The spec is very clear on this: 4.1.3.1 Driver Requirements: PCI Device Layout
The driver MUST access each field using the “natural” access method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses for 16-bit fields and 8-bit accesses for 8-bit fields. Add type-safe wrappers to prevent access with incorrect width. Signed-off-by: Michael S. Tsirkin <[email protected]> --- drivers/virtio/virtio_pci_modern.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c index 2aa38e5..4e73ef7 100644 --- a/drivers/virtio/virtio_pci_modern.c +++ b/drivers/virtio/virtio_pci_modern.c @@ -20,6 +20,43 @@ #define VIRTIO_PCI_NO_LEGACY #include "virtio_pci_common.h" +/* + * Type-safe wrappers for io accesses. + * Use these to enforce at compile time the following spec requirement: + * + * The driver MUST access each field using the “natural” access + * method, i.e. 32-bit accesses for 32-bit fields, 16-bit accesses + * for 16-bit fields and 8-bit accesses for 8-bit fields. + */ +static inline u8 vp_ioread8(u8 __iomem *addr) +{ + return ioread8(addr); +} +static inline u16 vp_ioread16 (u16 __iomem *addr) +{ + return ioread16(addr); +} + +static inline u32 vp_ioread32(u32 __iomem *addr) +{ + return ioread32(addr); +} + +static inline void vp_iowrite8(u8 value, u8 __iomem *addr) +{ + iowrite8(value, addr); +} + +static inline void vp_iowrite16(u16 value, u16 __iomem *addr) +{ + iowrite16(value, addr); +} + +static inline void vp_iowrite32(u32 value, u32 __iomem *addr) +{ + iowrite16(value, addr); +} + static void __iomem *map_capability(struct pci_dev *dev, int off, size_t minlen, u32 align, -- MST _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
