xen/pci: Request ACS when Xen-SWIOTLB is activated.

It used to done in the Xen startup code but that is not really
appropiate.

[v2: Update Kconfig with PCI requirement]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c
index a013ec9d0c54..be4d80a6fae9 100644
--- a/arch/x86/xen/pci-swiotlb-xen.c
+++ b/arch/x86/xen/pci-swiotlb-xen.c
@@ -1,6 +1,7 @@
 /* Glue code to lib/swiotlb-xen.c */
 
 #include <linux/dma-mapping.h>
+#include <linux/pci.h>
 #include <xen/swiotlb-xen.h>
 
 #include <asm/xen/hypervisor.h>
@@ -54,5 +55,8 @@ void __init pci_xen_swiotlb_init(void)
         if (xen_swiotlb) {
                 xen_swiotlb_init(1);
                 dma_ops = &xen_swiotlb_dma_ops;
+
+                /* Make sure ACS will be enabled */
+                pci_request_acs();
         }
 }