From: Niklas Schnelle schnelle@linux.ibm.com
commit df057c914a9c219ac8b8ed22caf7da2f80c1fe26 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/s390/pci/pci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/s390/pci/pci.c +++ b/arch/s390/pci/pci.c @@ -424,7 +424,7 @@ static void zpci_map_resources(struct pc
if (zpci_use_mio(zdev)) pdev->resource[i].start = - (resource_size_t __force) zdev->bars[i].mio_wb; + (resource_size_t __force) zdev->bars[i].mio_wt; else pdev->resource[i].start = (resource_size_t __force) pci_iomap_range_fh(pdev, i, 0, 0); @@ -531,7 +531,7 @@ static int zpci_setup_bus_resources(stru flags |= IORESOURCE_MEM_64;
if (zpci_use_mio(zdev)) - addr = (unsigned long) zdev->bars[i].mio_wb; + addr = (unsigned long) zdev->bars[i].mio_wt; else addr = ZPCI_ADDR(entry); size = 1UL << zdev->bars[i].size;