Commit 13790728 authored by Michael Buesch's avatar Michael Buesch Committed by John W. Linville
Browse files

b43: Remove unnecessary MMIO in interrupt hotpath 



This removes unnecessary MMIO accesses in the interrupt hotpath.

Signed-off-by: default avatarMichael Buesch <mb@bu3sch.de>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent a2caba6b

drivers/net/wireless/b43/b43.h

+2 −2
Original line number Diff line number Diff line
@@ -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. */

drivers/net/wireless/b43/main.c

+19 −42
Original line number Diff line number Diff line
@@ -673,32 +673,6 @@ static void b43_short_slot_timing_disable(struct b43_wldev *dev) 
	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_wldev *dev) 
	/* 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_wldev *dev) 
	/* 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_work(struct work_struct *work) 
	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 b43_wldev *dev) 
	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_wldev *dev, u32 reason) 
	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(int irq, void *dev_id) 
	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;
@@ -1928,12 +1903,14 @@ static irqreturn_t b43_interrupt_handler(int irq, void *dev_id) 
	    & 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);
@@ -3799,7 +3776,7 @@ static void b43_wireless_core_stop(struct b43_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 = 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(struct b43_wldev *dev) 


	/* 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);
@@ -4003,9 +3980,9 @@ static void setup_struct_wldev_for_init(struct b43_wldev *dev) 
	/* 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;