Merge tag 'arm64-mmiowb' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull mmiowb removal from Will Deacon:
 "Remove Mysterious Macro Intended to Obscure Weird Behaviours (mmiowb())

  Remove mmiowb() from the kernel memory barrier API and instead, for
  architectures that need it, hide the barrier inside spin_unlock() when
  MMIO has been performed inside the critical section.

  The only relatively recent changes have been addressing review
  comments on the documentation, which is in a much better shape thanks
  to the efforts of Ben and Ingo.

  I was initially planning to split this into two pull requests so that
  you could run the coccinelle script yourself, however it's been plain
  sailing in linux-next so I've just included the whole lot here to keep
  things simple"

* tag 'arm64-mmiowb' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (23 commits)
  docs/memory-barriers.txt: Update I/O section to be clearer about CPU vs thread
  docs/memory-barriers.txt: Fix style, spacing and grammar in I/O section
  arch: Remove dummy mmiowb() definitions from arch code
  net/ethernet/silan/sc92031: Remove stale comment about mmiowb()
  i40iw: Redefine i40iw_mmiowb() to do nothing
  scsi/qla1280: Remove stale comment about mmiowb()
  drivers: Remove explicit invocations of mmiowb()
  drivers: Remove useless trailing comments from mmiowb() invocations
  Documentation: Kill all references to mmiowb()
  riscv/mmiowb: Hook up mmwiob() implementation to asm-generic code
  powerpc/mmiowb: Hook up mmwiob() implementation to asm-generic code
  ia64/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
  mips/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
  sh/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()
  m68k/io: Remove useless definition of mmiowb()
  nds32/io: Remove useless definition of mmiowb()
  x86/io: Remove useless definition of mmiowb()
  arm64/io: Remove useless definition of mmiowb()
  ARM/io: Remove useless definition of mmiowb()
  mmiowb: Hook up mmiowb helpers to spinlocks and generic I/O accessors
  ...

6 files changed, 0 insertions, 11 deletions

diff --git a/drivers/staging/comedi/drivers/mite.c b/drivers/staging/comedi/drivers/mite.c
index 61e03ad84123..639ec1586976 100644
--- a/drivers/staging/comedi/drivers/mite.c
+++ b/drivers/staging/comedi/drivers/mite.c
@@ -371,7 +371,6 @@ static unsigned int mite_get_status(struct mite_channel *mite_chan)
 		writel(CHOR_CLRDONE,
 		       mite->mmio + MITE_CHOR(mite_chan->channel));
 	}
-	mmiowb();
 	spin_unlock_irqrestore(&mite->lock, flags);
 	return status;
 }
@@ -451,7 +450,6 @@ void mite_dma_arm(struct mite_channel *mite_chan)
 	mite_chan->done = 0;
 	/* arm */
 	writel(CHOR_START, mite->mmio + MITE_CHOR(mite_chan->channel));
-	mmiowb();
 	spin_unlock_irqrestore(&mite->lock, flags);
 }
 EXPORT_SYMBOL_GPL(mite_dma_arm);
@@ -638,7 +636,6 @@ void mite_release_channel(struct mite_channel *mite_chan)
 		       CHCR_CLR_LC_IE | CHCR_CLR_CONT_RB_IE,
 		       mite->mmio + MITE_CHCR(mite_chan->channel));
 		mite_chan->ring = NULL;
-		mmiowb();
 	}
 	spin_unlock_irqrestore(&mite->lock, flags);
 }
diff --git a/drivers/staging/comedi/drivers/ni_660x.c b/drivers/staging/comedi/drivers/ni_660x.c
index 405573e927cf..4ee9b260eab0 100644
--- a/drivers/staging/comedi/drivers/ni_660x.c
+++ b/drivers/staging/comedi/drivers/ni_660x.c
@@ -320,7 +320,6 @@ static inline void ni_660x_set_dma_channel(struct comedi_device *dev,
 	ni_660x_write(dev, chip, devpriv->dma_cfg[chip] |
 		      NI660X_DMA_CFG_RESET(mite_channel),
 		      NI660X_DMA_CFG);
-	mmiowb();
 }
 
 static inline void ni_660x_unset_dma_channel(struct comedi_device *dev,
@@ -333,7 +332,6 @@ static inline void ni_660x_unset_dma_channel(struct comedi_device *dev,
 	devpriv->dma_cfg[chip] &= ~NI660X_DMA_CFG_SEL_MASK(mite_channel);
 	devpriv->dma_cfg[chip] |= NI660X_DMA_CFG_SEL_NONE(mite_channel);
 	ni_660x_write(dev, chip, devpriv->dma_cfg[chip], NI660X_DMA_CFG);
-	mmiowb();
 }
 
 static int ni_660x_request_mite_channel(struct comedi_device *dev,
diff --git a/drivers/staging/comedi/drivers/ni_mio_common.c b/drivers/staging/comedi/drivers/ni_mio_common.c
index b04dad8c7092..668f2aa16baa 100644
--- a/drivers/staging/comedi/drivers/ni_mio_common.c
+++ b/drivers/staging/comedi/drivers/ni_mio_common.c
@@ -547,7 +547,6 @@ static inline void ni_set_bitfield(struct comedi_device *dev, int reg,
 			reg);
 		break;
 	}
-	mmiowb();
 	spin_unlock_irqrestore(&devpriv->soft_reg_copy_lock, flags);
 }
 
diff --git a/drivers/staging/comedi/drivers/ni_pcidio.c b/drivers/staging/comedi/drivers/ni_pcidio.c
index 4bdef87d5dd7..8f3864799c19 100644
--- a/drivers/staging/comedi/drivers/ni_pcidio.c
+++ b/drivers/staging/comedi/drivers/ni_pcidio.c
@@ -310,7 +310,6 @@ static int ni_pcidio_request_di_mite_channel(struct comedi_device *dev)
 	writeb(primary_DMAChannel_bits(devpriv->di_mite_chan->channel) |
 	       secondary_DMAChannel_bits(devpriv->di_mite_chan->channel),
 	       dev->mmio + DMA_LINE_CONTROL_GROUP1);
-	mmiowb();
 	spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags);
 	return 0;
 }
@@ -327,7 +326,6 @@ static void ni_pcidio_release_di_mite_channel(struct comedi_device *dev)
 		writeb(primary_DMAChannel_bits(0) |
 		       secondary_DMAChannel_bits(0),
 		       dev->mmio + DMA_LINE_CONTROL_GROUP1);
-		mmiowb();
 	}
 	spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags);
 }
diff --git a/drivers/staging/comedi/drivers/ni_tio.c b/drivers/staging/comedi/drivers/ni_tio.c
index 048cb35723ad..c1131a1622c0 100644
--- a/drivers/staging/comedi/drivers/ni_tio.c
+++ b/drivers/staging/comedi/drivers/ni_tio.c
@@ -234,7 +234,6 @@ static void ni_tio_set_bits_transient(struct ni_gpct *counter,
 		regs[reg] &= ~mask;
 		regs[reg] |= (value & mask);
 		ni_tio_write(counter, regs[reg] | transient, reg);
-		mmiowb();
 		spin_unlock_irqrestore(&counter_dev->regs_lock, flags);
 	}
 }
diff --git a/drivers/staging/comedi/drivers/s626.c b/drivers/staging/comedi/drivers/s626.c
index f5af6f4069dc..39049d3c56d7 100644
--- a/drivers/staging/comedi/drivers/s626.c
+++ b/drivers/staging/comedi/drivers/s626.c
@@ -108,7 +108,6 @@ static void s626_mc_enable(struct comedi_device *dev,
 {
 	unsigned int val = (cmd << 16) | cmd;
 
-	mmiowb();
 	writel(val, dev->mmio + reg);
 }
 
@@ -116,7 +115,6 @@ static void s626_mc_disable(struct comedi_device *dev,
 			    unsigned int cmd, unsigned int reg)
 {
 	writel(cmd << 16, dev->mmio + reg);
-	mmiowb();
 }
 
 static bool s626_mc_test(struct comedi_device *dev,