/*      $NetBSD: virtiovar.h,v 1.31 2026/04/10 03:44:43 isaki Exp $     */

/*
 * 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 _DEV_PCI_VIRTIOVAR_H_
#define _DEV_PCI_VIRTIOVAR_H_

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/bus.h>
#include <dev/pci/virtioreg.h>

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

        /* vring pointers (KVA) */
        struct vring_desc       *vq_desc;
        struct vring_avail      *vq_avail;
        struct vring_used       *vq_used;
        struct vring_desc       *vq_indirect;
        uint16_t                *vq_used_event;         /* trails avail */
        uint16_t                *vq_avail_event;        /* trails used  */

        /* virtqueue allocation info */
        void                    *vq_vaddr;
        int                     vq_availoffset;
        int                     vq_usedoffset;
        int                     vq_indirectoffset;
        bus_dma_segment_t       vq_segs[1];
        unsigned int            vq_bytesize;
        bus_dmamap_t            vq_dmamap;

        int                     vq_maxsegsize;
        int                     vq_maxnsegs;

        /* enqueue/dequeue status */
        uint16_t                vq_avail_idx;
        uint16_t                vq_used_idx;
        uint16_t                vq_free_idx;
        int                     vq_queued;
        kmutex_t                vq_aring_lock;
        kmutex_t                vq_uring_lock;
        kmutex_t                vq_freedesc_lock;

        /* interrupt handler */
        int                     (*vq_done)(struct virtqueue*); /* for compatibility */
        int                     (*vq_intrhand)(void *);
        void                    *vq_intrhand_arg;

        /* for 1.0 */
        uint32_t                vq_notify_off;

        struct vring_desc_extra {
                bool            use_indirect; /* true if using indirect */
                struct vring_desc
                                *desc_base;
                uint16_t         desc_free_idx;
        }                       *vq_descx;
};

struct virtio_attach_args {
        int                     sc_childdevid;
};

typedef int (*virtio_callback)(struct virtio_softc*);

#ifdef VIRTIO_PRIVATE
struct virtio_ops {
        void            (*kick)(struct virtio_softc *, uint16_t);
        uint16_t        (*read_queue_size)(struct virtio_softc *, uint16_t);
        void            (*setup_queue)(struct virtio_softc *, uint16_t, uint64_t);
        void            (*set_status)(struct virtio_softc *, int);
        void            (*neg_features)(struct virtio_softc *, uint64_t);
        int             (*alloc_interrupts)(struct virtio_softc *);
        void            (*free_interrupts)(struct virtio_softc *);
        int             (*setup_interrupts)(struct virtio_softc *, int);
};

struct virtio_softc {
        device_t                sc_dev;
        const struct virtio_ops *sc_ops;
        bus_dma_tag_t           sc_dmat;

        int                     sc_bus_endian;
        int                     sc_struct_endian;

        bus_space_tag_t         sc_devcfg_iot;
        bus_space_handle_t      sc_devcfg_ioh;
        bus_size_t              sc_devcfg_iosize;

        int                     sc_ipl; /* set by child */
        void                    *sc_soft_ih;

        int                     sc_flags; /* set by child */

        uint64_t                sc_active_features;
        bool                    sc_indirect;
        bool                    sc_version_1;

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

        int                     sc_childdevid;
        device_t                sc_child;               /* set by child */
        enum {
                VIRTIO_NO_CHILD = 0,
                VIRTIO_CHILD_ATTACH_FINISHED,
                VIRTIO_CHILD_ATTACH_FAILED
        }                       sc_child_state;

        virtio_callback         sc_config_change;       /* set by child */
        virtio_callback         sc_intrhand;
};
#else
struct virtio_softc;
#endif


/* interrupt types, stored in virtio_softc->sc_flags */
#define VIRTIO_F_INTR_MPSAFE    (1 << 0)
#define VIRTIO_F_INTR_SOFTINT   (1 << 1)
#define VIRTIO_F_INTR_MSIX      (1 << 2)
#define VIRTIO_F_INTR_PERVQ     (1 << 3)

/* public interface */
void virtio_negotiate_features(struct virtio_softc*, uint64_t);

uint8_t virtio_read_device_config_1(struct virtio_softc *, int);
uint16_t virtio_read_device_config_2(struct virtio_softc *, int);
uint32_t virtio_read_device_config_4(struct virtio_softc *, int);
uint64_t virtio_read_device_config_8(struct virtio_softc *, int);
uint16_t virtio_read_device_config_le_2(struct virtio_softc *, int);
uint32_t virtio_read_device_config_le_4(struct virtio_softc *, int);
void virtio_write_device_config_1(struct virtio_softc *, int, uint8_t);
void virtio_write_device_config_2(struct virtio_softc *, int, uint16_t);
void virtio_write_device_config_4(struct virtio_softc *, int, uint32_t);
void virtio_write_device_config_8(struct virtio_softc *, int, uint64_t);
void virtio_write_device_config_le_2(struct virtio_softc *, int, uint16_t);
void virtio_write_device_config_le_4(struct virtio_softc *, int, uint32_t);

void virtio_init_vq(struct virtio_softc *, struct virtqueue *, int,
                    int (*)(void *), void *);
void virtio_init_vq_vqdone(struct virtio_softc *,struct virtqueue *, int,
                    int (*)(struct virtqueue *));
int virtio_alloc_vq(struct virtio_softc*, struct virtqueue*, int, int,
                    const char*);
int virtio_free_vq(struct virtio_softc*, struct virtqueue*);
void virtio_reset(struct virtio_softc *);
int virtio_reinit_start(struct virtio_softc *);
void virtio_reinit_end(struct virtio_softc *);
void virtio_child_attach_start(struct virtio_softc *, device_t, int,
                    uint64_t, const char *);
int virtio_child_attach_finish(struct virtio_softc *,
                    struct virtqueue *, size_t,
                    virtio_callback, int);
void virtio_child_attach_failed(struct virtio_softc *);
void virtio_child_detach(struct virtio_softc *);

int virtio_enqueue_prep(struct virtio_softc*, struct virtqueue*, int*);
int virtio_enqueue_reserve(struct virtio_softc*, struct virtqueue*, int, int);
int virtio_enqueue(struct virtio_softc*, struct virtqueue*, int,
                   bus_dmamap_t, bool);
int virtio_enqueue_p(struct virtio_softc*, struct virtqueue*, int,
                     bus_dmamap_t, bus_addr_t, bus_size_t, bool);
int virtio_enqueue_commit(struct virtio_softc*, struct virtqueue*, int, bool);
int virtio_enqueue_abort(struct virtio_softc*, struct virtqueue*, int);

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

bool virtio_vq_is_enqueued(struct virtio_softc *, struct virtqueue *);
int virtio_postpone_intr(struct virtio_softc *sc, struct virtqueue *vq,
                uint16_t nslots);
int virtio_postpone_intr_smart(struct virtio_softc *sc, struct virtqueue *vq);
int virtio_postpone_intr_far(struct virtio_softc *sc, struct virtqueue *vq);
void virtio_stop_vq_intr(struct virtio_softc *, struct virtqueue *);
int virtio_start_vq_intr(struct virtio_softc *, struct virtqueue *);

/* encapsulation */
bus_dma_tag_t   virtio_dmat(struct virtio_softc *);
device_t        virtio_child(struct virtio_softc *);
int             virtio_intrhand(struct virtio_softc *);
uint64_t        virtio_features(struct virtio_softc *);
bool            virtio_version_1(struct virtio_softc *);

/* autoconf(9) common */
void virtio_set_status(struct virtio_softc *, int);
void virtio_print_device_type(device_t, int, int);
int virtio_attach_failed(struct virtio_softc *);

#define virtio_device_reset(sc) virtio_set_status((sc), 0)

/* endian conversion */

/*
 * Virtio structures are read/written in host endian for 0.9 but little endian
 * for 1.0. One notable exception is AArch BE that always uses little endian.
 */
uint16_t virtio_rw16(struct virtio_softc *sc, uint16_t val);
uint32_t virtio_rw32(struct virtio_softc *sc, uint32_t val);
uint64_t virtio_rw64(struct virtio_softc *sc, uint64_t val);

#endif /* _DEV_PCI_VIRTIOVAR_H_ */