From: Michael S. Tsirkin Date: Wed, 22 Oct 2014 12:35:56 +0000 (+0300) Subject: virtio: memory access APIs X-Git-Tag: v4.14-rc1~6242^2~78 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=eef960a04354d13426c43a4e3750a5e2b383040c;p=platform%2Fkernel%2Flinux-rpi.git virtio: memory access APIs virtio 1.0 makes all memory structures LE, so we need APIs to conditionally do a byteswap on BE architectures. To make it easier to check code statically, add virtio specific types for multi-byte integers in memory. Add low level wrappers that do a byteswap conditionally, these will be useful e.g. for vhost. Add high level wrappers that query device endian-ness and act accordingly. Signed-off-by: Michael S. Tsirkin Reviewed-by: Cornelia Huck --- diff --git a/include/linux/virtio_byteorder.h b/include/linux/virtio_byteorder.h new file mode 100644 index 0000000..51865d0 --- /dev/null +++ b/include/linux/virtio_byteorder.h @@ -0,0 +1,59 @@ +#ifndef _LINUX_VIRTIO_BYTEORDER_H +#define _LINUX_VIRTIO_BYTEORDER_H +#include +#include + +/* + * Low-level memory accessors for handling virtio in modern little endian and in + * compatibility native endian format. + */ + +static inline u16 __virtio16_to_cpu(bool little_endian, __virtio16 val) +{ + if (little_endian) + return le16_to_cpu((__force __le16)val); + else + return (__force u16)val; +} + +static inline __virtio16 __cpu_to_virtio16(bool little_endian, u16 val) +{ + if (little_endian) + return (__force __virtio16)cpu_to_le16(val); + else + return (__force __virtio16)val; +} + +static inline u32 __virtio32_to_cpu(bool little_endian, __virtio32 val) +{ + if (little_endian) + return le32_to_cpu((__force __le32)val); + else + return (__force u32)val; +} + +static inline __virtio32 __cpu_to_virtio32(bool little_endian, u32 val) +{ + if (little_endian) + return (__force __virtio32)cpu_to_le32(val); + else + return (__force __virtio32)val; +} + +static inline u64 __virtio64_to_cpu(bool little_endian, __virtio64 val) +{ + if (little_endian) + return le64_to_cpu((__force __le64)val); + else + return (__force u64)val; +} + +static inline __virtio64 __cpu_to_virtio64(bool little_endian, u64 val) +{ + if (little_endian) + return (__force __virtio64)cpu_to_le64(val); + else + return (__force __virtio64)val; +} + +#endif /* _LINUX_VIRTIO_BYTEORDER */ diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index f517884..02f0acb 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -4,6 +4,7 @@ #include #include #include +#include #include /** @@ -199,6 +200,37 @@ 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 { \ diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild index 8523f9b..615f96a 100644 --- a/include/uapi/linux/Kbuild +++ b/include/uapi/linux/Kbuild @@ -423,6 +423,7 @@ header-y += virtio_blk.h header-y += virtio_config.h header-y += virtio_console.h header-y += virtio_ids.h +header-y += virtio_types.h header-y += virtio_net.h header-y += virtio_pci.h header-y += virtio_ring.h diff --git a/include/uapi/linux/virtio_ring.h b/include/uapi/linux/virtio_ring.h index a99f9b7..61c818a 100644 --- a/include/uapi/linux/virtio_ring.h +++ b/include/uapi/linux/virtio_ring.h @@ -32,6 +32,7 @@ * * Copyright Rusty Russell IBM Corporation 2007. */ #include +#include /* This marks a buffer as continuing via the next field. */ #define VRING_DESC_F_NEXT 1 @@ -61,32 +62,32 @@ /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */ struct vring_desc { /* Address (guest-physical). */ - __u64 addr; + __virtio64 addr; /* Length. */ - __u32 len; + __virtio32 len; /* The flags as indicated above. */ - __u16 flags; + __virtio16 flags; /* We chain unused descriptors via this, too */ - __u16 next; + __virtio16 next; }; struct vring_avail { - __u16 flags; - __u16 idx; - __u16 ring[]; + __virtio16 flags; + __virtio16 idx; + __virtio16 ring[]; }; /* u32 is used here for ids for padding reasons. */ struct vring_used_elem { /* Index of start of used descriptor chain. */ - __u32 id; + __virtio32 id; /* Total length of the descriptor chain which was used (written to) */ - __u32 len; + __virtio32 len; }; struct vring_used { - __u16 flags; - __u16 idx; + __virtio16 flags; + __virtio16 idx; struct vring_used_elem ring[]; }; @@ -109,25 +110,25 @@ struct vring { * struct vring_desc desc[num]; * * // A ring of available descriptor heads with free-running index. - * __u16 avail_flags; - * __u16 avail_idx; - * __u16 available[num]; - * __u16 used_event_idx; + * __virtio16 avail_flags; + * __virtio16 avail_idx; + * __virtio16 available[num]; + * __virtio16 used_event_idx; * * // Padding to the next align boundary. * char pad[]; * * // A ring of used descriptor heads with free-running index. - * __u16 used_flags; - * __u16 used_idx; + * __virtio16 used_flags; + * __virtio16 used_idx; * struct vring_used_elem used[num]; - * __u16 avail_event_idx; + * __virtio16 avail_event_idx; * }; */ /* We publish the used event index at the end of the available ring, and vice * versa. They are at the end for backwards compatibility. */ #define vring_used_event(vr) ((vr)->avail->ring[(vr)->num]) -#define vring_avail_event(vr) (*(__u16 *)&(vr)->used->ring[(vr)->num]) +#define vring_avail_event(vr) (*(__virtio16 *)&(vr)->used->ring[(vr)->num]) static inline void vring_init(struct vring *vr, unsigned int num, void *p, unsigned long align) @@ -135,15 +136,15 @@ static inline void vring_init(struct vring *vr, unsigned int num, void *p, vr->num = num; vr->desc = p; vr->avail = p + num*sizeof(struct vring_desc); - vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + sizeof(__u16) + vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + sizeof(__virtio16) + align-1) & ~(align - 1)); } static inline unsigned vring_size(unsigned int num, unsigned long align) { - return ((sizeof(struct vring_desc) * num + sizeof(__u16) * (3 + num) + return ((sizeof(struct vring_desc) * num + sizeof(__virtio16) * (3 + num) + align - 1) & ~(align - 1)) - + sizeof(__u16) * 3 + sizeof(struct vring_used_elem) * num; + + sizeof(__virtio16) * 3 + sizeof(struct vring_used_elem) * num; } /* The following is used with USED_EVENT_IDX and AVAIL_EVENT_IDX */ diff --git a/include/uapi/linux/virtio_types.h b/include/uapi/linux/virtio_types.h new file mode 100644 index 0000000..e845e8c --- /dev/null +++ b/include/uapi/linux/virtio_types.h @@ -0,0 +1,46 @@ +#ifndef _UAPI_LINUX_VIRTIO_TYPES_H +#define _UAPI_LINUX_VIRTIO_TYPES_H +/* Type definitions for virtio implementations. + * + * This header is BSD licensed so anyone can use the definitions to implement + * compatible drivers/servers. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of IBM nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * Copyright (C) 2014 Red Hat, Inc. + * Author: Michael S. Tsirkin + */ +#include + +/* + * __virtio{16,32,64} have the following meaning: + * - __u{16,32,64} for virtio devices in legacy mode, accessed in native endian + * - __le{16,32,64} for standard-compliant virtio devices + */ + +typedef __u16 __bitwise__ __virtio16; +typedef __u32 __bitwise__ __virtio32; +typedef __u64 __bitwise__ __virtio64; + +#endif /* _UAPI_LINUX_VIRTIO_TYPES_H */