drivers: Remove explicit invocations of mmiowb()

mmiowb() is now implied by spin_unlock() on architectures that require
it, so there is no reason to call it from driver code. This patch was
generated using coccinelle:

	@mmiowb@
	@@
	- mmiowb();

and invoked as:

$ for d in drivers include/linux/qed sound; do \
spatch --include-headers --sp-file mmiowb.cocci --dir $d --in-place; done

NOTE: mmiowb() has only ever guaranteed ordering in conjunction with
spin_unlock(). However, pairing each mmiowb() removal in this patch with
the corresponding call to spin_unlock() is not at all trivial, so there
is a small chance that this change may regress any drivers incorrectly
relying on mmiowb() to order MMIO writes between CPUs using lock-free
synchronisation. If you've ended up bisecting to this commit, you can
reintroduce the mmiowb() calls using wmb() instead, which should restore
the old behaviour on all architectures other than some esoteric ia64
systems.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

12 files changed, 0 insertions, 51 deletions

diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
index a2351ef45ae0..65a4c142640d 100644
--- a/drivers/net/wireless/ath/ath5k/base.c
+++ b/drivers/net/wireless/ath/ath5k/base.c
@@ -837,7 +837,6 @@ ath5k_txbuf_setup(struct ath5k_hw *ah, struct ath5k_buf *bf,
 
 	txq->link = &ds->ds_link;
 	ath5k_hw_start_tx_dma(ah, txq->qnum);
-	mmiowb();
 	spin_unlock_bh(&txq->lock);
 
 	return 0;
@@ -2174,7 +2173,6 @@ ath5k_beacon_config(struct ath5k_hw *ah)
 	}
 
 	ath5k_hw_set_imr(ah, ah->imask);
-	mmiowb();
 	spin_unlock_bh(&ah->block);
 }
 
@@ -2779,7 +2777,6 @@ int ath5k_start(struct ieee80211_hw *hw)
 
 	ret = 0;
 done:
-	mmiowb();
 	mutex_unlock(&ah->lock);
 
 	set_bit(ATH_STAT_STARTED, ah->status);
@@ -2839,7 +2836,6 @@ void ath5k_stop(struct ieee80211_hw *hw)
 				"putting device to sleep\n");
 	}
 
-	mmiowb();
 	mutex_unlock(&ah->lock);
 
 	ath5k_stop_tasklets(ah);
diff --git a/drivers/net/wireless/ath/ath5k/mac80211-ops.c b/drivers/net/wireless/ath/ath5k/mac80211-ops.c
index 16e052d02c94..5e866a193ed0 100644
--- a/drivers/net/wireless/ath/ath5k/mac80211-ops.c
+++ b/drivers/net/wireless/ath/ath5k/mac80211-ops.c
@@ -263,7 +263,6 @@ ath5k_bss_info_changed(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 		memcpy(common->curbssid, bss_conf->bssid, ETH_ALEN);
 		common->curaid = 0;
 		ath5k_hw_set_bssid(ah);
-		mmiowb();
 	}
 
 	if (changes & BSS_CHANGED_BEACON_INT)
@@ -528,7 +527,6 @@ ath5k_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 		ret = -EINVAL;
 	}
 
-	mmiowb();
 	mutex_unlock(&ah->lock);
 	return ret;
 }
diff --git a/drivers/net/wireless/broadcom/b43/main.c b/drivers/net/wireless/broadcom/b43/main.c
index 74be3c809225..4c7980f84591 100644
--- a/drivers/net/wireless/broadcom/b43/main.c
+++ b/drivers/net/wireless/broadcom/b43/main.c
@@ -485,7 +485,6 @@ static void b43_ram_write(struct b43_wldev *dev, u16 offset, u32 val)
 		val = swab32(val);
 
 	b43_write32(dev, B43_MMIO_RAM_CONTROL, offset);
-	mmiowb();
 	b43_write32(dev, B43_MMIO_RAM_DATA, val);
 }
 
@@ -656,9 +655,7 @@ static void b43_tsf_write_locked(struct b43_wldev *dev, u64 tsf)
 	/* The hardware guarantees us an atomic write, if we
 	 * write the low register first. */
 	b43_write32(dev, B43_MMIO_REV3PLUS_TSF_LOW, low);
-	mmiowb();
 	b43_write32(dev, B43_MMIO_REV3PLUS_TSF_HIGH, high);
-	mmiowb();
 }
 
 void b43_tsf_write(struct b43_wldev *dev, u64 tsf)
@@ -1822,11 +1819,9 @@ static void b43_beacon_update_trigger_work(struct work_struct *work)
 		if (b43_bus_host_is_sdio(dev->dev)) {
 			/* wl->mutex is enough. */
 			b43_do_beacon_update_trigger_work(dev);
-			mmiowb();
 		} else {
 			spin_lock_irq(&wl->hardirq_lock);
 			b43_do_beacon_update_trigger_work(dev);
-			mmiowb();
 			spin_unlock_irq(&wl->hardirq_lock);
 		}
 	}
@@ -2078,7 +2073,6 @@ static irqreturn_t b43_interrupt_thread_handler(int irq, void *dev_id)
 
 	mutex_lock(&dev->wl->mutex);
 	b43_do_interrupt_thread(dev);
-	mmiowb();
 	mutex_unlock(&dev->wl->mutex);
 
 	return IRQ_HANDLED;
@@ -2143,7 +2137,6 @@ static irqreturn_t b43_interrupt_handler(int irq, void *dev_id)
 
 	spin_lock(&dev->wl->hardirq_lock);
 	ret = b43_do_interrupt(dev);
-	mmiowb();
 	spin_unlock(&dev->wl->hardirq_lock);
 
 	return ret;
diff --git a/drivers/net/wireless/broadcom/b43/sysfs.c b/drivers/net/wireless/broadcom/b43/sysfs.c
index 3190493bd07f..93d03b673670 100644
--- a/drivers/net/wireless/broadcom/b43/sysfs.c
+++ b/drivers/net/wireless/broadcom/b43/sysfs.c
@@ -129,7 +129,6 @@ static ssize_t b43_attr_interfmode_store(struct device *dev,
 	} else
 		err = -ENOSYS;
 
-	mmiowb();
 	mutex_unlock(&wldev->wl->mutex);
 
 	return err ? err : count;
diff --git a/drivers/net/wireless/broadcom/b43legacy/ilt.c b/drivers/net/wireless/broadcom/b43legacy/ilt.c
index ee5682e54204..6d15fb4d30c6 100644
--- a/drivers/net/wireless/broadcom/b43legacy/ilt.c
+++ b/drivers/net/wireless/broadcom/b43legacy/ilt.c
@@ -315,14 +315,12 @@ const u16 b43legacy_ilt_sigmasqr2[B43legacy_ILT_SIGMASQR_SIZE] = {
 void b43legacy_ilt_write(struct b43legacy_wldev *dev, u16 offset, u16 val)
 {
 	b43legacy_phy_write(dev, B43legacy_PHY_ILT_G_CTRL, offset);
-	mmiowb();
 	b43legacy_phy_write(dev, B43legacy_PHY_ILT_G_DATA1, val);
 }
 
 void b43legacy_ilt_write32(struct b43legacy_wldev *dev, u16 offset, u32 val)
 {
 	b43legacy_phy_write(dev, B43legacy_PHY_ILT_G_CTRL, offset);
-	mmiowb();
 	b43legacy_phy_write(dev, B43legacy_PHY_ILT_G_DATA2,
 			    (val & 0xFFFF0000) >> 16);
 	b43legacy_phy_write(dev, B43legacy_PHY_ILT_G_DATA1,
diff --git a/drivers/net/wireless/broadcom/b43legacy/main.c b/drivers/net/wireless/broadcom/b43legacy/main.c
index 55f411925960..c777efc6dc13 100644
--- a/drivers/net/wireless/broadcom/b43legacy/main.c
+++ b/drivers/net/wireless/broadcom/b43legacy/main.c
@@ -264,7 +264,6 @@ static void b43legacy_ram_write(struct b43legacy_wldev *dev, u16 offset,
 		val = swab32(val);
 
 	b43legacy_write32(dev, B43legacy_MMIO_RAM_CONTROL, offset);
-	mmiowb();
 	b43legacy_write32(dev, B43legacy_MMIO_RAM_DATA, val);
 }
 
@@ -341,14 +340,11 @@ void b43legacy_shm_write32(struct b43legacy_wldev *dev,
 		if (offset & 0x0003) {
 			/* Unaligned access */
 			b43legacy_shm_control_word(dev, routing, offset >> 2);
-			mmiowb();
 			b43legacy_write16(dev,
 					  B43legacy_MMIO_SHM_DATA_UNALIGNED,
 					  (value >> 16) & 0xffff);
-			mmiowb();
 			b43legacy_shm_control_word(dev, routing,
 						   (offset >> 2) + 1);
-			mmiowb();
 			b43legacy_write16(dev, B43legacy_MMIO_SHM_DATA,
 					  value & 0xffff);
 			return;
@@ -356,7 +352,6 @@ void b43legacy_shm_write32(struct b43legacy_wldev *dev,
 		offset >>= 2;
 	}
 	b43legacy_shm_control_word(dev, routing, offset);
-	mmiowb();
 	b43legacy_write32(dev, B43legacy_MMIO_SHM_DATA, value);
 }
 
@@ -368,7 +363,6 @@ void b43legacy_shm_write16(struct b43legacy_wldev *dev, u16 routing, u16 offset,
 		if (offset & 0x0003) {
 			/* Unaligned access */
 			b43legacy_shm_control_word(dev, routing, offset >> 2);
-			mmiowb();
 			b43legacy_write16(dev,
 					  B43legacy_MMIO_SHM_DATA_UNALIGNED,
 					  value);
@@ -377,7 +371,6 @@ void b43legacy_shm_write16(struct b43legacy_wldev *dev, u16 routing, u16 offset,
 		offset >>= 2;
 	}
 	b43legacy_shm_control_word(dev, routing, offset);
-	mmiowb();
 	b43legacy_write16(dev, B43legacy_MMIO_SHM_DATA, value);
 }
 
@@ -471,7 +464,6 @@ static void b43legacy_time_lock(struct b43legacy_wldev *dev)
 	status = b43legacy_read32(dev, B43legacy_MMIO_MACCTL);
 	status |= B43legacy_MACCTL_TBTTHOLD;
 	b43legacy_write32(dev, B43legacy_MMIO_MACCTL, status);
-	mmiowb();
 }
 
 static void b43legacy_time_unlock(struct b43legacy_wldev *dev)
@@ -494,10 +486,8 @@ static void b43legacy_tsf_write_locked(struct b43legacy_wldev *dev, u64 tsf)
 		u32 hi = (tsf & 0xFFFFFFFF00000000ULL) >> 32;
 
 		b43legacy_write32(dev, B43legacy_MMIO_REV3PLUS_TSF_LOW, 0);
-		mmiowb();
 		b43legacy_write32(dev, B43legacy_MMIO_REV3PLUS_TSF_HIGH,
 				    hi);
-		mmiowb();
 		b43legacy_write32(dev, B43legacy_MMIO_REV3PLUS_TSF_LOW,
 				    lo);
 	} else {
@@ -507,13 +497,9 @@ static void b43legacy_tsf_write_locked(struct b43legacy_wldev *dev, u64 tsf)
 		u16 v3 = (tsf & 0xFFFF000000000000ULL) >> 48;
 
 		b43legacy_write16(dev, B43legacy_MMIO_TSF_0, 0);
-		mmiowb();
 		b43legacy_write16(dev, B43legacy_MMIO_TSF_3, v3);
-		mmiowb();
 		b43legacy_write16(dev, B43legacy_MMIO_TSF_2, v2);
-		mmiowb();
 		b43legacy_write16(dev, B43legacy_MMIO_TSF_1, v1);
-		mmiowb();
 		b43legacy_write16(dev, B43legacy_MMIO_TSF_0, v0);
 	}
 }
@@ -1250,7 +1236,6 @@ static void b43legacy_beacon_update_trigger_work(struct work_struct *work)
 		/* The handler might have updated the IRQ mask. */
 		b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK,
 				  dev->irq_mask);
-		mmiowb();
 		spin_unlock_irq(&wl->irq_lock);
 	}
 	mutex_unlock(&wl->mutex);
@@ -1346,7 +1331,6 @@ static void b43legacy_interrupt_tasklet(struct b43legacy_wldev *dev)
 			       dma_reason[2], dma_reason[3],
 			       dma_reason[4], dma_reason[5]);
 			b43legacy_controller_restart(dev, "DMA error");
-			mmiowb();
 			spin_unlock_irqrestore(&dev->wl->irq_lock, flags);
 			return;
 		}
@@ -1396,7 +1380,6 @@ static void b43legacy_interrupt_tasklet(struct b43legacy_wldev *dev)
 		handle_irq_transmit_status(dev);
 
 	b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, dev->irq_mask);
-	mmiowb();
 	spin_unlock_irqrestore(&dev->wl->irq_lock, flags);
 }
 
@@ -1488,7 +1471,6 @@ static irqreturn_t b43legacy_interrupt_handler(int irq, void *dev_id)
 	dev->irq_reason = reason;
 	tasklet_schedule(&dev->isr_tasklet);
 out:
-	mmiowb();
 	spin_unlock(&dev->wl->irq_lock);
 
 	return ret;
@@ -2781,7 +2763,6 @@ static int b43legacy_op_dev_config(struct ieee80211_hw *hw,
 
 	spin_lock_irqsave(&wl->irq_lock, flags);
 	b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, dev->irq_mask);
-	mmiowb();
 	spin_unlock_irqrestore(&wl->irq_lock, flags);
 out_unlock_mutex:
 	mutex_unlock(&wl->mutex);
@@ -2900,7 +2881,6 @@ static void b43legacy_op_bss_info_changed(struct ieee80211_hw *hw,
 	spin_lock_irqsave(&wl->irq_lock, flags);
 	b43legacy_write32(dev, B43legacy_MMIO_GEN_IRQ_MASK, dev->irq_mask);
 	/* XXX: why? */
-	mmiowb();
 	spin_unlock_irqrestore(&wl->irq_lock, flags);
  out_unlock_mutex:
 	mutex_unlock(&wl->mutex);
diff --git a/drivers/net/wireless/broadcom/b43legacy/phy.c b/drivers/net/wireless/broadcom/b43legacy/phy.c
index 995c7d0c212a..f949766d27ca 100644
--- a/drivers/net/wireless/broadcom/b43legacy/phy.c
+++ b/drivers/net/wireless/broadcom/b43legacy/phy.c
@@ -134,7 +134,6 @@ u16 b43legacy_phy_read(struct b43legacy_wldev *dev, u16 offset)
 void b43legacy_phy_write(struct b43legacy_wldev *dev, u16 offset, u16 val)
 {
 	b43legacy_write16(dev, B43legacy_MMIO_PHY_CONTROL, offset);
-	mmiowb();
 	b43legacy_write16(dev, B43legacy_MMIO_PHY_DATA, val);
 }
 
diff --git a/drivers/net/wireless/broadcom/b43legacy/pio.h b/drivers/net/wireless/broadcom/b43legacy/pio.h
index 1cd1b9ca5e9c..08cd02282beb 100644
--- a/drivers/net/wireless/broadcom/b43legacy/pio.h
+++ b/drivers/net/wireless/broadcom/b43legacy/pio.h
@@ -92,7 +92,6 @@ void b43legacy_pio_write(struct b43legacy_pioqueue *queue,
 		       u16 offset, u16 value)
 {
 	b43legacy_write16(queue->dev, queue->mmio_base + offset, value);
-	mmiowb();
 }
 
 
diff --git a/drivers/net/wireless/broadcom/b43legacy/radio.c b/drivers/net/wireless/broadcom/b43legacy/radio.c
index eab1c9387846..c6db444ea07e 100644
--- a/drivers/net/wireless/broadcom/b43legacy/radio.c
+++ b/drivers/net/wireless/broadcom/b43legacy/radio.c
@@ -95,7 +95,6 @@ void b43legacy_radio_lock(struct b43legacy_wldev *dev)
 	B43legacy_WARN_ON(status & B43legacy_MACCTL_RADIOLOCK);
 	status |= B43legacy_MACCTL_RADIOLOCK;
 	b43legacy_write32(dev, B43legacy_MMIO_MACCTL, status);
-	mmiowb();
 	udelay(10);
 }
 
@@ -108,7 +107,6 @@ void b43legacy_radio_unlock(struct b43legacy_wldev *dev)
 	B43legacy_WARN_ON(!(status & B43legacy_MACCTL_RADIOLOCK));
 	status &= ~B43legacy_MACCTL_RADIOLOCK;
 	b43legacy_write32(dev, B43legacy_MMIO_MACCTL, status);
-	mmiowb();
 }
 
 u16 b43legacy_radio_read16(struct b43legacy_wldev *dev, u16 offset)
@@ -141,7 +139,6 @@ u16 b43legacy_radio_read16(struct b43legacy_wldev *dev, u16 offset)
 void b43legacy_radio_write16(struct b43legacy_wldev *dev, u16 offset, u16 val)
 {
 	b43legacy_write16(dev, B43legacy_MMIO_RADIO_CONTROL, offset);
-	mmiowb();
 	b43legacy_write16(dev, B43legacy_MMIO_RADIO_DATA_LOW, val);
 }
 
@@ -333,7 +330,6 @@ u8 b43legacy_radio_aci_scan(struct b43legacy_wldev *dev)
 void b43legacy_nrssi_hw_write(struct b43legacy_wldev *dev, u16 offset, s16 val)
 {
 	b43legacy_phy_write(dev, B43legacy_PHY_NRSSILT_CTRL, offset);
-	mmiowb();
 	b43legacy_phy_write(dev, B43legacy_PHY_NRSSILT_DATA, (u16)val);
 }
 
diff --git a/drivers/net/wireless/broadcom/b43legacy/sysfs.c b/drivers/net/wireless/broadcom/b43legacy/sysfs.c
index 2a1da15c913b..2db83eec7a11 100644
--- a/drivers/net/wireless/broadcom/b43legacy/sysfs.c
+++ b/drivers/net/wireless/broadcom/b43legacy/sysfs.c
@@ -143,7 +143,6 @@ static ssize_t b43legacy_attr_interfmode_store(struct device *dev,
 	if (err)
 		b43legacyerr(wldev->wl, "Interference Mitigation not "
 		       "supported by device\n");
-	mmiowb();
 	spin_unlock_irqrestore(&wldev->wl->irq_lock, flags);
 	mutex_unlock(&wldev->wl->mutex);
 
diff --git a/drivers/net/wireless/intel/iwlegacy/common.h b/drivers/net/wireless/intel/iwlegacy/common.h
index b079c64ca014..986646af8dfd 100644
--- a/drivers/net/wireless/intel/iwlegacy/common.h
+++ b/drivers/net/wireless/intel/iwlegacy/common.h
@@ -2030,13 +2030,6 @@ static inline void
 _il_release_nic_access(struct il_priv *il)
 {
 	_il_clear_bit(il, CSR_GP_CNTRL, CSR_GP_CNTRL_REG_FLAG_MAC_ACCESS_REQ);
-	/*
-	 * In above we are reading CSR_GP_CNTRL register, what will flush any
-	 * previous writes, but still want write, which clear MAC_ACCESS_REQ
-	 * bit, be performed on PCI bus before any other writes scheduled on
-	 * different CPUs (after we drop reg_lock).
-	 */
-	mmiowb();
 }
 
 static inline u32
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index fe8269d023de..abbfc9cc80fc 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
@@ -2067,7 +2067,6 @@ static void iwl_trans_pcie_release_nic_access(struct iwl_trans *trans,
 	 * MAC_ACCESS_REQ bit to be performed before any other writes
 	 * scheduled on different CPUs (after we drop reg_lock).
 	 */
-	mmiowb();
 out:
 	spin_unlock_irqrestore(&trans_pcie->reg_lock, *flags);
 }