virtio/linux/virtio_config.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #include <linux/virtio_byteorder.h>
0003 #include <linux/virtio.h>
0004 #include <uapi/linux/virtio_config.h>
0005
0006 struct virtio_config_ops {
0007     int (*disable_vq_and_reset)(struct virtqueue *vq);
0008     int (*enable_vq_after_reset)(struct virtqueue *vq);
0009 };
0010
0011 /*
0012  * __virtio_test_bit - helper to test feature bits. For use by transports.
0013  *                     Devices should normally use virtio_has_feature,
0014  *                     which includes more checks.
0015  * @vdev: the device
0016  * @fbit: the feature bit
0017  */
0018 static inline bool __virtio_test_bit(const struct virtio_device *vdev,
0019                      unsigned int fbit)
0020 {
0021     return vdev->features & (1ULL << fbit);
0022 }
0023
0024 /**
0025  * __virtio_set_bit - helper to set feature bits. For use by transports.
0026  * @vdev: the device
0027  * @fbit: the feature bit
0028  */
0029 static inline void __virtio_set_bit(struct virtio_device *vdev,
0030                     unsigned int fbit)
0031 {
0032     vdev->features |= (1ULL << fbit);
0033 }
0034
0035 /**
0036  * __virtio_clear_bit - helper to clear feature bits. For use by transports.
0037  * @vdev: the device
0038  * @fbit: the feature bit
0039  */
0040 static inline void __virtio_clear_bit(struct virtio_device *vdev,
0041                       unsigned int fbit)
0042 {
0043     vdev->features &= ~(1ULL << fbit);
0044 }
0045
0046 #define virtio_has_feature(dev, feature) \
0047     (__virtio_test_bit((dev), feature))
0048
0049 /**
0050  * virtio_has_dma_quirk - determine whether this device has the DMA quirk
0051  * @vdev: the device
0052  */
0053 static inline bool virtio_has_dma_quirk(const struct virtio_device *vdev)
0054 {
0055     /*
0056      * Note the reverse polarity of the quirk feature (compared to most
0057      * other features), this is for compatibility with legacy systems.
0058      */
0059     return !virtio_has_feature(vdev, VIRTIO_F_ACCESS_PLATFORM);
0060 }
0061
0062 static inline bool virtio_is_little_endian(struct virtio_device *vdev)
0063 {
0064     return virtio_has_feature(vdev, VIRTIO_F_VERSION_1) ||
0065         virtio_legacy_is_little_endian();
0066 }
0067
0068 /* Memory accessors */
0069 static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val)
0070 {
0071     return __virtio16_to_cpu(virtio_is_little_endian(vdev), val);
0072 }
0073
0074 static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val)
0075 {
0076     return __cpu_to_virtio16(virtio_is_little_endian(vdev), val);
0077 }
0078
0079 static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val)
0080 {
0081     return __virtio32_to_cpu(virtio_is_little_endian(vdev), val);
0082 }
0083
0084 static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val)
0085 {
0086     return __cpu_to_virtio32(virtio_is_little_endian(vdev), val);
0087 }
0088
0089 static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val)
0090 {
0091     return __virtio64_to_cpu(virtio_is_little_endian(vdev), val);
0092 }
0093
0094 static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
0095 {
0096     return __cpu_to_virtio64(virtio_is_little_endian(vdev), val);
0097 }