[PATCH 3.16.y-ckt 162/180] powerpc/cell: Fix cell iommu after it_page_shift changes

From: Luis Henriques
Date: Thu May 07 2015 - 06:02:19 EST


3.16.7-ckt11 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Michael Ellerman <mpe@xxxxxxxxxxxxxx>

commit 7261b956b276aa97fbf60d00f1d7717d2ea6ee78 upstream.

The patch to add it_page_shift incorrectly changed the increment of
uaddr to use it_page_shift, rather then (1 << it_page_shift).

This broke booting on at least some Cell blades, as the iommu was
basically non-functional.

Fixes: 3a553170d35d ("powerpc/iommu: Add it_page_shift field to determine iommu page size")
Signed-off-by: Michael Ellerman <michael@xxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
arch/powerpc/platforms/cell/iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index 2b90ff8a93be..59ef76c5f4f4 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -197,7 +197,7 @@ static int tce_build_cell(struct iommu_table *tbl, long index, long npages,

io_pte = (unsigned long *)tbl->it_base + (index - tbl->it_offset);

- for (i = 0; i < npages; i++, uaddr += tbl->it_page_shift)
+ for (i = 0; i < npages; i++, uaddr += (1 << tbl->it_page_shift))
io_pte[i] = base_pte | (__pa(uaddr) & CBE_IOPTE_RPN_Mask);

mb();
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