irqrestore(&bcm->irq_lock, flags);
+	mutex_unlock(&bcm->mutex);
 	res = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
 	up(&big_buffer_sem);
 	return res;

@@ -221,7 +227,8 @@
 	        res = -EFAULT;
 		goto out_up;
 	}
-	bcm43xx_lock_irqsafe(bcm, flags);
+	mutex_lock(&bcm->mutex);
+	spin_lock_irqsave(&bcm->irq_lock, flags);
 	if (bcm43xx_status(bcm) != BCM43xx_STAT_INITIALIZED) {
 		printk(KERN_INFO PFX "debugfs: Board not initialized.\n");
 		res = -EFAULT;

@@ -237,7 +244,8 @@
 	res = buf_size;
 	
 out_unlock:
-	bcm43xx_unlock_irqsafe(bcm, flags);
+	spin_unlock_irqrestore(&bcm->irq_lock, flags);
+	mutex_unlock(&bcm->mutex);
 out_up:
 	up(&big_buffer_sem);
 	return res;

@@ -258,7 +266,8 @@
 	int i, cnt, j = 0;
 
 	down(&big_buffer_sem);
-	bcm43xx_lock_irqsafe(bcm, flags);
+	mutex_lock(&bcm->mutex);
+	spin_lock_irqsave(&bcm->irq_lock, flags);
 
 	fappend("Last %d logged xmitstatus blobs (Latest first):\n\n",
 		BCM43xx_NR_LOGGED_XMITSTATUS);

@@ -294,14 +303,15 @@
 			i = BCM43xx_NR_LOGGED_XMITSTATUS - 1;
 	}
 
-	bcm43xx_unlock_irqsafe(bcm, flags);
+	spin_unlock_irqrestore(&bcm->irq_lock, flags);
 	res = simple_read_from_buffer(userbuf, count, ppos, buf, pos);
-	bcm43xx_lock_irqsafe(bcm, flags);
+	spin_lock_irqsave(&bcm->irq_lock, flags);
 	if (*ppos == pos) {
 		/* Done. Drop the copied data. */
 		e->xmitstatus_printing = 0;
 	}
-	bcm43xx_unlock_irqsafe(bcm, flags);
+	spin_unlock_irqrestore(&bcm->irq_lock, flags);
+	mutex_unlock(&bcm->mutex);
 	up(&big_buffer_sem);
 	return res;
 }

Index: wireless-dev-dscapeports/drivers/net/wireless/d80211/bcm43xx/bcm43xx_leds.c
===================================================================
@@ -51,12 +51,12 @@
 	struct bcm43xx_private *bcm = led->bcm;
 	unsigned long flags;
 
-	bcm43xx_lock_irqonly(bcm, flags);
+	spin_lock_irqsave(&bcm->leds_lock, flags);
 	if (led->blink_interval) {
 		bcm43xx_led_changestate(led);
 		mod_timer(&led->blink_timer, jiffies + led->blink_interval);
 	}
-	bcm43xx_unlock_irqonly(bcm, flags);
+	spin_unlock_irqrestore(&bcm->leds_lock, flags);
 }
 
 static void bcm43xx_led_blink_start(struct bcm43xx_led *led,

@@ -177,7 +177,9 @@
 	int i, turn_on;
 	unsigned long interval = 0;
 	u16 ledctl;
+	unsigned long flags;
 
+	spin_lock_irqsave(&bcm->leds_lock, flags);
 	ledctl = bcm43xx_read16(bcm, BCM43xx_MMIO_GPIO_CONTROL);
 	for (i = 0; i < BCM43xx_NR_LEDS; i++) {
 		led = &(bcm->leds[i]);

@@ -266,6 +268,7 @@
 			ledctl &= ~(1 << i);
 	}
 	bcm43xx_write16(bcm, BCM43xx_MMIO_GPIO_CONTROL, ledctl);
+	spin_unlock_irqrestore(&bcm->leds_lock, flags);
 }
 
 void bcm43xx_leds_switch_all(struct bcm43xx_private *bcm, int on)

@@ -274,7 +277,9 @@
 	u16 ledctl;
 	int i;
 	int bit_on;
+	unsigned long flags;
 
+	spin_lock_irqsave(&bcm->leds_lock, flags);
 	ledctl = bcm43xx_read16(bcm, BCM43xx_MMIO_GPIO_CONTROL);
 	for (i = 0; i < BCM43xx_NR_LEDS; i++) {
 		led = &(bcm->leds[i]);

@@ -290,4 +295,5 @@
 			ledctl &= ~(1 << i);
 	}
 	bcm43xx_write16(bcm, BCM43xx_MMIO_GPIO_CONTROL, ledctl);
+	spin_unlock_irqrestore(&bcm->leds_lock, flags);
 }

323 lines not on this page · raw message

Index: wireless-dev-dscapeports/drivers/net/wireless/d80211/bcm43xx/bcm43xx_pio.c
===================================================================
@@ -263,7 +263,7 @@
 	int err;
 	u16 txctl;
 
-	bcm43xx_lock_irqonly(bcm, flags);
+	spin_lock_irqsave(&bcm->irq_lock, flags);
 	if (queue->tx_frozen)
 		goto out_unlock;
 	txctl = bcm43xx_pio_read(queue, BCM43xx_PIO_TXCTL);

@@ -283,7 +283,7 @@
 			break;
 	}
 out_unlock:
-	bcm43xx_unlock_irqonly(bcm, flags);
+	spin_unlock_irqrestore(&bcm->irq_lock, flags);
 }
 
 static void setup_txqueues(struct bcm43xx_pioqueue *queue)

Index: wireless-dev-dscapeports/drivers/net/wireless/d80211/bcm43xx/bcm43xx_sysfs.c
===================================================================
@@ -120,12 +120,14 @@
 			GFP_KERNEL);
 	if (!sprom)
 		return -ENOMEM;
-	bcm43xx_lock_irqsafe(bcm, flags);
+	mutex_lock(&bcm->mutex);
+	spin_lock_irqsave(&bcm->irq_lock, flags);
 	err = bcm43xx_sprom_read(bcm, sprom);
 	if (!err)
 		err = sprom2hex(sprom, buf, PAGE_SIZE);
 	mmiowb();
-	bcm43xx_unlock_irqsafe(bcm, flags);
+	spin_unlock_irqrestore(&bcm->irq_lock, flags);
+	mutex_unlock(&bcm->mutex);
 	kfree(sprom);
 
 	return err;

@@ -150,10 +152,14 @@
 	err = hex2sprom(sprom, buf, count);
 	if (err)
 		goto out_kfree;
-	bcm43xx_lock_irqsafe(bcm, flags);
+	mutex_lock(&bcm->mutex);
+	spin_lock_irqsave(&bcm->irq_lock, flags);
+	spin_lock(&bcm->leds_lock);
 	err = bcm43xx_sprom_write(bcm, sprom);
 	mmiowb();
-	bcm43xx_unlock_irqsafe(bcm, flags);
+	spin_unlock(&bcm->leds_lock);
+	spin_unlock_irqrestore(&bcm->irq_lock, flags);
+	mutex_unlock(&bcm->mutex);
 out_kfree:
 	kfree(sprom);
 

@@ -176,7 +182,7 @@
 	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;
 
-	bcm43xx_lock_noirq(bcm);
+	mutex_lock(&bcm->mutex);
 
 	switch (bcm43xx_current_radio(bcm)->interfmode) {
 	case BCM43xx_RADIO_INTERFMODE_NONE:

@@ -193,7 +199,7 @@
 	}
 	err = 0;
 
-	bcm43xx_unlock_noirq(bcm);
+	mutex_unlock(&bcm->mutex);
 
 	return err ? err : count;
 

@@ -229,7 +235,8 @@
 		return -EINVAL;
 	}
 
-	bcm43xx_lock_irqsafe(bcm, flags);
+	mutex_lock(&bcm->mutex);
+	spin_lock_irqsave(&bcm->irq_lock, flags);
 
 	err = bcm43xx_radio_set_interference_mitigation(bcm, mode);
 	if (err) {

@@ -237,7 +244,8 @@
 				    "supported by device\n");
 	}
 	mmiowb();
-	bcm43xx_unlock_irqsafe(bcm, flags);
+	spin_unlock_irqrestore(&bcm->irq_lock, flags);
+	mutex_unlock(&bcm->mutex);
 
 	return err ? err : count;
 }

@@ -257,7 +265,7 @@
 	if (!capable(CAP_NET_ADMIN))
 		return -EPERM;
 
-	bcm43xx_lock_noirq(bcm);
+	mutex_lock(&bcm->mutex);
 
 	if (bcm->short_preamble)
 		count = snprintf(buf, PAGE_SIZE, "1 (Short Preamble enabled)\n");

@@ -265,7 +273,7 @@
 		count = snprintf(buf, PAGE_SIZE, "0 (Short Preamble disabled)\n");
 
 	err = 0;
-	bcm43xx_unlock_noirq(bcm);
+	mutex_unlock(&bcm->mutex);
 
 	return err ? err : count;
 }

@@ -285,12 +293,14 @@
 	value = get_boolean(buf, count);
 	if (value < 0)
 		return value;
-	bcm43xx_lock_irqsafe(bcm, flags);
+	mutex_lock(&bcm->mutex);
+	spin_lock_irqsave(&bcm->irq_lock, flags);
 
 	bcm->short_preamble = !!value;
 
 	err = 0;
-	bcm43xx_unlock_irqsafe(bcm, flags);
+	spin_unlock_irqrestore(&bcm->irq_lock, flags);
+	mutex_unlock(&bcm->mutex);
 
 	return err ? err : count;
 }