b43legacy: Remove unnecessary MMIO in interrupt hotpath

This removes unnecessary MMIO accesses in the interrupt hotpath. The
patch by Michael Buesch for b43 has been ported to b43legacy.

Signed-off-by: Stefano Brivio <stefano.brivio@polimi.it>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/b43legacy/b43legacy.h b/drivers/net/wireless/b43legacy/b43legacy.h
index da59ef02b6efac0aa2ef3f8d3b859769c67b76f0..19a4b0bc0d872c3de0b99c2c45751807b701b191 100644 (file)
--- a/drivers/net/wireless/b43legacy/b43legacy.h
+++ b/drivers/net/wireless/b43legacy/b43legacy.h
@@ -694,8 +694,8 @@ struct b43legacy_wldev {
        /* Reason code of the last interrupt. */
        u32 irq_reason;
        u32 dma_reason[6];
-       /* saved irq enable/disable state bitfield. */
-       u32 irq_savedstate;
+       /* The currently active generic-interrupt mask. */
+       u32 irq_mask;
        /* Link Quality calculation context. */
        struct b43legacy_noise_calculation noisecalc;
        /* if > 0 MAC is suspended. if == 0 MAC is enabled. */

diff --git a/drivers/net/wireless/b43legacy/main.c b/drivers/net/wireless/b43legacy/main.c
index 07c7898c87ac0189d4be971d8dd05460d9073399..0062b340d98985e36219f5d5fc093bb4a958fcaf 100644 (file)
--- a/drivers/net/wireless/b43legacy/main.c
+++ b/drivers/net/wireless/b43legacy/main.c
@@ -583,35 +583,6 @@ static void b43legacy_short_slot_timing_disable(struct b43legacy_wldev *dev)
        b43legacy_set_slot_time(dev, 20);
 }
 
-/* Enable a Generic IRQ. "mask" is the mask of which IRQs to enable.
- * Returns the _previously_ enabled IRQ mask.
- */
-static inline u32 b43legacy_interrupt_enable(struct b43legacy_wldev *dev,
-                                            u32 mask)
-{
-       u32 old_mask;
-
-       old_mask = b43legacy_read32(dev, B43legacy_MMIO_GEN_IRQ_MASK);
-       b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, old_mask |
-                         mask);
-
-       return old_mask;
-}
-
-/* Disable a Generic IRQ. "mask" is the mask of which IRQs to disable.
- * Returns the _previously_ enabled IRQ mask.
- */
-static inline u32 b43legacy_interrupt_disable(struct b43legacy_wldev *dev,
-                                             u32 mask)
-{
-       u32 old_mask;
-
-       old_mask = b43legacy_read32(dev, B43legacy_MMIO_GEN_IRQ_MASK);
-       b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, old_mask & ~mask);
-
-       return old_mask;
-}
-
 /* Synchronize IRQ top- and bottom-half.
  * IRQs must be masked before calling this.
  * This must not be called with the irq_lock held.
@@ -1200,7 +1171,7 @@ static void handle_irq_beacon(struct b43legacy_wldev *dev)
        /* This is the bottom half of the asynchronous beacon update. */
 
        /* Ignore interrupt in the future. */
-       dev->irq_savedstate &= ~B43legacy_IRQ_BEACON;
+       dev->irq_mask &= ~B43legacy_IRQ_BEACON;
 
        cmd = b43legacy_read32(dev, B43legacy_MMIO_MACCMD);
        beacon0_valid = (cmd & B43legacy_MACCMD_BEACON0_VALID);
@@ -1209,7 +1180,7 @@ static void handle_irq_beacon(struct b43legacy_wldev *dev)
        /* Schedule interrupt manually, if busy. */
        if (beacon0_valid && beacon1_valid) {
                b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_REASON, B43legacy_IRQ_BEACON);
-               dev->irq_savedstate |= B43legacy_IRQ_BEACON;
+               dev->irq_mask |= B43legacy_IRQ_BEACON;
                return;
        }
 
@@ -1247,12 +1218,11 @@ static void b43legacy_beacon_update_trigger_work(struct work_struct *work)
        dev = wl->current_dev;
        if (likely(dev && (b43legacy_status(dev) >= B43legacy_STAT_INITIALIZED))) {
                spin_lock_irq(&wl->irq_lock);
-               /* update beacon right away or defer to irq */
-               dev->irq_savedstate = b43legacy_read32(dev, B43legacy_MMIO_GEN_IRQ_MASK);
+               /* Update beacon right away or defer to IRQ. */
                handle_irq_beacon(dev);
                /* The handler might have updated the IRQ mask. */
                b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK,
-                           dev->irq_savedstate);
+                                 dev->irq_mask);
                mmiowb();
                spin_unlock_irq(&wl->irq_lock);
        }
@@ -1398,7 +1368,7 @@ static void b43legacy_interrupt_tasklet(struct b43legacy_wldev *dev)
        if (reason & B43legacy_IRQ_TX_OK)
                handle_irq_transmit_status(dev);
 
-       b43legacy_interrupt_enable(dev, dev->irq_savedstate);
+       b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, dev->irq_mask);
        mmiowb();
        spin_unlock_irqrestore(&dev->wl->irq_lock, flags);
 }
@@ -1450,18 +1420,18 @@ static irqreturn_t b43legacy_interrupt_handler(int irq, void *dev_id)
        struct b43legacy_wldev *dev = dev_id;
        u32 reason;
 
-       if (!dev)
-               return IRQ_NONE;
+       B43legacy_WARN_ON(!dev);
 
        spin_lock(&dev->wl->irq_lock);
 
-       if (b43legacy_status(dev) < B43legacy_STAT_STARTED)
+       if (unlikely(b43legacy_status(dev) < B43legacy_STAT_STARTED))
+               /* This can only happen on shared IRQ lines. */
                goto out;
        reason = b43legacy_read32(dev, B43legacy_MMIO_GEN_IRQ_REASON);
        if (reason == 0xffffffff) /* shared IRQ */
                goto out;
        ret = IRQ_HANDLED;
-       reason &= b43legacy_read32(dev, B43legacy_MMIO_GEN_IRQ_MASK);
+       reason &= dev->irq_mask;
        if (!reason)
                goto out;
 
@@ -1485,10 +1455,9 @@ static irqreturn_t b43legacy_interrupt_handler(int irq, void *dev_id)
                                              & 0x0000DC00;
 
        b43legacy_interrupt_ack(dev, reason);
-       /* disable all IRQs. They are enabled again in the bottom half. */
-       dev->irq_savedstate = b43legacy_interrupt_disable(dev,
-                                                         B43legacy_IRQ_ALL);
-       /* save the reason code and call our bottom half. */
+       /* Disable all IRQs. They are enabled again in the bottom half. */
+       b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, 0);
+       /* Save the reason code and call our bottom half. */
        dev->irq_reason = reason;
        tasklet_schedule(&dev->isr_tasklet);
 out:
@@ -1948,7 +1917,8 @@ void b43legacy_mac_enable(struct b43legacy_wldev *dev)
 
                /* Re-enable IRQs. */
                spin_lock_irq(&dev->wl->irq_lock);
-               b43legacy_interrupt_enable(dev, dev->irq_savedstate);
+               b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK,
+                                 dev->irq_mask);
                spin_unlock_irq(&dev->wl->irq_lock);
        }
 }
@@ -1967,10 +1937,9 @@ void b43legacy_mac_suspend(struct b43legacy_wldev *dev)
                /* Mask IRQs before suspending MAC. Otherwise
                 * the MAC stays busy and won't suspend. */
                spin_lock_irq(&dev->wl->irq_lock);
-               tmp = b43legacy_interrupt_disable(dev, B43legacy_IRQ_ALL);
+               b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, 0);
                spin_unlock_irq(&dev->wl->irq_lock);
                b43legacy_synchronize_irq(dev);
-               dev->irq_savedstate = tmp;
 
                b43legacy_power_saving_ctl_bits(dev, -1, 1);
                b43legacy_write32(dev, B43legacy_MMIO_MACCTL,
@@ -2659,7 +2628,6 @@ static int b43legacy_op_dev_config(struct ieee80211_hw *hw,
        int antenna_tx;
        int antenna_rx;
        int err = 0;
-       u32 savedirqs;
 
        antenna_tx = B43legacy_ANTENNA_DEFAULT;
        antenna_rx = B43legacy_ANTENNA_DEFAULT;
@@ -2699,7 +2667,7 @@ static int b43legacy_op_dev_config(struct ieee80211_hw *hw,
                spin_unlock_irqrestore(&wl->irq_lock, flags);
                goto out_unlock_mutex;
        }
-       savedirqs = b43legacy_interrupt_disable(dev, B43legacy_IRQ_ALL);
+       b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, 0);
        spin_unlock_irqrestore(&wl->irq_lock, flags);
        b43legacy_synchronize_irq(dev);
 
@@ -2738,7 +2706,7 @@ static int b43legacy_op_dev_config(struct ieee80211_hw *hw,
        }
 
        spin_lock_irqsave(&wl->irq_lock, flags);
-       b43legacy_interrupt_enable(dev, savedirqs);
+       b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, dev->irq_mask);
        mmiowb();
        spin_unlock_irqrestore(&wl->irq_lock, flags);
 out_unlock_mutex:
@@ -2801,7 +2769,6 @@ static void b43legacy_op_bss_info_changed(struct ieee80211_hw *hw,
        struct b43legacy_wldev *dev;
        struct b43legacy_phy *phy;
        unsigned long flags;
-       u32 savedirqs;
 
        mutex_lock(&wl->mutex);
        B43legacy_WARN_ON(wl->vif != vif);
@@ -2817,7 +2784,7 @@ static void b43legacy_op_bss_info_changed(struct ieee80211_hw *hw,
                spin_unlock_irqrestore(&wl->irq_lock, flags);
                goto out_unlock_mutex;
        }
-       savedirqs = b43legacy_interrupt_disable(dev, B43legacy_IRQ_ALL);
+       b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, 0);
 
        if (changed & BSS_CHANGED_BSSID) {
                spin_unlock_irqrestore(&wl->irq_lock, flags);
@@ -2862,7 +2829,7 @@ static void b43legacy_op_bss_info_changed(struct ieee80211_hw *hw,
        b43legacy_mac_enable(dev);
 
        spin_lock_irqsave(&wl->irq_lock, flags);
-       b43legacy_interrupt_enable(dev, savedirqs);
+       b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, dev->irq_mask);
        /* XXX: why? */
        mmiowb();
        spin_unlock_irqrestore(&wl->irq_lock, flags);
@@ -2922,8 +2889,7 @@ static void b43legacy_wireless_core_stop(struct b43legacy_wldev *dev)
         * setting the status to INITIALIZED, as the interrupt handler
         * won't care about IRQs then. */
        spin_lock_irqsave(&wl->irq_lock, flags);
-       dev->irq_savedstate = b43legacy_interrupt_disable(dev,
-                                                         B43legacy_IRQ_ALL);
+       b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, 0);
        b43legacy_read32(dev, B43legacy_MMIO_GEN_IRQ_MASK); /* flush */
        spin_unlock_irqrestore(&wl->irq_lock, flags);
        b43legacy_synchronize_irq(dev);
@@ -2963,7 +2929,7 @@ static int b43legacy_wireless_core_start(struct b43legacy_wldev *dev)
 
        /* Start data flow (TX/RX) */
        b43legacy_mac_enable(dev);
-       b43legacy_interrupt_enable(dev, dev->irq_savedstate);
+       b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, dev->irq_mask);
 
        /* Start maintenance work */
        b43legacy_periodic_tasks_setup(dev);
@@ -3126,7 +3092,7 @@ static void setup_struct_wldev_for_init(struct b43legacy_wldev *dev)
        /* IRQ related flags */
        dev->irq_reason = 0;
        memset(dev->dma_reason, 0, sizeof(dev->dma_reason));
-       dev->irq_savedstate = B43legacy_IRQ_MASKTEMPLATE;
+       dev->irq_mask = B43legacy_IRQ_MASKTEMPLATE;
 
        dev->mac_suspended = 1;
 

diff --git a/drivers/net/wireless/b43legacy/pio.c b/drivers/net/wireless/b43legacy/pio.c
index 746d5361bba017b56838c6cf5b5c54add2cd0317..51866c9a2769108ad974e9a9bc60e015c7869a9a 100644 (file)
--- a/drivers/net/wireless/b43legacy/pio.c
+++ b/drivers/net/wireless/b43legacy/pio.c
@@ -443,7 +443,7 @@ int b43legacy_pio_init(struct b43legacy_wldev *dev)
        pio->queue3 = queue;
 
        if (dev->dev->id.revision < 3)
-               dev->irq_savedstate |= B43legacy_IRQ_PIO_WORKAROUND;
+               dev->irq_mask |= B43legacy_IRQ_PIO_WORKAROUND;
 
        b43legacydbg(dev->wl, "PIO initialized\n");
        err = 0;