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- #ifndef _LINUX_VIRTIO_CONFIG_H
- #define _LINUX_VIRTIO_CONFIG_H
- #include <linux/err.h>
- #include <linux/bug.h>
- #include <linux/virtio.h>
- #include <uapi/linux/virtio_config.h>
- /**
- * virtio_config_ops - operations for configuring a virtio device
- * @get: read the value of a configuration field
- * vdev: the virtio_device
- * offset: the offset of the configuration field
- * buf: the buffer to write the field value into.
- * len: the length of the buffer
- * @set: write the value of a configuration field
- * vdev: the virtio_device
- * offset: the offset of the configuration field
- * buf: the buffer to read the field value from.
- * len: the length of the buffer
- * @get_status: read the status byte
- * vdev: the virtio_device
- * Returns the status byte
- * @set_status: write the status byte
- * vdev: the virtio_device
- * status: the new status byte
- * @reset: reset the device
- * vdev: the virtio device
- * After this, status and feature negotiation must be done again
- * Device must not be reset from its vq/config callbacks, or in
- * parallel with being added/removed.
- * @find_vqs: find virtqueues and instantiate them.
- * vdev: the virtio_device
- * nvqs: the number of virtqueues to find
- * vqs: on success, includes new virtqueues
- * callbacks: array of callbacks, for each virtqueue
- * include a NULL entry for vqs that do not need a callback
- * names: array of virtqueue names (mainly for debugging)
- * include a NULL entry for vqs unused by driver
- * Returns 0 on success or error status
- * @del_vqs: free virtqueues found by find_vqs().
- * @get_features: get the array of feature bits for this device.
- * vdev: the virtio_device
- * Returns the first 32 feature bits (all we currently need).
- * @finalize_features: confirm what device features we'll be using.
- * vdev: the virtio_device
- * This gives the final feature bits for the device: it can change
- * the dev->feature bits if it wants.
- * @bus_name: return the bus name associated with the device
- * vdev: the virtio_device
- * This returns a pointer to the bus name a la pci_name from which
- * the caller can then copy.
- * @set_vq_affinity: set the affinity for a virtqueue.
- */
- typedef void vq_callback_t(struct virtqueue *);
- struct virtio_config_ops {
- void (*get)(struct virtio_device *vdev, unsigned offset,
- void *buf, unsigned len);
- void (*set)(struct virtio_device *vdev, unsigned offset,
- const void *buf, unsigned len);
- u8 (*get_status)(struct virtio_device *vdev);
- void (*set_status)(struct virtio_device *vdev, u8 status);
- void (*reset)(struct virtio_device *vdev);
- int (*find_vqs)(struct virtio_device *, unsigned nvqs,
- struct virtqueue *vqs[],
- vq_callback_t *callbacks[],
- const char *names[]);
- void (*del_vqs)(struct virtio_device *);
- u32 (*get_features)(struct virtio_device *vdev);
- void (*finalize_features)(struct virtio_device *vdev);
- const char *(*bus_name)(struct virtio_device *vdev);
- int (*set_vq_affinity)(struct virtqueue *vq, int cpu);
- };
- /* If driver didn't advertise the feature, it will never appear. */
- void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
- unsigned int fbit);
- /**
- * virtio_has_feature - helper to determine if this device has this feature.
- * @vdev: the device
- * @fbit: the feature bit
- */
- static inline bool virtio_has_feature(const struct virtio_device *vdev,
- unsigned int fbit)
- {
- /* Did you forget to fix assumptions on max features? */
- if (__builtin_constant_p(fbit))
- BUILD_BUG_ON(fbit >= 32);
- else
- BUG_ON(fbit >= 32);
- if (fbit < VIRTIO_TRANSPORT_F_START)
- virtio_check_driver_offered_feature(vdev, fbit);
- return test_bit(fbit, vdev->features);
- }
- static inline
- struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
- vq_callback_t *c, const char *n)
- {
- vq_callback_t *callbacks[] = { c };
- const char *names[] = { n };
- struct virtqueue *vq;
- int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names);
- if (err < 0)
- return ERR_PTR(err);
- return vq;
- }
- static inline
- const char *virtio_bus_name(struct virtio_device *vdev)
- {
- if (!vdev->config->bus_name)
- return "virtio";
- return vdev->config->bus_name(vdev);
- }
- /**
- * virtqueue_set_affinity - setting affinity for a virtqueue
- * @vq: the virtqueue
- * @cpu: the cpu no.
- *
- * Pay attention the function are best-effort: the affinity hint may not be set
- * due to config support, irq type and sharing.
- *
- */
- static inline
- int virtqueue_set_affinity(struct virtqueue *vq, int cpu)
- {
- struct virtio_device *vdev = vq->vdev;
- if (vdev->config->set_vq_affinity)
- return vdev->config->set_vq_affinity(vq, cpu);
- return 0;
- }
- /* Config space accessors. */
- #define virtio_cread(vdev, structname, member, ptr) \
- do { \
- /* Must match the member's type, and be integer */ \
- if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
- (*ptr) = 1; \
- \
- switch (sizeof(*ptr)) { \
- case 1: \
- *(ptr) = virtio_cread8(vdev, \
- offsetof(structname, member)); \
- break; \
- case 2: \
- *(ptr) = virtio_cread16(vdev, \
- offsetof(structname, member)); \
- break; \
- case 4: \
- *(ptr) = virtio_cread32(vdev, \
- offsetof(structname, member)); \
- break; \
- case 8: \
- *(ptr) = virtio_cread64(vdev, \
- offsetof(structname, member)); \
- break; \
- default: \
- BUG(); \
- } \
- } while(0)
- /* Config space accessors. */
- #define virtio_cwrite(vdev, structname, member, ptr) \
- do { \
- /* Must match the member's type, and be integer */ \
- if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
- BUG_ON((*ptr) == 1); \
- \
- switch (sizeof(*ptr)) { \
- case 1: \
- virtio_cwrite8(vdev, \
- offsetof(structname, member), \
- *(ptr)); \
- break; \
- case 2: \
- virtio_cwrite16(vdev, \
- offsetof(structname, member), \
- *(ptr)); \
- break; \
- case 4: \
- virtio_cwrite32(vdev, \
- offsetof(structname, member), \
- *(ptr)); \
- break; \
- case 8: \
- virtio_cwrite64(vdev, \
- offsetof(structname, member), \
- *(ptr)); \
- break; \
- default: \
- BUG(); \
- } \
- } while(0)
- static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
- {
- u8 ret;
- vdev->config->get(vdev, offset, &ret, sizeof(ret));
- return ret;
- }
- static inline void virtio_cread_bytes(struct virtio_device *vdev,
- unsigned int offset,
- void *buf, size_t len)
- {
- vdev->config->get(vdev, offset, buf, len);
- }
- static inline void virtio_cwrite8(struct virtio_device *vdev,
- unsigned int offset, u8 val)
- {
- vdev->config->set(vdev, offset, &val, sizeof(val));
- }
- static inline u16 virtio_cread16(struct virtio_device *vdev,
- unsigned int offset)
- {
- u16 ret;
- vdev->config->get(vdev, offset, &ret, sizeof(ret));
- return ret;
- }
- static inline void virtio_cwrite16(struct virtio_device *vdev,
- unsigned int offset, u16 val)
- {
- vdev->config->set(vdev, offset, &val, sizeof(val));
- }
- static inline u32 virtio_cread32(struct virtio_device *vdev,
- unsigned int offset)
- {
- u32 ret;
- vdev->config->get(vdev, offset, &ret, sizeof(ret));
- return ret;
- }
- static inline void virtio_cwrite32(struct virtio_device *vdev,
- unsigned int offset, u32 val)
- {
- vdev->config->set(vdev, offset, &val, sizeof(val));
- }
- static inline u64 virtio_cread64(struct virtio_device *vdev,
- unsigned int offset)
- {
- u64 ret;
- vdev->config->get(vdev, offset, &ret, sizeof(ret));
- return ret;
- }
- static inline void virtio_cwrite64(struct virtio_device *vdev,
- unsigned int offset, u64 val)
- {
- vdev->config->set(vdev, offset, &val, sizeof(val));
- }
- /* Conditional config space accessors. */
- #define virtio_cread_feature(vdev, fbit, structname, member, ptr) \
- ({ \
- int _r = 0; \
- if (!virtio_has_feature(vdev, fbit)) \
- _r = -ENOENT; \
- else \
- virtio_cread((vdev), structname, member, ptr); \
- _r; \
- })
- #endif /* _LINUX_VIRTIO_CONFIG_H */
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