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>

1 files changed, 0 insertions, 13 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index a8141ff9be03..42e1bad024f4 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1807,7 +1807,6 @@ void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
 			sdhci_send_command(host, mrq->cmd);
 	}
 
-	mmiowb();
 	spin_unlock_irqrestore(&host->lock, flags);
 }
 EXPORT_SYMBOL_GPL(sdhci_request);
@@ -2010,8 +2009,6 @@ void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 	 */
 	if (host->quirks & SDHCI_QUIRK_RESET_CMD_DATA_ON_IOS)
 		sdhci_do_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
-
-	mmiowb();
 }
 EXPORT_SYMBOL_GPL(sdhci_set_ios);
 
@@ -2105,7 +2102,6 @@ static void sdhci_enable_sdio_irq_nolock(struct sdhci_host *host, int enable)
 
 		sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
 		sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
-		mmiowb();
 	}
 }
 
@@ -2353,7 +2349,6 @@ void sdhci_send_tuning(struct sdhci_host *host, u32 opcode)
 
 	host->tuning_done = 0;
 
-	mmiowb();
 	spin_unlock_irqrestore(&host->lock, flags);
 
 	/* Wait for Buffer Read Ready interrupt */
@@ -2705,7 +2700,6 @@ static bool sdhci_request_done(struct sdhci_host *host)
 
 	host->mrqs_done[i] = NULL;
 
-	mmiowb();
 	spin_unlock_irqrestore(&host->lock, flags);
 
 	mmc_request_done(host->mmc, mrq);
@@ -2739,7 +2733,6 @@ static void sdhci_timeout_timer(struct timer_list *t)
 		sdhci_finish_mrq(host, host->cmd->mrq);
 	}
 
-	mmiowb();
 	spin_unlock_irqrestore(&host->lock, flags);
 }
 
@@ -2770,7 +2763,6 @@ static void sdhci_timeout_data_timer(struct timer_list *t)
 		}
 	}
 
-	mmiowb();
 	spin_unlock_irqrestore(&host->lock, flags);
 }
 
@@ -3251,7 +3243,6 @@ int sdhci_resume_host(struct sdhci_host *host)
 		mmc->ops->set_ios(mmc, &mmc->ios);
 	} else {
 		sdhci_init(host, (host->mmc->pm_flags & MMC_PM_KEEP_POWER));
-		mmiowb();
 	}
 
 	if (host->irq_wake_enabled) {
@@ -3391,7 +3382,6 @@ void sdhci_cqe_enable(struct mmc_host *mmc)
 		 mmc_hostname(mmc), host->ier,
 		 sdhci_readl(host, SDHCI_INT_STATUS));
 
-	mmiowb();
 	spin_unlock_irqrestore(&host->lock, flags);
 }
 EXPORT_SYMBOL_GPL(sdhci_cqe_enable);
@@ -3416,7 +3406,6 @@ void sdhci_cqe_disable(struct mmc_host *mmc, bool recovery)
 		 mmc_hostname(mmc), host->ier,
 		 sdhci_readl(host, SDHCI_INT_STATUS));
 
-	mmiowb();
 	spin_unlock_irqrestore(&host->lock, flags);
 }
 EXPORT_SYMBOL_GPL(sdhci_cqe_disable);
@@ -4255,8 +4244,6 @@ int __sdhci_add_host(struct sdhci_host *host)
 		goto unirq;
 	}
 
-	mmiowb();
-
 	ret = mmc_add_host(mmc);
 	if (ret)
 		goto unled;