This removes unnecessary MMIO accesses in the interrupt hotpath.
Signed-off-by: Michael Buesch <mb@xxxxxxxxx>
---
John, please queue for the next feature round.
Index: compat-wireless-2009-03-31/drivers/net/wireless/b43/b43.h
===================================================================
--- compat-wireless-2009-03-31.orig/drivers/net/wireless/b43/b43.h 2009-04-08 20:27:37.000000000 +0200
+++ compat-wireless-2009-03-31/drivers/net/wireless/b43/b43.h 2009-04-08 20:28:14.000000000 +0200
@@ -778,8 +778,8 @@ struct b43_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 b43_noise_calculation noisecalc;
/* if > 0 MAC is suspended. if == 0 MAC is enabled. */
Index: compat-wireless-2009-03-31/drivers/net/wireless/b43/main.c
===================================================================
--- compat-wireless-2009-03-31.orig/drivers/net/wireless/b43/main.c 2009-04-08 20:22:24.000000000 +0200
+++ compat-wireless-2009-03-31/drivers/net/wireless/b43/main.c 2009-04-08 20:41:43.000000000 +0200
@@ -673,32 +673,6 @@ static void b43_short_slot_timing_disabl
b43_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 b43_interrupt_enable(struct b43_wldev *dev, u32 mask)
-{
- u32 old_mask;
-
- old_mask = b43_read32(dev, B43_MMIO_GEN_IRQ_MASK);
- b43_write32(dev, B43_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 b43_interrupt_disable(struct b43_wldev *dev, u32 mask)
-{
- u32 old_mask;
-
- old_mask = b43_read32(dev, B43_MMIO_GEN_IRQ_MASK);
- b43_write32(dev, B43_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.
@@ -1593,7 +1567,7 @@ static void handle_irq_beacon(struct b43
/* This is the bottom half of the asynchronous beacon update. */
/* Ignore interrupt in the future. */
- dev->irq_savedstate &= ~B43_IRQ_BEACON;
+ dev->irq_mask &= ~B43_IRQ_BEACON;
cmd = b43_read32(dev, B43_MMIO_MACCMD);
beacon0_valid = (cmd & B43_MACCMD_BEACON0_VALID);
@@ -1602,7 +1576,7 @@ static void handle_irq_beacon(struct b43
/* Schedule interrupt manually, if busy. */
if (beacon0_valid && beacon1_valid) {
b43_write32(dev, B43_MMIO_GEN_IRQ_REASON, B43_IRQ_BEACON);
- dev->irq_savedstate |= B43_IRQ_BEACON;
+ dev->irq_mask |= B43_IRQ_BEACON;
return;
}
@@ -1641,11 +1615,9 @@ static void b43_beacon_update_trigger_wo
if (likely(dev && (b43_status(dev) >= B43_STAT_INITIALIZED))) {
spin_lock_irq(&wl->irq_lock);
/* update beacon right away or defer to irq */
- dev->irq_savedstate = b43_read32(dev, B43_MMIO_GEN_IRQ_MASK);
handle_irq_beacon(dev);
/* The handler might have updated the IRQ mask. */
- b43_write32(dev, B43_MMIO_GEN_IRQ_MASK,
- dev->irq_savedstate);
+ b43_write32(dev, B43_MMIO_GEN_IRQ_MASK, dev->irq_mask);
mmiowb();
spin_unlock_irq(&wl->irq_lock);
}
@@ -1879,7 +1851,7 @@ static void b43_interrupt_tasklet(struct
if (reason & B43_IRQ_TX_OK)
handle_irq_transmit_status(dev);
- b43_interrupt_enable(dev, dev->irq_savedstate);
+ b43_write32(dev, B43_MMIO_GEN_IRQ_MASK, dev->irq_mask);
mmiowb();
spin_unlock_irqrestore(&dev->wl->irq_lock, flags);
}
@@ -1893,7 +1865,9 @@ static void b43_interrupt_ack(struct b43
b43_write32(dev, B43_MMIO_DMA2_REASON, dev->dma_reason[2]);
b43_write32(dev, B43_MMIO_DMA3_REASON, dev->dma_reason[3]);
b43_write32(dev, B43_MMIO_DMA4_REASON, dev->dma_reason[4]);
+/* Unused ring
b43_write32(dev, B43_MMIO_DMA5_REASON, dev->dma_reason[5]);
+*/
}
/* Interrupt handler top-half */
@@ -1903,18 +1877,19 @@ static irqreturn_t b43_interrupt_handler
struct b43_wldev *dev = dev_id;
u32 reason;
- if (!dev)
- return IRQ_NONE;
+ B43_WARN_ON(!dev);
spin_lock(&dev->wl->irq_lock);
- if (b43_status(dev) < B43_STAT_STARTED)
+ if (unlikely(b43_status(dev) < B43_STAT_STARTED)) {
+ /* This can only happen on shared IRQ lines. */
goto out;
+ }
reason = b43_read32(dev, B43_MMIO_GEN_IRQ_REASON);
if (reason == 0xffffffff) /* shared IRQ */
goto out;
ret = IRQ_HANDLED;
- reason &= b43_read32(dev, B43_MMIO_GEN_IRQ_MASK);
+ reason &= dev->irq_mask;
if (!reason)
goto out;
@@ -1928,16 +1903,18 @@ static irqreturn_t b43_interrupt_handler
& 0x0001DC00;
dev->dma_reason[4] = b43_read32(dev, B43_MMIO_DMA4_REASON)
& 0x0000DC00;
+/* Unused ring
dev->dma_reason[5] = b43_read32(dev, B43_MMIO_DMA5_REASON)
& 0x0000DC00;
+*/
b43_interrupt_ack(dev, reason);
/* disable all IRQs. They are enabled again in the bottom half. */
- dev->irq_savedstate = b43_interrupt_disable(dev, B43_IRQ_ALL);
+ b43_write32(dev, B43_MMIO_GEN_IRQ_MASK, 0);
/* save the reason code and call our bottom half. */
dev->irq_reason = reason;
tasklet_schedule(&dev->isr_tasklet);
- out:
+out:
mmiowb();
spin_unlock(&dev->wl->irq_lock);
@@ -3799,7 +3776,7 @@ static void b43_wireless_core_stop(struc
* 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 = b43_interrupt_disable(dev, B43_IRQ_ALL);
+ b43_write32(dev, B43_MMIO_GEN_IRQ_MASK, 0);
b43_read32(dev, B43_MMIO_GEN_IRQ_MASK); /* flush */
spin_unlock_irqrestore(&wl->irq_lock, flags);
b43_synchronize_irq(dev);
@@ -3840,7 +3817,7 @@ static int b43_wireless_core_start(struc
/* Start data flow (TX/RX). */
b43_mac_enable(dev);
- b43_interrupt_enable(dev, dev->irq_savedstate);
+ b43_write32(dev, B43_MMIO_GEN_IRQ_MASK, dev->irq_mask);
/* Start maintainance work */
b43_periodic_tasks_setup(dev);
@@ -3998,9 +3975,9 @@ static void setup_struct_wldev_for_init(
/* IRQ related flags */
dev->irq_reason = 0;
memset(dev->dma_reason, 0, sizeof(dev->dma_reason));
- dev->irq_savedstate = B43_IRQ_MASKTEMPLATE;
+ dev->irq_mask = B43_IRQ_MASKTEMPLATE;
if (b43_modparam_verbose < B43_VERBOSITY_DEBUG)
- dev->irq_savedstate &= ~B43_IRQ_PHY_TXERR;
+ dev->irq_mask &= ~B43_IRQ_PHY_TXERR;
dev->mac_suspended = 1;
--
Greetings, Michael.
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
