/*
 * Copyright (C) 2011-2014 Universita` di Pisa. 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 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 THE AUTHOR 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.
 */

/*
 * $FreeBSD: stable/11/sys/dev/netmap/if_igb_netmap.h 343771 2019-02-05 10:33:22Z vmaffione $
 *
 * Netmap support for igb, partly contributed by Ahmed Kooli
 * For details on netmap support please see ixgbe_netmap.h
 */


#include <net/netmap.h>
#include <sys/selinfo.h>
#include <vm/vm.h>
#include <vm/pmap.h>    /* vtophys ? */
#include <dev/netmap/netmap_kern.h>

/*
 * Adaptation to different versions of the driver.
 */

#ifndef IGB_MEDIA_RESET
/* at the same time as IGB_MEDIA_RESET was defined, the
 * tx buffer descriptor was renamed, so use this to revert
 * back to the old name.
 */
#define igb_tx_buf igb_tx_buffer
#endif


/*
 * Register/unregister. We are already under netmap lock.
 */
static int
igb_netmap_reg(struct netmap_adapter *na, int onoff)
{
	struct ifnet *ifp = na->ifp;
	struct adapter *adapter = ifp->if_softc;

	IGB_CORE_LOCK(adapter);
	igb_disable_intr(adapter);

	/* Tell the stack that the interface is no longer active */
	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);

	/* enable or disable flags and callbacks in na and ifp */
	if (onoff) {
		nm_set_native_flags(na);
	} else {
		nm_clear_native_flags(na);
	}
	igb_init_locked(adapter);	/* also enable intr */
	IGB_CORE_UNLOCK(adapter);
	return (ifp->if_drv_flags & IFF_DRV_RUNNING ? 0 : 1);
}


/*
 * Reconcile kernel and user view of the transmit ring.
 */
static int
igb_netmap_txsync(struct netmap_kring *kring, int flags)
{
	struct netmap_adapter *na = kring->na;
	struct ifnet *ifp = na->ifp;
	struct netmap_ring *ring = kring->ring;
	u_int nm_i;	/* index into the netmap ring */
	u_int nic_i;	/* index into the NIC ring */
	u_int n;
	u_int const lim = kring->nkr_num_slots - 1;
	u_int const head = kring->rhead;
	/* generate an interrupt approximately every half ring */
	u_int report_frequency = kring->nkr_num_slots >> 1;

	/* device-specific */
	struct adapter *adapter = ifp->if_softc;
	struct tx_ring *txr = &adapter->tx_rings[kring->ring_id];
	/* 82575 needs the queue index added */
	u32 olinfo_status =
	    (adapter->hw.mac.type == e1000_82575) ? (txr->me << 4) : 0;

	bus_dmamap_sync(txr->txdma.dma_tag, txr->txdma.dma_map,
			BUS_DMASYNC_POSTREAD);

	/*
	 * First part: process new packets to send.
	 */

	nm_i = kring->nr_hwcur;
	if (nm_i != head) {	/* we have new packets to send */
		nic_i = netmap_idx_k2n(kring, nm_i);
		for (n = 0; nm_i != head; n++) {
			struct netmap_slot *slot = &ring->slot[nm_i];
			u_int len = slot->len;
			uint64_t paddr;
			void *addr = PNMB(na, slot, &paddr);

			/* device-specific */
			union e1000_adv_tx_desc *curr =
			    (union e1000_adv_tx_desc *)&txr->tx_base[nic_i];
			struct igb_tx_buf *txbuf = &txr->tx_buffers[nic_i];
			int flags = (slot->flags & NS_REPORT ||
				nic_i == 0 || nic_i == report_frequency) ?
				E1000_ADVTXD_DCMD_RS : 0;

			NM_CHECK_ADDR_LEN(na, addr, len);

			if (slot->flags & NS_BUF_CHANGED) {
				/* buffer has changed, reload map */
				netmap_reload_map(na, txr->txtag, txbuf->map, addr);
			}
			slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);

			/* Fill the slot in the NIC ring. */
			curr->read.buffer_addr = htole64(paddr);
			// XXX check olinfo and cmd_type_len
			curr->read.olinfo_status =
			    htole32(olinfo_status |
				(len<< E1000_ADVTXD_PAYLEN_SHIFT));
			curr->read.cmd_type_len =
			    htole32(len | E1000_ADVTXD_DTYP_DATA |
			    E1000_ADVTXD_DCMD_IFCS |
			    E1000_ADVTXD_DCMD_DEXT |
			    E1000_ADVTXD_DCMD_EOP | flags);

			/* make sure changes to the buffer are synced */
			bus_dmamap_sync(txr->txtag, txbuf->map,
				BUS_DMASYNC_PREWRITE);

			nm_i = nm_next(nm_i, lim);
			nic_i = nm_next(nic_i, lim);
		}
		kring->nr_hwcur = head;

		/* Set the watchdog XXX ? */
		txr->queue_status = IGB_QUEUE_WORKING;
		txr->watchdog_time = ticks;

		/* synchronize the NIC ring */
		bus_dmamap_sync(txr->txdma.dma_tag, txr->txdma.dma_map,
			BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);

		/* (re)start the tx unit up to slot nic_i (excluded) */
		E1000_WRITE_REG(&adapter->hw, E1000_TDT(txr->me), nic_i);
	}

	/*
	 * Second part: reclaim buffers for completed transmissions.
	 */
	if (flags & NAF_FORCE_RECLAIM || nm_kr_txempty(kring)) {
		/* record completed transmissions using TDH */
		nic_i = E1000_READ_REG(&adapter->hw, E1000_TDH(kring->ring_id));
		if (unlikely(nic_i >= kring->nkr_num_slots)) {
			nm_prerr("TDH wrap at idx %d", nic_i);
			nic_i -= kring->nkr_num_slots;
		}
		txr->next_to_clean = nic_i;
		kring->nr_hwtail = nm_prev(netmap_idx_n2k(kring, nic_i), lim);
	}

	return 0;
}


/*
 * Reconcile kernel and user view of the receive ring.
 */
static int
igb_netmap_rxsync(struct netmap_kring *kring, int flags)
{
	struct netmap_adapter *na = kring->na;
	struct ifnet *ifp = na->ifp;
	struct netmap_ring *ring = kring->ring;
	u_int nm_i;	/* index into the netmap ring */
	u_int nic_i;	/* index into the NIC ring */
	u_int n;
	u_int const lim = kring->nkr_num_slots - 1;
	u_int const head = kring->rhead;
	int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;

	/* device-specific */
	struct adapter *adapter = ifp->if_softc;
	struct rx_ring *rxr = &adapter->rx_rings[kring->ring_id];

	if (head > lim)
		return netmap_ring_reinit(kring);

	/* XXX check sync modes */
	bus_dmamap_sync(rxr->rxdma.dma_tag, rxr->rxdma.dma_map,
			BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);

	/*
	 * First part: import newly received packets.
	 */
	if (netmap_no_pendintr || force_update) {
		nic_i = rxr->next_to_check;
		nm_i = netmap_idx_n2k(kring, nic_i);

		for (n = 0; ; n++) {
			union e1000_adv_rx_desc *curr = &rxr->rx_base[nic_i];
			uint32_t staterr = le32toh(curr->wb.upper.status_error);

			if ((staterr & E1000_RXD_STAT_DD) == 0)
				break;
			ring->slot[nm_i].len = le16toh(curr->wb.upper.length);
			ring->slot[nm_i].flags = 0;
			bus_dmamap_sync(rxr->ptag,
			    rxr->rx_buffers[nic_i].pmap, BUS_DMASYNC_POSTREAD);
			nm_i = nm_next(nm_i, lim);
			nic_i = nm_next(nic_i, lim);
		}
		if (n) { /* update the state variables */
			rxr->next_to_check = nic_i;
			kring->nr_hwtail = nm_i;
		}
		kring->nr_kflags &= ~NKR_PENDINTR;
	}

	/*
	 * Second part: skip past packets that userspace has released.
	 */
	nm_i = kring->nr_hwcur;
	if (nm_i != head) {
		nic_i = netmap_idx_k2n(kring, nm_i);
		for (n = 0; nm_i != head; n++) {
			struct netmap_slot *slot = &ring->slot[nm_i];
			uint64_t paddr;
			void *addr = PNMB(na, slot, &paddr);

			union e1000_adv_rx_desc *curr = &rxr->rx_base[nic_i];
			struct igb_rx_buf *rxbuf = &rxr->rx_buffers[nic_i];

			if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
				goto ring_reset;

			if (slot->flags & NS_BUF_CHANGED) {
				/* buffer has changed, reload map */
				netmap_reload_map(na, rxr->ptag, rxbuf->pmap, addr);
				slot->flags &= ~NS_BUF_CHANGED;
			}
			curr->wb.upper.status_error = 0;
			curr->read.pkt_addr = htole64(paddr);
			bus_dmamap_sync(rxr->ptag, rxbuf->pmap,
			    BUS_DMASYNC_PREREAD);
			nm_i = nm_next(nm_i, lim);
			nic_i = nm_next(nic_i, lim);
		}
		kring->nr_hwcur = head;

		bus_dmamap_sync(rxr->rxdma.dma_tag, rxr->rxdma.dma_map,
		    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
		/*
		 * IMPORTANT: we must leave one free slot in the ring,
		 * so move nic_i back by one unit
		 */
		nic_i = nm_prev(nic_i, lim);
		E1000_WRITE_REG(&adapter->hw, E1000_RDT(rxr->me), nic_i);
	}

	return 0;

ring_reset:
	return netmap_ring_reinit(kring);
}


static void
igb_netmap_attach(struct adapter *adapter)
{
	struct netmap_adapter na;

	bzero(&na, sizeof(na));

	na.ifp = adapter->ifp;
	na.na_flags = NAF_BDG_MAYSLEEP;
	na.num_tx_desc = adapter->num_tx_desc;
	na.num_rx_desc = adapter->num_rx_desc;
	na.nm_txsync = igb_netmap_txsync;
	na.nm_rxsync = igb_netmap_rxsync;
	na.nm_register = igb_netmap_reg;
	na.num_tx_rings = na.num_rx_rings = adapter->num_queues;
	netmap_attach(&na);
}

/* end of file */