/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2011, Bryan Venteicher <bryanv@FreeBSD.org>
 * 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 unmodified, 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.
 *
 * $FreeBSD$
 */

#ifndef _IF_VTNETVAR_H
#define _IF_VTNETVAR_H

struct vtnet_softc;

struct vtnet_statistics {
	uint64_t	mbuf_alloc_failed;

	uint64_t	rx_frame_too_large;
	uint64_t	rx_enq_replacement_failed;
	uint64_t	rx_mergeable_failed;
	uint64_t	rx_csum_bad_ethtype;
	uint64_t	rx_csum_bad_ipproto;
	uint64_t	rx_csum_bad_offset;
	uint64_t	rx_csum_bad_proto;
	uint64_t	tx_csum_bad_ethtype;
	uint64_t	tx_tso_bad_ethtype;
	uint64_t	tx_tso_not_tcp;
	uint64_t	tx_defragged;
	uint64_t	tx_defrag_failed;

	/*
	 * These are accumulated from each Rx/Tx queue.
	 */
	uint64_t	rx_csum_failed;
	uint64_t	rx_csum_offloaded;
	uint64_t	rx_task_rescheduled;
	uint64_t	tx_csum_offloaded;
	uint64_t	tx_tso_offloaded;
	uint64_t	tx_task_rescheduled;
};

struct vtnet_rxq_stats {
	uint64_t	vrxs_ipackets;	/* if_ipackets */
	uint64_t	vrxs_ibytes;	/* if_ibytes */
	uint64_t	vrxs_iqdrops;	/* if_iqdrops */
	uint64_t	vrxs_ierrors;	/* if_ierrors */
	uint64_t	vrxs_csum;
	uint64_t	vrxs_csum_failed;
	uint64_t	vrxs_rescheduled;
};

struct vtnet_rxq {
	struct mtx		 vtnrx_mtx;
	struct vtnet_softc	*vtnrx_sc;
	struct virtqueue	*vtnrx_vq;
	struct sglist		*vtnrx_sg;
	int			 vtnrx_id;
	struct vtnet_rxq_stats	 vtnrx_stats;
	struct taskqueue	*vtnrx_tq;
	struct task		 vtnrx_intrtask;
#ifdef DEV_NETMAP
	uint32_t		 vtnrx_nm_refill;
	struct virtio_net_hdr_mrg_rxbuf vtnrx_shrhdr;
#endif  /* DEV_NETMAP */
	char			 vtnrx_name[16];
} __aligned(CACHE_LINE_SIZE);

#define VTNET_RXQ_LOCK(_rxq)	mtx_lock(&(_rxq)->vtnrx_mtx)
#define VTNET_RXQ_UNLOCK(_rxq)	mtx_unlock(&(_rxq)->vtnrx_mtx)
#define VTNET_RXQ_LOCK_ASSERT(_rxq)		\
    mtx_assert(&(_rxq)->vtnrx_mtx, MA_OWNED)
#define VTNET_RXQ_LOCK_ASSERT_NOTOWNED(_rxq)	\
    mtx_assert(&(_rxq)->vtnrx_mtx, MA_NOTOWNED)

struct vtnet_txq_stats {
	uint64_t vtxs_opackets;	/* if_opackets */
	uint64_t vtxs_obytes;	/* if_obytes */
	uint64_t vtxs_omcasts;	/* if_omcasts */
	uint64_t vtxs_csum;
	uint64_t vtxs_tso;
	uint64_t vtxs_rescheduled;
};

struct vtnet_txq {
	struct mtx		 vtntx_mtx;
	struct vtnet_softc	*vtntx_sc;
	struct virtqueue	*vtntx_vq;
	struct sglist		*vtntx_sg;
#ifndef VTNET_LEGACY_TX
	struct buf_ring		*vtntx_br;
#endif
	int			 vtntx_id;
	int			 vtntx_watchdog;
	struct vtnet_txq_stats	 vtntx_stats;
	struct taskqueue	*vtntx_tq;
	struct task		 vtntx_intrtask;
#ifndef VTNET_LEGACY_TX
	struct task		 vtntx_defrtask;
#endif
#ifdef DEV_NETMAP
	struct virtio_net_hdr_mrg_rxbuf vtntx_shrhdr;
#endif  /* DEV_NETMAP */
	char			 vtntx_name[16];
} __aligned(CACHE_LINE_SIZE);

#define VTNET_TXQ_LOCK(_txq)	mtx_lock(&(_txq)->vtntx_mtx)
#define VTNET_TXQ_TRYLOCK(_txq)	mtx_trylock(&(_txq)->vtntx_mtx)
#define VTNET_TXQ_UNLOCK(_txq)	mtx_unlock(&(_txq)->vtntx_mtx)
#define VTNET_TXQ_LOCK_ASSERT(_txq)		\
    mtx_assert(&(_txq)->vtntx_mtx, MA_OWNED)
#define VTNET_TXQ_LOCK_ASSERT_NOTOWNED(_txq)	\
    mtx_assert(&(_txq)->vtntx_mtx, MA_NOTOWNED)

struct vtnet_softc {
	device_t		 vtnet_dev;
	struct ifnet		*vtnet_ifp;
	struct vtnet_rxq	*vtnet_rxqs;
	struct vtnet_txq	*vtnet_txqs;
	pfil_head_t		 vtnet_pfil;

	uint32_t		 vtnet_flags;
#define VTNET_FLAG_SUSPENDED	 0x0001
#define VTNET_FLAG_MAC		 0x0002
#define VTNET_FLAG_CTRL_VQ	 0x0004
#define VTNET_FLAG_CTRL_RX	 0x0008
#define VTNET_FLAG_CTRL_MAC	 0x0010
#define VTNET_FLAG_VLAN_FILTER	 0x0020
#define VTNET_FLAG_TSO_ECN	 0x0040
#define VTNET_FLAG_MRG_RXBUFS	 0x0080
#define VTNET_FLAG_LRO_NOMRG	 0x0100
#define VTNET_FLAG_MULTIQ	 0x0200
#define VTNET_FLAG_INDIRECT	 0x0400
#define VTNET_FLAG_EVENT_IDX	 0x0800

	int			 vtnet_link_active;
	int			 vtnet_hdr_size;
	int			 vtnet_rx_process_limit;
	int			 vtnet_rx_nsegs;
	int			 vtnet_rx_nmbufs;
	int			 vtnet_rx_clsize;
	int			 vtnet_rx_new_clsize;
	int			 vtnet_tx_intr_thresh;
	int			 vtnet_tx_nsegs;
	int			 vtnet_if_flags;
	int			 vtnet_act_vq_pairs;
	int			 vtnet_max_vq_pairs;
	int			 vtnet_requested_vq_pairs;

	struct virtqueue	*vtnet_ctrl_vq;
	struct vtnet_mac_filter	*vtnet_mac_filter;
	uint32_t		*vtnet_vlan_filter;

	uint64_t		 vtnet_features;
	struct vtnet_statistics	 vtnet_stats;
	struct callout		 vtnet_tick_ch;
	struct ifmedia		 vtnet_media;
	eventhandler_tag	 vtnet_vlan_attach;
	eventhandler_tag	 vtnet_vlan_detach;

	struct mtx		 vtnet_mtx;
	char			 vtnet_mtx_name[16];
	char			 vtnet_hwaddr[ETHER_ADDR_LEN];
};

/*
 * Maximum number of queue pairs we will autoconfigure to.
 */
#define VTNET_MAX_QUEUE_PAIRS	8

/*
 * Additional completed entries can appear in a virtqueue before we can
 * reenable interrupts. Number of times to retry before scheduling the
 * taskqueue to process the completed entries.
 */
#define VTNET_INTR_DISABLE_RETRIES	4

/*
 * Similarly, additional completed entries can appear in a virtqueue
 * between when lasted checked and before notifying the host. Number
 * of times to retry before scheduling the taskqueue to process the
 * queue.
 */
#define VTNET_NOTIFY_RETRIES		4

/*
 * Fake the media type. The host does not provide us with any real media
 * information.
 */
#define VTNET_MEDIATYPE		 (IFM_ETHER | IFM_10G_T | IFM_FDX)

/*
 * Number of words to allocate for the VLAN shadow table. There is one
 * bit for each VLAN.
 */
#define VTNET_VLAN_FILTER_NWORDS	(4096 / 32)

/*
 * When mergeable buffers are not negotiated, the vtnet_rx_header structure
 * below is placed at the beginning of the mbuf data. Use 4 bytes of pad to
 * both keep the VirtIO header and the data non-contiguous and to keep the
 * frame's payload 4 byte aligned. Note that non-legacy drivers still want
 * room for a full mergeable buffer header.
 *
 * When mergeable buffers are negotiated, the host puts the VirtIO header in
 * the beginning of the first mbuf's data.
 */
#define VTNET_RX_HEADER_PAD	4
struct vtnet_rx_header {
	union {
		struct virtio_net_hdr		hdr;
		struct virtio_net_hdr_mrg_rxbuf	mhdr;
	} vrh_uhdr;

	char	vrh_pad[VTNET_RX_HEADER_PAD];
} __packed;

/*
 * For each outgoing frame, the vtnet_tx_header below is allocated from
 * the vtnet_tx_header_zone.
 */
struct vtnet_tx_header {
	union {
		struct virtio_net_hdr		hdr;
		struct virtio_net_hdr_mrg_rxbuf	mhdr;
	} vth_uhdr;

	struct mbuf *vth_mbuf;
};

/*
 * The VirtIO specification does not place a limit on the number of MAC
 * addresses the guest driver may request to be filtered. In practice,
 * the host is constrained by available resources. To simplify this driver,
 * impose a reasonably high limit of MAC addresses we will filter before
 * falling back to promiscuous or all-multicast modes.
 */
#define VTNET_MAX_MAC_ENTRIES	128

struct vtnet_mac_table {
	uint32_t	nentries;
	uint8_t		macs[VTNET_MAX_MAC_ENTRIES][ETHER_ADDR_LEN];
} __packed;

struct vtnet_mac_filter {
	struct vtnet_mac_table	vmf_unicast;
	uint32_t		vmf_pad; /* Make tables non-contiguous. */
	struct vtnet_mac_table	vmf_multicast;
};

/*
 * The MAC filter table is malloc(9)'d when needed. Ensure it will
 * always fit in one segment.
 */
CTASSERT(sizeof(struct vtnet_mac_filter) <= PAGE_SIZE);

#define VTNET_TX_TIMEOUT	5
#define VTNET_CSUM_OFFLOAD	(CSUM_TCP | CSUM_UDP)
#define VTNET_CSUM_OFFLOAD_IPV6	(CSUM_TCP_IPV6 | CSUM_UDP_IPV6)

#define VTNET_CSUM_ALL_OFFLOAD	\
    (VTNET_CSUM_OFFLOAD | VTNET_CSUM_OFFLOAD_IPV6 | CSUM_TSO)

/* Features desired/implemented by this driver. */
#define VTNET_FEATURES \
    (VIRTIO_NET_F_MAC			| \
     VIRTIO_NET_F_STATUS		| \
     VIRTIO_NET_F_CTRL_VQ		| \
     VIRTIO_NET_F_CTRL_RX		| \
     VIRTIO_NET_F_CTRL_MAC_ADDR		| \
     VIRTIO_NET_F_CTRL_VLAN		| \
     VIRTIO_NET_F_CSUM			| \
     VIRTIO_NET_F_GSO			| \
     VIRTIO_NET_F_HOST_TSO4		| \
     VIRTIO_NET_F_HOST_TSO6		| \
     VIRTIO_NET_F_HOST_ECN		| \
     VIRTIO_NET_F_GUEST_CSUM		| \
     VIRTIO_NET_F_GUEST_TSO4		| \
     VIRTIO_NET_F_GUEST_TSO6		| \
     VIRTIO_NET_F_GUEST_ECN		| \
     VIRTIO_NET_F_MRG_RXBUF		| \
     VIRTIO_NET_F_MQ			| \
     VIRTIO_RING_F_EVENT_IDX		| \
     VIRTIO_RING_F_INDIRECT_DESC	| \
     VIRTIO_F_VERSION_1)

/*
 * The VIRTIO_NET_F_HOST_TSO[46] features permit us to send the host
 * frames larger than 1514 bytes.
 */
#define VTNET_TSO_FEATURES (VIRTIO_NET_F_GSO | VIRTIO_NET_F_HOST_TSO4 | \
    VIRTIO_NET_F_HOST_TSO6 | VIRTIO_NET_F_HOST_ECN)

/*
 * The VIRTIO_NET_F_GUEST_TSO[46] features permit the host to send us
 * frames larger than 1514 bytes. We do not yet support software LRO
 * via tcp_lro_rx().
 */
#define VTNET_LRO_FEATURES (VIRTIO_NET_F_GUEST_TSO4 | \
    VIRTIO_NET_F_GUEST_TSO6 | VIRTIO_NET_F_GUEST_ECN)

#define VTNET_MAX_MTU		65536
#define VTNET_MAX_RX_SIZE	65550

/*
 * Used to preallocate the Vq indirect descriptors. The first segment
 * is reserved for the header, except for mergeable buffers since the
 * header is placed inline with the data.
 */
#define VTNET_MRG_RX_SEGS	1
#define VTNET_MIN_RX_SEGS	2
#define VTNET_MAX_RX_SEGS	34
#define VTNET_MIN_TX_SEGS	32
#define VTNET_MAX_TX_SEGS	64

/*
 * Assert we can receive and transmit the maximum with regular
 * size clusters.
 */
CTASSERT(((VTNET_MAX_RX_SEGS - 1) * MCLBYTES) >= VTNET_MAX_RX_SIZE);
CTASSERT(((VTNET_MAX_TX_SEGS - 1) * MCLBYTES) >= VTNET_MAX_MTU);

/*
 * Number of slots in the Tx bufrings. This value matches most other
 * multiqueue drivers.
 */
#define VTNET_DEFAULT_BUFRING_SIZE	4096

/*
 * Determine how many mbufs are in each receive buffer. For LRO without
 * mergeable buffers, we must allocate an mbuf chain large enough to
 * hold both the vtnet_rx_header and the maximum receivable data.
 */
#define VTNET_NEEDED_RX_MBUFS(_sc, _clsize)				\
	((_sc)->vtnet_flags & VTNET_FLAG_LRO_NOMRG) == 0 ? 1 :		\
	    howmany(sizeof(struct vtnet_rx_header) + VTNET_MAX_RX_SIZE,	\
	        (_clsize))

#define VTNET_CORE_MTX(_sc)		&(_sc)->vtnet_mtx
#define VTNET_CORE_LOCK(_sc)		mtx_lock(VTNET_CORE_MTX((_sc)))
#define VTNET_CORE_UNLOCK(_sc)		mtx_unlock(VTNET_CORE_MTX((_sc)))
#define VTNET_CORE_LOCK_DESTROY(_sc)	mtx_destroy(VTNET_CORE_MTX((_sc)))
#define VTNET_CORE_LOCK_ASSERT(_sc)		\
    mtx_assert(VTNET_CORE_MTX((_sc)), MA_OWNED)
#define VTNET_CORE_LOCK_ASSERT_NOTOWNED(_sc)	\
    mtx_assert(VTNET_CORE_MTX((_sc)), MA_NOTOWNED)

#define VTNET_CORE_LOCK_INIT(_sc) do {					\
    snprintf((_sc)->vtnet_mtx_name, sizeof((_sc)->vtnet_mtx_name),	\
        "%s", device_get_nameunit((_sc)->vtnet_dev));			\
    mtx_init(VTNET_CORE_MTX((_sc)), (_sc)->vtnet_mtx_name,		\
        "VTNET Core Lock", MTX_DEF);					\
} while (0)

/*
 * Values for the init_mode argument of vtnet_init_locked().
 */
#define VTNET_INIT_NETMAP_ENTER		1
#define VTNET_INIT_NETMAP_EXIT		2

#endif /* _IF_VTNETVAR_H */