On Wed, May 22, 2024 at 04:21:25PM -0700, Ramesh Thomas wrote: > ioread64 and iowrite64 macros called by vfio pci implementations are > defined in asm/io.h if CONFIG_GENERIC_IOMAP is not 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. > > Refer patch series the requirement originated from: > https://lore.kernel.org/all/20240522150651.1999584-1-gbayer@xxxxxxxxxxxxx/ > > Signed-off-by: Ramesh Thomas <ramesh.thomas@xxxxxxxxx> > --- > drivers/vfio/pci/vfio_pci_priv.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/vfio/pci/vfio_pci_priv.h b/drivers/vfio/pci/vfio_pci_priv.h > index 5e4fa69aee16..5eab5abf2ff2 100644 > --- a/drivers/vfio/pci/vfio_pci_priv.h > +++ b/drivers/vfio/pci/vfio_pci_priv.h > @@ -3,6 +3,7 @@ > #define VFIO_PCI_PRIV_H > > #include <linux/vfio_pci_core.h> > +#include <linux/io-64-nonatomic-lo-hi.h> Why include it here though? It should go in vfio_pci_rdwr.c and this patch should remove all the "#ifdef iowrite64"'s from that file too. But the idea looks right to me Thanks, Jason
