From 88fbd1d31291da3387f0807cbafc343687c91bee Mon Sep 17 00:00:00 2001 From: Niklas Schnelle Date: Thu, 27 Feb 2020 12:17:18 +0100 Subject: [PATCH] s390/pci: Fix unexpected write combine on resource 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 Reviewed-by: Pierre Morel Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman --- arch/s390/pci/pci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c index 5b24fcc..6105b1b 100644 --- a/arch/s390/pci/pci.c +++ b/arch/s390/pci/pci.c @@ -423,7 +423,7 @@ static void zpci_map_resources(struct pci_dev *pdev) 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); @@ -530,7 +530,7 @@ static int zpci_setup_bus_resources(struct zpci_dev *zdev, 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; -- 2.7.4