Re: [PATCH v2 2/9] rpmsg: Introduce __rpmsg{16|32|64} types
From: Mathieu Poirier
Date: Thu Oct 15 2020 - 15:32:48 EST
Good day,
On Wed, Oct 14, 2020 at 06:31:49PM +0200, Arnaud POULIQUEN wrote:
> Hi Mathieu,
>
> On 10/14/20 1:25 AM, Mathieu Poirier wrote:
> > 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
> > +}
>
> A suggestion:
>
> static inline bool rpmsg_is_little_endian(void)
> #if defined(__BYTE_ORDER)
> # if __BYTE_ORDER == __BIG_ENDIAN
> return true;
> # elif __BYTE_ORDER == __LITTLE_ENDIAN
> return false;
> # else
> # warning "unknown endianess, set to little by default"
> return true;
> # endif
> #endif
> }
I found that __BYTE_ORDER is not defined stm32mp157 - have you used it before?
>
> Otherwise
>
> Reviewed-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx>
>
> Thanks,
> Arnaud
>
> > +
> > +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 */
> >