1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef LINUX_VIRTIO_CONFIG_H
3#define LINUX_VIRTIO_CONFIG_H
4#include <linux/virtio_byteorder.h>
5#include <linux/virtio.h>
6#include <uapi/linux/virtio_config.h>
7
8struct virtio_config_ops {
9	int (*disable_vq_and_reset)(struct virtqueue *vq);
10	int (*enable_vq_after_reset)(struct virtqueue *vq);
11};
12
13/*
14 * __virtio_test_bit - helper to test feature bits. For use by transports.
15 *                     Devices should normally use virtio_has_feature,
16 *                     which includes more checks.
17 * @vdev: the device
18 * @fbit: the feature bit
19 */
20static inline bool __virtio_test_bit(const struct virtio_device *vdev,
21				     unsigned int fbit)
22{
23	return vdev->features & (1ULL << fbit);
24}
25
26/**
27 * __virtio_set_bit - helper to set feature bits. For use by transports.
28 * @vdev: the device
29 * @fbit: the feature bit
30 */
31static inline void __virtio_set_bit(struct virtio_device *vdev,
32				    unsigned int fbit)
33{
34	vdev->features |= (1ULL << fbit);
35}
36
37/**
38 * __virtio_clear_bit - helper to clear feature bits. For use by transports.
39 * @vdev: the device
40 * @fbit: the feature bit
41 */
42static inline void __virtio_clear_bit(struct virtio_device *vdev,
43				      unsigned int fbit)
44{
45	vdev->features &= ~(1ULL << fbit);
46}
47
48#define virtio_has_feature(dev, feature) \
49	(__virtio_test_bit((dev), feature))
50
51/**
52 * virtio_has_dma_quirk - determine whether this device has the DMA quirk
53 * @vdev: the device
54 */
55static inline bool virtio_has_dma_quirk(const struct virtio_device *vdev)
56{
57	/*
58	 * Note the reverse polarity of the quirk feature (compared to most
59	 * other features), this is for compatibility with legacy systems.
60	 */
61	return !virtio_has_feature(vdev, VIRTIO_F_ACCESS_PLATFORM);
62}
63
64static inline bool virtio_is_little_endian(struct virtio_device *vdev)
65{
66	return virtio_has_feature(vdev, VIRTIO_F_VERSION_1) ||
67		virtio_legacy_is_little_endian();
68}
69
70/* Memory accessors */
71static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val)
72{
73	return __virtio16_to_cpu(virtio_is_little_endian(vdev), val);
74}
75
76static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val)
77{
78	return __cpu_to_virtio16(virtio_is_little_endian(vdev), val);
79}
80
81static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val)
82{
83	return __virtio32_to_cpu(virtio_is_little_endian(vdev), val);
84}
85
86static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val)
87{
88	return __cpu_to_virtio32(virtio_is_little_endian(vdev), val);
89}
90
91static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val)
92{
93	return __virtio64_to_cpu(virtio_is_little_endian(vdev), val);
94}
95
96static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
97{
98	return __cpu_to_virtio64(virtio_is_little_endian(vdev), val);
99}
100
101#endif
102