minix3/include/minix/virtio.h

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2020-02-21 00:59:27 +05:30
/*
* Generic virtio library for MINIX 3
*
* Copyright (c) 2013, A. Welzel, <arne.welzel@gmail.com>
*
* This software is released under the BSD license. See the LICENSE file
* included in the main directory of this source distribution for the
* license terms and conditions.
*/
#ifndef _MINIX_VIRTIO_H
#define _MINIX_VIRTIO_H 1
#include <sys/types.h>
#define VIRTIO_VENDOR_ID 0x1AF4
#define VIRTIO_HOST_F_OFF 0x0000
#define VIRTIO_GUEST_F_OFF 0x0004
#define VIRTIO_QADDR_OFF 0x0008
#define VIRTIO_QSIZE_OFF 0x000C
#define VIRTIO_QSEL_OFF 0x000E
#define VIRTIO_QNOTFIY_OFF 0x0010
#define VIRTIO_DEV_STATUS_OFF 0x0012
#define VIRTIO_ISR_STATUS_OFF 0x0013
#define VIRTIO_DEV_SPECIFIC_OFF 0x0014
/* if msi is enabled, device specific headers shift by 4 */
#define VIRTIO_MSI_ADD_OFF 0x0004
#define VIRTIO_STATUS_ACK 0x01
#define VIRTIO_STATUS_DRV 0x02
#define VIRTIO_STATUS_DRV_OK 0x04
#define VIRTIO_STATUS_FAIL 0x80
/* Feature description */
struct virtio_feature {
const char *name;
u8_t bit;
u8_t host_support;
u8_t guest_support;
};
/* Forward declaration of struct virtio_device.
*
* This structure is opaque to the caller.
*/
struct virtio_device;
/* Find a virtio device with subdevice id subdevid. Returns a pointer
* to an opaque virtio_device instance.
*/
struct virtio_device *virtio_setup_device(u16_t subdevid,
const char *name,
struct virtio_feature *features,
int feature_count,
int threads, int skip);
/* Attempt to allocate queue_cnt memory for queues */
int virtio_alloc_queues(struct virtio_device *dev, int num_queues);
/* Register the IRQ policy and indicate to the host we are ready to go */
void virtio_device_ready(struct virtio_device *dev);
/* Unregister the IRQ and reset the device */
void virtio_reset_device(struct virtio_device *dev);
/* Free the memory used by all queues */
void virtio_free_queues(struct virtio_device *dev);
/* Free all memory allocated for the device (except the queue memory,
* which has to be freed before with virtio_free_queues()).
*
* Don't touch the device afterwards! This is like free(dev).
*/
void virtio_free_device(struct virtio_device *dev);
/* Feature helpers */
int virtio_guest_supports(struct virtio_device *dev, int bit);
int virtio_host_supports(struct virtio_device *dev, int bit);
/*
* Use num vumap_phys elements and chain these as vring_desc elements
* into the vring.
*
* Kick the queue if needed.
*
* data is opaque and returned by virtio_from_queue() when the host
* processed the descriptor chain.
*
* Note: The last bit of vp_addr is used to flag whether an iovec is
* writable. This implies that only word aligned buffers can be
* used.
*/
int virtio_to_queue(struct virtio_device *dev, int qidx,
struct vumap_phys *bufs, size_t num, void *data);
/*
* If the host used a chain of descriptors, return 0 and set data
* as was given to virtio_to_queue(). If the host has not processed
* any element returns -1.
*/
int virtio_from_queue(struct virtio_device *dev, int qidx, void **data);
/* IRQ related functions */
void virtio_irq_enable(struct virtio_device *dev);
void virtio_irq_disable(struct virtio_device *dev);
/* Checks the ISR field of the device and returns true if
* the interrupt was for this device.
*/
int virtio_had_irq(struct virtio_device *dev);
u32_t virtio_read32(struct virtio_device *dev, i32_t offset);
u16_t virtio_read16(struct virtio_device *dev, i32_t offset);
u8_t virtio_read8(struct virtio_device *dev, i32_t offset);
void virtio_write32(struct virtio_device *dev, i32_t offset, u32_t val);
void virtio_write16(struct virtio_device *dev, i32_t offset, u16_t val);
void virtio_write8(struct virtio_device *dev, i32_t offset, u8_t val);
/*
* Device specific reads take MSI offset into account and all reads
* are at offset 20.
*
* Something like:
* read(off) --> readX(20 + (msi ? 4 : 0) + off)
*/
u32_t virtio_sread32(struct virtio_device *dev, i32_t offset);
u16_t virtio_sread16(struct virtio_device *dev, i32_t offset);
u8_t virtio_sread8(struct virtio_device *dev, i32_t offset);
void virtio_swrite32(struct virtio_device *dev, i32_t offset, u32_t val);
void virtio_swrite16(struct virtio_device *dev, i32_t offset, u16_t val);
void virtio_swrite8(struct virtio_device *dev, i32_t offset, u8_t val);
#endif /* _MINIX_VIRTIO_H */