summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorAlexey Kardashevskiy <aik@ozlabs.ru>2016-02-17 10:26:31 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2016-02-17 15:52:17 +0300
commit6ecad912a0073c768db1491c27ca55ad2d0ee68f (patch)
tree96345d14a7c00b56cb8afa50cfa32d6b7e0bda9c /arch
parentc777e2a8b65420b31dac28a453e35be984f5808b (diff)
downloadlinux-6ecad912a0073c768db1491c27ca55ad2d0ee68f.tar.xz
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: 10b35b2b7485 ("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: Alexey Kardashevskiy <aik@ozlabs.ru> Tested-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/platforms/powernv/pci.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index d25ff2292ae2..b1ef84a6c9d1 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -599,6 +599,9 @@ 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);
@@ -620,6 +623,9 @@ 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);