| Message ID | 1455693991-31405-1-git-send-email-aik@ozlabs.ru (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Wed, 2016-02-17 at 18:26 +1100, Alexey Kardashevskiy wrote: > Quite often drivers set only "write" permission assuming that this > includes "read" permission as well and this works on plenty > platforms. > However IODA2 is strict about this and produces an EEH when "read" > permission is not and reading happens. > > This adds a workaround in IODA code to always add the "read" bit when > the "write" bit is set. > > This fixes breakage introduced in > 10b35b2b74 powerpc/powernv: Do not set "read" flag if > direction==DMA_NONE > > Cc: stable@vger.kernel.org # 4.2+ Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> > Tested-by: Douglas Miller <dougmill@linux.vnet.ibm.com> > --- > arch/powerpc/platforms/powernv/pci.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/arch/powerpc/platforms/powernv/pci.c > b/arch/powerpc/platforms/powernv/pci.c > index 2f55c86..6a97ba4 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);
On Wed, 2016-17-02 at 07:26:31 UTC, Alexey Kardashevskiy wrote: > Quite often drivers set only "write" permission assuming that this > includes "read" permission as well and this works on plenty platforms. > However IODA2 is strict about this and produces an EEH when "read" > permission is not and reading happens. > > This adds a workaround in IODA code to always add the "read" bit when > the "write" bit is set. > > This fixes breakage introduced in > 10b35b2b74 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> Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/6ecad912a0073c768db1491c27 cheers
diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c index 2f55c86..6a97ba4 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);