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opnsense-src/sys/dev/netmap/netmap_kloop.c

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/*
* Copyright (C) 2016-2018 Vincenzo Maffione
* Copyright (C) 2015 Stefano Garzarella
* 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.
*
* $FreeBSD$
*/
/*
* common headers
*/
#if defined(__FreeBSD__)
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/types.h>
#include <sys/selinfo.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_var.h>
#include <machine/bus.h>
#define usleep_range(_1, _2) \
pause_sbt("sync-kloop-sleep", SBT_1US * _1, SBT_1US * 1, C_ABSOLUTE)
#elif defined(linux)
#include <bsd_glue.h>
#include <linux/file.h>
#include <linux/eventfd.h>
#endif
#include <net/netmap.h>
#include <dev/netmap/netmap_kern.h>
#include <net/netmap_virt.h>
#include <dev/netmap/netmap_mem2.h>
/* Support for eventfd-based notifications. */
#if defined(linux)
#define SYNC_KLOOP_POLL
#endif
/* Write kring pointers (hwcur, hwtail) to the CSB.
* This routine is coupled with ptnetmap_guest_read_kring_csb(). */
static inline void
sync_kloop_kernel_write(struct nm_csb_ktoa __user *ptr, uint32_t hwcur,
uint32_t hwtail)
{
/* Issue a first store-store barrier to make sure writes to the
* netmap ring do not overcome updates on ktoa->hwcur and ktoa->hwtail. */
nm_stst_barrier();
/*
* The same scheme used in nm_sync_kloop_appl_write() applies here.
* We allow the application to read a value of hwcur more recent than the value
* of hwtail, since this would anyway result in a consistent view of the
* ring state (and hwcur can never wraparound hwtail, since hwcur must be
* behind head).
*
* The following memory barrier scheme is used to make this happen:
*
* Application Kernel
*
* STORE(hwcur) LOAD(hwtail)
* wmb() <-------------> rmb()
* STORE(hwtail) LOAD(hwcur)
*/
CSB_WRITE(ptr, hwcur, hwcur);
nm_stst_barrier();
CSB_WRITE(ptr, hwtail, hwtail);
}
/* Read kring pointers (head, cur, sync_flags) from the CSB.
* This routine is coupled with ptnetmap_guest_write_kring_csb(). */
static inline void
sync_kloop_kernel_read(struct nm_csb_atok __user *ptr,
struct netmap_ring *shadow_ring,
uint32_t num_slots)
{
/*
* We place a memory barrier to make sure that the update of head never
* overtakes the update of cur.
* (see explanation in sync_kloop_kernel_write).
*/
CSB_READ(ptr, head, shadow_ring->head);
nm_ldld_barrier();
CSB_READ(ptr, cur, shadow_ring->cur);
CSB_READ(ptr, sync_flags, shadow_ring->flags);
/* Make sure that loads from atok->head and atok->cur are not delayed
* after the loads from the netmap ring. */
nm_ldld_barrier();
}
/* Enable or disable application --> kernel kicks. */
static inline void
csb_ktoa_kick_enable(struct nm_csb_ktoa __user *csb_ktoa, uint32_t val)
{
CSB_WRITE(csb_ktoa, kern_need_kick, val);
}
#ifdef SYNC_KLOOP_POLL
/* Are application interrupt enabled or disabled? */
static inline uint32_t
csb_atok_intr_enabled(struct nm_csb_atok __user *csb_atok)
{
uint32_t v;
CSB_READ(csb_atok, appl_need_kick, v);
return v;
}
#endif /* SYNC_KLOOP_POLL */
static inline void
sync_kloop_kring_dump(const char *title, const struct netmap_kring *kring)
{
nm_prinf("%s, kring %s, hwcur %d, rhead %d, "
"rcur %d, rtail %d, hwtail %d",
title, kring->name, kring->nr_hwcur, kring->rhead,
kring->rcur, kring->rtail, kring->nr_hwtail);
}
/* Arguments for netmap_sync_kloop_tx_ring() and
* netmap_sync_kloop_rx_ring().
*/
struct sync_kloop_ring_args {
struct netmap_kring *kring;
struct nm_csb_atok *csb_atok;
struct nm_csb_ktoa *csb_ktoa;
#ifdef SYNC_KLOOP_POLL
struct eventfd_ctx *irq_ctx;
#endif /* SYNC_KLOOP_POLL */
/* Are we busy waiting rather than using a schedule() loop ? */
bool busy_wait;
/* Are we processing in the context of VM exit ? */
bool direct;
};
static void
netmap_sync_kloop_tx_ring(const struct sync_kloop_ring_args *a)
{
struct netmap_kring *kring = a->kring;
struct nm_csb_atok *csb_atok = a->csb_atok;
struct nm_csb_ktoa *csb_ktoa = a->csb_ktoa;
struct netmap_ring shadow_ring; /* shadow copy of the netmap_ring */
bool more_txspace = false;
uint32_t num_slots;
int batch;
if (unlikely(nm_kr_tryget(kring, 1, NULL))) {
return;
}
num_slots = kring->nkr_num_slots;
/* Disable application --> kernel notifications. */
if (!a->direct) {
csb_ktoa_kick_enable(csb_ktoa, 0);
}
/* Copy the application kring pointers from the CSB */
sync_kloop_kernel_read(csb_atok, &shadow_ring, num_slots);
for (;;) {
batch = shadow_ring.head - kring->nr_hwcur;
if (batch < 0)
batch += num_slots;
#ifdef PTN_TX_BATCH_LIM
if (batch > PTN_TX_BATCH_LIM(num_slots)) {
/* If application moves ahead too fast, let's cut the move so
* that we don't exceed our batch limit. */
uint32_t head_lim = kring->nr_hwcur + PTN_TX_BATCH_LIM(num_slots);
if (head_lim >= num_slots)
head_lim -= num_slots;
nm_prdis(1, "batch: %d head: %d head_lim: %d", batch, shadow_ring.head,
head_lim);
shadow_ring.head = head_lim;
batch = PTN_TX_BATCH_LIM(num_slots);
}
#endif /* PTN_TX_BATCH_LIM */
if (nm_kr_txspace(kring) <= (num_slots >> 1)) {
shadow_ring.flags |= NAF_FORCE_RECLAIM;
}
/* Netmap prologue */
shadow_ring.tail = kring->rtail;
if (unlikely(nm_txsync_prologue(kring, &shadow_ring) >= num_slots)) {
/* Reinit ring and enable notifications. */
netmap_ring_reinit(kring);
if (!a->busy_wait) {
csb_ktoa_kick_enable(csb_ktoa, 1);
}
break;
}
if (unlikely(netmap_debug & NM_DEBUG_TXSYNC)) {
sync_kloop_kring_dump("pre txsync", kring);
}
if (unlikely(kring->nm_sync(kring, shadow_ring.flags))) {
if (!a->busy_wait) {
/* Re-enable notifications. */
csb_ktoa_kick_enable(csb_ktoa, 1);
}
nm_prerr("txsync() failed");
break;
}
/*
* Finalize
* Copy kernel hwcur and hwtail into the CSB for the application sync(), and
* do the nm_sync_finalize.
*/
sync_kloop_kernel_write(csb_ktoa, kring->nr_hwcur,
kring->nr_hwtail);
if (kring->rtail != kring->nr_hwtail) {
/* Some more room available in the parent adapter. */
kring->rtail = kring->nr_hwtail;
more_txspace = true;
}
if (unlikely(netmap_debug & NM_DEBUG_TXSYNC)) {
sync_kloop_kring_dump("post txsync", kring);
}
/* Interrupt the application if needed. */
#ifdef SYNC_KLOOP_POLL
if (a->irq_ctx && more_txspace && csb_atok_intr_enabled(csb_atok)) {
/* We could disable kernel --> application kicks here,
* to avoid spurious interrupts. */
eventfd_signal(a->irq_ctx, 1);
more_txspace = false;
}
#endif /* SYNC_KLOOP_POLL */
/* Read CSB to see if there is more work to do. */
sync_kloop_kernel_read(csb_atok, &shadow_ring, num_slots);
if (shadow_ring.head == kring->rhead) {
if (a->busy_wait) {
break;
}
/*
* No more packets to transmit. We enable notifications and
* go to sleep, waiting for a kick from the application when new
* new slots are ready for transmission.
*/
/* Re-enable notifications. */
csb_ktoa_kick_enable(csb_ktoa, 1);
/* Double check, with store-load memory barrier. */
nm_stld_barrier();
sync_kloop_kernel_read(csb_atok, &shadow_ring, num_slots);
if (shadow_ring.head != kring->rhead) {
/* We won the race condition, there are more packets to
* transmit. Disable notifications and do another cycle */
csb_ktoa_kick_enable(csb_ktoa, 0);
continue;
}
break;
}
if (nm_kr_txempty(kring)) {
/* No more available TX slots. We stop waiting for a notification
* from the backend (netmap_tx_irq). */
nm_prdis(1, "TX ring");
break;
}
}
nm_kr_put(kring);
#ifdef SYNC_KLOOP_POLL
if (a->irq_ctx && more_txspace && csb_atok_intr_enabled(csb_atok)) {
eventfd_signal(a->irq_ctx, 1);
}
#endif /* SYNC_KLOOP_POLL */
}
/* RX cycle without receive any packets */
#define SYNC_LOOP_RX_DRY_CYCLES_MAX 2
static inline int
sync_kloop_norxslots(struct netmap_kring *kring, uint32_t g_head)
{
return (NM_ACCESS_ONCE(kring->nr_hwtail) == nm_prev(g_head,
kring->nkr_num_slots - 1));
}
static void
netmap_sync_kloop_rx_ring(const struct sync_kloop_ring_args *a)
{
struct netmap_kring *kring = a->kring;
struct nm_csb_atok *csb_atok = a->csb_atok;
struct nm_csb_ktoa *csb_ktoa = a->csb_ktoa;
struct netmap_ring shadow_ring; /* shadow copy of the netmap_ring */
int dry_cycles = 0;
bool some_recvd = false;
uint32_t num_slots;
if (unlikely(nm_kr_tryget(kring, 1, NULL))) {
return;
}
num_slots = kring->nkr_num_slots;
/* Get RX csb_atok and csb_ktoa pointers from the CSB. */
num_slots = kring->nkr_num_slots;
/* Disable notifications. */
if (!a->direct) {
csb_ktoa_kick_enable(csb_ktoa, 0);
}
/* Copy the application kring pointers from the CSB */
sync_kloop_kernel_read(csb_atok, &shadow_ring, num_slots);
for (;;) {
uint32_t hwtail;
/* Netmap prologue */
shadow_ring.tail = kring->rtail;
if (unlikely(nm_rxsync_prologue(kring, &shadow_ring) >= num_slots)) {
/* Reinit ring and enable notifications. */
netmap_ring_reinit(kring);
if (!a->busy_wait) {
csb_ktoa_kick_enable(csb_ktoa, 1);
}
break;
}
if (unlikely(netmap_debug & NM_DEBUG_RXSYNC)) {
sync_kloop_kring_dump("pre rxsync", kring);
}
if (unlikely(kring->nm_sync(kring, shadow_ring.flags))) {
if (!a->busy_wait) {
/* Re-enable notifications. */
csb_ktoa_kick_enable(csb_ktoa, 1);
}
nm_prerr("rxsync() failed");
break;
}
/*
* Finalize
* Copy kernel hwcur and hwtail into the CSB for the application sync()
*/
hwtail = NM_ACCESS_ONCE(kring->nr_hwtail);
sync_kloop_kernel_write(csb_ktoa, kring->nr_hwcur, hwtail);
if (kring->rtail != hwtail) {
kring->rtail = hwtail;
some_recvd = true;
dry_cycles = 0;
} else {
dry_cycles++;
}
if (unlikely(netmap_debug & NM_DEBUG_RXSYNC)) {
sync_kloop_kring_dump("post rxsync", kring);
}
#ifdef SYNC_KLOOP_POLL
/* Interrupt the application if needed. */
if (a->irq_ctx && some_recvd && csb_atok_intr_enabled(csb_atok)) {
/* We could disable kernel --> application kicks here,
* to avoid spurious interrupts. */
eventfd_signal(a->irq_ctx, 1);
some_recvd = false;
}
#endif /* SYNC_KLOOP_POLL */
/* Read CSB to see if there is more work to do. */
sync_kloop_kernel_read(csb_atok, &shadow_ring, num_slots);
if (sync_kloop_norxslots(kring, shadow_ring.head)) {
if (a->busy_wait) {
break;
}
/*
* No more slots available for reception. We enable notification and
* go to sleep, waiting for a kick from the application when new receive
* slots are available.
*/
/* Re-enable notifications. */
csb_ktoa_kick_enable(csb_ktoa, 1);
/* Double check, with store-load memory barrier. */
nm_stld_barrier();
sync_kloop_kernel_read(csb_atok, &shadow_ring, num_slots);
if (!sync_kloop_norxslots(kring, shadow_ring.head)) {
/* We won the race condition, more slots are available. Disable
* notifications and do another cycle. */
csb_ktoa_kick_enable(csb_ktoa, 0);
continue;
}
break;
}
hwtail = NM_ACCESS_ONCE(kring->nr_hwtail);
if (unlikely(hwtail == kring->rhead ||
dry_cycles >= SYNC_LOOP_RX_DRY_CYCLES_MAX)) {
/* No more packets to be read from the backend. We stop and
* wait for a notification from the backend (netmap_rx_irq). */
nm_prdis(1, "nr_hwtail: %d rhead: %d dry_cycles: %d",
hwtail, kring->rhead, dry_cycles);
break;
}
}
nm_kr_put(kring);
#ifdef SYNC_KLOOP_POLL
/* Interrupt the application if needed. */
if (a->irq_ctx && some_recvd && csb_atok_intr_enabled(csb_atok)) {
eventfd_signal(a->irq_ctx, 1);
}
#endif /* SYNC_KLOOP_POLL */
}
#ifdef SYNC_KLOOP_POLL
struct sync_kloop_poll_ctx;
struct sync_kloop_poll_entry {
/* Support for receiving notifications from
* a netmap ring or from the application. */
struct file *filp;
wait_queue_t wait;
wait_queue_head_t *wqh;
/* Support for sending notifications to the application. */
struct eventfd_ctx *irq_ctx;
struct file *irq_filp;
/* Arguments for the ring processing function. Useful
* in case of custom wake-up function. */
struct sync_kloop_ring_args *args;
struct sync_kloop_poll_ctx *parent;
};
struct sync_kloop_poll_ctx {
poll_table wait_table;
unsigned int next_entry;
int (*next_wake_fun)(wait_queue_t *, unsigned, int, void *);
unsigned int num_entries;
unsigned int num_tx_rings;
unsigned int num_rings;
/* First num_tx_rings entries are for the TX kicks.
* Then the RX kicks entries follow. The last two
* entries are for TX irq, and RX irq. */
struct sync_kloop_poll_entry entries[0];
};
static void
sync_kloop_poll_table_queue_proc(struct file *file, wait_queue_head_t *wqh,
poll_table *pt)
{
struct sync_kloop_poll_ctx *poll_ctx =
container_of(pt, struct sync_kloop_poll_ctx, wait_table);
struct sync_kloop_poll_entry *entry = poll_ctx->entries +
poll_ctx->next_entry;
BUG_ON(poll_ctx->next_entry >= poll_ctx->num_entries);
entry->wqh = wqh;
entry->filp = file;
/* Use the default wake up function. */
if (poll_ctx->next_wake_fun == NULL) {
init_waitqueue_entry(&entry->wait, current);
} else {
init_waitqueue_func_entry(&entry->wait,
poll_ctx->next_wake_fun);
}
add_wait_queue(wqh, &entry->wait);
}
static int
sync_kloop_tx_kick_wake_fun(wait_queue_t *wait, unsigned mode,
int wake_flags, void *key)
{
struct sync_kloop_poll_entry *entry =
container_of(wait, struct sync_kloop_poll_entry, wait);
netmap_sync_kloop_tx_ring(entry->args);
return 0;
}
static int
sync_kloop_tx_irq_wake_fun(wait_queue_t *wait, unsigned mode,
int wake_flags, void *key)
{
struct sync_kloop_poll_entry *entry =
container_of(wait, struct sync_kloop_poll_entry, wait);
struct sync_kloop_poll_ctx *poll_ctx = entry->parent;
int i;
for (i = 0; i < poll_ctx->num_tx_rings; i++) {
struct eventfd_ctx *irq_ctx = poll_ctx->entries[i].irq_ctx;
if (irq_ctx) {
eventfd_signal(irq_ctx, 1);
}
}
return 0;
}
static int
sync_kloop_rx_kick_wake_fun(wait_queue_t *wait, unsigned mode,
int wake_flags, void *key)
{
struct sync_kloop_poll_entry *entry =
container_of(wait, struct sync_kloop_poll_entry, wait);
netmap_sync_kloop_rx_ring(entry->args);
return 0;
}
static int
sync_kloop_rx_irq_wake_fun(wait_queue_t *wait, unsigned mode,
int wake_flags, void *key)
{
struct sync_kloop_poll_entry *entry =
container_of(wait, struct sync_kloop_poll_entry, wait);
struct sync_kloop_poll_ctx *poll_ctx = entry->parent;
int i;
for (i = poll_ctx->num_tx_rings; i < poll_ctx->num_rings; i++) {
struct eventfd_ctx *irq_ctx = poll_ctx->entries[i].irq_ctx;
if (irq_ctx) {
eventfd_signal(irq_ctx, 1);
}
}
return 0;
}
#endif /* SYNC_KLOOP_POLL */
int
netmap_sync_kloop(struct netmap_priv_d *priv, struct nmreq_header *hdr)
{
struct nmreq_sync_kloop_start *req =
(struct nmreq_sync_kloop_start *)(uintptr_t)hdr->nr_body;
struct nmreq_opt_sync_kloop_eventfds *eventfds_opt = NULL;
#ifdef SYNC_KLOOP_POLL
struct sync_kloop_poll_ctx *poll_ctx = NULL;
#endif /* SYNC_KLOOP_POLL */
int num_rx_rings, num_tx_rings, num_rings;
struct sync_kloop_ring_args *args = NULL;
uint32_t sleep_us = req->sleep_us;
struct nm_csb_atok* csb_atok_base;
struct nm_csb_ktoa* csb_ktoa_base;
struct netmap_adapter *na;
struct nmreq_option *opt;
bool na_could_sleep = false;
bool busy_wait = true;
bool direct_tx = false;
bool direct_rx = false;
int err = 0;
int i;
if (sleep_us > 1000000) {
/* We do not accept sleeping for more than a second. */
return EINVAL;
}
if (priv->np_nifp == NULL) {
return ENXIO;
}
mb(); /* make sure following reads are not from cache */
na = priv->np_na;
if (!nm_netmap_on(na)) {
return ENXIO;
}
NMG_LOCK();
/* Make sure the application is working in CSB mode. */
if (!priv->np_csb_atok_base || !priv->np_csb_ktoa_base) {
NMG_UNLOCK();
nm_prerr("sync-kloop on %s requires "
"NETMAP_REQ_OPT_CSB option", na->name);
return EINVAL;
}
csb_atok_base = priv->np_csb_atok_base;
csb_ktoa_base = priv->np_csb_ktoa_base;
/* Make sure that no kloop is currently running. */
if (priv->np_kloop_state & NM_SYNC_KLOOP_RUNNING) {
err = EBUSY;
}
priv->np_kloop_state |= NM_SYNC_KLOOP_RUNNING;
NMG_UNLOCK();
if (err) {
return err;
}
num_rx_rings = priv->np_qlast[NR_RX] - priv->np_qfirst[NR_RX];
num_tx_rings = priv->np_qlast[NR_TX] - priv->np_qfirst[NR_TX];
num_rings = num_tx_rings + num_rx_rings;
args = nm_os_malloc(num_rings * sizeof(args[0]));
if (!args) {
err = ENOMEM;
goto out;
}
/* Prepare the arguments for netmap_sync_kloop_tx_ring()
* and netmap_sync_kloop_rx_ring(). */
for (i = 0; i < num_tx_rings; i++) {
struct sync_kloop_ring_args *a = args + i;
a->kring = NMR(na, NR_TX)[i + priv->np_qfirst[NR_TX]];
a->csb_atok = csb_atok_base + i;
a->csb_ktoa = csb_ktoa_base + i;
a->busy_wait = busy_wait;
a->direct = direct_tx;
}
for (i = 0; i < num_rx_rings; i++) {
struct sync_kloop_ring_args *a = args + num_tx_rings + i;
a->kring = NMR(na, NR_RX)[i + priv->np_qfirst[NR_RX]];
a->csb_atok = csb_atok_base + num_tx_rings + i;
a->csb_ktoa = csb_ktoa_base + num_tx_rings + i;
a->busy_wait = busy_wait;
a->direct = direct_rx;
}
/* Validate notification options. */
opt = nmreq_getoption(hdr, NETMAP_REQ_OPT_SYNC_KLOOP_MODE);
if (opt != NULL) {
struct nmreq_opt_sync_kloop_mode *mode_opt =
(struct nmreq_opt_sync_kloop_mode *)opt;
direct_tx = !!(mode_opt->mode & NM_OPT_SYNC_KLOOP_DIRECT_TX);
direct_rx = !!(mode_opt->mode & NM_OPT_SYNC_KLOOP_DIRECT_RX);
if (mode_opt->mode & ~(NM_OPT_SYNC_KLOOP_DIRECT_TX |
NM_OPT_SYNC_KLOOP_DIRECT_RX)) {
opt->nro_status = err = EINVAL;
goto out;
}
opt->nro_status = 0;
}
opt = nmreq_getoption(hdr, NETMAP_REQ_OPT_SYNC_KLOOP_EVENTFDS);
if (opt != NULL) {
if (opt->nro_size != sizeof(*eventfds_opt) +
sizeof(eventfds_opt->eventfds[0]) * num_rings) {
/* Option size not consistent with the number of
* entries. */
opt->nro_status = err = EINVAL;
goto out;
}
#ifdef SYNC_KLOOP_POLL
eventfds_opt = (struct nmreq_opt_sync_kloop_eventfds *)opt;
opt->nro_status = 0;
/* Check if some ioeventfd entry is not defined, and force sleep
* synchronization in that case. */
busy_wait = false;
for (i = 0; i < num_rings; i++) {
if (eventfds_opt->eventfds[i].ioeventfd < 0) {
busy_wait = true;
break;
}
}
if (busy_wait && (direct_tx || direct_rx)) {
/* For direct processing we need all the
* ioeventfds to be valid. */
opt->nro_status = err = EINVAL;
goto out;
}
/* We need 2 poll entries for TX and RX notifications coming
* from the netmap adapter, plus one entries per ring for the
* notifications coming from the application. */
poll_ctx = nm_os_malloc(sizeof(*poll_ctx) +
(num_rings + 2) * sizeof(poll_ctx->entries[0]));
init_poll_funcptr(&poll_ctx->wait_table,
sync_kloop_poll_table_queue_proc);
poll_ctx->num_entries = 2 + num_rings;
poll_ctx->num_tx_rings = num_tx_rings;
poll_ctx->num_rings = num_rings;
poll_ctx->next_entry = 0;
poll_ctx->next_wake_fun = NULL;
if (direct_tx && (na->na_flags & NAF_BDG_MAYSLEEP)) {
/* In direct mode, VALE txsync is called from
* wake-up context, where it is not possible
* to sleep.
*/
na->na_flags &= ~NAF_BDG_MAYSLEEP;
na_could_sleep = true;
}
for (i = 0; i < num_rings + 2; i++) {
poll_ctx->entries[i].args = args + i;
poll_ctx->entries[i].parent = poll_ctx;
}
/* Poll for notifications coming from the applications through
* eventfds. */
for (i = 0; i < num_rings; i++, poll_ctx->next_entry++) {
struct eventfd_ctx *irq = NULL;
struct file *filp = NULL;
unsigned long mask;
bool tx_ring = (i < num_tx_rings);
if (eventfds_opt->eventfds[i].irqfd >= 0) {
filp = eventfd_fget(
eventfds_opt->eventfds[i].irqfd);
if (IS_ERR(filp)) {
err = PTR_ERR(filp);
goto out;
}
irq = eventfd_ctx_fileget(filp);
if (IS_ERR(irq)) {
err = PTR_ERR(irq);
goto out;
}
}
poll_ctx->entries[i].irq_filp = filp;
poll_ctx->entries[i].irq_ctx = irq;
poll_ctx->entries[i].args->busy_wait = busy_wait;
/* Don't let netmap_sync_kloop_*x_ring() use
* IRQs in direct mode. */
poll_ctx->entries[i].args->irq_ctx =
((tx_ring && direct_tx) ||
(!tx_ring && direct_rx)) ? NULL :
poll_ctx->entries[i].irq_ctx;
poll_ctx->entries[i].args->direct =
(tx_ring ? direct_tx : direct_rx);
if (!busy_wait) {
filp = eventfd_fget(
eventfds_opt->eventfds[i].ioeventfd);
if (IS_ERR(filp)) {
err = PTR_ERR(filp);
goto out;
}
if (tx_ring && direct_tx) {
/* Override the wake up function
* so that it can directly call
* netmap_sync_kloop_tx_ring().
*/
poll_ctx->next_wake_fun =
sync_kloop_tx_kick_wake_fun;
} else if (!tx_ring && direct_rx) {
/* Same for direct RX. */
poll_ctx->next_wake_fun =
sync_kloop_rx_kick_wake_fun;
} else {
poll_ctx->next_wake_fun = NULL;
}
mask = filp->f_op->poll(filp,
&poll_ctx->wait_table);
if (mask & POLLERR) {
err = EINVAL;
goto out;
}
}
}
/* Poll for notifications coming from the netmap rings bound to
* this file descriptor. */
if (!busy_wait) {
NMG_LOCK();
/* In direct mode, override the wake up function so
* that it can forward the netmap_tx_irq() to the
* guest. */
poll_ctx->next_wake_fun = direct_tx ?
sync_kloop_tx_irq_wake_fun : NULL;
poll_wait(priv->np_filp, priv->np_si[NR_TX],
&poll_ctx->wait_table);
poll_ctx->next_entry++;
poll_ctx->next_wake_fun = direct_rx ?
sync_kloop_rx_irq_wake_fun : NULL;
poll_wait(priv->np_filp, priv->np_si[NR_RX],
&poll_ctx->wait_table);
poll_ctx->next_entry++;
NMG_UNLOCK();
}
#else /* SYNC_KLOOP_POLL */
opt->nro_status = EOPNOTSUPP;
goto out;
#endif /* SYNC_KLOOP_POLL */
}
nm_prinf("kloop busy_wait %u, direct_tx %u, direct_rx %u, "
"na_could_sleep %u", busy_wait, direct_tx, direct_rx,
na_could_sleep);
/* Main loop. */
for (;;) {
if (unlikely(NM_ACCESS_ONCE(priv->np_kloop_state) & NM_SYNC_KLOOP_STOPPING)) {
break;
}
#ifdef SYNC_KLOOP_POLL
if (!busy_wait) {
/* It is important to set the task state as
* interruptible before processing any TX/RX ring,
* so that if a notification on ring Y comes after
* we have processed ring Y, but before we call
* schedule(), we don't miss it. This is true because
* the wake up function will change the task state,
* and therefore the schedule_timeout() call below
* will observe the change).
*/
set_current_state(TASK_INTERRUPTIBLE);
}
#endif /* SYNC_KLOOP_POLL */
/* Process all the TX rings bound to this file descriptor. */
for (i = 0; !direct_tx && i < num_tx_rings; i++) {
struct sync_kloop_ring_args *a = args + i;
netmap_sync_kloop_tx_ring(a);
}
/* Process all the RX rings bound to this file descriptor. */
for (i = 0; !direct_rx && i < num_rx_rings; i++) {
struct sync_kloop_ring_args *a = args + num_tx_rings + i;
netmap_sync_kloop_rx_ring(a);
}
if (busy_wait) {
/* Default synchronization method: sleep for a while. */
usleep_range(sleep_us, sleep_us);
}
#ifdef SYNC_KLOOP_POLL
else {
/* Yield to the scheduler waiting for a notification
* to come either from netmap or the application. */
schedule_timeout(msecs_to_jiffies(3000));
}
#endif /* SYNC_KLOOP_POLL */
}
out:
#ifdef SYNC_KLOOP_POLL
if (poll_ctx) {
/* Stop polling from netmap and the eventfds, and deallocate
* the poll context. */
if (!busy_wait) {
__set_current_state(TASK_RUNNING);
}
for (i = 0; i < poll_ctx->next_entry; i++) {
struct sync_kloop_poll_entry *entry =
poll_ctx->entries + i;
if (entry->wqh)
remove_wait_queue(entry->wqh, &entry->wait);
/* We did not get a reference to the eventfds, but
* don't do that on netmap file descriptors (since
* a reference was not taken. */
if (entry->filp && entry->filp != priv->np_filp)
fput(entry->filp);
if (entry->irq_ctx)
eventfd_ctx_put(entry->irq_ctx);
if (entry->irq_filp)
fput(entry->irq_filp);
}
nm_os_free(poll_ctx);
poll_ctx = NULL;
}
#endif /* SYNC_KLOOP_POLL */
if (args) {
nm_os_free(args);
args = NULL;
}
/* Reset the kloop state. */
NMG_LOCK();
priv->np_kloop_state = 0;
if (na_could_sleep) {
na->na_flags |= NAF_BDG_MAYSLEEP;
}
NMG_UNLOCK();
return err;
}
int
netmap_sync_kloop_stop(struct netmap_priv_d *priv)
{
struct netmap_adapter *na;
bool running = true;
int err = 0;
if (priv->np_nifp == NULL) {
return ENXIO;
}
mb(); /* make sure following reads are not from cache */
na = priv->np_na;
if (!nm_netmap_on(na)) {
return ENXIO;
}
/* Set the kloop stopping flag. */
NMG_LOCK();
priv->np_kloop_state |= NM_SYNC_KLOOP_STOPPING;
NMG_UNLOCK();
/* Send a notification to the kloop, in case it is blocked in
* schedule_timeout(). We can use either RX or TX, because the
* kloop is waiting on both. */
nm_os_selwakeup(priv->np_si[NR_RX]);
/* Wait for the kloop to actually terminate. */
while (running) {
usleep_range(1000, 1500);
NMG_LOCK();
running = (NM_ACCESS_ONCE(priv->np_kloop_state)
& NM_SYNC_KLOOP_RUNNING);
NMG_UNLOCK();
}
return err;
}
#ifdef WITH_PTNETMAP
/*
* Guest ptnetmap txsync()/rxsync() routines, used in ptnet device drivers.
* These routines are reused across the different operating systems supported
* by netmap.
*/
/*
* Reconcile host and guest views of the transmit ring.
*
* Guest user wants to transmit packets up to the one before ring->head,
* and guest kernel knows tx_ring->hwcur is the first packet unsent
* by the host kernel.
*
* We push out as many packets as possible, and possibly
* reclaim buffers from previously completed transmission.
*
* Notifications from the host are enabled only if the user guest would
* block (no space in the ring).
*/
bool
netmap_pt_guest_txsync(struct nm_csb_atok *atok, struct nm_csb_ktoa *ktoa,
struct netmap_kring *kring, int flags)
{
bool notify = false;
/* Disable notifications */
atok->appl_need_kick = 0;
/*
* First part: tell the host to process the new packets,
* updating the CSB.
*/
kring->nr_hwcur = ktoa->hwcur;
nm_sync_kloop_appl_write(atok, kring->rcur, kring->rhead);
/* Ask for a kick from a guest to the host if needed. */
if (((kring->rhead != kring->nr_hwcur || nm_kr_wouldblock(kring))
&& NM_ACCESS_ONCE(ktoa->kern_need_kick)) ||
(flags & NAF_FORCE_RECLAIM)) {
atok->sync_flags = flags;
notify = true;
}
/*
* Second part: reclaim buffers for completed transmissions.
*/
if (nm_kr_wouldblock(kring) || (flags & NAF_FORCE_RECLAIM)) {
nm_sync_kloop_appl_read(ktoa, &kring->nr_hwtail,
&kring->nr_hwcur);
}
/*
* No more room in the ring for new transmissions. The user thread will
* go to sleep and we need to be notified by the host when more free
* space is available.
*/
if (nm_kr_wouldblock(kring) && !(kring->nr_kflags & NKR_NOINTR)) {
/* Re-enable notifications. */
atok->appl_need_kick = 1;
/* Double check, with store-load memory barrier. */
nm_stld_barrier();
nm_sync_kloop_appl_read(ktoa, &kring->nr_hwtail,
&kring->nr_hwcur);
/* If there is new free space, disable notifications */
if (unlikely(!nm_kr_wouldblock(kring))) {
atok->appl_need_kick = 0;
}
}
nm_prdis(1, "%s CSB(head:%u cur:%u hwtail:%u) KRING(head:%u cur:%u tail:%u)",
kring->name, atok->head, atok->cur, ktoa->hwtail,
kring->rhead, kring->rcur, kring->nr_hwtail);
return notify;
}
/*
* Reconcile host and guest view of the receive ring.
*
* Update hwcur/hwtail from host (reading from CSB).
*
* If guest user has released buffers up to the one before ring->head, we
* also give them to the host.
*
* Notifications from the host are enabled only if the user guest would
* block (no more completed slots in the ring).
*/
bool
netmap_pt_guest_rxsync(struct nm_csb_atok *atok, struct nm_csb_ktoa *ktoa,
struct netmap_kring *kring, int flags)
{
bool notify = false;
/* Disable notifications */
atok->appl_need_kick = 0;
/*
* First part: import newly received packets, by updating the kring
* hwtail to the hwtail known from the host (read from the CSB).
* This also updates the kring hwcur.
*/
nm_sync_kloop_appl_read(ktoa, &kring->nr_hwtail, &kring->nr_hwcur);
kring->nr_kflags &= ~NKR_PENDINTR;
/*
* Second part: tell the host about the slots that guest user has
* released, by updating cur and head in the CSB.
*/
if (kring->rhead != kring->nr_hwcur) {
nm_sync_kloop_appl_write(atok, kring->rcur, kring->rhead);
}
/*
* No more completed RX slots. The user thread will go to sleep and
* we need to be notified by the host when more RX slots have been
* completed.
*/
if (nm_kr_wouldblock(kring) && !(kring->nr_kflags & NKR_NOINTR)) {
/* Re-enable notifications. */
atok->appl_need_kick = 1;
/* Double check, with store-load memory barrier. */
nm_stld_barrier();
nm_sync_kloop_appl_read(ktoa, &kring->nr_hwtail,
&kring->nr_hwcur);
/* If there are new slots, disable notifications. */
if (!nm_kr_wouldblock(kring)) {
atok->appl_need_kick = 0;
}
}
/* Ask for a kick from the guest to the host if needed. */
if ((kring->rhead != kring->nr_hwcur || nm_kr_wouldblock(kring))
&& NM_ACCESS_ONCE(ktoa->kern_need_kick)) {
atok->sync_flags = flags;
notify = true;
}
nm_prdis(1, "%s CSB(head:%u cur:%u hwtail:%u) KRING(head:%u cur:%u tail:%u)",
kring->name, atok->head, atok->cur, ktoa->hwtail,
kring->rhead, kring->rcur, kring->nr_hwtail);
return notify;
}
/*
* Callbacks for ptnet drivers: nm_krings_create, nm_krings_delete, nm_dtor.
*/
int
ptnet_nm_krings_create(struct netmap_adapter *na)
{
struct netmap_pt_guest_adapter *ptna =
(struct netmap_pt_guest_adapter *)na; /* Upcast. */
struct netmap_adapter *na_nm = &ptna->hwup.up;
struct netmap_adapter *na_dr = &ptna->dr.up;
int ret;
if (ptna->backend_users) {
return 0;
}
/* Create krings on the public netmap adapter. */
ret = netmap_hw_krings_create(na_nm);
if (ret) {
return ret;
}
/* Copy krings into the netmap adapter private to the driver. */
na_dr->tx_rings = na_nm->tx_rings;
na_dr->rx_rings = na_nm->rx_rings;
return 0;
}
void
ptnet_nm_krings_delete(struct netmap_adapter *na)
{
struct netmap_pt_guest_adapter *ptna =
(struct netmap_pt_guest_adapter *)na; /* Upcast. */
struct netmap_adapter *na_nm = &ptna->hwup.up;
struct netmap_adapter *na_dr = &ptna->dr.up;
if (ptna->backend_users) {
return;
}
na_dr->tx_rings = NULL;
na_dr->rx_rings = NULL;
netmap_hw_krings_delete(na_nm);
}
void
ptnet_nm_dtor(struct netmap_adapter *na)
{
struct netmap_pt_guest_adapter *ptna =
(struct netmap_pt_guest_adapter *)na;
netmap_mem_put(ptna->dr.up.nm_mem);
memset(&ptna->dr, 0, sizeof(ptna->dr));
netmap_mem_pt_guest_ifp_del(na->nm_mem, na->ifp);
}
int
netmap_pt_guest_attach(struct netmap_adapter *arg,
unsigned int nifp_offset, unsigned int memid)
{
struct netmap_pt_guest_adapter *ptna;
struct ifnet *ifp = arg ? arg->ifp : NULL;
int error;
/* get allocator */
arg->nm_mem = netmap_mem_pt_guest_new(ifp, nifp_offset, memid);
if (arg->nm_mem == NULL)
return ENOMEM;
arg->na_flags |= NAF_MEM_OWNER;
error = netmap_attach_ext(arg, sizeof(struct netmap_pt_guest_adapter), 1);
if (error)
return error;
/* get the netmap_pt_guest_adapter */
ptna = (struct netmap_pt_guest_adapter *) NA(ifp);
/* Initialize a separate pass-through netmap adapter that is going to
* be used by the ptnet driver only, and so never exposed to netmap
* applications. We only need a subset of the available fields. */
memset(&ptna->dr, 0, sizeof(ptna->dr));
ptna->dr.up.ifp = ifp;
ptna->dr.up.nm_mem = netmap_mem_get(ptna->hwup.up.nm_mem);
ptna->dr.up.nm_config = ptna->hwup.up.nm_config;
ptna->backend_users = 0;
return 0;
}
#endif /* WITH_PTNETMAP */
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