From: Ramesh Thomas ramesh.thomas@intel.com

[ Upstream commit 2b938e3db335e3670475e31a722c2bee34748c5a ]

Definitions of ioread64 and iowrite64 macros in asm/io.h called by vfio pci implementations are enclosed inside check for CONFIG_GENERIC_IOMAP. They don't get defined if CONFIG_GENERIC_IOMAP is defined. Include linux/io-64-nonatomic-lo-hi.h to define iowrite64 and ioread64 macros when they are not defined. io-64-nonatomic-lo-hi.h maps the macros to generic implementation in lib/iomap.c. The generic implementation does 64 bit rw if readq/writeq is defined for the architecture, otherwise it would do 32 bit back to back rw.

Note that there are two versions of the generic implementation that differs in the order the 32 bit words are written if 64 bit support is not present. This is not the little/big endian ordering, which is handled separately. This patch uses the lo followed by hi word ordering which is consistent with current back to back implementation in the vfio/pci code.

Signed-off-by: Ramesh Thomas ramesh.thomas@intel.com Reviewed-by: Jason Gunthorpe jgg@nvidia.com Link: https://lore.kernel.org/r/20241210131938.303500-2-ramesh.thomas@intel.com Signed-off-by: Alex Williamson alex.williamson@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/vfio/pci/vfio_pci_rdwr.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c index e27de61ac9fe7..8191c8fcfb256 100644 --- a/drivers/vfio/pci/vfio_pci_rdwr.c +++ b/drivers/vfio/pci/vfio_pci_rdwr.c @@ -16,6 +16,7 @@ #include <linux/io.h> #include <linux/vfio.h> #include <linux/vgaarb.h> +#include <linux/io-64-nonatomic-lo-hi.h>

#include "vfio_pci_priv.h"