Commit 4df13a68 authored by Ben Segal's avatar Ben Segal Committed by Alex Williamson
Browse files

vfio/pci: Support 8-byte PCI loads and stores 



Many PCI adapters can benefit or even require full 64bit read
and write access to their registers. In order to enable work on
user-space drivers for these devices add two new variations
vfio_pci_core_io{read|write}64 of the existing access methods
when the architecture supports 64-bit ioreads and iowrites.

Signed-off-by: default avatarBen Segal <bpsegal@us.ibm.com>
Co-developed-by: default avatarGerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: default avatarGerd Bayer <gbayer@linux.ibm.com>
Link: https://lore.kernel.org/r/20240619115847.1344875-3-gbayer@linux.ibm.com


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 186bfe44

drivers/vfio/pci/vfio_pci_rdwr.c

+16 −0
Original line number Diff line number Diff line
@@ -89,6 +89,9 @@ EXPORT_SYMBOL_GPL(vfio_pci_core_ioread##size); 
VFIO_IOREAD(8)

VFIO_IOREAD(16)

VFIO_IOREAD(32)

#ifdef ioread64

VFIO_IOREAD(64)

#endif



#define VFIO_IORDWR(size)						\

static int vfio_pci_iordwr##size(struct vfio_pci_core_device *vdev,\
@@ -124,6 +127,10 @@ static int vfio_pci_iordwr##size(struct vfio_pci_core_device *vdev,\ 
VFIO_IORDWR(8)

VFIO_IORDWR(16)

VFIO_IORDWR(32)

#if defined(ioread64) && defined(iowrite64)

VFIO_IORDWR(64)

#endif



/*

 * Read or write from an __iomem region (MMIO or I/O port) with an excluded

 * range which is inaccessible.  The excluded range drops writes and fills
@@ -148,6 +155,15 @@ ssize_t vfio_pci_core_do_io_rw(struct vfio_pci_core_device *vdev, bool test_mem, 
		else

			fillable = 0;



#if defined(ioread64) && defined(iowrite64)

		if (fillable >= 8 && !(off % 8)) {

			ret = vfio_pci_iordwr64(vdev, iswrite, test_mem,

						io, buf, off, &filled);

			if (ret)

				return ret;



		} else

#endif

		if (fillable >= 4 && !(off % 4)) {

			ret = vfio_pci_iordwr32(vdev, iswrite, test_mem,

						io, buf, off, &filled);

include/linux/vfio_pci_core.h

+3 −0
Original line number Diff line number Diff line
@@ -155,5 +155,8 @@ int vfio_pci_core_ioread##size(struct vfio_pci_core_device *vdev, \ 
VFIO_IOREAD_DECLATION(8)

VFIO_IOREAD_DECLATION(16)

VFIO_IOREAD_DECLATION(32)

#ifdef ioread64

VFIO_IOREAD_DECLATION(64)

#endif



#endif /* VFIO_PCI_CORE_H */