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>

3 files changed, 0 insertions, 13 deletions

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 8154b38c08f7..316b47741d3f 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -728,7 +728,6 @@ static irqreturn_t ravb_emac_interrupt(int irq, void *dev_id)
 
 	spin_lock(&priv->lock);
 	ravb_emac_interrupt_unlocked(ndev);
-	mmiowb();
 	spin_unlock(&priv->lock);
 	return IRQ_HANDLED;
 }
@@ -848,7 +847,6 @@ static irqreturn_t ravb_interrupt(int irq, void *dev_id)
 		result = IRQ_HANDLED;
 	}
 
-	mmiowb();
 	spin_unlock(&priv->lock);
 	return result;
 }
@@ -881,7 +879,6 @@ static irqreturn_t ravb_multi_interrupt(int irq, void *dev_id)
 		result = IRQ_HANDLED;
 	}
 
-	mmiowb();
 	spin_unlock(&priv->lock);
 	return result;
 }
@@ -898,7 +895,6 @@ static irqreturn_t ravb_dma_interrupt(int irq, void *dev_id, int q)
 	if (ravb_queue_interrupt(ndev, q))
 		result = IRQ_HANDLED;
 
-	mmiowb();
 	spin_unlock(&priv->lock);
 	return result;
 }
@@ -943,7 +939,6 @@ static int ravb_poll(struct napi_struct *napi, int budget)
 			ravb_write(ndev, ~(mask | TIS_RESERVED), TIS);
 			ravb_tx_free(ndev, q, true);
 			netif_wake_subqueue(ndev, q);
-			mmiowb();
 			spin_unlock_irqrestore(&priv->lock, flags);
 		}
 	}
@@ -959,7 +954,6 @@ static int ravb_poll(struct napi_struct *napi, int budget)
 		ravb_write(ndev, mask, RIE0);
 		ravb_write(ndev, mask, TIE);
 	}
-	mmiowb();
 	spin_unlock_irqrestore(&priv->lock, flags);
 
 	/* Receive error message handling */
@@ -1008,7 +1002,6 @@ static void ravb_adjust_link(struct net_device *ndev)
 	if (priv->no_avb_link && phydev->link)
 		ravb_rcv_snd_enable(ndev);
 
-	mmiowb();
 	spin_unlock_irqrestore(&priv->lock, flags);
 
 	if (new_state && netif_msg_link(priv))
@@ -1601,7 +1594,6 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 		netif_stop_subqueue(ndev, q);
 
 exit:
-	mmiowb();
 	spin_unlock_irqrestore(&priv->lock, flags);
 	return NETDEV_TX_OK;
 
@@ -1673,7 +1665,6 @@ static void ravb_set_rx_mode(struct net_device *ndev)
 	spin_lock_irqsave(&priv->lock, flags);
 	ravb_modify(ndev, ECMR, ECMR_PRM,
 		    ndev->flags & IFF_PROMISC ? ECMR_PRM : 0);
-	mmiowb();
 	spin_unlock_irqrestore(&priv->lock, flags);
 }
 
diff --git a/drivers/net/ethernet/renesas/ravb_ptp.c b/drivers/net/ethernet/renesas/ravb_ptp.c
index dce2a40a31e3..9a42580693cb 100644
--- a/drivers/net/ethernet/renesas/ravb_ptp.c
+++ b/drivers/net/ethernet/renesas/ravb_ptp.c
@@ -196,7 +196,6 @@ static int ravb_ptp_extts(struct ptp_clock_info *ptp,
 		ravb_write(ndev, GIE_PTCS, GIE);
 	else
 		ravb_write(ndev, GID_PTCD, GID);
-	mmiowb();
 	spin_unlock_irqrestore(&priv->lock, flags);
 
 	return 0;
@@ -259,7 +258,6 @@ static int ravb_ptp_perout(struct ptp_clock_info *ptp,
 		else
 			ravb_write(ndev, GID_PTMD0, GID);
 	}
-	mmiowb();
 	spin_unlock_irqrestore(&priv->lock, flags);
 
 	return error;
@@ -331,7 +329,6 @@ void ravb_ptp_init(struct net_device *ndev, struct platform_device *pdev)
 	spin_lock_irqsave(&priv->lock, flags);
 	ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
 	ravb_modify(ndev, GCCR, GCCR_TCSS, GCCR_TCSS_ADJGPTP);
-	mmiowb();
 	spin_unlock_irqrestore(&priv->lock, flags);
 
 	priv->ptp.clock = ptp_clock_register(&priv->ptp.info, &pdev->dev);
diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index e33af371b169..ed30aebdb941 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -2010,7 +2010,6 @@ static void sh_eth_adjust_link(struct net_device *ndev)
 	if ((mdp->cd->no_psr || mdp->no_ether_link) && phydev->link)
 		sh_eth_rcv_snd_enable(ndev);
 
-	mmiowb();
 	spin_unlock_irqrestore(&mdp->lock, flags);
 
 	if (new_state && netif_msg_link(mdp))