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authorMichael S. Tsirkin <mst@redhat.com>2015-04-01 06:03:20 +0300
committerRusty Russell <rusty@rustcorp.com.au>2015-04-01 07:07:15 +0300
commitc5d4c2c9ce4f4b6980a71dec50f2db4c2e55778d (patch)
tree237c8573d47db80749a3353eee128f7ec1d57c2c /drivers/virtio
parent3eebd233fcb392286d385e764eb91e90d6218cdf (diff)
downloadlinux-c5d4c2c9ce4f4b6980a71dec50f2db4c2e55778d.tar.xz
virtio_pci_modern: type-safe io accessors
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 <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/virtio_pci_modern.c37
1 files changed, 37 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 2aa38e59db2e..826e500d4819 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)
+{
+ iowrite32(value, addr);
+}
+
static void __iomem *map_capability(struct pci_dev *dev, int off,
size_t minlen,
u32 align,