s390 updates for 5.6-rc5

- Fix panic in gup_fast on large pud by providing an implementation of
  pud_write. This has been overlooked during migration to common gup code.

- Fix unexpected write combining on PCI stores.
s390/pci: Fix unexpected write combine on resource

In the initial MIO support introduced in

commit 71ba41c9b1d9 ("s390/pci: provide support for MIO instructions")

zpci_map_resource() and zpci_setup_resources() default to using the
mio_wb address as the resource's start address. This means users of the
mapping, which includes most drivers, will get write combining on PCI
Stores. This may lead to problems when drivers expect write through
behavior when not using an explicit ioremap_wc().

Cc: stable@vger.kernel.org
Fixes: 71ba41c9b1d9 ("s390/pci: provide support for MIO instructions")
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
1 file changed