From: Michael Büsch Date: Wed, 8 Apr 2009 19:03:10 +0000 (+0000) Subject: b43: Remove unnecessary MMIO accesses in the interrupt hotpath. X-Git-Tag: reboot~24008 X-Git-Url: http://git.openwrt.org/?p=openwrt%2Fopenwrt.git;a=commitdiff_plain;h=efceb0938c7a8c923668e7044250dabf63ca2fa7 b43: Remove unnecessary MMIO accesses in the interrupt hotpath. SVN-Revision: 15160 --- diff --git a/package/mac80211/patches/530-b43-optimize-hotpath-mmio.patch b/package/mac80211/patches/530-b43-optimize-hotpath-mmio.patch new file mode 100644 index 0000000000..3413731993 --- /dev/null +++ b/package/mac80211/patches/530-b43-optimize-hotpath-mmio.patch @@ -0,0 +1,177 @@ +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; +