#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;
}
/**
* virtio_device_ready - enable vq use in probe function
* @vdev: the device
*
* Driver must call this to use vqs in the probe function.
*
* Note: vqs are enabled automatically after probe returns.
*/
static inline
void virtio_device_ready(struct virtio_device *dev)
{
unsigned status = dev->config->get_status(dev);
BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK);
dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK);
}
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 */