linux-next/include/linux/virtio.h
Koichiro Den 8d2da07c81 virtio_ring: add a func argument 'recycle_done' to virtqueue_reset()
When virtqueue_reset() has actually recycled all unused buffers,
additional work may be required in some cases. Relying solely on its
return status is fragile, so introduce a new function argument
'recycle_done', which is invoked when it really occurs.

Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-12-10 11:22:21 +01:00

295 lines
10 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_VIRTIO_H
#define _LINUX_VIRTIO_H
/* Everything a virtio driver needs to work with any particular virtio
* implementation. */
#include <linux/types.h>
#include <linux/scatterlist.h>
#include <linux/spinlock.h>
#include <linux/device.h>
#include <linux/mod_devicetable.h>
#include <linux/gfp.h>
#include <linux/dma-mapping.h>
#include <linux/completion.h>
/**
* struct virtqueue - a queue to register buffers for sending or receiving.
* @list: the chain of virtqueues for this device
* @callback: the function to call when buffers are consumed (can be NULL).
* @name: the name of this virtqueue (mainly for debugging)
* @vdev: the virtio device this queue was created for.
* @priv: a pointer for the virtqueue implementation to use.
* @index: the zero-based ordinal number for this queue.
* @num_free: number of elements we expect to be able to fit.
* @num_max: the maximum number of elements supported by the device.
* @reset: vq is in reset state or not.
*
* A note on @num_free: with indirect buffers, each buffer needs one
* element in the queue, otherwise a buffer will need one element per
* sg element.
*/
struct virtqueue {
struct list_head list;
void (*callback)(struct virtqueue *vq);
const char *name;
struct virtio_device *vdev;
unsigned int index;
unsigned int num_free;
unsigned int num_max;
bool reset;
void *priv;
};
int virtqueue_add_outbuf(struct virtqueue *vq,
struct scatterlist sg[], unsigned int num,
void *data,
gfp_t gfp);
int virtqueue_add_inbuf(struct virtqueue *vq,
struct scatterlist sg[], unsigned int num,
void *data,
gfp_t gfp);
int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
struct scatterlist sg[], unsigned int num,
void *data,
void *ctx,
gfp_t gfp);
int virtqueue_add_inbuf_premapped(struct virtqueue *vq,
struct scatterlist *sg, unsigned int num,
void *data,
void *ctx,
gfp_t gfp);
int virtqueue_add_outbuf_premapped(struct virtqueue *vq,
struct scatterlist *sg, unsigned int num,
void *data,
gfp_t gfp);
int virtqueue_add_sgs(struct virtqueue *vq,
struct scatterlist *sgs[],
unsigned int out_sgs,
unsigned int in_sgs,
void *data,
gfp_t gfp);
struct device *virtqueue_dma_dev(struct virtqueue *vq);
bool virtqueue_kick(struct virtqueue *vq);
bool virtqueue_kick_prepare(struct virtqueue *vq);
bool virtqueue_notify(struct virtqueue *vq);
void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
void **ctx);
void virtqueue_disable_cb(struct virtqueue *vq);
bool virtqueue_enable_cb(struct virtqueue *vq);
unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
bool virtqueue_poll(struct virtqueue *vq, unsigned);
bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
void *virtqueue_detach_unused_buf(struct virtqueue *vq);
unsigned int virtqueue_get_vring_size(const struct virtqueue *vq);
bool virtqueue_is_broken(const struct virtqueue *vq);
const struct vring *virtqueue_get_vring(const struct virtqueue *vq);
dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq);
dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq);
dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq);
int virtqueue_resize(struct virtqueue *vq, u32 num,
void (*recycle)(struct virtqueue *vq, void *buf),
void (*recycle_done)(struct virtqueue *vq));
int virtqueue_reset(struct virtqueue *vq,
void (*recycle)(struct virtqueue *vq, void *buf),
void (*recycle_done)(struct virtqueue *vq));
struct virtio_admin_cmd {
__le16 opcode;
__le16 group_type;
__le64 group_member_id;
struct scatterlist *data_sg;
struct scatterlist *result_sg;
struct completion completion;
u32 result_sg_size;
int ret;
};
/**
* struct virtio_device - representation of a device using virtio
* @index: unique position on the virtio bus
* @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
* @config_core_enabled: configuration change reporting enabled by core
* @config_driver_disabled: configuration change reporting disabled by
* a driver
* @config_change_pending: configuration change reported while disabled
* @config_lock: protects configuration change reporting
* @vqs_list_lock: protects @vqs.
* @dev: underlying device.
* @id: the device type identification (used to match it with a driver).
* @config: the configuration ops for this device.
* @vringh_config: configuration ops for host vrings.
* @vqs: the list of virtqueues for this device.
* @features: the features supported by both driver and device.
* @priv: private pointer for the driver's use.
* @debugfs_dir: debugfs directory entry.
* @debugfs_filter_features: features to be filtered set by debugfs.
*/
struct virtio_device {
int index;
bool failed;
bool config_core_enabled;
bool config_driver_disabled;
bool config_change_pending;
spinlock_t config_lock;
spinlock_t vqs_list_lock;
struct device dev;
struct virtio_device_id id;
const struct virtio_config_ops *config;
const struct vringh_config_ops *vringh_config;
struct list_head vqs;
u64 features;
void *priv;
#ifdef CONFIG_VIRTIO_DEBUG
struct dentry *debugfs_dir;
u64 debugfs_filter_features;
#endif
};
#define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev)
void virtio_add_status(struct virtio_device *dev, unsigned int status);
int register_virtio_device(struct virtio_device *dev);
void unregister_virtio_device(struct virtio_device *dev);
bool is_virtio_device(struct device *dev);
void virtio_break_device(struct virtio_device *dev);
void __virtio_unbreak_device(struct virtio_device *dev);
void __virtqueue_break(struct virtqueue *_vq);
void __virtqueue_unbreak(struct virtqueue *_vq);
void virtio_config_changed(struct virtio_device *dev);
void virtio_config_driver_disable(struct virtio_device *dev);
void virtio_config_driver_enable(struct virtio_device *dev);
#ifdef CONFIG_PM_SLEEP
int virtio_device_freeze(struct virtio_device *dev);
int virtio_device_restore(struct virtio_device *dev);
#endif
void virtio_reset_device(struct virtio_device *dev);
size_t virtio_max_dma_size(const struct virtio_device *vdev);
#define virtio_device_for_each_vq(vdev, vq) \
list_for_each_entry(vq, &vdev->vqs, list)
/**
* struct virtio_driver - operations for a virtio I/O driver
* @driver: underlying device driver (populate name).
* @id_table: the ids serviced by this driver.
* @feature_table: an array of feature numbers supported by this driver.
* @feature_table_size: number of entries in the feature table array.
* @feature_table_legacy: same as feature_table but when working in legacy mode.
* @feature_table_size_legacy: number of entries in feature table legacy array.
* @validate: the function to call to validate features and config space.
* Returns 0 or -errno.
* @probe: the function to call when a device is found. Returns 0 or -errno.
* @scan: optional function to call after successful probe; intended
* for virtio-scsi to invoke a scan.
* @remove: the function to call when a device is removed.
* @config_changed: optional function to call when the device configuration
* changes; may be called in interrupt context.
* @freeze: optional function to call during suspend/hibernation.
* @restore: optional function to call on resume.
*/
struct virtio_driver {
struct device_driver driver;
const struct virtio_device_id *id_table;
const unsigned int *feature_table;
unsigned int feature_table_size;
const unsigned int *feature_table_legacy;
unsigned int feature_table_size_legacy;
int (*validate)(struct virtio_device *dev);
int (*probe)(struct virtio_device *dev);
void (*scan)(struct virtio_device *dev);
void (*remove)(struct virtio_device *dev);
void (*config_changed)(struct virtio_device *dev);
int (*freeze)(struct virtio_device *dev);
int (*restore)(struct virtio_device *dev);
};
#define drv_to_virtio(__drv) container_of_const(__drv, struct virtio_driver, driver)
/* use a macro to avoid include chaining to get THIS_MODULE */
#define register_virtio_driver(drv) \
__register_virtio_driver(drv, THIS_MODULE)
int __register_virtio_driver(struct virtio_driver *drv, struct module *owner);
void unregister_virtio_driver(struct virtio_driver *drv);
/* module_virtio_driver() - Helper macro for drivers that don't do
* anything special in module init/exit. This eliminates a lot of
* boilerplate. Each module may only use this macro once, and
* calling it replaces module_init() and module_exit()
*/
#define module_virtio_driver(__virtio_driver) \
module_driver(__virtio_driver, register_virtio_driver, \
unregister_virtio_driver)
dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr, size_t size,
enum dma_data_direction dir, unsigned long attrs);
void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr,
size_t size, enum dma_data_direction dir,
unsigned long attrs);
int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr);
bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr);
void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, dma_addr_t addr,
unsigned long offset, size_t size,
enum dma_data_direction dir);
void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr,
unsigned long offset, size_t size,
enum dma_data_direction dir);
#ifdef CONFIG_VIRTIO_DEBUG
void virtio_debug_device_init(struct virtio_device *dev);
void virtio_debug_device_exit(struct virtio_device *dev);
void virtio_debug_device_filter_features(struct virtio_device *dev);
void virtio_debug_init(void);
void virtio_debug_exit(void);
#else
static inline void virtio_debug_device_init(struct virtio_device *dev)
{
}
static inline void virtio_debug_device_exit(struct virtio_device *dev)
{
}
static inline void virtio_debug_device_filter_features(struct virtio_device *dev)
{
}
static inline void virtio_debug_init(void)
{
}
static inline void virtio_debug_exit(void)
{
}
#endif
#endif /* _LINUX_VIRTIO_H */