1 files changed, 93 insertions, 10 deletions

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 7f4ef66..7979f85 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -4,6 +4,7 @@
 #include <linux/err.h>
 #include <linux/bug.h>
 #include <linux/virtio.h>
+#include <linux/virtio_byteorder.h>
 #include <uapi/linux/virtio_config.h>
 
 /**
@@ -46,6 +47,7 @@
  *	vdev: the virtio_device
  *	This gives the final feature bits for the device: it can change
  *	the dev->feature bits if it wants.
+ *	Returns 0 on success or error status
  * @bus_name: return the bus name associated with the device
  *	vdev: the virtio_device
  *      This returns a pointer to the bus name a la pci_name from which
@@ -66,8 +68,8 @@ struct virtio_config_ops {
 			vq_callback_t *callbacks[],
 			const char *names[]);
 	void (*del_vqs)(struct virtio_device *);
-	u32 (*get_features)(struct virtio_device *vdev);
-	void (*finalize_features)(struct virtio_device *vdev);
+	u64 (*get_features)(struct virtio_device *vdev);
+	int (*finalize_features)(struct virtio_device *vdev);
 	const char *(*bus_name)(struct virtio_device *vdev);
 	int (*set_vq_affinity)(struct virtqueue *vq, int cpu);
 };
@@ -77,23 +79,70 @@ void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
 					 unsigned int fbit);
 
 /**
- * virtio_has_feature - helper to determine if this device has this feature.
+ * __virtio_test_bit - helper to test feature bits. For use by transports.
+ *                     Devices should normally use virtio_has_feature,
+ *                     which includes more checks.
  * @vdev: the device
  * @fbit: the feature bit
  */
-static inline bool virtio_has_feature(const struct virtio_device *vdev,
+static inline bool __virtio_test_bit(const struct virtio_device *vdev,
+				     unsigned int fbit)
+{
+	/* Did you forget to fix assumptions on max features? */
+	if (__builtin_constant_p(fbit))
+		BUILD_BUG_ON(fbit >= 64);
+	else
+		BUG_ON(fbit >= 64);
+
+	return vdev->features & BIT_ULL(fbit);
+}
+
+/**
+ * __virtio_set_bit - helper to set feature bits. For use by transports.
+ * @vdev: the device
+ * @fbit: the feature bit
+ */
+static inline void __virtio_set_bit(struct virtio_device *vdev,
+				    unsigned int fbit)
+{
+	/* Did you forget to fix assumptions on max features? */
+	if (__builtin_constant_p(fbit))
+		BUILD_BUG_ON(fbit >= 64);
+	else
+		BUG_ON(fbit >= 64);
+
+	vdev->features |= BIT_ULL(fbit);
+}
+
+/**
+ * __virtio_clear_bit - helper to clear feature bits. For use by transports.
+ * @vdev: the device
+ * @fbit: the feature bit
+ */
+static inline void __virtio_clear_bit(struct virtio_device *vdev,
 				      unsigned int fbit)
 {
 	/* Did you forget to fix assumptions on max features? */
 	if (__builtin_constant_p(fbit))
-		BUILD_BUG_ON(fbit >= 32);
+		BUILD_BUG_ON(fbit >= 64);
 	else
-		BUG_ON(fbit >= 32);
+		BUG_ON(fbit >= 64);
 
+	vdev->features &= ~BIT_ULL(fbit);
+}
+
+/**
+ * virtio_has_feature - helper to determine if this device has this feature.
+ * @vdev: the device
+ * @fbit: the feature bit
+ */
+static inline bool virtio_has_feature(const struct virtio_device *vdev,
+				      unsigned int fbit)
+{
 	if (fbit < VIRTIO_TRANSPORT_F_START)
 		virtio_check_driver_offered_feature(vdev, fbit);
 
-	return test_bit(fbit, vdev->features);
+	return __virtio_test_bit(vdev, fbit);
 }
 
 static inline
@@ -152,6 +201,37 @@ int virtqueue_set_affinity(struct virtqueue *vq, int cpu)
 	return 0;
 }
 
+/* Memory accessors */
+static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val)
+{
+	return __virtio16_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
+}
+
+static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val)
+{
+	return __cpu_to_virtio16(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
+}
+
+static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val)
+{
+	return __virtio32_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
+}
+
+static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val)
+{
+	return __cpu_to_virtio32(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
+}
+
+static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val)
+{
+	return __virtio64_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
+}
+
+static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
+{
+	return __cpu_to_virtio64(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
+}
+
 /* Config space accessors. */
 #define virtio_cread(vdev, structname, member, ptr)			\
 	do {								\
@@ -239,12 +319,13 @@ static inline u16 virtio_cread16(struct virtio_device *vdev,
 {
 	u16 ret;
 	vdev->config->get(vdev, offset, &ret, sizeof(ret));
-	return ret;
+	return virtio16_to_cpu(vdev, (__force __virtio16)ret);
 }
 
 static inline void virtio_cwrite16(struct virtio_device *vdev,
 				   unsigned int offset, u16 val)
 {
+	val = (__force u16)cpu_to_virtio16(vdev, val);
 	vdev->config->set(vdev, offset, &val, sizeof(val));
 }
 
@@ -253,12 +334,13 @@ static inline u32 virtio_cread32(struct virtio_device *vdev,
 {
 	u32 ret;
 	vdev->config->get(vdev, offset, &ret, sizeof(ret));
-	return ret;
+	return virtio32_to_cpu(vdev, (__force __virtio32)ret);
 }
 
 static inline void virtio_cwrite32(struct virtio_device *vdev,
 				   unsigned int offset, u32 val)
 {
+	val = (__force u32)cpu_to_virtio32(vdev, val);
 	vdev->config->set(vdev, offset, &val, sizeof(val));
 }
 
@@ -267,12 +349,13 @@ static inline u64 virtio_cread64(struct virtio_device *vdev,
 {
 	u64 ret;
 	vdev->config->get(vdev, offset, &ret, sizeof(ret));
-	return ret;
+	return virtio64_to_cpu(vdev, (__force __virtio64)ret);
 }
 
 static inline void virtio_cwrite64(struct virtio_device *vdev,
 				   unsigned int offset, u64 val)
 {
+	val = (__force u64)cpu_to_virtio64(vdev, val);
 	vdev->config->set(vdev, offset, &val, sizeof(val));
 }