tools/virtio/linux/virtio_config.h

   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
   8 struct 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  */
  20 static 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  */
  31 static 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  */
  42 static 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  */
  55 static 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
  64 static 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 */
  71 static 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
  76 static 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
  81 static 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
  86 static 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
  91 static 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
  96 static 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