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ixgbe_netmap_linux.h
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ixgbe_netmap_linux.h
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/*
* Copyright (C) 2012-2014 Matteo Landi, 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.
*/
/*
* $FreeBSD: head/sys/dev/netmap/ixgbe_netmap.h 230572 2012-01-26 09:55:16Z luigi $
*
* netmap support for: ixgbe (LINUX version)
*
* This file is meant to be a reference on how to implement
* netmap support for a network driver.
* This file contains code but only static or inline functions used
* by a single driver. To avoid replication of code we just #include
* it near the beginning of the standard driver.
*/
#include <bsd_glue.h>
#include <net/netmap.h>
#include <netmap/netmap_kern.h>
#define SOFTC_T ixgbe_adapter
#define ixgbe_driver_name netmap_ixgbe_driver_name
char ixgbe_driver_name[] = "ixgbe" NETMAP_LINUX_DRIVER_SUFFIX;
/*
* Adaptation to different versions of the driver.
*/
#ifndef NETMAP_LINUX_IXGBE_DESC
#error "unsupported ixgbe driver version"
#else
#if NETMAP_LINUX_IXGBE_DESC == 1
#define NM_IXGBE_TX_DESC(_1, _2) IXGBE_TX_DESC_ADV(*(_1), _2)
#define NM_IXGBE_RX_DESC(_1, _2) IXGBE_RX_DESC_ADV(*(_1), _2)
#elif NETMAP_LINUX_IXGBE_DESC == 2
#define NM_IXGBE_TX_DESC(_1, _2) IXGBE_TX_DESC_ADV(_1, _2)
#define NM_IXGBE_RX_DESC(_1, _2) IXGBE_RX_DESC_ADV(_1, _2)
#elif NETMAP_LINUX_IXGBE_DESC == 3
#define NM_IXGBE_TX_DESC(_1, _2) IXGBE_TX_DESC(_1, _2)
#define NM_IXGBE_RX_DESC(_1, _2) IXGBE_RX_DESC(_1, _2)
#else
#error "netmap build error: unexpected NETMAP_LINUX_IXGBE_DESC == " #NETMAP_LINUX_IXGBE_DESC
#endif
#endif
#ifdef NETMAP_LINUX_IXGBE_PTR_ARRAY
#define NM_IXGBE_TX_RING(a, r) ((a)->tx_ring[(r)])
#define NM_IXGBE_RX_RING(a, r) ((a)->rx_ring[(r)])
#else
#define NM_IXGBE_TX_RING(a, r) (&(a)->tx_ring[(r)])
#define NM_IXGBE_RX_RING(a, r) (&(a)->rx_ring[(r)])
#endif
/*
* Register/unregister. We are already under netmap lock.
* Only called on the first register or the last unregister.
*/
static int
ixgbe_netmap_reg(struct netmap_adapter *na, int onoff)
{
struct ifnet *ifp = na->ifp;
struct SOFTC_T *adapter = netdev_priv(ifp);
// adapter->netdev->trans_start = jiffies; // disable watchdog ?
/* protect against other reinit */
while (test_and_set_bit(__IXGBE_RESETTING, &adapter->state))
usleep_range(1000, 2000);
if (netif_running(adapter->netdev))
ixgbe_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);
}
/* XXX SRIOV migth need another 2sec wait */
if (netif_running(adapter->netdev))
ixgbe_up(adapter); /* also enables intr */
clear_bit(__IXGBE_RESETTING, &adapter->state);
return (0);
}
static inline void ixgbe_irq_enable_queues(struct ixgbe_adapter *adapter,
u64 qmask);
static inline void ixgbe_irq_disable_queues(struct ixgbe_adapter *adapter,
u64 qmask);
static void
ixgbe_netmap_intr(struct netmap_adapter *na, int onoff)
{
struct ifnet *ifp = na->ifp;
struct SOFTC_T *adapter = netdev_priv(ifp);
if (onoff) {
ixgbe_irq_enable_queues(adapter, ~0);
} else {
ixgbe_irq_disable_queues(adapter, ~0);
}
}
/*
* Reconcile kernel and user view of the transmit ring.
*
* Userspace wants to send packets up to the one before ring->head,
* kernel knows kring->nr_hwcur is the first unsent packet.
*
* Here we push packets out (as many as possible), and possibly
* reclaim buffers from previously completed transmission.
*
* ring->tail is updated on return.
* ring->head is never used here.
*
* The caller (netmap) guarantees that there is only one instance
* running at any time. Any interference with other driver
* methods should be handled by the individual drivers.
*/
static int
ixgbe_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;
/*
* interrupts on every tx packet are expensive so request
* them every half ring, or where NS_REPORT is set
*/
u_int report_frequency = kring->nkr_num_slots >> 1;
/* device-specific */
struct SOFTC_T *adapter = netdev_priv(ifp);
struct ixgbe_ring *txr = NM_IXGBE_TX_RING(adapter, ring_nr);
int reclaim_tx;
/*
* First part: process new packets to send.
* nm_i is the current index in the netmap ring,
* nic_i is the corresponding index in the NIC ring.
* The two numbers differ because upon a *_init() we reset
* the NIC ring but leave the netmap ring unchanged.
* For the transmit ring, we have
*
* nm_i = kring->nr_hwcur
* nic_i = IXGBE_TDT (not tracked in the driver)
* and
* nm_i == (nic_i + kring->nkr_hwofs) % ring_size
*
* In this driver kring->nkr_hwofs >= 0, but for other
* drivers it might be negative as well.
*/
/*
* If we have packets to send (kring->nr_hwcur != ring->cur)
* iterate over the netmap ring, fetch length and update
* the corresponding slot in the NIC ring. Some drivers also
* need to update the buffer's physical address in the NIC slot
* even NS_BUF_CHANGED is not set (PNMB computes the addresses).
*
* The netmap_reload_map() calls is especially expensive,
* even when (as in this case) the tag is 0, so do only
* when the buffer has actually changed.
*
* If possible do not set the report/intr bit on all slots,
* but only a few times per ring or when NS_REPORT is set.
*
* Finally, on 10G and faster drivers, it might be useful
* to prefetch the next slot and txr entry.
*/
if (!netif_carrier_ok(ifp)) {
goto out;
}
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 ixgbe_adv_tx_desc *curr = NM_IXGBE_TX_DESC(txr, nic_i);
int flags = (slot->flags & NS_REPORT ||
nic_i == 0 || nic_i == report_frequency) ?
IXGBE_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_addr, addr);
}
slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
/* Fill the slot in the NIC ring. */
curr->read.buffer_addr = htole64(paddr);
curr->read.olinfo_status = htole32(len << IXGBE_ADVTXD_PAYLEN_SHIFT);
curr->read.cmd_type_len = htole32(len | flags |
IXGBE_ADVTXD_DTYP_DATA | IXGBE_ADVTXD_DCMD_DEXT |
IXGBE_ADVTXD_DCMD_IFCS | IXGBE_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 */
/* (re)start the tx unit up to slot nic_i (excluded) */
IXGBE_WRITE_REG(&adapter->hw, IXGBE_TDT(txr->reg_idx), nic_i);
}
/*
* Second part: reclaim buffers for completed transmissions.
* Because this is expensive (we read a NIC register etc.)
* we only do it in specific cases (see below).
*/
if (flags & NAF_FORCE_RECLAIM) {
reclaim_tx = 1; /* forced reclaim */
} else if (!nm_kr_txempty(kring)) {
reclaim_tx = 0; /* have buffers, no reclaim */
} else {
/*
* No buffers available. Locate previous slot with
* REPORT_STATUS set.
* If the slot has DD set, we can reclaim space,
* otherwise wait for the next interrupt.
* This enables interrupt moderation on the tx
* side though it might reduce throughput.
*/
union ixgbe_adv_tx_desc *txd = NM_IXGBE_TX_DESC(txr, 0);
nic_i = txr->next_to_clean + report_frequency;
if (nic_i > lim)
nic_i -= lim + 1;
// round to the closest with dd set
nic_i = (nic_i < kring->nkr_num_slots / 4 ||
nic_i >= kring->nkr_num_slots*3/4) ?
0 : report_frequency;
reclaim_tx = txd[nic_i].wb.status & IXGBE_TXD_STAT_DD; // XXX cpu_to_le32 ?
}
if (reclaim_tx) {
/*
* Record completed transmissions.
* We (re)use the driver's txr->next_to_clean to keep
* track of the most recently completed transmission.
*
* The datasheet discourages the use of TDH to find
* out the number of sent packets, but we only set
* REPORT STATUS in a few slots so TDH is the only
* good way.
*/
nic_i = IXGBE_READ_REG(&adapter->hw, IXGBE_TDH(ring_nr));
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_clean = 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.
* Same as for the txsync, this routine must be efficient.
* The caller guarantees a single invocations, but races against
* the rest of the driver should be handled here.
*
* When called, userspace has released buffers up to ring->head
* (last one excluded).
*
* If (flags & NAF_FORCE_READ) also check for incoming packets irrespective
* of whether or not we received an interrupt.
*/
static int
ixgbe_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 ixgbe_ring *rxr = NM_IXGBE_RX_RING(adapter, ring_nr);
if (!netif_carrier_ok(ifp))
return 0;
if (head > lim)
return netmap_ring_reinit(kring);
rmb();
/*
* First part: import newly received packets.
*
* nm_i is the index of the next free slot in the netmap ring,
* nic_i is the index of the next received packet in the NIC ring,
* and they may differ in case if_init() has been called while
* in netmap mode. For the receive ring we have
*
* nm_i = (kring->nr_hwtail)
* nic_i = rxr->next_to_clean; // really next to check
* and
* nm_i == (nic_i + kring->nkr_hwofs) % ring_size
*
* rxr->next_to_clean is set to 0 on a ring reinit
*/
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 ixgbe_adv_rx_desc *curr = NM_IXGBE_RX_DESC(rxr, nic_i);
uint32_t staterr = le32toh(curr->wb.upper.status_error);
if ((staterr & IXGBE_RXD_STAT_DD) == 0)
break;
ring->slot[nm_i].len = le16toh(curr->wb.upper.length);
ring->slot[nm_i].flags = (!(staterr & IXGBE_RXD_STAT_EOP) ? NS_MOREFRAG |
slot_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.
* (kring->nr_hwcur to ring->head excluded),
* and make the buffers available for reception.
* As usual nm_i is the index in the netmap ring,
* nic_i is the index in the NIC ring, and
* nm_i == (nic_i + kring->nkr_hwofs) % ring_size
*/
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 ixgbe_adv_rx_desc *curr = NM_IXGBE_RX_DESC(rxr, 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(pdev, DMA_TO_DEVICE, old_addr, addr);
slot->flags &= ~NS_BUF_CHANGED;
}
curr->wb.upper.status_error = 0;
curr->read.pkt_addr = htole64(paddr);
nm_i = nm_next(nm_i, lim);
nic_i = nm_next(nic_i, lim);
}
kring->nr_hwcur = head;
rxr->next_to_use = nic_i; // XXX not really used
wmb();
/*
* 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);
IXGBE_WRITE_REG(&adapter->hw, IXGBE_RDT(rxr->reg_idx), nic_i);
}
return 0;
ring_reset:
return netmap_ring_reinit(kring);
}
/*
* if in netmap mode, attach the netmap buffers to the ring and return true.
* Otherwise return false.
*/
static int
ixgbe_netmap_configure_tx_ring(struct SOFTC_T *adapter, int ring_nr)
{
struct netmap_adapter *na = NA(adapter->netdev);
struct netmap_slot *slot;
//int j;
slot = netmap_reset(na, NR_TX, ring_nr, 0);
if (!slot)
return 0; // not in native netmap mode
#if 0
/*
* on a generic card we should set the address in the slot.
* But on the ixgbe, the address needs to be rewritten
* after a transmission so there is nothing do to except
* loading the map.
*/
for (j = 0; j < na->num_tx_desc; j++) {
int sj = netmap_idx_n2k(&na->tx_rings[ring_nr], j);
uint64_t paddr;
void *addr = PNMB(na, slot + sj, &paddr);
}
#endif
return 1;
}
/*
* In netmap mode, overwrite the srrctl register with netmap_buf_size
* to properly configure the Receive Buffer Size
*/
static void
ixgbe_netmap_configure_srrctl(struct SOFTC_T *adapter, struct ixgbe_ring *rx_ring)
{
struct netmap_adapter *na = NA(adapter->netdev);
struct ixgbe_hw *hw = &adapter->hw;
u32 srrctl;
u8 reg_idx = rx_ring->reg_idx;
if (hw->mac.type == ixgbe_mac_82598EB) {
u16 mask = adapter->ring_feature[RING_F_RSS].mask;
reg_idx &= mask;
}
srrctl = IXGBE_RX_HDR_SIZE << 2;
srrctl |= NETMAP_BUF_SIZE(na) >> IXGBE_SRRCTL_BSIZEPKT_SHIFT;
D("bufsz: %d srrctl: %d", NETMAP_BUF_SIZE(na),
NETMAP_BUF_SIZE(na) >> IXGBE_SRRCTL_BSIZEPKT_SHIFT);
/*
* XXX
* With Advanced RX descriptor, the address needs to be rewritten,
* but with Legacy RX descriptor, it simply has to zero the status
* byte in the descriptor to make it ready for reuse by hardware.
* (ixgbe datasheet - Section 7.1.9)
*/
srrctl |= IXGBE_SRRCTL_DESCTYPE_ADV_ONEBUF;
IXGBE_WRITE_REG(hw, IXGBE_SRRCTL(reg_idx), srrctl);
}
static int
ixgbe_netmap_configure_rx_ring(struct SOFTC_T *adapter, int ring_nr)
{
/*
* In netmap mode, we must preserve the buffers made
* available to userspace before the if_init()
* (this is true by default on the TX side, because
* init makes all buffers available to userspace).
*
* netmap_reset() and the device-specific routines
* (e.g. ixgbe_setup_receive_rings()) map these
* buffers at the end of the NIC ring, so here we
* must set the RDT (tail) register to make sure
* they are not overwritten.
*
* In this driver the NIC ring starts at RDH = 0,
* RDT points to the last slot available for reception (?),
* so RDT = num_rx_desc - 1 means the whole ring is available.
*/
struct netmap_adapter *na = NA(adapter->netdev);
struct netmap_slot *slot;
int lim, i;
struct ixgbe_ring *ring = NM_IXGBE_RX_RING(adapter, ring_nr);
slot = netmap_reset(na, NR_RX, ring_nr, 0);
/* same as in ixgbe_setup_transmit_ring() */
if (!slot)
return 0; // not in native netmap mode
// XXX can we move it later ?
ixgbe_netmap_configure_srrctl(adapter, ring);
lim = na->num_rx_desc - 1 - nm_kr_rxspace(&na->rx_rings[ring_nr]);
for (i = 0; i < na->num_rx_desc; i++) {
/*
* Fill the map and set the buffer address in the NIC ring,
* considering the offset between the netmap and NIC rings
* (see comment in ixgbe_setup_transmit_ring() ).
*/
int si = netmap_idx_n2k(&na->rx_rings[ring_nr], i);
uint64_t paddr;
PNMB(na, slot + si, &paddr);
// netmap_load_map(rxr->ptag, rxbuf->pmap, addr);
/* Update descriptor */
NM_IXGBE_RX_DESC(ring, i)->read.pkt_addr = htole64(paddr);
}
IXGBE_WRITE_REG(&adapter->hw, IXGBE_RDT(ring_nr), lim);
return 1;
}
/*
* The attach routine, called near the end of ixgbe_attach(),
* fills the parameters for netmap_attach() and calls it.
* It cannot fail, in the worst case (such as no memory)
* netmap mode will be disabled and the driver will only
* operate in standard mode.
*/
static void
ixgbe_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 = NM_IXGBE_TX_RING(adapter, 0)->count;
na.num_rx_desc = NM_IXGBE_RX_RING(adapter, 0)->count;
na.nm_txsync = ixgbe_netmap_txsync;
na.nm_rxsync = ixgbe_netmap_rxsync;
na.nm_register = ixgbe_netmap_reg;
na.num_tx_rings = adapter->num_tx_queues;
na.num_rx_rings = adapter->num_rx_queues;
na.nm_intr = ixgbe_netmap_intr;
netmap_attach(&na);
}
/* end of file */