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

Luis Henriques luis.henriques at canonical.com
Thu May 7 09:46:11 UTC 2015


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

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

From: Michael Ellerman <mpe at ellerman.id.au>

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 at ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 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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