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