[PATCH kernel] powerpc/powernv: Fix it_ops::get() callback to return in cpu endian

[PATCH kernel] powerpc/powernv: Fix it_ops::get() callback to return in cpu endian

[Alexey Kardashevskiy]

The iommu_table_ops callbacks are declared CPU endian as they take and
return "unsigned long"; underlying hardware tables are big-endian.

However get() was missing be64_to_cpu(), this adds the missing conversion.

The only caller of this is crash dump at arch/powerpc/kernel/iommu.c,
iommu_table_clear() which only compares TCE to zero so this change
should not cause behavioral change.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 arch/powerpc/platforms/powernv/pci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index c6d554fe585c..3f7f267a3d04 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -758,7 +758,7 @@ void pnv_tce_free(struct iommu_table *tbl, long index, long npages)
 
 unsigned long pnv_tce_get(struct iommu_table *tbl, long index)
 {
-	return *(pnv_tce(tbl, index - tbl->it_offset));
+	return be64_to_cpu(*(pnv_tce(tbl, index - tbl->it_offset)));
 }
 
 struct iommu_table *pnv_pci_table_alloc(int nid)
-- 
2.11.0

Re: [PATCH kernel] powerpc/powernv: Fix it_ops::get() callback to return in cpu endian

[David Gibson]

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On Tue, Feb 21, 2017 at 01:38:54PM +1100, Alexey Kardashevskiy wrote:
> The iommu_table_ops callbacks are declared CPU endian as they take and
> return "unsigned long"; underlying hardware tables are big-endian.
> 
> However get() was missing be64_to_cpu(), this adds the missing conversion.
> 
> The only caller of this is crash dump at arch/powerpc/kernel/iommu.c,
> iommu_table_clear() which only compares TCE to zero so this change
> should not cause behavioral change.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

> ---
>  arch/powerpc/platforms/powernv/pci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
> index c6d554fe585c..3f7f267a3d04 100644
> --- a/arch/powerpc/platforms/powernv/pci.c
> +++ b/arch/powerpc/platforms/powernv/pci.c
> @@ -758,7 +758,7 @@ void pnv_tce_free(struct iommu_table *tbl, long index, long npages)
>  
>  unsigned long pnv_tce_get(struct iommu_table *tbl, long index)
>  {
> -	return *(pnv_tce(tbl, index - tbl->it_offset));
> +	return be64_to_cpu(*(pnv_tce(tbl, index - tbl->it_offset)));
>  }
>  
>  struct iommu_table *pnv_pci_table_alloc(int nid)

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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Re: [PATCH kernel] powerpc/powernv: Fix it_ops::get() callback to return in cpu endian

[Gavin Shan]

On Tue, Feb 21, 2017 at 01:38:54PM +1100, Alexey Kardashevskiy wrote:
>The iommu_table_ops callbacks are declared CPU endian as they take and
>return "unsigned long"; underlying hardware tables are big-endian.
>
>However get() was missing be64_to_cpu(), this adds the missing conversion.
>
>The only caller of this is crash dump at arch/powerpc/kernel/iommu.c,
>iommu_table_clear() which only compares TCE to zero so this change
>should not cause behavioral change.
>
>Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>

Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>

Re: [kernel] powerpc/powernv: Fix it_ops::get() callback to return in cpu endian

[Michael Ellerman]

On Tue, 2017-02-21 at 02:38:54 UTC, Alexey Kardashevskiy wrote:
> The iommu_table_ops callbacks are declared CPU endian as they take and
> return "unsigned long"; underlying hardware tables are big-endian.
> 
> However get() was missing be64_to_cpu(), this adds the missing conversion.
> 
> The only caller of this is crash dump at arch/powerpc/kernel/iommu.c,
> iommu_table_clear() which only compares TCE to zero so this change
> should not cause behavioral change.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> Acked-by: Gavin Shan <gwshan@linux.vnet.ibm.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/81d5fe1a3b1acfaadc7921d08609e0

cheers