text: /*
   * Copyright (C) 2012-2014 Luigi Rizzo. 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.
   */
  
  /*
   * $Id: if_igb_netmap.h 10878 2012-04-12 22:28:48Z luigi $
   *
   * netmap support for: igb (linux version)
   * For details on netmap support please see ixgbe_netmap.h
   */
  
  
  #include <bsd_glue.h>
  #include <net/netmap.h>
  #include <netmap/netmap_kern.h>
  
  #define SOFTC_T	igb_adapter
  
  #define igb_driver_name netmap_igb_driver_name
  char netmap_igb_driver_name[] = "igb" NETMAP_LINUX_DRIVER_SUFFIX;
  
  /*
   * Adapt to different versions of the driver.
   * E1000_TX_DESC_ADV etc. have dropped the _ADV suffix at some point.
   * Also the first argument is now a pointer not the object.
   */
  #ifndef E1000_TX_DESC_ADV
  #define	E1000_TX_DESC_ADV(_r, _i)	IGB_TX_DESC(&(_r), _i)
  #define	E1000_RX_DESC_ADV(_r, _i)	IGB_RX_DESC(&(_r), _i)
  #define	READ_TDH(_txr)			({struct e1000_hw *hw = &adapter->hw;rd32(E1000_TDH((_txr)->reg_idx));} )
  #else /* up to 3.2, approximately */
  #define	igb_tx_buffer			igb_buffer
  #define	tx_buffer_info			buffer_info
  #define	igb_rx_buffer			igb_buffer
  #define	rx_buffer_info			buffer_info
  #define	READ_TDH(_txr)			readl((_txr)->head)
  #endif
  
  
  /*
   * Register/unregister. We are already under netmap lock.
   * Only called on the first register or the last unregister.
   */
  static int
  igb_netmap_reg(struct netmap_adapter *na, int onoff)
  {
  	struct ifnet *ifp = na->ifp;
  	struct SOFTC_T *adapter = netdev_priv(ifp);
  
  	/* protect against other reinit */
  	while (test_and_set_bit(__IGB_RESETTING, &adapter->state))
  		usleep_range(1000, 2000);
  
  	if (netif_running(adapter->netdev))
  		igb_down(adapter);
  
  	/* enable or disable flags and callbacks in na and ifp */
  	if (onoff) {
  		nm_set_native_flags(na);
  	} else {
  		nm_clear_native_flags(na);
  	}
  	if (netif_running(adapter->netdev))
  		igb_up(adapter);
  	else
  		igb_reset(adapter); // XXX is it needed ?
  
  	clear_bit(__IGB_RESETTING, &adapter->state);
  	return (0);
  }
  
  
  /*
   * 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 ring_nr = kring->ring_id;
  	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 SOFTC_T *adapter = netdev_priv(ifp);
  	struct igb_ring* txr = adapter->tx_ring[ring_nr];
  
  	rmb();	// XXX not in ixgbe ?
  
  	/*
  	 * First part: process new packets to send.
  	 */
  	if (!netif_carrier_ok(ifp)) {
  		goto out;
  	}
  
  	nm_i = kring->nr_hwcur;
  	if (nm_i != head) {	/* we have new packets to send */
  		uint32_t olinfo_status=0;
  
  		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 =
  			    E1000_TX_DESC_ADV(*txr, nic_i);
  			int flags = (slot->flags & NS_REPORT ||
  				nic_i == 0 || nic_i == report_frequency) ?
  				E1000_TXD_CMD_RS : 0;
  
  			NM_CHECK_ADDR_LEN(na, addr, len);
  
  			if (slot->flags & NS_BUF_CHANGED) {
  				/* buffer has changed, reload map */
  				// netmap_reload_map(pdev, DMA_TO_DEVICE, old_paddr, 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 | flags |
  				E1000_ADVTXD_DTYP_DATA | E1000_ADVTXD_DCMD_DEXT |
  				E1000_ADVTXD_DCMD_IFCS | E1000_TXD_CMD_EOP);
  			nm_i = nm_next(nm_i, lim);
  			nic_i = nm_next(nic_i, lim);
  		}
  		kring->nr_hwcur = head;
  
  		wmb();	/* synchronize writes to the NIC ring */
  
  		txr->next_to_use = nic_i; /* XXX what for ? */
  		/* (re)start the tx unit up to slot nic_i (excluded) */
  		writel(nic_i, txr->tail);
  		mmiowb(); // XXX where do we need this ?
  	}
  
  	/*
  	 * Second part: reclaim buffers for completed transmissions.
  	 */
  	if (flags & NAF_FORCE_RECLAIM || nm_kr_txempty(kring)) {
  		/* record completed transmissions using TDH */
  		nic_i = READ_TDH(txr);
  		if (nic_i >= kring->nkr_num_slots) { /* XXX can it happen ? */
  			D("TDH wrap %d", nic_i);
  			nic_i -= kring->nkr_num_slots;
  		}
  		txr->next_to_use = nic_i;
  		kring->nr_hwtail = nm_prev(netmap_idx_n2k(kring, nic_i), lim);
  	}
  out:
  
  	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 ring_nr = kring->ring_id;
  	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 SOFTC_T *adapter = netdev_priv(ifp);
  	struct igb_ring *rxr = adapter->rx_ring[ring_nr];
  
  	if (!netif_carrier_ok(ifp))
  		return 0;
  
  	if (head > lim)
  		return netmap_ring_reinit(kring);
  
  	rmb();
  
  	/*
  	 * First part: import newly received packets.
  	 */
  	if (netmap_no_pendintr || force_update) {
  		uint16_t slot_flags = kring->nkr_slot_flags;
  
  		nic_i = rxr->next_to_clean;
  		nm_i = netmap_idx_n2k(kring, nic_i);
  
  		for (n = 0; ; n++) {
  			union e1000_adv_rx_desc *curr =
  					E1000_RX_DESC_ADV(*rxr, 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 = slot_flags;
  			nm_i = nm_next(nm_i, lim);
  			nic_i = nm_next(nic_i, lim);
  		}
  		if (n) { /* update the state variables */
  			rxr->next_to_clean = 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 = E1000_RX_DESC_ADV(*rxr, nic_i);
  
  			if (addr == NETMAP_BUF_BASE(na)) /* bad buf */
  				goto ring_reset;
  
  			if (slot->flags & NS_BUF_CHANGED) {
  				// netmap_reload_map(pdev, DMA_FROM_DEVICE, old_paddr, addr);
  				slot->flags &= ~NS_BUF_CHANGED;
  			}
  			curr->read.pkt_addr = htole64(paddr);
  			curr->read.hdr_addr = 0;
  			nm_i = nm_next(nm_i, lim);
  			nic_i = nm_next(nic_i, lim);
  		}
  		kring->nr_hwcur = head;
  		wmb();
  		rxr->next_to_use = nic_i; // XXX not really used
  		/*
  		 * 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);
  		writel(nic_i, rxr->tail);
  	}
  
  
  	return 0;
  
  ring_reset:
  	return netmap_ring_reinit(kring);
  }
  
  
  static int
  igb_netmap_configure_tx_ring(struct SOFTC_T *adapter, int ring_nr)
  {
  	struct ifnet *ifp = adapter->netdev;
  	struct netmap_adapter* na = NA(ifp);
  	struct netmap_slot* slot;
  	struct igb_ring *txr = adapter->tx_ring[ring_nr];
  	int i, si;
  	void *addr;
  	uint64_t paddr;
  
          slot = netmap_reset(na, NR_TX, ring_nr, 0);
  	if (!slot)
  		return 0;  // not in netmap native mode
  	for (i = 0; i < na->num_tx_desc; i++) {
  		union e1000_adv_tx_desc *tx_desc;
  		si = netmap_idx_n2k(&na->tx_rings[ring_nr], i);
  		addr = PNMB(na, slot + si, &paddr);
  		tx_desc = E1000_TX_DESC_ADV(*txr, i);
  		tx_desc->read.buffer_addr = htole64(paddr);
  		/* actually we don't care to init the rings here */
  	}
  	return 1;	// success
  }
  
  
  static int
  igb_netmap_configure_rx_ring(struct igb_ring *rxr)
  {
  	struct ifnet *ifp = rxr->netdev;
  	struct netmap_adapter* na = NA(ifp);
  	int reg_idx = rxr->reg_idx;
  	struct netmap_slot* slot;
  	u_int i;
  
  	/*
  	 * XXX watch out, the main driver must not use
  	 * split headers. The buffer len should be written
  	 * into wr32(E1000_SRRCTL(reg_idx), srrctl) with options
  	 * something like
  	 *	srrctl = ALIGN(buffer_len, 1024) >>
  	 *		E1000_SRRCTL_BSIZEPKT_SHIFT;
  	 *	srrctl |= E1000_SRRCTL_DESCTYPE_ADV_ONEBUF;
  	 *	srrctl |= E1000_SRRCTL_DROP_EN;
  	 */
          slot = netmap_reset(na, NR_RX, reg_idx, 0);
  	if (!slot)
  		return 0;	// not in native netmap mode
  
  	for (i = 0; i < rxr->count; i++) {
  		union e1000_adv_rx_desc *rx_desc;
  		uint64_t paddr;
  		int si = netmap_idx_n2k(&na->rx_rings[reg_idx], i);
  
  #if 0
  		// XXX the skb check can go away
  		struct igb_rx_buffer *bi = &rxr->rx_buffer_info[i];
  		if (bi->skb)
  			D("rx buf %d was set", i);
  		bi->skb = NULL; // XXX leak if set
  #endif /* useless */
  
  		PNMB(na, slot + si, &paddr);
  		rx_desc = E1000_RX_DESC_ADV(*rxr, i);
  		rx_desc->read.hdr_addr = 0;
  		rx_desc->read.pkt_addr = htole64(paddr);
  	}
  	rxr->next_to_use = 0;
  	/* preserve buffers already made available to clients */
  	i = rxr->count - 1 - nm_kr_rxspace(&na->rx_rings[reg_idx]);
  
  	wmb();	/* Force memory writes to complete */
  	ND("%s rxr%d.tail %d", na->name, reg_idx, i);
  	writel(i, rxr->tail);
  	return 1;	// success
  }
  
  
  static void
  igb_netmap_attach(struct SOFTC_T *adapter)
  {
  	struct netmap_adapter na;
  
  	bzero(&na, sizeof(na));
  
  	na.ifp = adapter->netdev;
  	na.pdev = &adapter->pdev->dev;
  	na.num_tx_desc = adapter->tx_ring_count;
  	na.num_rx_desc = adapter->rx_ring_count;
  	na.nm_register = igb_netmap_reg;
  	na.nm_txsync = igb_netmap_txsync;
  	na.nm_rxsync = igb_netmap_rxsync;
  	na.num_tx_rings = adapter->num_tx_queues;
  	na.num_rx_rings = adapter->num_rx_queues;
  	netmap_attach(&na);
  }
  
  /* end of file */
  