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freebsd/sys/dev/xen/netfront/netfront.c
Gleb Smirnoff c6b15dd50d Fix typo in r257515. 
Submitted by:	az
2013-11-10 09:36:51 +00:00

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/*-
* Copyright (c) 2004-2006 Kip Macy
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sockio.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/queue.h>
#include <sys/lock.h>
#include <sys/sx.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <net/bpf.h>
#include <net/if_types.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/if_ether.h>
#if __FreeBSD_version >= 700000
#include <netinet/tcp.h>
#include <netinet/tcp_lro.h>
#endif
#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/clock.h> /* for DELAY */
#include <machine/bus.h>
#include <machine/resource.h>
#include <machine/frame.h>
#include <machine/vmparam.h>
#include <sys/bus.h>
#include <sys/rman.h>
#include <machine/intr_machdep.h>
#include <xen/xen-os.h>
#include <xen/hypervisor.h>
#include <xen/xen_intr.h>
#include <xen/gnttab.h>
#include <xen/interface/memory.h>
#include <xen/interface/io/netif.h>
#include <xen/xenbus/xenbusvar.h>
#include <machine/xen/xenvar.h>
#include <dev/xen/netfront/mbufq.h>
#include "xenbus_if.h"
/* Features supported by all backends. TSO and LRO can be negotiated */
#define XN_CSUM_FEATURES (CSUM_TCP | CSUM_UDP)
#define NET_TX_RING_SIZE __RING_SIZE((netif_tx_sring_t *)0, PAGE_SIZE)
#define NET_RX_RING_SIZE __RING_SIZE((netif_rx_sring_t *)0, PAGE_SIZE)
#if __FreeBSD_version >= 700000
/*
* Should the driver do LRO on the RX end
* this can be toggled on the fly, but the
* interface must be reset (down/up) for it
* to take effect.
*/
static int xn_enable_lro = 1;
TUNABLE_INT("hw.xn.enable_lro", &xn_enable_lro);
#else
#define IFCAP_TSO4 0
#define CSUM_TSO 0
#endif
#ifdef CONFIG_XEN
static int MODPARM_rx_copy = 0;
module_param_named(rx_copy, MODPARM_rx_copy, bool, 0);
MODULE_PARM_DESC(rx_copy, "Copy packets from network card (rather than flip)");
static int MODPARM_rx_flip = 0;
module_param_named(rx_flip, MODPARM_rx_flip, bool, 0);
MODULE_PARM_DESC(rx_flip, "Flip packets from network card (rather than copy)");
#else
static const int MODPARM_rx_copy = 1;
static const int MODPARM_rx_flip = 0;
#endif
/**
* \brief The maximum allowed data fragments in a single transmit
* request.
*
* This limit is imposed by the backend driver. We assume here that
* we are dealing with a Linux driver domain and have set our limit
* to mirror the Linux MAX_SKB_FRAGS constant.
*/
#define MAX_TX_REQ_FRAGS (65536 / PAGE_SIZE + 2)
#define NF_TSO_MAXBURST ((IP_MAXPACKET / PAGE_SIZE) * MCLBYTES)
#define RX_COPY_THRESHOLD 256
#define net_ratelimit() 0
struct netfront_info;
struct netfront_rx_info;
static void xn_txeof(struct netfront_info *);
static void xn_rxeof(struct netfront_info *);
static void network_alloc_rx_buffers(struct netfront_info *);
static void xn_tick_locked(struct netfront_info *);
static void xn_tick(void *);
static void xn_intr(void *);
static inline int xn_count_frags(struct mbuf *m);
static int xn_assemble_tx_request(struct netfront_info *sc,
struct mbuf *m_head);
static void xn_start_locked(struct ifnet *);
static void xn_start(struct ifnet *);
static int xn_ioctl(struct ifnet *, u_long, caddr_t);
static void xn_ifinit_locked(struct netfront_info *);
static void xn_ifinit(void *);
static void xn_stop(struct netfront_info *);
static void xn_query_features(struct netfront_info *np);
static int xn_configure_features(struct netfront_info *np);
#ifdef notyet
static void xn_watchdog(struct ifnet *);
#endif
#ifdef notyet
static void netfront_closing(device_t dev);
#endif
static void netif_free(struct netfront_info *info);
static int netfront_detach(device_t dev);
static int talk_to_backend(device_t dev, struct netfront_info *info);
static int create_netdev(device_t dev);
static void netif_disconnect_backend(struct netfront_info *info);
static int setup_device(device_t dev, struct netfront_info *info);
static void free_ring(int *ref, void *ring_ptr_ref);
static int xn_ifmedia_upd(struct ifnet *ifp);
static void xn_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr);
/* Xenolinux helper functions */
int network_connect(struct netfront_info *);
static void xn_free_rx_ring(struct netfront_info *);
static void xn_free_tx_ring(struct netfront_info *);
static int xennet_get_responses(struct netfront_info *np,
struct netfront_rx_info *rinfo, RING_IDX rp, RING_IDX *cons,
struct mbuf **list, int *pages_flipped_p);
#define virt_to_mfn(x) (vtomach(x) >> PAGE_SHIFT)
#define INVALID_P2M_ENTRY (~0UL)
/*
* Mbuf pointers. We need these to keep track of the virtual addresses
* of our mbuf chains since we can only convert from virtual to physical,
* not the other way around. The size must track the free index arrays.
*/
struct xn_chain_data {
struct mbuf *xn_tx_chain[NET_TX_RING_SIZE+1];
int xn_tx_chain_cnt;
struct mbuf *xn_rx_chain[NET_RX_RING_SIZE+1];
};
struct net_device_stats
{
u_long rx_packets; /* total packets received */
u_long tx_packets; /* total packets transmitted */
u_long rx_bytes; /* total bytes received */
u_long tx_bytes; /* total bytes transmitted */
u_long rx_errors; /* bad packets received */
u_long tx_errors; /* packet transmit problems */
u_long rx_dropped; /* no space in linux buffers */
u_long tx_dropped; /* no space available in linux */
u_long multicast; /* multicast packets received */
u_long collisions;
/* detailed rx_errors: */
u_long rx_length_errors;
u_long rx_over_errors; /* receiver ring buff overflow */
u_long rx_crc_errors; /* recved pkt with crc error */
u_long rx_frame_errors; /* recv'd frame alignment error */
u_long rx_fifo_errors; /* recv'r fifo overrun */
u_long rx_missed_errors; /* receiver missed packet */
/* detailed tx_errors */
u_long tx_aborted_errors;
u_long tx_carrier_errors;
u_long tx_fifo_errors;
u_long tx_heartbeat_errors;
u_long tx_window_errors;
/* for cslip etc */
u_long rx_compressed;
u_long tx_compressed;
};
struct netfront_info {
struct ifnet *xn_ifp;
#if __FreeBSD_version >= 700000
struct lro_ctrl xn_lro;
#endif
struct net_device_stats stats;
u_int tx_full;
netif_tx_front_ring_t tx;
netif_rx_front_ring_t rx;
struct mtx tx_lock;
struct mtx rx_lock;
struct mtx sc_lock;
xen_intr_handle_t xen_intr_handle;
u_int copying_receiver;
u_int carrier;
u_int maxfrags;
/* Receive-ring batched refills. */
#define RX_MIN_TARGET 32
#define RX_MAX_TARGET NET_RX_RING_SIZE
int rx_min_target;
int rx_max_target;
int rx_target;
grant_ref_t gref_tx_head;
grant_ref_t grant_tx_ref[NET_TX_RING_SIZE + 1];
grant_ref_t gref_rx_head;
grant_ref_t grant_rx_ref[NET_TX_RING_SIZE + 1];
device_t xbdev;
int tx_ring_ref;
int rx_ring_ref;
uint8_t mac[ETHER_ADDR_LEN];
struct xn_chain_data xn_cdata; /* mbufs */
struct mbuf_head xn_rx_batch; /* head of the batch queue */
int xn_if_flags;
struct callout xn_stat_ch;
u_long rx_pfn_array[NET_RX_RING_SIZE];
multicall_entry_t rx_mcl[NET_RX_RING_SIZE+1];
mmu_update_t rx_mmu[NET_RX_RING_SIZE];
struct ifmedia sc_media;
};
#define rx_mbufs xn_cdata.xn_rx_chain
#define tx_mbufs xn_cdata.xn_tx_chain
#define XN_LOCK_INIT(_sc, _name) \
mtx_init(&(_sc)->tx_lock, #_name"_tx", "network transmit lock", MTX_DEF); \
mtx_init(&(_sc)->rx_lock, #_name"_rx", "network receive lock", MTX_DEF); \
mtx_init(&(_sc)->sc_lock, #_name"_sc", "netfront softc lock", MTX_DEF)
#define XN_RX_LOCK(_sc) mtx_lock(&(_sc)->rx_lock)
#define XN_RX_UNLOCK(_sc) mtx_unlock(&(_sc)->rx_lock)
#define XN_TX_LOCK(_sc) mtx_lock(&(_sc)->tx_lock)
#define XN_TX_UNLOCK(_sc) mtx_unlock(&(_sc)->tx_lock)
#define XN_LOCK(_sc) mtx_lock(&(_sc)->sc_lock);
#define XN_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_lock);
#define XN_LOCK_ASSERT(_sc) mtx_assert(&(_sc)->sc_lock, MA_OWNED);
#define XN_RX_LOCK_ASSERT(_sc) mtx_assert(&(_sc)->rx_lock, MA_OWNED);
#define XN_TX_LOCK_ASSERT(_sc) mtx_assert(&(_sc)->tx_lock, MA_OWNED);
#define XN_LOCK_DESTROY(_sc) mtx_destroy(&(_sc)->rx_lock); \
mtx_destroy(&(_sc)->tx_lock); \
mtx_destroy(&(_sc)->sc_lock);
struct netfront_rx_info {
struct netif_rx_response rx;
struct netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
};
#define netfront_carrier_on(netif) ((netif)->carrier = 1)
#define netfront_carrier_off(netif) ((netif)->carrier = 0)
#define netfront_carrier_ok(netif) ((netif)->carrier)
/* Access macros for acquiring freeing slots in xn_free_{tx,rx}_idxs[]. */
static inline void
add_id_to_freelist(struct mbuf **list, uintptr_t id)
{
KASSERT(id != 0,
("%s: the head item (0) must always be free.", __func__));
list[id] = list[0];
list[0] = (struct mbuf *)id;
}
static inline unsigned short
get_id_from_freelist(struct mbuf **list)
{
uintptr_t id;
id = (uintptr_t)list[0];
KASSERT(id != 0,
("%s: the head item (0) must always remain free.", __func__));
list[0] = list[id];
return (id);
}
static inline int
xennet_rxidx(RING_IDX idx)
{
return idx & (NET_RX_RING_SIZE - 1);
}
static inline struct mbuf *
xennet_get_rx_mbuf(struct netfront_info *np, RING_IDX ri)
{
int i = xennet_rxidx(ri);
struct mbuf *m;
m = np->rx_mbufs[i];
np->rx_mbufs[i] = NULL;
return (m);
}
static inline grant_ref_t
xennet_get_rx_ref(struct netfront_info *np, RING_IDX ri)
{
int i = xennet_rxidx(ri);
grant_ref_t ref = np->grant_rx_ref[i];
KASSERT(ref != GRANT_REF_INVALID, ("Invalid grant reference!\n"));
np->grant_rx_ref[i] = GRANT_REF_INVALID;
return ref;
}
#define IPRINTK(fmt, args...) \
printf("[XEN] " fmt, ##args)
#ifdef INVARIANTS
#define WPRINTK(fmt, args...) \
printf("[XEN] " fmt, ##args)
#else
#define WPRINTK(fmt, args...)
#endif
#ifdef DEBUG
#define DPRINTK(fmt, args...) \
printf("[XEN] %s: " fmt, __func__, ##args)
#else
#define DPRINTK(fmt, args...)
#endif
/**
* Read the 'mac' node at the given device's node in the store, and parse that
* as colon-separated octets, placing result the given mac array. mac must be
* a preallocated array of length ETH_ALEN (as declared in linux/if_ether.h).
* Return 0 on success, or errno on error.
*/
static int
xen_net_read_mac(device_t dev, uint8_t mac[])
{
int error, i;
char *s, *e, *macstr;
const char *path;
path = xenbus_get_node(dev);
error = xs_read(XST_NIL, path, "mac", NULL, (void **) &macstr);
if (error == ENOENT) {
/*
* Deal with missing mac XenStore nodes on devices with
* HVM emulation (the 'ioemu' configuration attribute)
* enabled.
*
* The HVM emulator may execute in a stub device model
* domain which lacks the permission, only given to Dom0,
* to update the guest's XenStore tree. For this reason,
* the HVM emulator doesn't even attempt to write the
* front-side mac node, even when operating in Dom0.
* However, there should always be a mac listed in the
* backend tree. Fallback to this version if our query
* of the front side XenStore location doesn't find
* anything.
*/
path = xenbus_get_otherend_path(dev);
error = xs_read(XST_NIL, path, "mac", NULL, (void **) &macstr);
}
if (error != 0) {
xenbus_dev_fatal(dev, error, "parsing %s/mac", path);
return (error);
}
s = macstr;
for (i = 0; i < ETHER_ADDR_LEN; i++) {
mac[i] = strtoul(s, &e, 16);
if (s == e || (e[0] != ':' && e[0] != 0)) {
free(macstr, M_XENBUS);
return (ENOENT);
}
s = &e[1];
}
free(macstr, M_XENBUS);
return (0);
}
/**
* Entry point to this code when a new device is created. Allocate the basic
* structures and the ring buffers for communication with the backend, and
* inform the backend of the appropriate details for those. Switch to
* Connected state.
*/
static int
netfront_probe(device_t dev)
{
if (!strcmp(xenbus_get_type(dev), "vif")) {
device_set_desc(dev, "Virtual Network Interface");
return (0);
}
return (ENXIO);
}
static int
netfront_attach(device_t dev)
{
int err;
err = create_netdev(dev);
if (err) {
xenbus_dev_fatal(dev, err, "creating netdev");
return (err);
}
#if __FreeBSD_version >= 700000
SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
OID_AUTO, "enable_lro", CTLTYPE_INT|CTLFLAG_RW,
&xn_enable_lro, 0, "Large Receive Offload");
#endif
return (0);
}
static int
netfront_suspend(device_t dev)
{
struct netfront_info *info = device_get_softc(dev);
XN_RX_LOCK(info);
XN_TX_LOCK(info);
netfront_carrier_off(info);
XN_TX_UNLOCK(info);
XN_RX_UNLOCK(info);
return (0);
}
/**
* We are reconnecting to the backend, due to a suspend/resume, or a backend
* driver restart. We tear down our netif structure and recreate it, but
* leave the device-layer structures intact so that this is transparent to the
* rest of the kernel.
*/
static int
netfront_resume(device_t dev)
{
struct netfront_info *info = device_get_softc(dev);
netif_disconnect_backend(info);
return (0);
}
/* Common code used when first setting up, and when resuming. */
static int
talk_to_backend(device_t dev, struct netfront_info *info)
{
const char *message;
struct xs_transaction xst;
const char *node = xenbus_get_node(dev);
int err;
err = xen_net_read_mac(dev, info->mac);
if (err) {
xenbus_dev_fatal(dev, err, "parsing %s/mac", node);
goto out;
}
/* Create shared ring, alloc event channel. */
err = setup_device(dev, info);
if (err)
goto out;
again:
err = xs_transaction_start(&xst);
if (err) {
xenbus_dev_fatal(dev, err, "starting transaction");
goto destroy_ring;
}
err = xs_printf(xst, node, "tx-ring-ref","%u",
info->tx_ring_ref);
if (err) {
message = "writing tx ring-ref";
goto abort_transaction;
}
err = xs_printf(xst, node, "rx-ring-ref","%u",
info->rx_ring_ref);
if (err) {
message = "writing rx ring-ref";
goto abort_transaction;
}
err = xs_printf(xst, node,
"event-channel", "%u",
xen_intr_port(info->xen_intr_handle));
if (err) {
message = "writing event-channel";
goto abort_transaction;
}
err = xs_printf(xst, node, "request-rx-copy", "%u",
info->copying_receiver);
if (err) {
message = "writing request-rx-copy";
goto abort_transaction;
}
err = xs_printf(xst, node, "feature-rx-notify", "%d", 1);
if (err) {
message = "writing feature-rx-notify";
goto abort_transaction;
}
err = xs_printf(xst, node, "feature-sg", "%d", 1);
if (err) {
message = "writing feature-sg";
goto abort_transaction;
}
#if __FreeBSD_version >= 700000
err = xs_printf(xst, node, "feature-gso-tcpv4", "%d", 1);
if (err) {
message = "writing feature-gso-tcpv4";
goto abort_transaction;
}
#endif
err = xs_transaction_end(xst, 0);
if (err) {
if (err == EAGAIN)
goto again;
xenbus_dev_fatal(dev, err, "completing transaction");
goto destroy_ring;
}
return 0;
abort_transaction:
xs_transaction_end(xst, 1);
xenbus_dev_fatal(dev, err, "%s", message);
destroy_ring:
netif_free(info);
out:
return err;
}
static int
setup_device(device_t dev, struct netfront_info *info)
{
netif_tx_sring_t *txs;
netif_rx_sring_t *rxs;
int error;
struct ifnet *ifp;
ifp = info->xn_ifp;
info->tx_ring_ref = GRANT_REF_INVALID;
info->rx_ring_ref = GRANT_REF_INVALID;
info->rx.sring = NULL;
info->tx.sring = NULL;
txs = (netif_tx_sring_t *)malloc(PAGE_SIZE, M_DEVBUF, M_NOWAIT|M_ZERO);
if (!txs) {
error = ENOMEM;
xenbus_dev_fatal(dev, error, "allocating tx ring page");
goto fail;
}
SHARED_RING_INIT(txs);
FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
error = xenbus_grant_ring(dev, virt_to_mfn(txs), &info->tx_ring_ref);
if (error)
goto fail;
rxs = (netif_rx_sring_t *)malloc(PAGE_SIZE, M_DEVBUF, M_NOWAIT|M_ZERO);
if (!rxs) {
error = ENOMEM;
xenbus_dev_fatal(dev, error, "allocating rx ring page");
goto fail;
}
SHARED_RING_INIT(rxs);
FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
error = xenbus_grant_ring(dev, virt_to_mfn(rxs), &info->rx_ring_ref);
if (error)
goto fail;
error = xen_intr_alloc_and_bind_local_port(dev,
xenbus_get_otherend_id(dev), /*filter*/NULL, xn_intr, info,
INTR_TYPE_NET | INTR_MPSAFE | INTR_ENTROPY, &info->xen_intr_handle);
if (error) {
xenbus_dev_fatal(dev, error,
"xen_intr_alloc_and_bind_local_port failed");
goto fail;
}
return (0);
fail:
netif_free(info);
return (error);
}
#ifdef INET
/**
* If this interface has an ipv4 address, send an arp for it. This
* helps to get the network going again after migrating hosts.
*/
static void
netfront_send_fake_arp(device_t dev, struct netfront_info *info)
{
struct ifnet *ifp;
struct ifaddr *ifa;
ifp = info->xn_ifp;
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family == AF_INET) {
arp_ifinit(ifp, ifa);
}
}
}
#endif
/**
* Callback received when the backend's state changes.
*/
static void
netfront_backend_changed(device_t dev, XenbusState newstate)
{
struct netfront_info *sc = device_get_softc(dev);
DPRINTK("newstate=%d\n", newstate);
switch (newstate) {
case XenbusStateInitialising:
case XenbusStateInitialised:
case XenbusStateConnected:
case XenbusStateUnknown:
case XenbusStateClosed:
case XenbusStateReconfigured:
case XenbusStateReconfiguring:
break;
case XenbusStateInitWait:
if (xenbus_get_state(dev) != XenbusStateInitialising)
break;
if (network_connect(sc) != 0)
break;
xenbus_set_state(dev, XenbusStateConnected);
#ifdef INET
netfront_send_fake_arp(dev, sc);
#endif
break;
case XenbusStateClosing:
xenbus_set_state(dev, XenbusStateClosed);
break;
}
}
static void
xn_free_rx_ring(struct netfront_info *sc)
{
#if 0
int i;
for (i = 0; i < NET_RX_RING_SIZE; i++) {
if (sc->xn_cdata.rx_mbufs[i] != NULL) {
m_freem(sc->rx_mbufs[i]);
sc->rx_mbufs[i] = NULL;
}
}
sc->rx.rsp_cons = 0;
sc->xn_rx_if->req_prod = 0;
sc->xn_rx_if->event = sc->rx.rsp_cons ;
#endif
}
static void
xn_free_tx_ring(struct netfront_info *sc)
{
#if 0
int i;
for (i = 0; i < NET_TX_RING_SIZE; i++) {
if (sc->tx_mbufs[i] != NULL) {
m_freem(sc->tx_mbufs[i]);
sc->xn_cdata.xn_tx_chain[i] = NULL;
}
}
return;
#endif
}
/**
* \brief Verify that there is sufficient space in the Tx ring
* buffer for a maximally sized request to be enqueued.
*
* A transmit request requires a transmit descriptor for each packet
* fragment, plus up to 2 entries for "options" (e.g. TSO).
*/
static inline int
xn_tx_slot_available(struct netfront_info *np)
{
return (RING_FREE_REQUESTS(&np->tx) > (MAX_TX_REQ_FRAGS + 2));
}
static void
netif_release_tx_bufs(struct netfront_info *np)
{
int i;
for (i = 1; i <= NET_TX_RING_SIZE; i++) {
struct mbuf *m;
m = np->tx_mbufs[i];
/*
* We assume that no kernel addresses are
* less than NET_TX_RING_SIZE. Any entry
* in the table that is below this number
* must be an index from free-list tracking.
*/
if (((uintptr_t)m) <= NET_TX_RING_SIZE)
continue;
gnttab_end_foreign_access_ref(np->grant_tx_ref[i]);
gnttab_release_grant_reference(&np->gref_tx_head,
np->grant_tx_ref[i]);
np->grant_tx_ref[i] = GRANT_REF_INVALID;
add_id_to_freelist(np->tx_mbufs, i);
np->xn_cdata.xn_tx_chain_cnt--;
if (np->xn_cdata.xn_tx_chain_cnt < 0) {
panic("%s: tx_chain_cnt must be >= 0", __func__);
}
m_free(m);
}
}
static void
network_alloc_rx_buffers(struct netfront_info *sc)
{
int otherend_id = xenbus_get_otherend_id(sc->xbdev);
unsigned short id;
struct mbuf *m_new;
int i, batch_target, notify;
RING_IDX req_prod;
struct xen_memory_reservation reservation;
grant_ref_t ref;
int nr_flips;
netif_rx_request_t *req;
vm_offset_t vaddr;
u_long pfn;
req_prod = sc->rx.req_prod_pvt;
if (__predict_false(sc->carrier == 0))
return;
/*
* Allocate mbufs greedily, even though we batch updates to the
* receive ring. This creates a less bursty demand on the memory
* allocator, and so should reduce the chance of failed allocation
* requests both for ourself and for other kernel subsystems.
*
* Here we attempt to maintain rx_target buffers in flight, counting
* buffers that we have yet to process in the receive ring.
*/
batch_target = sc->rx_target - (req_prod - sc->rx.rsp_cons);
for (i = mbufq_len(&sc->xn_rx_batch); i < batch_target; i++) {
MGETHDR(m_new, M_NOWAIT, MT_DATA);
if (m_new == NULL) {
printf("%s: MGETHDR failed\n", __func__);
goto no_mbuf;
}
m_cljget(m_new, M_NOWAIT, MJUMPAGESIZE);
if ((m_new->m_flags & M_EXT) == 0) {
printf("%s: m_cljget failed\n", __func__);
m_freem(m_new);
no_mbuf:
if (i != 0)
goto refill;
/*
* XXX set timer
*/
break;
}
m_new->m_len = m_new->m_pkthdr.len = MJUMPAGESIZE;
/* queue the mbufs allocated */
mbufq_tail(&sc->xn_rx_batch, m_new);
}
/*
* If we've allocated at least half of our target number of entries,
* submit them to the backend - we have enough to make the overhead
* of submission worthwhile. Otherwise wait for more mbufs and
* request entries to become available.
*/
if (i < (sc->rx_target/2)) {
if (req_prod >sc->rx.sring->req_prod)
goto push;
return;
}
/*
* Double floating fill target if we risked having the backend
* run out of empty buffers for receive traffic. We define "running
* low" as having less than a fourth of our target buffers free
* at the time we refilled the queue.
*/
if ((req_prod - sc->rx.sring->rsp_prod) < (sc->rx_target / 4)) {
sc->rx_target *= 2;
if (sc->rx_target > sc->rx_max_target)
sc->rx_target = sc->rx_max_target;
}
refill:
for (nr_flips = i = 0; ; i++) {
if ((m_new = mbufq_dequeue(&sc->xn_rx_batch)) == NULL)
break;
m_new->m_ext.ext_arg1 = (vm_paddr_t *)(uintptr_t)(
vtophys(m_new->m_ext.ext_buf) >> PAGE_SHIFT);
id = xennet_rxidx(req_prod + i);
KASSERT(sc->rx_mbufs[id] == NULL, ("non-NULL xm_rx_chain"));
sc->rx_mbufs[id] = m_new;
ref = gnttab_claim_grant_reference(&sc->gref_rx_head);
KASSERT(ref != GNTTAB_LIST_END,
("reserved grant references exhuasted"));
sc->grant_rx_ref[id] = ref;
vaddr = mtod(m_new, vm_offset_t);
pfn = vtophys(vaddr) >> PAGE_SHIFT;
req = RING_GET_REQUEST(&sc->rx, req_prod + i);
if (sc->copying_receiver == 0) {
gnttab_grant_foreign_transfer_ref(ref,
otherend_id, pfn);
sc->rx_pfn_array[nr_flips] = PFNTOMFN(pfn);
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
/* Remove this page before passing
* back to Xen.
*/
set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
MULTI_update_va_mapping(&sc->rx_mcl[i],
vaddr, 0, 0);
}
nr_flips++;
} else {
gnttab_grant_foreign_access_ref(ref,
otherend_id,
PFNTOMFN(pfn), 0);
}
req->id = id;
req->gref = ref;
sc->rx_pfn_array[i] =
vtomach(mtod(m_new,vm_offset_t)) >> PAGE_SHIFT;
}
KASSERT(i, ("no mbufs processed")); /* should have returned earlier */
KASSERT(mbufq_len(&sc->xn_rx_batch) == 0, ("not all mbufs processed"));
/*
* We may have allocated buffers which have entries outstanding
* in the page * update queue -- make sure we flush those first!
*/
PT_UPDATES_FLUSH();
if (nr_flips != 0) {
#ifdef notyet
/* Tell the ballon driver what is going on. */
balloon_update_driver_allowance(i);
#endif
set_xen_guest_handle(reservation.extent_start, sc->rx_pfn_array);
reservation.nr_extents = i;
reservation.extent_order = 0;
reservation.address_bits = 0;
reservation.domid = DOMID_SELF;
if (!xen_feature(XENFEAT_auto_translated_physmap)) {
/* After all PTEs have been zapped, flush the TLB. */
sc->rx_mcl[i-1].args[MULTI_UVMFLAGS_INDEX] =
UVMF_TLB_FLUSH|UVMF_ALL;
/* Give away a batch of pages. */
sc->rx_mcl[i].op = __HYPERVISOR_memory_op;
sc->rx_mcl[i].args[0] = XENMEM_decrease_reservation;
sc->rx_mcl[i].args[1] = (u_long)&reservation;
/* Zap PTEs and give away pages in one big multicall. */
(void)HYPERVISOR_multicall(sc->rx_mcl, i+1);
if (__predict_false(sc->rx_mcl[i].result != i ||
HYPERVISOR_memory_op(XENMEM_decrease_reservation,
&reservation) != i))
panic("%s: unable to reduce memory "
"reservation\n", __func__);
}
} else {
wmb();
}
/* Above is a suitable barrier to ensure backend will see requests. */
sc->rx.req_prod_pvt = req_prod + i;
push:
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&sc->rx, notify);
if (notify)
xen_intr_signal(sc->xen_intr_handle);
}
static void
xn_rxeof(struct netfront_info *np)
{
struct ifnet *ifp;
#if __FreeBSD_version >= 700000 && (defined(INET) || defined(INET6))
struct lro_ctrl *lro = &np->xn_lro;
struct lro_entry *queued;
#endif
struct netfront_rx_info rinfo;
struct netif_rx_response *rx = &rinfo.rx;
struct netif_extra_info *extras = rinfo.extras;
RING_IDX i, rp;
multicall_entry_t *mcl;
struct mbuf *m;
struct mbuf_head rxq, errq;
int err, pages_flipped = 0, work_to_do;
do {
XN_RX_LOCK_ASSERT(np);
if (!netfront_carrier_ok(np))
return;
mbufq_init(&errq);
mbufq_init(&rxq);
ifp = np->xn_ifp;
rp = np->rx.sring->rsp_prod;
rmb(); /* Ensure we see queued responses up to 'rp'. */
i = np->rx.rsp_cons;
while ((i != rp)) {
memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
memset(extras, 0, sizeof(rinfo.extras));
m = NULL;
err = xennet_get_responses(np, &rinfo, rp, &i, &m,
&pages_flipped);
if (__predict_false(err)) {
if (m)
mbufq_tail(&errq, m);
np->stats.rx_errors++;
continue;
}
m->m_pkthdr.rcvif = ifp;
if ( rx->flags & NETRXF_data_validated ) {
/* Tell the stack the checksums are okay */
/*
* XXX this isn't necessarily the case - need to add
* check
*/
m->m_pkthdr.csum_flags |=
(CSUM_IP_CHECKED | CSUM_IP_VALID | CSUM_DATA_VALID
| CSUM_PSEUDO_HDR);
m->m_pkthdr.csum_data = 0xffff;
}
np->stats.rx_packets++;
np->stats.rx_bytes += m->m_pkthdr.len;
mbufq_tail(&rxq, m);
np->rx.rsp_cons = i;
}
if (pages_flipped) {
/* Some pages are no longer absent... */
#ifdef notyet
balloon_update_driver_allowance(-pages_flipped);
#endif
/* Do all the remapping work, and M->P updates, in one big
* hypercall.
*/
if (!!xen_feature(XENFEAT_auto_translated_physmap)) {
mcl = np->rx_mcl + pages_flipped;
mcl->op = __HYPERVISOR_mmu_update;
mcl->args[0] = (u_long)np->rx_mmu;
mcl->args[1] = pages_flipped;
mcl->args[2] = 0;
mcl->args[3] = DOMID_SELF;
(void)HYPERVISOR_multicall(np->rx_mcl,
pages_flipped + 1);
}
}
while ((m = mbufq_dequeue(&errq)))
m_freem(m);
/*
* Process all the mbufs after the remapping is complete.
* Break the mbuf chain first though.
*/
while ((m = mbufq_dequeue(&rxq)) != NULL) {
ifp->if_ipackets++;
/*
* Do we really need to drop the rx lock?
*/
XN_RX_UNLOCK(np);
#if __FreeBSD_version >= 700000 && (defined(INET) || defined(INET6))
/* Use LRO if possible */
if ((ifp->if_capenable & IFCAP_LRO) == 0 ||
lro->lro_cnt == 0 || tcp_lro_rx(lro, m, 0)) {
/*
* If LRO fails, pass up to the stack
* directly.
*/
(*ifp->if_input)(ifp, m);
}
#else
(*ifp->if_input)(ifp, m);
#endif
XN_RX_LOCK(np);
}
np->rx.rsp_cons = i;
#if __FreeBSD_version >= 700000 && (defined(INET) || defined(INET6))
/*
* Flush any outstanding LRO work
*/
while (!SLIST_EMPTY(&lro->lro_active)) {
queued = SLIST_FIRST(&lro->lro_active);
SLIST_REMOVE_HEAD(&lro->lro_active, next);
tcp_lro_flush(lro, queued);
}
#endif
#if 0
/* If we get a callback with very few responses, reduce fill target. */
/* NB. Note exponential increase, linear decrease. */
if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) >
((3*np->rx_target) / 4)) && (--np->rx_target < np->rx_min_target))
np->rx_target = np->rx_min_target;
#endif
network_alloc_rx_buffers(np);
RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, work_to_do);
} while (work_to_do);
}
static void
xn_txeof(struct netfront_info *np)
{
RING_IDX i, prod;
unsigned short id;
struct ifnet *ifp;
netif_tx_response_t *txr;
struct mbuf *m;
XN_TX_LOCK_ASSERT(np);
if (!netfront_carrier_ok(np))
return;
ifp = np->xn_ifp;
do {
prod = np->tx.sring->rsp_prod;
rmb(); /* Ensure we see responses up to 'rp'. */
for (i = np->tx.rsp_cons; i != prod; i++) {
txr = RING_GET_RESPONSE(&np->tx, i);
if (txr->status == NETIF_RSP_NULL)
continue;
if (txr->status != NETIF_RSP_OKAY) {
printf("%s: WARNING: response is %d!\n",
__func__, txr->status);
}
id = txr->id;
m = np->tx_mbufs[id];
KASSERT(m != NULL, ("mbuf not found in xn_tx_chain"));
KASSERT((uintptr_t)m > NET_TX_RING_SIZE,
("mbuf already on the free list, but we're "
"trying to free it again!"));
M_ASSERTVALID(m);
/*
* Increment packet count if this is the last
* mbuf of the chain.
*/
if (!m->m_next)
ifp->if_opackets++;
if (__predict_false(gnttab_query_foreign_access(
np->grant_tx_ref[id]) != 0)) {
panic("%s: grant id %u still in use by the "
"backend", __func__, id);
}
gnttab_end_foreign_access_ref(
np->grant_tx_ref[id]);
gnttab_release_grant_reference(
&np->gref_tx_head, np->grant_tx_ref[id]);
np->grant_tx_ref[id] = GRANT_REF_INVALID;
np->tx_mbufs[id] = NULL;
add_id_to_freelist(np->tx_mbufs, id);
np->xn_cdata.xn_tx_chain_cnt--;
m_free(m);
/* Only mark the queue active if we've freed up at least one slot to try */
ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
}
np->tx.rsp_cons = prod;
/*
* Set a new event, then check for race with update of
* tx_cons. Note that it is essential to schedule a
* callback, no matter how few buffers are pending. Even if
* there is space in the transmit ring, higher layers may
* be blocked because too much data is outstanding: in such
* cases notification from Xen is likely to be the only kick
* that we'll get.
*/
np->tx.sring->rsp_event =
prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
mb();
} while (prod != np->tx.sring->rsp_prod);
if (np->tx_full &&
((np->tx.sring->req_prod - prod) < NET_TX_RING_SIZE)) {
np->tx_full = 0;
#if 0
if (np->user_state == UST_OPEN)
netif_wake_queue(dev);
#endif
}
}
static void
xn_intr(void *xsc)
{
struct netfront_info *np = xsc;
struct ifnet *ifp = np->xn_ifp;
#if 0
if (!(np->rx.rsp_cons != np->rx.sring->rsp_prod &&
likely(netfront_carrier_ok(np)) &&
ifp->if_drv_flags & IFF_DRV_RUNNING))
return;
#endif
if (RING_HAS_UNCONSUMED_RESPONSES(&np->tx)) {
XN_TX_LOCK(np);
xn_txeof(np);
XN_TX_UNLOCK(np);
}
XN_RX_LOCK(np);
xn_rxeof(np);
XN_RX_UNLOCK(np);
if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
!IFQ_DRV_IS_EMPTY(&ifp->if_snd))
xn_start(ifp);
}
static void
xennet_move_rx_slot(struct netfront_info *np, struct mbuf *m,
grant_ref_t ref)
{
int new = xennet_rxidx(np->rx.req_prod_pvt);
KASSERT(np->rx_mbufs[new] == NULL, ("rx_mbufs != NULL"));
np->rx_mbufs[new] = m;
np->grant_rx_ref[new] = ref;
RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
np->rx.req_prod_pvt++;
}
static int
xennet_get_extras(struct netfront_info *np,
struct netif_extra_info *extras, RING_IDX rp, RING_IDX *cons)
{
struct netif_extra_info *extra;
int err = 0;
do {
struct mbuf *m;
grant_ref_t ref;
if (__predict_false(*cons + 1 == rp)) {
#if 0
if (net_ratelimit())
WPRINTK("Missing extra info\n");
#endif
err = EINVAL;
break;
}
extra = (struct netif_extra_info *)
RING_GET_RESPONSE(&np->rx, ++(*cons));
if (__predict_false(!extra->type ||
extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
#if 0
if (net_ratelimit())
WPRINTK("Invalid extra type: %d\n",
extra->type);
#endif
err = EINVAL;
} else {
memcpy(&extras[extra->type - 1], extra, sizeof(*extra));
}
m = xennet_get_rx_mbuf(np, *cons);
ref = xennet_get_rx_ref(np, *cons);
xennet_move_rx_slot(np, m, ref);
} while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
return err;
}
static int
xennet_get_responses(struct netfront_info *np,
struct netfront_rx_info *rinfo, RING_IDX rp, RING_IDX *cons,
struct mbuf **list,
int *pages_flipped_p)
{
int pages_flipped = *pages_flipped_p;
struct mmu_update *mmu;
struct multicall_entry *mcl;
struct netif_rx_response *rx = &rinfo->rx;
struct netif_extra_info *extras = rinfo->extras;
struct mbuf *m, *m0, *m_prev;
grant_ref_t ref = xennet_get_rx_ref(np, *cons);
RING_IDX ref_cons = *cons;
int frags = 1;
int err = 0;
u_long ret;
m0 = m = m_prev = xennet_get_rx_mbuf(np, *cons);
if (rx->flags & NETRXF_extra_info) {
err = xennet_get_extras(np, extras, rp, cons);
}
if (m0 != NULL) {
m0->m_pkthdr.len = 0;
m0->m_next = NULL;
}
for (;;) {
u_long mfn;
#if 0
DPRINTK("rx->status=%hd rx->offset=%hu frags=%u\n",
rx->status, rx->offset, frags);
#endif
if (__predict_false(rx->status < 0 ||
rx->offset + rx->status > PAGE_SIZE)) {
#if 0
if (net_ratelimit())
WPRINTK("rx->offset: %x, size: %u\n",
rx->offset, rx->status);
#endif
xennet_move_rx_slot(np, m, ref);
if (m0 == m)
m0 = NULL;
m = NULL;
err = EINVAL;
goto next_skip_queue;
}
/*
* This definitely indicates a bug, either in this driver or in
* the backend driver. In future this should flag the bad
* situation to the system controller to reboot the backed.
*/
if (ref == GRANT_REF_INVALID) {
#if 0
if (net_ratelimit())
WPRINTK("Bad rx response id %d.\n", rx->id);
#endif
printf("%s: Bad rx response id %d.\n", __func__,rx->id);
err = EINVAL;
goto next;
}
if (!np->copying_receiver) {
/* Memory pressure, insufficient buffer
* headroom, ...
*/
if (!(mfn = gnttab_end_foreign_transfer_ref(ref))) {
WPRINTK("Unfulfilled rx req (id=%d, st=%d).\n",
rx->id, rx->status);
xennet_move_rx_slot(np, m, ref);
err = ENOMEM;
goto next;
}
if (!xen_feature( XENFEAT_auto_translated_physmap)) {
/* Remap the page. */
void *vaddr = mtod(m, void *);
uint32_t pfn;
mcl = np->rx_mcl + pages_flipped;
mmu = np->rx_mmu + pages_flipped;
MULTI_update_va_mapping(mcl, (u_long)vaddr,
(((vm_paddr_t)mfn) << PAGE_SHIFT) | PG_RW |
PG_V | PG_M | PG_A, 0);
pfn = (uintptr_t)m->m_ext.ext_arg1;
mmu->ptr = ((vm_paddr_t)mfn << PAGE_SHIFT) |
MMU_MACHPHYS_UPDATE;
mmu->val = pfn;
set_phys_to_machine(pfn, mfn);
}
pages_flipped++;
} else {
ret = gnttab_end_foreign_access_ref(ref);
KASSERT(ret, ("ret != 0"));
}
gnttab_release_grant_reference(&np->gref_rx_head, ref);
next:
if (m == NULL)
break;
m->m_len = rx->status;
m->m_data += rx->offset;
m0->m_pkthdr.len += rx->status;
next_skip_queue:
if (!(rx->flags & NETRXF_more_data))
break;
if (*cons + frags == rp) {
if (net_ratelimit())
WPRINTK("Need more frags\n");
err = ENOENT;
printf("%s: cons %u frags %u rp %u, not enough frags\n",
__func__, *cons, frags, rp);
break;
}
/*
* Note that m can be NULL, if rx->status < 0 or if
* rx->offset + rx->status > PAGE_SIZE above.
*/
m_prev = m;
rx = RING_GET_RESPONSE(&np->rx, *cons + frags);
m = xennet_get_rx_mbuf(np, *cons + frags);
/*
* m_prev == NULL can happen if rx->status < 0 or if
* rx->offset + * rx->status > PAGE_SIZE above.
*/
if (m_prev != NULL)
m_prev->m_next = m;
/*
* m0 can be NULL if rx->status < 0 or if * rx->offset +
* rx->status > PAGE_SIZE above.
*/
if (m0 == NULL)
m0 = m;
m->m_next = NULL;
ref = xennet_get_rx_ref(np, *cons + frags);
ref_cons = *cons + frags;
frags++;
}
*list = m0;
*cons += frags;
*pages_flipped_p = pages_flipped;
return (err);
}
static void
xn_tick_locked(struct netfront_info *sc)
{
XN_RX_LOCK_ASSERT(sc);
callout_reset(&sc->xn_stat_ch, hz, xn_tick, sc);
/* XXX placeholder for printing debug information */
}
static void
xn_tick(void *xsc)
{
struct netfront_info *sc;
sc = xsc;
XN_RX_LOCK(sc);
xn_tick_locked(sc);
XN_RX_UNLOCK(sc);
}
/**
* \brief Count the number of fragments in an mbuf chain.
*
* Surprisingly, there isn't an M* macro for this.
*/
static inline int
xn_count_frags(struct mbuf *m)
{
int nfrags;
for (nfrags = 0; m != NULL; m = m->m_next)
nfrags++;
return (nfrags);
}
/**
* Given an mbuf chain, make sure we have enough room and then push
* it onto the transmit ring.
*/
static int
xn_assemble_tx_request(struct netfront_info *sc, struct mbuf *m_head)
{
struct ifnet *ifp;
struct mbuf *m;
u_int nfrags;
netif_extra_info_t *extra;
int otherend_id;
ifp = sc->xn_ifp;
/**
* Defragment the mbuf if necessary.
*/
nfrags = xn_count_frags(m_head);
/*
* Check to see whether this request is longer than netback
* can handle, and try to defrag it.
*/
/**
* It is a bit lame, but the netback driver in Linux can't
* deal with nfrags > MAX_TX_REQ_FRAGS, which is a quirk of
* the Linux network stack.
*/
if (nfrags > sc->maxfrags) {
m = m_defrag(m_head, M_NOWAIT);
if (!m) {
/*
* Defrag failed, so free the mbuf and
* therefore drop the packet.
*/
m_freem(m_head);
return (EMSGSIZE);
}
m_head = m;
}
/* Determine how many fragments now exist */
nfrags = xn_count_frags(m_head);
/*
* Check to see whether the defragmented packet has too many
* segments for the Linux netback driver.
*/
/**
* The FreeBSD TCP stack, with TSO enabled, can produce a chain
* of mbufs longer than Linux can handle. Make sure we don't
* pass a too-long chain over to the other side by dropping the
* packet. It doesn't look like there is currently a way to
* tell the TCP stack to generate a shorter chain of packets.
*/
if (nfrags > MAX_TX_REQ_FRAGS) {
#ifdef DEBUG
printf("%s: nfrags %d > MAX_TX_REQ_FRAGS %d, netback "
"won't be able to handle it, dropping\n",
__func__, nfrags, MAX_TX_REQ_FRAGS);
#endif
m_freem(m_head);
return (EMSGSIZE);
}
/*
* This check should be redundant. We've already verified that we
* have enough slots in the ring to handle a packet of maximum
* size, and that our packet is less than the maximum size. Keep
* it in here as an assert for now just to make certain that
* xn_tx_chain_cnt is accurate.
*/
KASSERT((sc->xn_cdata.xn_tx_chain_cnt + nfrags) <= NET_TX_RING_SIZE,
("%s: xn_tx_chain_cnt (%d) + nfrags (%d) > NET_TX_RING_SIZE "
"(%d)!", __func__, (int) sc->xn_cdata.xn_tx_chain_cnt,
(int) nfrags, (int) NET_TX_RING_SIZE));
/*
* Start packing the mbufs in this chain into
* the fragment pointers. Stop when we run out
* of fragments or hit the end of the mbuf chain.
*/
m = m_head;
extra = NULL;
otherend_id = xenbus_get_otherend_id(sc->xbdev);
for (m = m_head; m; m = m->m_next) {
netif_tx_request_t *tx;
uintptr_t id;
grant_ref_t ref;
u_long mfn; /* XXX Wrong type? */
tx = RING_GET_REQUEST(&sc->tx, sc->tx.req_prod_pvt);
id = get_id_from_freelist(sc->tx_mbufs);
if (id == 0)
panic("%s: was allocated the freelist head!\n",
__func__);
sc->xn_cdata.xn_tx_chain_cnt++;
if (sc->xn_cdata.xn_tx_chain_cnt > NET_TX_RING_SIZE)
panic("%s: tx_chain_cnt must be <= NET_TX_RING_SIZE\n",
__func__);
sc->tx_mbufs[id] = m;
tx->id = id;
ref = gnttab_claim_grant_reference(&sc->gref_tx_head);
KASSERT((short)ref >= 0, ("Negative ref"));
mfn = virt_to_mfn(mtod(m, vm_offset_t));
gnttab_grant_foreign_access_ref(ref, otherend_id,
mfn, GNTMAP_readonly);
tx->gref = sc->grant_tx_ref[id] = ref;
tx->offset = mtod(m, vm_offset_t) & (PAGE_SIZE - 1);
tx->flags = 0;
if (m == m_head) {
/*
* The first fragment has the entire packet
* size, subsequent fragments have just the
* fragment size. The backend works out the
* true size of the first fragment by
* subtracting the sizes of the other
* fragments.
*/
tx->size = m->m_pkthdr.len;
/*
* The first fragment contains the checksum flags
* and is optionally followed by extra data for
* TSO etc.
*/
/**
* CSUM_TSO requires checksum offloading.
* Some versions of FreeBSD fail to
* set CSUM_TCP in the CSUM_TSO case,
* so we have to test for CSUM_TSO
* explicitly.
*/
if (m->m_pkthdr.csum_flags
& (CSUM_DELAY_DATA | CSUM_TSO)) {
tx->flags |= (NETTXF_csum_blank
| NETTXF_data_validated);
}
#if __FreeBSD_version >= 700000
if (m->m_pkthdr.csum_flags & CSUM_TSO) {
struct netif_extra_info *gso =
(struct netif_extra_info *)
RING_GET_REQUEST(&sc->tx,
++sc->tx.req_prod_pvt);
tx->flags |= NETTXF_extra_info;
gso->u.gso.size = m->m_pkthdr.tso_segsz;
gso->u.gso.type =
XEN_NETIF_GSO_TYPE_TCPV4;
gso->u.gso.pad = 0;
gso->u.gso.features = 0;
gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
gso->flags = 0;
}
#endif
} else {
tx->size = m->m_len;
}
if (m->m_next)
tx->flags |= NETTXF_more_data;
sc->tx.req_prod_pvt++;
}
BPF_MTAP(ifp, m_head);
sc->stats.tx_bytes += m_head->m_pkthdr.len;
sc->stats.tx_packets++;
return (0);
}
static void
xn_start_locked(struct ifnet *ifp)
{
struct netfront_info *sc;
struct mbuf *m_head;
int notify;
sc = ifp->if_softc;
if (!netfront_carrier_ok(sc))
return;
/*
* While we have enough transmit slots available for at least one
* maximum-sized packet, pull mbufs off the queue and put them on
* the transmit ring.
*/
while (xn_tx_slot_available(sc)) {
IF_DEQUEUE(&ifp->if_snd, m_head);
if (m_head == NULL)
break;
if (xn_assemble_tx_request(sc, m_head) != 0)
break;
}
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&sc->tx, notify);
if (notify)
xen_intr_signal(sc->xen_intr_handle);
if (RING_FULL(&sc->tx)) {
sc->tx_full = 1;
#if 0
netif_stop_queue(dev);
#endif
}
}
static void
xn_start(struct ifnet *ifp)
{
struct netfront_info *sc;
sc = ifp->if_softc;
XN_TX_LOCK(sc);
xn_start_locked(ifp);
XN_TX_UNLOCK(sc);
}
/* equivalent of network_open() in Linux */
static void
xn_ifinit_locked(struct netfront_info *sc)
{
struct ifnet *ifp;
XN_LOCK_ASSERT(sc);
ifp = sc->xn_ifp;
if (ifp->if_drv_flags & IFF_DRV_RUNNING)
return;
xn_stop(sc);
network_alloc_rx_buffers(sc);
sc->rx.sring->rsp_event = sc->rx.rsp_cons + 1;
ifp->if_drv_flags |= IFF_DRV_RUNNING;
ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
if_link_state_change(ifp, LINK_STATE_UP);
callout_reset(&sc->xn_stat_ch, hz, xn_tick, sc);
}
static void
xn_ifinit(void *xsc)
{
struct netfront_info *sc = xsc;
XN_LOCK(sc);
xn_ifinit_locked(sc);
XN_UNLOCK(sc);
}
static int
xn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
struct netfront_info *sc = ifp->if_softc;
struct ifreq *ifr = (struct ifreq *) data;
#ifdef INET
struct ifaddr *ifa = (struct ifaddr *)data;
#endif
int mask, error = 0;
switch(cmd) {
case SIOCSIFADDR:
case SIOCGIFADDR:
#ifdef INET
XN_LOCK(sc);
if (ifa->ifa_addr->sa_family == AF_INET) {
ifp->if_flags |= IFF_UP;
if (!(ifp->if_drv_flags & IFF_DRV_RUNNING))
xn_ifinit_locked(sc);
arp_ifinit(ifp, ifa);
XN_UNLOCK(sc);
} else {
XN_UNLOCK(sc);
#endif
error = ether_ioctl(ifp, cmd, data);
#ifdef INET
}
#endif
break;
case SIOCSIFMTU:
/* XXX can we alter the MTU on a VN ?*/
#ifdef notyet
if (ifr->ifr_mtu > XN_JUMBO_MTU)
error = EINVAL;
else
#endif
{
ifp->if_mtu = ifr->ifr_mtu;
ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
xn_ifinit(sc);
}
break;
case SIOCSIFFLAGS:
XN_LOCK(sc);
if (ifp->if_flags & IFF_UP) {
/*
* If only the state of the PROMISC flag changed,
* then just use the 'set promisc mode' command
* instead of reinitializing the entire NIC. Doing
* a full re-init means reloading the firmware and
* waiting for it to start up, which may take a
* second or two.
*/
#ifdef notyet
/* No promiscuous mode with Xen */
if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
ifp->if_flags & IFF_PROMISC &&
!(sc->xn_if_flags & IFF_PROMISC)) {
XN_SETBIT(sc, XN_RX_MODE,
XN_RXMODE_RX_PROMISC);
} else if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
!(ifp->if_flags & IFF_PROMISC) &&
sc->xn_if_flags & IFF_PROMISC) {
XN_CLRBIT(sc, XN_RX_MODE,
XN_RXMODE_RX_PROMISC);
} else
#endif
xn_ifinit_locked(sc);
} else {
if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
xn_stop(sc);
}
}
sc->xn_if_flags = ifp->if_flags;
XN_UNLOCK(sc);
error = 0;
break;
case SIOCSIFCAP:
mask = ifr->ifr_reqcap ^ ifp->if_capenable;
if (mask & IFCAP_TXCSUM) {
if (IFCAP_TXCSUM & ifp->if_capenable) {
ifp->if_capenable &= ~(IFCAP_TXCSUM|IFCAP_TSO4);
ifp->if_hwassist &= ~(CSUM_TCP | CSUM_UDP
| CSUM_IP | CSUM_TSO);
} else {
ifp->if_capenable |= IFCAP_TXCSUM;
ifp->if_hwassist |= (CSUM_TCP | CSUM_UDP
| CSUM_IP);
}
}
if (mask & IFCAP_RXCSUM) {
ifp->if_capenable ^= IFCAP_RXCSUM;
}
#if __FreeBSD_version >= 700000
if (mask & IFCAP_TSO4) {
if (IFCAP_TSO4 & ifp->if_capenable) {
ifp->if_capenable &= ~IFCAP_TSO4;
ifp->if_hwassist &= ~CSUM_TSO;
} else if (IFCAP_TXCSUM & ifp->if_capenable) {
ifp->if_capenable |= IFCAP_TSO4;
ifp->if_hwassist |= CSUM_TSO;
} else {
IPRINTK("Xen requires tx checksum offload"
" be enabled to use TSO\n");
error = EINVAL;
}
}
if (mask & IFCAP_LRO) {
ifp->if_capenable ^= IFCAP_LRO;
}
#endif
error = 0;
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
#ifdef notyet
if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
XN_LOCK(sc);
xn_setmulti(sc);
XN_UNLOCK(sc);
error = 0;
}
#endif
/* FALLTHROUGH */
case SIOCSIFMEDIA:
case SIOCGIFMEDIA:
error = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd);
break;
default:
error = ether_ioctl(ifp, cmd, data);
}
return (error);
}
static void
xn_stop(struct netfront_info *sc)
{
struct ifnet *ifp;
XN_LOCK_ASSERT(sc);
ifp = sc->xn_ifp;
callout_stop(&sc->xn_stat_ch);
xn_free_rx_ring(sc);
xn_free_tx_ring(sc);
ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
if_link_state_change(ifp, LINK_STATE_DOWN);
}
/* START of Xenolinux helper functions adapted to FreeBSD */
int
network_connect(struct netfront_info *np)
{
int i, requeue_idx, error;
grant_ref_t ref;
netif_rx_request_t *req;
u_int feature_rx_copy, feature_rx_flip;
error = xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev),
"feature-rx-copy", NULL, "%u", &feature_rx_copy);
if (error)
feature_rx_copy = 0;
error = xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev),
"feature-rx-flip", NULL, "%u", &feature_rx_flip);
if (error)
feature_rx_flip = 1;
/*
* Copy packets on receive path if:
* (a) This was requested by user, and the backend supports it; or
* (b) Flipping was requested, but this is unsupported by the backend.
*/
np->copying_receiver = ((MODPARM_rx_copy && feature_rx_copy) ||
(MODPARM_rx_flip && !feature_rx_flip));
/* Recovery procedure: */
error = talk_to_backend(np->xbdev, np);
if (error)
return (error);
/* Step 1: Reinitialise variables. */
xn_query_features(np);
xn_configure_features(np);
netif_release_tx_bufs(np);
/* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
struct mbuf *m;
u_long pfn;
if (np->rx_mbufs[i] == NULL)
continue;
m = np->rx_mbufs[requeue_idx] = xennet_get_rx_mbuf(np, i);
ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
req = RING_GET_REQUEST(&np->rx, requeue_idx);
pfn = vtophys(mtod(m, vm_offset_t)) >> PAGE_SHIFT;
if (!np->copying_receiver) {
gnttab_grant_foreign_transfer_ref(ref,
xenbus_get_otherend_id(np->xbdev),
pfn);
} else {
gnttab_grant_foreign_access_ref(ref,
xenbus_get_otherend_id(np->xbdev),
PFNTOMFN(pfn), 0);
}
req->gref = ref;
req->id = requeue_idx;
requeue_idx++;
}
np->rx.req_prod_pvt = requeue_idx;
/* Step 3: All public and private state should now be sane. Get
* ready to start sending and receiving packets and give the driver
* domain a kick because we've probably just requeued some
* packets.
*/
netfront_carrier_on(np);
xen_intr_signal(np->xen_intr_handle);
XN_TX_LOCK(np);
xn_txeof(np);
XN_TX_UNLOCK(np);
network_alloc_rx_buffers(np);
return (0);
}
static void
xn_query_features(struct netfront_info *np)
{
int val;
device_printf(np->xbdev, "backend features:");
if (xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev),
"feature-sg", NULL, "%d", &val) < 0)
val = 0;
np->maxfrags = 1;
if (val) {
np->maxfrags = MAX_TX_REQ_FRAGS;
printf(" feature-sg");
}
if (xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev),
"feature-gso-tcpv4", NULL, "%d", &val) < 0)
val = 0;
np->xn_ifp->if_capabilities &= ~(IFCAP_TSO4|IFCAP_LRO);
if (val) {
np->xn_ifp->if_capabilities |= IFCAP_TSO4|IFCAP_LRO;
printf(" feature-gso-tcp4");
}
printf("\n");
}
static int
xn_configure_features(struct netfront_info *np)
{
int err;
err = 0;
#if __FreeBSD_version >= 700000 && (defined(INET) || defined(INET6))
if ((np->xn_ifp->if_capenable & IFCAP_LRO) != 0)
tcp_lro_free(&np->xn_lro);
#endif
np->xn_ifp->if_capenable =
np->xn_ifp->if_capabilities & ~(IFCAP_LRO|IFCAP_TSO4);
np->xn_ifp->if_hwassist &= ~CSUM_TSO;
#if __FreeBSD_version >= 700000 && (defined(INET) || defined(INET6))
if (xn_enable_lro && (np->xn_ifp->if_capabilities & IFCAP_LRO) != 0) {
err = tcp_lro_init(&np->xn_lro);
if (err) {
device_printf(np->xbdev, "LRO initialization failed\n");
} else {
np->xn_lro.ifp = np->xn_ifp;
np->xn_ifp->if_capenable |= IFCAP_LRO;
}
}
if ((np->xn_ifp->if_capabilities & IFCAP_TSO4) != 0) {
np->xn_ifp->if_capenable |= IFCAP_TSO4;
np->xn_ifp->if_hwassist |= CSUM_TSO;
}
#endif
return (err);
}
/**
* Create a network device.
* @param dev Newbus device representing this virtual NIC.
*/
int
create_netdev(device_t dev)
{
int i;
struct netfront_info *np;
int err;
struct ifnet *ifp;
np = device_get_softc(dev);
np->xbdev = dev;
XN_LOCK_INIT(np, xennetif);
ifmedia_init(&np->sc_media, 0, xn_ifmedia_upd, xn_ifmedia_sts);
ifmedia_add(&np->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
ifmedia_set(&np->sc_media, IFM_ETHER|IFM_MANUAL);
np->rx_target = RX_MIN_TARGET;
np->rx_min_target = RX_MIN_TARGET;
np->rx_max_target = RX_MAX_TARGET;
/* Initialise {tx,rx}_skbs to be a free chain containing every entry. */
for (i = 0; i <= NET_TX_RING_SIZE; i++) {
np->tx_mbufs[i] = (void *) ((u_long) i+1);
np->grant_tx_ref[i] = GRANT_REF_INVALID;
}
np->tx_mbufs[NET_TX_RING_SIZE] = (void *)0;
for (i = 0; i <= NET_RX_RING_SIZE; i++) {
np->rx_mbufs[i] = NULL;
np->grant_rx_ref[i] = GRANT_REF_INVALID;
}
/* A grant for every tx ring slot */
if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
&np->gref_tx_head) != 0) {
IPRINTK("#### netfront can't alloc tx grant refs\n");
err = ENOMEM;
goto exit;
}
/* A grant for every rx ring slot */
if (gnttab_alloc_grant_references(RX_MAX_TARGET,
&np->gref_rx_head) != 0) {
WPRINTK("#### netfront can't alloc rx grant refs\n");
gnttab_free_grant_references(np->gref_tx_head);
err = ENOMEM;
goto exit;
}
err = xen_net_read_mac(dev, np->mac);
if (err)
goto out;
/* Set up ifnet structure */
ifp = np->xn_ifp = if_alloc(IFT_ETHER);
ifp->if_softc = np;
if_initname(ifp, "xn", device_get_unit(dev));
ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
ifp->if_ioctl = xn_ioctl;
ifp->if_output = ether_output;
ifp->if_start = xn_start;
#ifdef notyet
ifp->if_watchdog = xn_watchdog;
#endif
ifp->if_init = xn_ifinit;
ifp->if_snd.ifq_maxlen = NET_TX_RING_SIZE - 1;
ifp->if_hwassist = XN_CSUM_FEATURES;
ifp->if_capabilities = IFCAP_HWCSUM;
ifp->if_hw_tsomax = NF_TSO_MAXBURST;
ether_ifattach(ifp, np->mac);
callout_init(&np->xn_stat_ch, CALLOUT_MPSAFE);
netfront_carrier_off(np);
return (0);
exit:
gnttab_free_grant_references(np->gref_tx_head);
out:
return (err);
}
/**
* Handle the change of state of the backend to Closing. We must delete our
* device-layer structures now, to ensure that writes are flushed through to
* the backend. Once is this done, we can switch to Closed in
* acknowledgement.
*/
#if 0
static void
netfront_closing(device_t dev)
{
#if 0
struct netfront_info *info = dev->dev_driver_data;
DPRINTK("netfront_closing: %s removed\n", dev->nodename);
close_netdev(info);
#endif
xenbus_switch_state(dev, XenbusStateClosed);
}
#endif
static int
netfront_detach(device_t dev)
{
struct netfront_info *info = device_get_softc(dev);
DPRINTK("%s\n", xenbus_get_node(dev));
netif_free(info);
return 0;
}
static void
netif_free(struct netfront_info *info)
{
XN_LOCK(info);
xn_stop(info);
XN_UNLOCK(info);
callout_drain(&info->xn_stat_ch);
netif_disconnect_backend(info);
if (info->xn_ifp != NULL) {
ether_ifdetach(info->xn_ifp);
if_free(info->xn_ifp);
info->xn_ifp = NULL;
}
ifmedia_removeall(&info->sc_media);
}
static void
netif_disconnect_backend(struct netfront_info *info)
{
XN_RX_LOCK(info);
XN_TX_LOCK(info);
netfront_carrier_off(info);
XN_TX_UNLOCK(info);
XN_RX_UNLOCK(info);
free_ring(&info->tx_ring_ref, &info->tx.sring);
free_ring(&info->rx_ring_ref, &info->rx.sring);
xen_intr_unbind(&info->xen_intr_handle);
}
static void
free_ring(int *ref, void *ring_ptr_ref)
{
void **ring_ptr_ptr = ring_ptr_ref;
if (*ref != GRANT_REF_INVALID) {
/* This API frees the associated storage. */
gnttab_end_foreign_access(*ref, *ring_ptr_ptr);
*ref = GRANT_REF_INVALID;
}
*ring_ptr_ptr = NULL;
}
static int
xn_ifmedia_upd(struct ifnet *ifp)
{
return (0);
}
static void
xn_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
{
ifmr->ifm_status = IFM_AVALID|IFM_ACTIVE;
ifmr->ifm_active = IFM_ETHER|IFM_MANUAL;
}
/* ** Driver registration ** */
static device_method_t netfront_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, netfront_probe),
DEVMETHOD(device_attach, netfront_attach),
DEVMETHOD(device_detach, netfront_detach),
DEVMETHOD(device_shutdown, bus_generic_shutdown),
DEVMETHOD(device_suspend, netfront_suspend),
DEVMETHOD(device_resume, netfront_resume),
/* Xenbus interface */
DEVMETHOD(xenbus_otherend_changed, netfront_backend_changed),
DEVMETHOD_END
};
static driver_t netfront_driver = {
"xn",
netfront_methods,
sizeof(struct netfront_info),
};
devclass_t netfront_devclass;
DRIVER_MODULE(xe, xenbusb_front, netfront_driver, netfront_devclass, NULL,
NULL);
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