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* [PATCH 2/9] ia64: remove the dead iommu_sac_force variable
@ 2018-09-17 17:10 Christoph Hellwig
  0 siblings, 0 replies; 3+ messages in thread
From: Christoph Hellwig @ 2018-09-17 17:10 UTC (permalink / raw)
  To: linux-ia64

Looks like copy and paste from x86 that never actually got used.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/ia64/kernel/pci-dma.c | 19 -------------------
 1 file changed, 19 deletions(-)

diff --git a/arch/ia64/kernel/pci-dma.c b/arch/ia64/kernel/pci-dma.c
index b5df084c0af4..50b6ad282a90 100644
--- a/arch/ia64/kernel/pci-dma.c
+++ b/arch/ia64/kernel/pci-dma.c
@@ -18,8 +18,6 @@
 dma_addr_t bad_dma_address __read_mostly;
 EXPORT_SYMBOL(bad_dma_address);
 
-static int iommu_sac_force __read_mostly;
-
 int no_iommu __read_mostly;
 #ifdef CONFIG_IOMMU_DEBUG
 int force_iommu __read_mostly = 1;
@@ -61,23 +59,6 @@ int iommu_dma_supported(struct device *dev, u64 mask)
 	if (mask < DMA_BIT_MASK(24))
 		return 0;
 
-	/* Tell the device to use SAC when IOMMU force is on.  This
-	   allows the driver to use cheaper accesses in some cases.
-
-	   Problem with this is that if we overflow the IOMMU area and
-	   return DAC as fallback address the device may not handle it
-	   correctly.
-
-	   As a special case some controllers have a 39bit address
-	   mode that is as efficient as 32bit (aic79xx). Don't force
-	   SAC for these.  Assume all masks <= 40 bits are of this
-	   type. Normally this doesn't make any difference, but gives
-	   more gentle handling of IOMMU overflow. */
-	if (iommu_sac_force && (mask >= DMA_BIT_MASK(40))) {
-		dev_info(dev, "Force SAC with mask %llx\n", mask);
-		return 0;
-	}
-
 	return 1;
 }
 EXPORT_SYMBOL(iommu_dma_supported);
-- 
2.18.0

^ permalink raw reply related	[flat|nested] 3+ messages in thread
* misc ia64 cleanups (resend)
@ 2018-09-20  7:26 Christoph Hellwig
  2018-09-20  7:26 ` [PATCH 2/9] ia64: remove the dead iommu_sac_force variable Christoph Hellwig
  0 siblings, 1 reply; 3+ messages in thread
From: Christoph Hellwig @ 2018-09-20  7:26 UTC (permalink / raw)
  To: Tony Luck, Fenghua Yu; +Cc: linux-ia64, iommu, linux-kernel

A couple random cleanups I stumbled upon when doing dma related work.

^ permalink raw reply	[flat|nested] 3+ messages in thread
* DMA related cleanups for IA64
@ 2018-08-01 16:02 Christoph Hellwig
  2018-08-01 16:02 ` [PATCH 2/9] ia64: remove the dead iommu_sac_force variable Christoph Hellwig
  0 siblings, 1 reply; 3+ messages in thread
From: Christoph Hellwig @ 2018-08-01 16:02 UTC (permalink / raw)
  To: Tony Luck, Fenghua Yu
  Cc: David Woodhouse, linux-ia64, linux-arch, linux-kernel, iommu

Hi all,

this is a resend of the last two series plus additional cleanups.  The
driver of it were the odd dma barriers in the ia64 sync_single_* methods,
but once I started to look into that area the fallback got bigger and
bigger..

^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-09-20  7:26 UTC | newest]

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2018-09-17 17:10 [PATCH 2/9] ia64: remove the dead iommu_sac_force variable Christoph Hellwig
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2018-09-20  7:26 misc ia64 cleanups (resend) Christoph Hellwig
2018-09-20  7:26 ` [PATCH 2/9] ia64: remove the dead iommu_sac_force variable Christoph Hellwig
2018-08-01 16:02 DMA related cleanups for IA64 Christoph Hellwig
2018-08-01 16:02 ` [PATCH 2/9] ia64: remove the dead iommu_sac_force variable Christoph Hellwig

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