[PATCH v2 2/9] rpmsg: Introduce __rpmsg{16|32|64} types

[Mathieu Poirier]

Introduce __rpmsg{16|32|64} types along with byte order conversion
functions based on an rpmsg_device operation as a foundation to
make RPMSG modular and transport agnostic.

Suggested-by: Guennadi Liakhovetski <guennadi.liakhovetski@xxxxxxxxxxxxxxx>
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
 include/linux/rpmsg.h            | 51 ++++++++++++++++++++++++
 include/linux/rpmsg_byteorder.h  | 67 ++++++++++++++++++++++++++++++++
 include/uapi/linux/rpmsg_types.h | 11 ++++++
 3 files changed, 129 insertions(+)
 create mode 100644 include/linux/rpmsg_byteorder.h
 create mode 100644 include/uapi/linux/rpmsg_types.h

diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
index 9fe1c54ae995..165e4c6d4cd3 100644
--- a/include/linux/rpmsg.h
+++ b/include/linux/rpmsg.h
@@ -17,6 +17,7 @@
 #include <linux/kref.h>
 #include <linux/mutex.h>
 #include <linux/poll.h>
+#include <linux/rpmsg_byteorder.h>
 
 #define RPMSG_ADDR_ANY		0xFFFFFFFF
 
@@ -40,6 +41,7 @@ typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32);
 
 /**
  * struct rpmsg_device_ops - indirection table for the rpmsg_device operations
+ * @is_little_endian:	returns true if using little endian byte ordering
  * @create_ept:		create backend-specific endpoint, required
  * @announce_create:	announce presence of new channel, optional
  * @announce_destroy:	announce destruction of channel, optional
@@ -49,6 +51,7 @@ typedef int (*rpmsg_rx_cb_t)(struct rpmsg_device *, void *, int, void *, u32);
  * advertise new channels implicitly by creating the endpoints.
  */
 struct rpmsg_device_ops {
+	bool (*is_little_endian)(struct rpmsg_device *rpdev);
 	struct rpmsg_endpoint *(*create_ept)(struct rpmsg_device *rpdev,
 					    rpmsg_rx_cb_t cb, void *priv,
 					    struct rpmsg_channel_info chinfo);
@@ -129,6 +132,54 @@ struct rpmsg_driver {
 	int (*callback)(struct rpmsg_device *, void *, int, void *, u32);
 };
 
+static inline u16 rpmsg16_to_cpu(struct rpmsg_device *rpdev, __rpmsg16 val)
+{
+	if (!rpdev || !rpdev->ops || !rpdev->ops->is_little_endian)
+		return __rpmsg16_to_cpu(rpmsg_is_little_endian(), val);
+	else
+		return __rpmsg16_to_cpu(rpdev->ops->is_little_endian(rpdev), val);
+}
+
+static inline __rpmsg16 cpu_to_rpmsg16(struct rpmsg_device *rpdev, u16 val)
+{
+	if (!rpdev || !rpdev->ops || !rpdev->ops->is_little_endian)
+		return __cpu_to_rpmsg16(rpmsg_is_little_endian(), val);
+	else
+		return __cpu_to_rpmsg16(rpdev->ops->is_little_endian(rpdev), val);
+}
+
+static inline u32 rpmsg32_to_cpu(struct rpmsg_device *rpdev, __rpmsg32 val)
+{
+	if (!rpdev || !rpdev->ops || !rpdev->ops->is_little_endian)
+		return __rpmsg32_to_cpu(rpmsg_is_little_endian(), val);
+	else
+		return __rpmsg32_to_cpu(rpdev->ops->is_little_endian(rpdev), val);
+}
+
+static inline __rpmsg32 cpu_to_rpmsg32(struct rpmsg_device *rpdev, u32 val)
+{
+	if (!rpdev || !rpdev->ops || !rpdev->ops->is_little_endian)
+		return __cpu_to_rpmsg32(rpmsg_is_little_endian(), val);
+	else
+		return __cpu_to_rpmsg32(rpdev->ops->is_little_endian(rpdev), val);
+}
+
+static inline u64 rpmsg64_to_cpu(struct rpmsg_device *rpdev, __rpmsg64 val)
+{
+	if (!rpdev || !rpdev->ops || !rpdev->ops->is_little_endian)
+		return __rpmsg64_to_cpu(rpmsg_is_little_endian(), val);
+	else
+		return __rpmsg64_to_cpu(rpdev->ops->is_little_endian(rpdev), val);
+}
+
+static inline __rpmsg64 cpu_to_rpmsg64(struct rpmsg_device *rpdev, u64 val)
+{
+	if (!rpdev || !rpdev->ops || !rpdev->ops->is_little_endian)
+		return __cpu_to_rpmsg64(rpmsg_is_little_endian(), val);
+	else
+		return __cpu_to_rpmsg64(rpdev->ops->is_little_endian(rpdev), val);
+}
+
 #if IS_ENABLED(CONFIG_RPMSG)
 
 int register_rpmsg_device(struct rpmsg_device *dev);
diff --git a/include/linux/rpmsg_byteorder.h b/include/linux/rpmsg_byteorder.h
new file mode 100644
index 000000000000..c0f565dbad6d
--- /dev/null
+++ b/include/linux/rpmsg_byteorder.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Follows implementation found in linux/virtio_byteorder.h
+ */
+#ifndef _LINUX_RPMSG_BYTEORDER_H
+#define _LINUX_RPMSG_BYTEORDER_H
+#include <linux/types.h>
+#include <uapi/linux/rpmsg_types.h>
+
+static inline bool rpmsg_is_little_endian(void)
+{
+#ifdef __LITTLE_ENDIAN
+	return true;
+#else
+	return false;
+#endif
+}
+
+static inline u16 __rpmsg16_to_cpu(bool little_endian, __rpmsg16 val)
+{
+	if (little_endian)
+		return le16_to_cpu((__force __le16)val);
+	else
+		return be16_to_cpu((__force __be16)val);
+}
+
+static inline __rpmsg16 __cpu_to_rpmsg16(bool little_endian, u16 val)
+{
+	if (little_endian)
+		return (__force __rpmsg16)cpu_to_le16(val);
+	else
+		return (__force __rpmsg16)cpu_to_be16(val);
+}
+
+static inline u32 __rpmsg32_to_cpu(bool little_endian, __rpmsg32 val)
+{
+	if (little_endian)
+		return le32_to_cpu((__force __le32)val);
+	else
+		return be32_to_cpu((__force __be32)val);
+}
+
+static inline __rpmsg32 __cpu_to_rpmsg32(bool little_endian, u32 val)
+{
+	if (little_endian)
+		return (__force __rpmsg32)cpu_to_le32(val);
+	else
+		return (__force __rpmsg32)cpu_to_be32(val);
+}
+
+static inline u64 __rpmsg64_to_cpu(bool little_endian, __rpmsg64 val)
+{
+	if (little_endian)
+		return le64_to_cpu((__force __le64)val);
+	else
+		return be64_to_cpu((__force __be64)val);
+}
+
+static inline __rpmsg64 __cpu_to_rpmsg64(bool little_endian, u64 val)
+{
+	if (little_endian)
+		return (__force __rpmsg64)cpu_to_le64(val);
+	else
+		return (__force __rpmsg64)cpu_to_be64(val);
+}
+
+#endif /* _LINUX_RPMSG_BYTEORDER_H */
diff --git a/include/uapi/linux/rpmsg_types.h b/include/uapi/linux/rpmsg_types.h
new file mode 100644
index 000000000000..36e3b9404391
--- /dev/null
+++ b/include/uapi/linux/rpmsg_types.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_LINUX_RPMSG_TYPES_H
+#define _UAPI_LINUX_RPMSG_TYPES_H
+
+#include <linux/types.h>
+
+typedef __u16 __bitwise __rpmsg16;
+typedef __u32 __bitwise __rpmsg32;
+typedef __u64 __bitwise __rpmsg64;
+
+#endif /* _UAPI_LINUX_RPMSG_TYPES_H */
-- 
2.25.1