Commit 6ecad912 authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Michael Ellerman

powerpc/ioda: Set "read" permission when "write" is set

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

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

Fixes: 10b35b2b ("powerpc/powernv: Do not set "read" flag if direction==DMA_NONE")
Cc: stable@vger.kernel.org # 4.2+
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: default avatarDouglas Miller <dougmill@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent c777e2a8
...@@ -599,6 +599,9 @@ int pnv_tce_build(struct iommu_table *tbl, long index, long npages, ...@@ -599,6 +599,9 @@ int pnv_tce_build(struct iommu_table *tbl, long index, long npages,
u64 rpn = __pa(uaddr) >> tbl->it_page_shift; u64 rpn = __pa(uaddr) >> tbl->it_page_shift;
long i; long i;
if (proto_tce & TCE_PCI_WRITE)
proto_tce |= TCE_PCI_READ;
for (i = 0; i < npages; i++) { for (i = 0; i < npages; i++) {
unsigned long newtce = proto_tce | unsigned long newtce = proto_tce |
((rpn + i) << tbl->it_page_shift); ((rpn + i) << tbl->it_page_shift);
...@@ -620,6 +623,9 @@ int pnv_tce_xchg(struct iommu_table *tbl, long index, ...@@ -620,6 +623,9 @@ int pnv_tce_xchg(struct iommu_table *tbl, long index,
BUG_ON(*hpa & ~IOMMU_PAGE_MASK(tbl)); 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)); oldtce = xchg(pnv_tce(tbl, idx), cpu_to_be64(newtce));
*hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ | TCE_PCI_WRITE); *hpa = be64_to_cpu(oldtce) & ~(TCE_PCI_READ | TCE_PCI_WRITE);
*direction = iommu_tce_direction(oldtce); *direction = iommu_tce_direction(oldtce);
......
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