Re: [RFC PATCH kernel] powerpc/ioda: Set "read" permission when "write" is set

2016-02-10 Thread Douglas Miller 

Tested-by: Douglas Miller 


On 01/11/2016 10:40 PM, Alexey Kardashevskiy wrote:

Quite often drivers set only "write" permission assuming that this
includes "read" permission as well and this works on plenty platforms.
However IODA2 is strict about this and produces an EEH when "read"
permission is not and reading happens.

This adds a workaround in IODA code to always add the "read" bit when
the "write" bit is set.

Cc: Benjamin Herrenschmidt 
Signed-off-by: Alexey Kardashevskiy 
---


Ben, what was the driver which did not set "read" and caused EEH?


---
  arch/powerpc/platforms/powernv/pci.c | 6 ++
  1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pci.c 
b/arch/powerpc/platforms/powernv/pci.c
index f2dd772..c7dcae5 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -601,6 +601,9 @@ int pnv_tce_build(struct iommu_table *tbl, long index, long 
npages,
u64 rpn = __pa(uaddr) >> tbl->it_page_shift;
long i;
  
+	if (proto_tce & TCE_PCI_WRITE)

+   proto_tce |= TCE_PCI_READ;
+
for (i = 0; i < npages; i++) {
unsigned long newtce = proto_tce |
((rpn + i) << tbl->it_page_shift);
@@ -622,6 +625,9 @@ int pnv_tce_xchg(struct iommu_table *tbl, long index,
  
  	BUG_ON(*hpa & ~IOMMU_PAGE_MASK(tbl));
  
+	if (newtce & TCE_PCI_WRITE)

+   newtce |= TCE_PCI_READ;
+
oldtce = xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce));
*hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ | TCE_PCI_WRITE);
*direction = iommu_tce_direction(oldtce);


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Re: [RFC PATCH kernel] powerpc/ioda: Set "read" permission when "write" is set

2016-02-09 Thread Douglas Miller 
We finally got the chance to test it end of last week. I forgot to 
update everyone Monday. B all appearances, the patch fixes the problem. 
We did not see any new issues with the patch (vs. same test scenarios 
without).


I'll also update the bugzilla.

Thanks,
Doug

On 02/08/2016 07:37 PM, Alexey Kardashevskiy wrote:

On 01/20/2016 06:01 AM, Douglas Miller wrote:



On 01/18/2016 09:52 PM, Alexey Kardashevskiy wrote:

On 01/13/2016 01:24 PM, Douglas Miller wrote:



On 01/12/2016 05:07 PM, Benjamin Herrenschmidt wrote:

On Tue, 2016-01-12 at 15:40 +1100, Alexey Kardashevskiy wrote:

Quite often drivers set only "write" permission assuming that this
includes "read" permission as well and this works on plenty
platforms.
However IODA2 is strict about this and produces an EEH when "read"
permission is not and reading happens.

This adds a workaround in IODA code to always add the "read" bit 
when

the "write" bit is set.

Cc: Benjamin Herrenschmidt 
Signed-off-by: Alexey Kardashevskiy 
---


Ben, what was the driver which did not set "read" and caused EEH?

aacraid

Cheers,
Ben.
Just to be precise, the driver wasn't responsible for setting READ. 
The
driver called scsi_dma_map() and the scsicmd was set (by scsi 
layer) as

DMA_FROM_DEVICE so the current code would set the permissions to
WRITE-ONLY. Previously, and in other architectures, this scsicmd 
would have

resulted in READ+WRITE permissions on the DMA map.



Does the patch fix the issue? Thanks.






---
  arch/powerpc/platforms/powernv/pci.c | 6 ++
  1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pci.c
b/arch/powerpc/platforms/powernv/pci.c
index f2dd772..c7dcae5 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -601,6 +601,9 @@ int pnv_tce_build(struct iommu_table *tbl, long
index, long npages,
  u64 rpn = __pa(uaddr) >> tbl->it_page_shift;
  long i;
+if (proto_tce & TCE_PCI_WRITE)
+proto_tce |= TCE_PCI_READ;
+
  for (i = 0; i < npages; i++) {
  unsigned long newtce = proto_tce |
  ((rpn + i) << tbl->it_page_shift);
@@ -622,6 +625,9 @@ int pnv_tce_xchg(struct iommu_table *tbl, long
index,
  BUG_ON(*hpa & ~IOMMU_PAGE_MASK(tbl));
+if (newtce & TCE_PCI_WRITE)
+newtce |= TCE_PCI_READ;
+
  oldtce = xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce));
  *hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ |
TCE_PCI_WRITE);
  *direction = iommu_tce_direction(oldtce);

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I am still working on getting a machine to try this on. From code
inspection, it looks like it should work. The problem is shortage of
machines and machines tied-up by Test.


Any progress here? Thanks.






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Re: [RFC PATCH kernel] powerpc/ioda: Set "read" permission when "write" is set

2016-02-09 Thread Alexey Kardashevskiy 

On 02/10/2016 01:28 AM, Douglas Miller wrote:

We finally got the chance to test it end of last week. I forgot to update
everyone Monday. B all appearances, the patch fixes the problem. We did not
see any new issues with the patch (vs. same test scenarios without).

I'll also update the bugzilla.


Thanks. Care to add "Tested-by"?




Thanks,
Doug

On 02/08/2016 07:37 PM, Alexey Kardashevskiy wrote:

On 01/20/2016 06:01 AM, Douglas Miller wrote:



On 01/18/2016 09:52 PM, Alexey Kardashevskiy wrote:

On 01/13/2016 01:24 PM, Douglas Miller wrote:



On 01/12/2016 05:07 PM, Benjamin Herrenschmidt wrote:

On Tue, 2016-01-12 at 15:40 +1100, Alexey Kardashevskiy wrote:

Quite often drivers set only "write" permission assuming that this
includes "read" permission as well and this works on plenty
platforms.
However IODA2 is strict about this and produces an EEH when "read"
permission is not and reading happens.

This adds a workaround in IODA code to always add the "read" bit when
the "write" bit is set.

Cc: Benjamin Herrenschmidt 
Signed-off-by: Alexey Kardashevskiy 
---


Ben, what was the driver which did not set "read" and caused EEH?

aacraid

Cheers,
Ben.

Just to be precise, the driver wasn't responsible for setting READ. The
driver called scsi_dma_map() and the scsicmd was set (by scsi layer) as
DMA_FROM_DEVICE so the current code would set the permissions to
WRITE-ONLY. Previously, and in other architectures, this scsicmd would
have
resulted in READ+WRITE permissions on the DMA map.



Does the patch fix the issue? Thanks.






---
  arch/powerpc/platforms/powernv/pci.c | 6 ++
  1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pci.c
b/arch/powerpc/platforms/powernv/pci.c
index f2dd772..c7dcae5 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -601,6 +601,9 @@ int pnv_tce_build(struct iommu_table *tbl, long
index, long npages,
  u64 rpn = __pa(uaddr) >> tbl->it_page_shift;
  long i;
+if (proto_tce & TCE_PCI_WRITE)
+proto_tce |= TCE_PCI_READ;
+
  for (i = 0; i < npages; i++) {
  unsigned long newtce = proto_tce |
  ((rpn + i) << tbl->it_page_shift);
@@ -622,6 +625,9 @@ int pnv_tce_xchg(struct iommu_table *tbl, long
index,
  BUG_ON(*hpa & ~IOMMU_PAGE_MASK(tbl));
+if (newtce & TCE_PCI_WRITE)
+newtce |= TCE_PCI_READ;
+
  oldtce = xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce));
  *hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ |
TCE_PCI_WRITE);
  *direction = iommu_tce_direction(oldtce);

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I am still working on getting a machine to try this on. From code
inspection, it looks like it should work. The problem is shortage of
machines and machines tied-up by Test.


Any progress here? Thanks.









--
Alexey
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Re: [RFC PATCH kernel] powerpc/ioda: Set "read" permission when "write" is set

2016-02-08 Thread Alexey Kardashevskiy 

On 01/20/2016 06:01 AM, Douglas Miller wrote:



On 01/18/2016 09:52 PM, Alexey Kardashevskiy wrote:

On 01/13/2016 01:24 PM, Douglas Miller wrote:



On 01/12/2016 05:07 PM, Benjamin Herrenschmidt wrote:

On Tue, 2016-01-12 at 15:40 +1100, Alexey Kardashevskiy wrote:

Quite often drivers set only "write" permission assuming that this
includes "read" permission as well and this works on plenty
platforms.
However IODA2 is strict about this and produces an EEH when "read"
permission is not and reading happens.

This adds a workaround in IODA code to always add the "read" bit when
the "write" bit is set.

Cc: Benjamin Herrenschmidt 
Signed-off-by: Alexey Kardashevskiy 
---


Ben, what was the driver which did not set "read" and caused EEH?

aacraid

Cheers,
Ben.

Just to be precise, the driver wasn't responsible for setting READ. The
driver called scsi_dma_map() and the scsicmd was set (by scsi layer) as
DMA_FROM_DEVICE so the current code would set the permissions to
WRITE-ONLY. Previously, and in other architectures, this scsicmd would have
resulted in READ+WRITE permissions on the DMA map.



Does the patch fix the issue? Thanks.






---
  arch/powerpc/platforms/powernv/pci.c | 6 ++
  1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pci.c
b/arch/powerpc/platforms/powernv/pci.c
index f2dd772..c7dcae5 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -601,6 +601,9 @@ int pnv_tce_build(struct iommu_table *tbl, long
index, long npages,
  u64 rpn = __pa(uaddr) >> tbl->it_page_shift;
  long i;
+if (proto_tce & TCE_PCI_WRITE)
+proto_tce |= TCE_PCI_READ;
+
  for (i = 0; i < npages; i++) {
  unsigned long newtce = proto_tce |
  ((rpn + i) << tbl->it_page_shift);
@@ -622,6 +625,9 @@ int pnv_tce_xchg(struct iommu_table *tbl, long
index,
  BUG_ON(*hpa & ~IOMMU_PAGE_MASK(tbl));
+if (newtce & TCE_PCI_WRITE)
+newtce |= TCE_PCI_READ;
+
  oldtce = xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce));
  *hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ |
TCE_PCI_WRITE);
  *direction = iommu_tce_direction(oldtce);

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I am still working on getting a machine to try this on. From code
inspection, it looks like it should work. The problem is shortage of
machines and machines tied-up by Test.


Any progress here? Thanks.




--
Alexey
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Re: [RFC PATCH kernel] powerpc/ioda: Set "read" permission when "write" is set

2016-01-19 Thread Douglas Miller 



On 01/18/2016 09:52 PM, Alexey Kardashevskiy wrote:

On 01/13/2016 01:24 PM, Douglas Miller wrote:



On 01/12/2016 05:07 PM, Benjamin Herrenschmidt wrote:

On Tue, 2016-01-12 at 15:40 +1100, Alexey Kardashevskiy wrote:

Quite often drivers set only "write" permission assuming that this
includes "read" permission as well and this works on plenty
platforms.
However IODA2 is strict about this and produces an EEH when "read"
permission is not and reading happens.

This adds a workaround in IODA code to always add the "read" bit when
the "write" bit is set.

Cc: Benjamin Herrenschmidt 
Signed-off-by: Alexey Kardashevskiy 
---


Ben, what was the driver which did not set "read" and caused EEH?

aacraid

Cheers,
Ben.

Just to be precise, the driver wasn't responsible for setting READ. The
driver called scsi_dma_map() and the scsicmd was set (by scsi layer) as
DMA_FROM_DEVICE so the current code would set the permissions to
WRITE-ONLY. Previously, and in other architectures, this scsicmd 
would have

resulted in READ+WRITE permissions on the DMA map.



Does the patch fix the issue? Thanks.






---
  arch/powerpc/platforms/powernv/pci.c | 6 ++
  1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pci.c
b/arch/powerpc/platforms/powernv/pci.c
index f2dd772..c7dcae5 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -601,6 +601,9 @@ int pnv_tce_build(struct iommu_table *tbl, long
index, long npages,
  u64 rpn = __pa(uaddr) >> tbl->it_page_shift;
  long i;
+if (proto_tce & TCE_PCI_WRITE)
+proto_tce |= TCE_PCI_READ;
+
  for (i = 0; i < npages; i++) {
  unsigned long newtce = proto_tce |
  ((rpn + i) << tbl->it_page_shift);
@@ -622,6 +625,9 @@ int pnv_tce_xchg(struct iommu_table *tbl, long
index,
  BUG_ON(*hpa & ~IOMMU_PAGE_MASK(tbl));
+if (newtce & TCE_PCI_WRITE)
+newtce |= TCE_PCI_READ;
+
  oldtce = xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce));
  *hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ |
TCE_PCI_WRITE);
  *direction = iommu_tce_direction(oldtce);

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I am still working on getting a machine to try this on. From code 
inspection, it looks like it should work. The problem is shortage of 
machines and machines tied-up by Test.


Thanks,
Doug

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Re: [RFC PATCH kernel] powerpc/ioda: Set "read" permission when "write" is set

2016-01-18 Thread Alexey Kardashevskiy 

On 01/13/2016 01:24 PM, Douglas Miller wrote:



On 01/12/2016 05:07 PM, Benjamin Herrenschmidt wrote:

On Tue, 2016-01-12 at 15:40 +1100, Alexey Kardashevskiy wrote:

Quite often drivers set only "write" permission assuming that this
includes "read" permission as well and this works on plenty
platforms.
However IODA2 is strict about this and produces an EEH when "read"
permission is not and reading happens.

This adds a workaround in IODA code to always add the "read" bit when
the "write" bit is set.

Cc: Benjamin Herrenschmidt 
Signed-off-by: Alexey Kardashevskiy 
---


Ben, what was the driver which did not set "read" and caused EEH?

aacraid

Cheers,
Ben.

Just to be precise, the driver wasn't responsible for setting READ. The
driver called scsi_dma_map() and the scsicmd was set (by scsi layer) as
DMA_FROM_DEVICE so the current code would set the permissions to
WRITE-ONLY. Previously, and in other architectures, this scsicmd would have
resulted in READ+WRITE permissions on the DMA map.



Does the patch fix the issue? Thanks.






---
  arch/powerpc/platforms/powernv/pci.c | 6 ++
  1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pci.c
b/arch/powerpc/platforms/powernv/pci.c
index f2dd772..c7dcae5 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -601,6 +601,9 @@ int pnv_tce_build(struct iommu_table *tbl, long
index, long npages,
  u64 rpn = __pa(uaddr) >> tbl->it_page_shift;
  long i;
+if (proto_tce & TCE_PCI_WRITE)
+proto_tce |= TCE_PCI_READ;
+
  for (i = 0; i < npages; i++) {
  unsigned long newtce = proto_tce |
  ((rpn + i) << tbl->it_page_shift);
@@ -622,6 +625,9 @@ int pnv_tce_xchg(struct iommu_table *tbl, long
index,
  BUG_ON(*hpa & ~IOMMU_PAGE_MASK(tbl));
+if (newtce & TCE_PCI_WRITE)
+newtce |= TCE_PCI_READ;
+
  oldtce = xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce));
  *hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ |
TCE_PCI_WRITE);
  *direction = iommu_tce_direction(oldtce);

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Re: [RFC PATCH kernel] powerpc/ioda: Set "read" permission when "write" is set

2016-01-12 Thread Douglas Miller 



On 01/12/2016 05:07 PM, Benjamin Herrenschmidt wrote:

On Tue, 2016-01-12 at 15:40 +1100, Alexey Kardashevskiy wrote:

Quite often drivers set only "write" permission assuming that this
includes "read" permission as well and this works on plenty
platforms.
However IODA2 is strict about this and produces an EEH when "read"
permission is not and reading happens.

This adds a workaround in IODA code to always add the "read" bit when
the "write" bit is set.

Cc: Benjamin Herrenschmidt 
Signed-off-by: Alexey Kardashevskiy 
---


Ben, what was the driver which did not set "read" and caused EEH?

aacraid

Cheers,
Ben.
Just to be precise, the driver wasn't responsible for setting READ. The 
driver called scsi_dma_map() and the scsicmd was set (by scsi layer) as 
DMA_FROM_DEVICE so the current code would set the permissions to 
WRITE-ONLY. Previously, and in other architectures, this scsicmd would 
have resulted in READ+WRITE permissions on the DMA map.



---
  arch/powerpc/platforms/powernv/pci.c | 6 ++
  1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pci.c
b/arch/powerpc/platforms/powernv/pci.c
index f2dd772..c7dcae5 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -601,6 +601,9 @@ int pnv_tce_build(struct iommu_table *tbl, long
index, long npages,
u64 rpn = __pa(uaddr) >> tbl->it_page_shift;
long i;
  
+	if (proto_tce & TCE_PCI_WRITE)

+   proto_tce |= TCE_PCI_READ;
+
for (i = 0; i < npages; i++) {
unsigned long newtce = proto_tce |
((rpn + i) << tbl->it_page_shift);
@@ -622,6 +625,9 @@ int pnv_tce_xchg(struct iommu_table *tbl, long
index,
  
  	BUG_ON(*hpa & ~IOMMU_PAGE_MASK(tbl));
  
+	if (newtce & TCE_PCI_WRITE)

+   newtce |= TCE_PCI_READ;
+
oldtce = xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce));
*hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ |
TCE_PCI_WRITE);
*direction = iommu_tce_direction(oldtce);

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Re: [RFC PATCH kernel] powerpc/ioda: Set "read" permission when "write" is set

2016-01-12 Thread Benjamin Herrenschmidt 
On Tue, 2016-01-12 at 15:40 +1100, Alexey Kardashevskiy wrote:
> Quite often drivers set only "write" permission assuming that this
> includes "read" permission as well and this works on plenty
> platforms.
> However IODA2 is strict about this and produces an EEH when "read"
> permission is not and reading happens.
> 
> This adds a workaround in IODA code to always add the "read" bit when
> the "write" bit is set.
> 
> Cc: Benjamin Herrenschmidt 
> Signed-off-by: Alexey Kardashevskiy 
> ---
> 
> 
> Ben, what was the driver which did not set "read" and caused EEH?

aacraid

Cheers,
Ben.

> 
> ---
>  arch/powerpc/platforms/powernv/pci.c | 6 ++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/powerpc/platforms/powernv/pci.c
> b/arch/powerpc/platforms/powernv/pci.c
> index f2dd772..c7dcae5 100644
> --- a/arch/powerpc/platforms/powernv/pci.c
> +++ b/arch/powerpc/platforms/powernv/pci.c
> @@ -601,6 +601,9 @@ int pnv_tce_build(struct iommu_table *tbl, long
> index, long npages,
>   u64 rpn = __pa(uaddr) >> tbl->it_page_shift;
>   long i;
>  
> + if (proto_tce & TCE_PCI_WRITE)
> + proto_tce |= TCE_PCI_READ;
> +
>   for (i = 0; i < npages; i++) {
>   unsigned long newtce = proto_tce |
>   ((rpn + i) << tbl->it_page_shift);
> @@ -622,6 +625,9 @@ int pnv_tce_xchg(struct iommu_table *tbl, long
> index,
>  
>   BUG_ON(*hpa & ~IOMMU_PAGE_MASK(tbl));
>  
> + if (newtce & TCE_PCI_WRITE)
> + newtce |= TCE_PCI_READ;
> +
>   oldtce = xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce));
>   *hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ |
> TCE_PCI_WRITE);
>   *direction = iommu_tce_direction(oldtce);
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[RFC PATCH kernel] powerpc/ioda: Set "read" permission when "write" is set

2016-01-11 Thread Alexey Kardashevskiy 
Quite often drivers set only "write" permission assuming that this
includes "read" permission as well and this works on plenty platforms.
However IODA2 is strict about this and produces an EEH when "read"
permission is not and reading happens.

This adds a workaround in IODA code to always add the "read" bit when
the "write" bit is set.

Cc: Benjamin Herrenschmidt 
Signed-off-by: Alexey Kardashevskiy 
---


Ben, what was the driver which did not set "read" and caused EEH?


---
 arch/powerpc/platforms/powernv/pci.c | 6 ++
 1 file changed, 6 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/pci.c 
b/arch/powerpc/platforms/powernv/pci.c
index f2dd772..c7dcae5 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -601,6 +601,9 @@ int pnv_tce_build(struct iommu_table *tbl, long index, long 
npages,
u64 rpn = __pa(uaddr) >> tbl->it_page_shift;
long i;
 
+   if (proto_tce & TCE_PCI_WRITE)
+   proto_tce |= TCE_PCI_READ;
+
for (i = 0; i < npages; i++) {
unsigned long newtce = proto_tce |
((rpn + i) << tbl->it_page_shift);
@@ -622,6 +625,9 @@ int pnv_tce_xchg(struct iommu_table *tbl, long index,
 
BUG_ON(*hpa & ~IOMMU_PAGE_MASK(tbl));
 
+   if (newtce & TCE_PCI_WRITE)
+   newtce |= TCE_PCI_READ;
+
oldtce = xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce));
*hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ | TCE_PCI_WRITE);
*direction = iommu_tce_direction(oldtce);
-- 
2.5.0.rc3

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