virtiovar.h

/*
 * Copyright (c) 2010 Minoura Makoto.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Part of the file derived from `Virtio PCI Card Specification v0.8.6 DRAFT'
 * Appendix A.
 */
/* An interface for efficient virtio implementation.
 *
 * This header is BSD licensed so anyone can use the definitions
 * to implement compatible drivers/servers.
 *
 * Copyright 2007, 2009, IBM Corporation
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of IBM nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * 
 */

#ifndef _VIRTIOVAR_H_
#define _VIRTIOVAR_H_

/* change to VIRTIO_DEBUG for dmesg info*/
#define NO_VIRTIO_DEBUG

#ifdef VIRTIO_DEBUG 
	#define debug(fmt, ...) do { kprintf("%s: " fmt "\n", __func__ , ##__VA_ARGS__); } \
	while(0)
#else 
	#define debug( fmt, ...)
#endif

//#include "virtioreg.h"

struct vq_entry {
	TAILQ_ENTRY(vq_entry)	qe_list;	/* free list */
	uint16_t				qe_index;	/* index in vq_desc array */

	/* followings are used only when it is the `head' entry */ 
	int16_t				qe_next;	/* next enq slot */
	bool				qe_indirect;	/* 1 if using indirect */
	struct vring_desc	*qe_desc_base;
};

struct virtqueue {
	struct virtio_softc	*vq_owner; 
	u_int32_t			vq_num;	/* queue size (# of entries) */
	u_int16_t				vq_index;	/* queue number (0, 1, ...) */

	/* vring pointers (KVA) */
	struct vring_desc       *vq_desc;
	struct vring_avail      *vq_avail;
	struct vring_used       *vq_used;
	void					*vq_indirect;

	/* virtqueue allocation info */
	void				*vq_vaddr;
	int32_t				vq_availoffset;
	int32_t				vq_usedoffset;
	int32_t				vq_indirectoffset;
	bus_dma_segment_t	vq_segs[1];
	u_int32_t			vq_bytesize;
	bus_dma_tag_t		vq_dmat;
	bus_dmamap_t		vq_dmamap;
	bus_addr_t			bus_addr;

	int32_t			vq_maxsegsize;
	int32_t			vq_maxnsegs;

	/* free entry management */
	struct vq_entry			*vq_entries;
	TAILQ_HEAD(,vq_entry)	vq_freelist;
	struct spinlock			vq_freelist_lock;

	/* enqueue/dequeue status */
	u_int16_t			vq_avail_idx;
	u_int16_t			vq_used_idx;
	int32_t				vq_queued;
	struct spinlock		vq_aring_lock;
	struct spinlock		vq_uring_lock;

	int (*vq_done)(struct virtqueue*);	/* interrupt handler */
};

struct virtio_softc {
	device_t		dev;
	int32_t			rid_ioport;
	int32_t			rid_memory;
	int32_t			rid_irq;

	int32_t				regs_rid;	/* resource id*/
	struct resource		*res_memory;	/* Resource for mem range. */
	struct resource		*res_irq;	/* Resource for irq range. */
	struct resource		*io; 

	bus_dma_tag_t		virtio_dmat;	/*Master tag*/

	int32_t				sc_config_offset;

	bus_space_tag_t		sc_iot;
	bus_space_handle_t	sc_ioh;

	int					sc_nvqs;	/* set by child */
	struct virtqueue	*sc_vqs;

	bus_dma_tag_t		requests_dmat;
	bus_dmamap_t		cmds_dmamap;
	bus_dma_tag_t		payloads_dmat;

	vm_paddr_t		phys_next;	/* next page from mem range */
	uint32_t		sc_features;
	bool			sc_indirect;
	int				sc_childdevid;
	device_t		sc_child;	/* set by child */
	void			*virtio_intr;

	int (*sc_config_change)(struct virtio_softc*);	/* set by child */
	int (*sc_intrhand)(struct virtio_softc*);	/* set by child */
};

/* The standard layout for the ring is a continuous chunk of memory which
 * looks like this.  We assume num is a power of 2.
 *
 * struct vring {
 * The actual descriptors (16 bytes each)
 *      struct vring_desc desc[num];
 *
 *      // A ring of available descriptor heads with free-running index.
 *      __u16 avail_flags;
 *      __u16 avail_idx;
 *      __u16 available[num];
 *
 *      // Padding to the next align boundary.
 *      char pad[];
 *
 *      // A ring of used descriptor heads with free-running index.
 *      __u16 used_flags;
 *      __u16 used_idx;
 *      struct vring_used_elem used[num];
 * };
 * Note: for virtio PCI, align is 4096.
 */

/* public interface */
uint32_t	virtio_negotiate_features(struct virtio_softc*, uint32_t);
void		virtio_set_status(struct virtio_softc *sc, int32_t );
uint8_t		virtio_read_device_config_1(struct virtio_softc *sc, int index);
uint16_t	virtio_read_device_config_2(struct virtio_softc *sc, int index);
uint32_t	virtio_read_device_config_4(struct virtio_softc *sc, int index);
uint64_t	virtio_read_device_config_8(struct virtio_softc *sc, int index);
void		virtio_write_device_config_1(struct virtio_softc *sc,
					     int32_t index, uint8_t value);

int	virtio_alloc_vq(struct virtio_softc*, struct virtqueue*, int, int, int,
		    const char*);
int	virtio_free_vq(struct virtio_softc*, struct virtqueue*);
void	virtio_reset(struct virtio_softc *);

int	virtio_enqueue_prep(struct virtio_softc*, struct virtqueue*, int*);
int	virtio_enqueue_p(struct virtio_softc *sc, struct virtqueue *vq,
			 int slot, bus_addr_t ds_addr, bus_size_t ds_len,
			 bus_dmamap_t dmamap, bus_addr_t start, bus_size_t len,
			 bool write);
int	virtio_enqueue(struct virtio_softc *sc, struct virtqueue *vq, int slot,
		       bus_dma_segment_t *segs, int nseg, bus_dmamap_t dmamap, 
		       bool write);
int	virtio_enqueue_reserve(struct virtio_softc*, struct virtqueue*, int, int);
int	virtio_enqueue_commit(struct virtio_softc*, struct virtqueue*, int, bool);

int	virtio_dequeue_commit(struct virtio_softc*, struct virtqueue*, int);
int virtio_enqueue_abort(struct virtio_softc*, struct virtqueue*, int);
int	virtio_dequeue(struct virtio_softc*, struct virtqueue*, int *, int *);

int	virtio_vq_intr(struct virtio_softc *);
void	virtio_stop_vq_intr(struct virtio_softc *, struct virtqueue *);
void	virtio_start_vq_intr(struct virtio_softc *, struct virtqueue *);
void virtio_reinit_start(struct virtio_softc *);
void virtio_reinit_end(struct virtio_softc *);
#endif /* _VIRTIOVAR_H_ */