From: Alexey Kardashevskiy Date: Wed, 17 Feb 2016 07:26:31 +0000 (+1100) Subject: powerpc/ioda: Set "read" permission when "write" is set X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=6ecad912a0073c768db1491c27ca55ad2d0ee68f;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git 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 Signed-off-by: Alexey Kardashevskiy Tested-by: Douglas Miller Signed-off-by: Michael Ellerman --- 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);