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, 8 deletions

diff --git a/drivers/media/pci/dt3155/dt3155.c b/drivers/media/pci/dt3155/dt3155.c
index 17d69bd5d7f1..49677ee889e3 100644
--- a/drivers/media/pci/dt3155/dt3155.c
+++ b/drivers/media/pci/dt3155/dt3155.c
@@ -46,7 +46,6 @@ static int read_i2c_reg(void __iomem *addr, u8 index, u8 *data)
 	u32 tmp = index;
 
 	iowrite32((tmp << 17) | IIC_READ, addr + IIC_CSR2);
-	mmiowb();
 	udelay(45); /* wait at least 43 usec for NEW_CYCLE to clear */
 	if (ioread32(addr + IIC_CSR2) & NEW_CYCLE)
 		return -EIO; /* error: NEW_CYCLE not cleared */
@@ -77,7 +76,6 @@ static int write_i2c_reg(void __iomem *addr, u8 index, u8 data)
 	u32 tmp = index;
 
 	iowrite32((tmp << 17) | IIC_WRITE | data, addr + IIC_CSR2);
-	mmiowb();
 	udelay(65); /* wait at least 63 usec for NEW_CYCLE to clear */
 	if (ioread32(addr + IIC_CSR2) & NEW_CYCLE)
 		return -EIO; /* error: NEW_CYCLE not cleared */
@@ -104,7 +102,6 @@ static void write_i2c_reg_nowait(void __iomem *addr, u8 index, u8 data)
 	u32 tmp = index;
 
 	iowrite32((tmp << 17) | IIC_WRITE | data, addr + IIC_CSR2);
-	mmiowb();
 }
 
 /**
@@ -264,7 +261,6 @@ static irqreturn_t dt3155_irq_handler_even(int irq, void *dev_id)
 						FLD_DN_ODD | FLD_DN_EVEN |
 						CAP_CONT_EVEN | CAP_CONT_ODD,
 							ipd->regs + CSR1);
-		mmiowb();
 	}
 
 	spin_lock(&ipd->lock);
@@ -282,7 +278,6 @@ static irqreturn_t dt3155_irq_handler_even(int irq, void *dev_id)
 		iowrite32(dma_addr + ipd->width, ipd->regs + ODD_DMA_START);
 		iowrite32(ipd->width, ipd->regs + EVEN_DMA_STRIDE);
 		iowrite32(ipd->width, ipd->regs + ODD_DMA_STRIDE);
-		mmiowb();
 	}
 
 	/* enable interrupts, clear all irq flags */
@@ -437,12 +432,10 @@ static int dt3155_init_board(struct dt3155_priv *pd)
 	/*  resetting the adapter  */
 	iowrite32(ADDR_ERR_ODD | ADDR_ERR_EVEN | FLD_CRPT_ODD | FLD_CRPT_EVEN |
 			FLD_DN_ODD | FLD_DN_EVEN, pd->regs + CSR1);
-	mmiowb();
 	msleep(20);
 
 	/*  initializing adapter registers  */
 	iowrite32(FIFO_EN | SRST, pd->regs + CSR1);
-	mmiowb();
 	iowrite32(0xEEEEEE01, pd->regs + EVEN_PIXEL_FMT);
 	iowrite32(0xEEEEEE01, pd->regs + ODD_PIXEL_FMT);
 	iowrite32(0x00000020, pd->regs + FIFO_TRIGER);
@@ -454,7 +447,6 @@ static int dt3155_init_board(struct dt3155_priv *pd)
 	iowrite32(0, pd->regs + MASK_LENGTH);
 	iowrite32(0x0005007C, pd->regs + FIFO_FLAG_CNT);
 	iowrite32(0x01010101, pd->regs + IIC_CLK_DUR);
-	mmiowb();
 
 	/* verifying that we have a DT3155 board (not just a SAA7116 chip) */
 	read_i2c_reg(pd->regs, DT_ID, &tmp);