Author: royger
Date: Wed Oct 22 16:57:11 2014
New Revision: 273474
URL: https://svnweb.freebsd.org/changeset/base/273474
Log:
xen: import a proper event channel user-space device
The user-space event channel device is used by applications to receive
and send event channel interrupts. This device is based on the Linux
evtchn device.
Sponsored by: Citrix Systems R&D
xen/evtchn/evtchn_dev.c:
- Remove the old event channel device, which was already disabled in
the build system.
dev/xen/evtchn/evtchn_dev.c:
- Import a new event channel device based on the one present in
Linux.
- This device allows the following operations:
- Bind VIRQ event channels (ioctl).
- Bind regular event channels (ioctl).
- Create and bind new event channels (ioctl).
- Unbind event channels (ioctl).
- Send notifications to event channels (ioctl).
- Reset the device shared memory ring (ioctl).
- Unmask event channels (write).
- Receive event channel upcalls (read).
- The new code is MP safe, and can be used concurrently.
conf/files:
- Add the new device to the build system.
Added:
head/sys/dev/xen/evtchn/
head/sys/dev/xen/evtchn/evtchn_dev.c (contents, props changed)
Deleted:
head/sys/xen/evtchn/evtchn_dev.c
Modified:
head/sys/conf/files
Modified: head/sys/conf/files
==============================================================================
--- head/sys/conf/files Wed Oct 22 16:51:52 2014 (r273473)
+++ head/sys/conf/files Wed Oct 22 16:57:11 2014 (r273474)
@@ -2647,6 +2647,7 @@ dev/xen/pvcpu/pvcpu.c optional xen | xe
dev/xen/xenstore/xenstore.c optional xen | xenhvm
dev/xen/xenstore/xenstore_dev.c optional xen | xenhvm
dev/xen/xenstore/xenstored_dev.c optional xen | xenhvm
+dev/xen/evtchn/evtchn_dev.c optional xen | xenhvm
dev/xl/if_xl.c optional xl pci
dev/xl/xlphy.c optional xl pci
fs/autofs/autofs.c optional autofs
Added: head/sys/dev/xen/evtchn/evtchn_dev.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/sys/dev/xen/evtchn/evtchn_dev.c Wed Oct 22 16:57:11 2014
(r273474)
@@ -0,0 +1,607 @@
+/******************************************************************************
+ * evtchn.c
+ *
+ * Driver for receiving and demuxing event-channel signals.
+ *
+ * Copyright (c) 2004-2005, K A Fraser
+ * Multi-process extensions Copyright (c) 2004, Steven Smith
+ * FreeBSD port Copyright (c) 2014, Roger Pau Monné
+ * Fetched from
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
+ * File: drivers/xen/evtchn.c
+ * Git commit: 0dc0064add422bc0ef5165ebe9ece3052bbd457d
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/uio.h>
+#include <sys/bus.h>
+#include <sys/malloc.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/sx.h>
+#include <sys/selinfo.h>
+#include <sys/poll.h>
+#include <sys/conf.h>
+#include <sys/fcntl.h>
+#include <sys/ioccom.h>
+#include <sys/rman.h>
+#include <sys/tree.h>
+#include <sys/module.h>
+#include <sys/filio.h>
+#include <sys/vnode.h>
+
+#include <machine/intr_machdep.h>
+#include <machine/xen/synch_bitops.h>
+
+#include <xen/xen-os.h>
+#include <xen/evtchn.h>
+#include <xen/xen_intr.h>
+
+#include <xen/evtchn/evtchnvar.h>
+
+MALLOC_DEFINE(M_EVTCHN, "evtchn_dev", "Xen event channel user-space device");
+
+struct user_evtchn;
+
+static int evtchn_cmp(struct user_evtchn *u1, struct user_evtchn *u2);
+
+RB_HEAD(evtchn_tree, user_evtchn);
+
+struct per_user_data {
+ struct mtx bind_mutex; /* serialize bind/unbind operations */
+ struct evtchn_tree evtchns;
+
+ /* Notification ring, accessed via /dev/xen/evtchn. */
+#define EVTCHN_RING_SIZE (PAGE_SIZE / sizeof(evtchn_port_t))
+#define EVTCHN_RING_MASK(_i) ((_i)&(EVTCHN_RING_SIZE-1))
+ evtchn_port_t *ring;
+ unsigned int ring_cons, ring_prod, ring_overflow;
+ struct sx ring_cons_mutex; /* protect against concurrent readers */
+ struct mtx ring_prod_mutex; /* product against concurrent interrupts */
+ struct selinfo ev_rsel;
+};
+
+struct user_evtchn {
+ RB_ENTRY(user_evtchn) node;
+ struct per_user_data *user;
+ evtchn_port_t port;
+ xen_intr_handle_t handle;
+ bool enabled;
+};
+
+RB_GENERATE_STATIC(evtchn_tree, user_evtchn, node, evtchn_cmp);
+
+static device_t evtchn_dev;
+
+static d_read_t evtchn_read;
+static d_write_t evtchn_write;
+static d_ioctl_t evtchn_ioctl;
+static d_poll_t evtchn_poll;
+static d_open_t evtchn_open;
+
+static void evtchn_release(void *arg);
+
+static struct cdevsw evtchn_devsw = {
+ .d_version = D_VERSION,
+ .d_open = evtchn_open,
+ .d_read = evtchn_read,
+ .d_write = evtchn_write,
+ .d_ioctl = evtchn_ioctl,
+ .d_poll = evtchn_poll,
+ .d_name = "evtchn",
+};
+
+/*------------------------- Red-black tree helpers
---------------------------*/
+static int
+evtchn_cmp(struct user_evtchn *u1, struct user_evtchn *u2)
+{
+
+ return (u1->port - u2->port);
+}
+
+static struct user_evtchn *
+find_evtchn(struct per_user_data *u, evtchn_port_t port)
+{
+ struct user_evtchn tmp = {
+ .port = port,
+ };
+
+ return (RB_FIND(evtchn_tree, &u->evtchns, &tmp));
+}
+
+/*--------------------------- Interrupt handlers
-----------------------------*/
+static int
+evtchn_filter(void *arg)
+{
+ struct user_evtchn *evtchn;
+
+ evtchn = arg;
+
+ if (!evtchn->enabled && bootverbose) {
+ device_printf(evtchn_dev,
+ "Received upcall for disabled event channel %d\n",
+ evtchn->port);
+ }
+
+ evtchn_mask_port(evtchn->port);
+ evtchn->enabled = false;
+
+ return (FILTER_SCHEDULE_THREAD);
+}
+
+static void
+evtchn_interrupt(void *arg)
+{
+ struct user_evtchn *evtchn;
+ struct per_user_data *u;
+
+ evtchn = arg;
+ u = evtchn->user;
+
+ /*
+ * Protect against concurrent events using this handler
+ * on different CPUs.
+ */
+ mtx_lock(&u->ring_prod_mutex);
+ if ((u->ring_prod - u->ring_cons) < EVTCHN_RING_SIZE) {
+ u->ring[EVTCHN_RING_MASK(u->ring_prod)] = evtchn->port;
+ wmb(); /* Ensure ring contents visible */
+ if (u->ring_cons == u->ring_prod++) {
+ wakeup(u);
+ selwakeup(&u->ev_rsel);
+ }
+ } else
+ u->ring_overflow = 1;
+ mtx_unlock(&u->ring_prod_mutex);
+}
+
+/*------------------------- Character device methods
-------------------------*/
+static int
+evtchn_open(struct cdev *dev, int flag, int otyp, struct thread *td)
+{
+ struct per_user_data *u;
+ int error;
+
+ u = malloc(sizeof(*u), M_EVTCHN, M_WAITOK | M_ZERO);
+ u->ring = malloc(PAGE_SIZE, M_EVTCHN, M_WAITOK | M_ZERO);
+
+ /* Initialize locks */
+ mtx_init(&u->bind_mutex, "evtchn_bind_mutex", NULL, MTX_DEF);
+ sx_init(&u->ring_cons_mutex, "evtchn_ringc_sx");
+ mtx_init(&u->ring_prod_mutex, "evtchn_ringp_mutex", NULL, MTX_DEF);
+
+ /* Initialize red-black tree. */
+ RB_INIT(&u->evtchns);
+
+ /* Assign the allocated per_user_data to this open instance. */
+ error = devfs_set_cdevpriv(u, evtchn_release);
+ if (error != 0) {
+ mtx_destroy(&u->bind_mutex);
+ mtx_destroy(&u->ring_prod_mutex);
+ sx_destroy(&u->ring_cons_mutex);
+ free(u->ring, M_EVTCHN);
+ free(u, M_EVTCHN);
+ }
+
+ return (error);
+}
+
+static void
+evtchn_release(void *arg)
+{
+ struct per_user_data *u;
+ struct user_evtchn *evtchn, *tmp;
+
+ u = arg;
+
+ seldrain(&u->ev_rsel);
+
+ RB_FOREACH_SAFE(evtchn, evtchn_tree, &u->evtchns, tmp) {
+ xen_intr_unbind(&evtchn->handle);
+
+ RB_REMOVE(evtchn_tree, &u->evtchns, evtchn);
+ free(evtchn, M_EVTCHN);
+ }
+
+ mtx_destroy(&u->bind_mutex);
+ mtx_destroy(&u->ring_prod_mutex);
+ sx_destroy(&u->ring_cons_mutex);
+ free(u->ring, M_EVTCHN);
+ free(u, M_EVTCHN);
+}
+
+static int
+evtchn_read(struct cdev *dev, struct uio *uio, int ioflag)
+{
+ int error, count;
+ unsigned int c, p, bytes1 = 0, bytes2 = 0;
+ struct per_user_data *u;
+
+ error = devfs_get_cdevpriv((void **)&u);
+ if (error != 0)
+ return (EINVAL);
+
+ /* Whole number of ports. */
+ count = uio->uio_resid;
+ count &= ~(sizeof(evtchn_port_t)-1);
+
+ if (count == 0)
+ return (0);
+
+ if (count > PAGE_SIZE)
+ count = PAGE_SIZE;
+
+ sx_xlock(&u->ring_cons_mutex);
+ for (;;) {
+ error = EFBIG;
+ if (u->ring_overflow)
+ goto unlock_out;
+
+ c = u->ring_cons;
+ p = u->ring_prod;
+ if (c != p)
+ break;
+
+ if (ioflag & IO_NDELAY) {
+ sx_xunlock(&u->ring_cons_mutex);
+ return (EWOULDBLOCK);
+ }
+
+ error = sx_sleep(u, &u->ring_cons_mutex, PCATCH, "evtchw", 0);
+ if ((error != 0) && (error != EWOULDBLOCK))
+ return (error);
+ }
+
+ /* Byte lengths of two chunks. Chunk split (if any) is at ring wrap. */
+ if (((c ^ p) & EVTCHN_RING_SIZE) != 0) {
+ bytes1 = (EVTCHN_RING_SIZE - EVTCHN_RING_MASK(c)) *
+ sizeof(evtchn_port_t);
+ bytes2 = EVTCHN_RING_MASK(p) * sizeof(evtchn_port_t);
+ } else {
+ bytes1 = (p - c) * sizeof(evtchn_port_t);
+ bytes2 = 0;
+ }
+
+ /* Truncate chunks according to caller's maximum byte count. */
+ if (bytes1 > count) {
+ bytes1 = count;
+ bytes2 = 0;
+ } else if ((bytes1 + bytes2) > count) {
+ bytes2 = count - bytes1;
+ }
+
+ error = EFAULT;
+ rmb(); /* Ensure that we see the port before we copy it. */
+
+ if (uiomove(&u->ring[EVTCHN_RING_MASK(c)], bytes1, uio) ||
+ ((bytes2 != 0) && uiomove(&u->ring[0], bytes2, uio)))
+ goto unlock_out;
+
+ u->ring_cons += (bytes1 + bytes2) / sizeof(evtchn_port_t);
+ error = 0;
+
+unlock_out:
+ sx_xunlock(&u->ring_cons_mutex);
+ return (error);
+}
+
+static int
+evtchn_write(struct cdev *dev, struct uio *uio, int ioflag)
+{
+ int error, i, count;
+ evtchn_port_t *kbuf;
+ struct per_user_data *u;
+
+ error = devfs_get_cdevpriv((void **)&u);
+ if (error != 0)
+ return (EINVAL);
+
+ kbuf = malloc(PAGE_SIZE, M_EVTCHN, M_WAITOK);
+ if (kbuf == NULL)
+ return (ENOMEM);
+
+ count = uio->uio_resid;
+ /* Whole number of ports. */
+ count &= ~(sizeof(evtchn_port_t)-1);
+
+ error = 0;
+ if (count == 0)
+ goto out;
+
+ if (count > PAGE_SIZE)
+ count = PAGE_SIZE;
+
+ error = uiomove(kbuf, count, uio);
+ if (error != 0)
+ goto out;
+
+ mtx_lock(&u->bind_mutex);
+
+ for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) {
+ evtchn_port_t port = kbuf[i];
+ struct user_evtchn *evtchn;
+
+ evtchn = find_evtchn(u, port);
+ if (evtchn && !evtchn->enabled) {
+ evtchn->enabled = true;
+ evtchn_unmask_port(evtchn->port);
+ }
+ }
+
+ mtx_unlock(&u->bind_mutex);
+ error = 0;
+
+out:
+ free(kbuf, M_EVTCHN);
+ return (error);
+}
+
+static inline int
+evtchn_bind_user_port(struct per_user_data *u, struct user_evtchn *evtchn)
+{
+ int error;
+
+ evtchn->port = xen_intr_port(evtchn->handle);
+ evtchn->user = u;
+ evtchn->enabled = true;
+ mtx_lock(&u->bind_mutex);
+ RB_INSERT(evtchn_tree, &u->evtchns, evtchn);
+ mtx_unlock(&u->bind_mutex);
+ error = xen_intr_add_handler(evtchn_dev, evtchn_filter,
+ evtchn_interrupt, evtchn, INTR_TYPE_MISC | INTR_MPSAFE,
+ evtchn->handle);
+ if (error != 0) {
+ xen_intr_unbind(&evtchn->handle);
+ mtx_lock(&u->bind_mutex);
+ RB_REMOVE(evtchn_tree, &u->evtchns, evtchn);
+ mtx_unlock(&u->bind_mutex);
+ free(evtchn, M_EVTCHN);
+ }
+ return (error);
+}
+
+static int
+evtchn_ioctl(struct cdev *dev, unsigned long cmd, caddr_t arg,
+ int mode, struct thread *td __unused)
+{
+ struct per_user_data *u;
+ int error;
+
+ error = devfs_get_cdevpriv((void **)&u);
+ if (error != 0)
+ return (EINVAL);
+
+ switch (cmd) {
+ case IOCTL_EVTCHN_BIND_VIRQ: {
+ struct ioctl_evtchn_bind_virq *bind;
+ struct user_evtchn *evtchn;
+
+ evtchn = malloc(sizeof(*evtchn), M_EVTCHN, M_WAITOK | M_ZERO);
+
+ bind = (struct ioctl_evtchn_bind_virq *)arg;
+
+ error = xen_intr_bind_virq(evtchn_dev, bind->virq, 0,
+ NULL, NULL, NULL, 0, &evtchn->handle);
+ if (error != 0) {
+ free(evtchn, M_EVTCHN);
+ break;
+ }
+ error = evtchn_bind_user_port(u, evtchn);
+ if (error != 0)
+ break;
+ bind->port = evtchn->port;
+ break;
+ }
+
+ case IOCTL_EVTCHN_BIND_INTERDOMAIN: {
+ struct ioctl_evtchn_bind_interdomain *bind;
+ struct user_evtchn *evtchn;
+
+ evtchn = malloc(sizeof(*evtchn), M_EVTCHN, M_WAITOK | M_ZERO);
+
+ bind = (struct ioctl_evtchn_bind_interdomain *)arg;
+
+ error = xen_intr_bind_remote_port(evtchn_dev,
+ bind->remote_domain, bind->remote_port, NULL,
+ NULL, NULL, 0, &evtchn->handle);
+ if (error != 0) {
+ free(evtchn, M_EVTCHN);
+ break;
+ }
+ error = evtchn_bind_user_port(u, evtchn);
+ if (error != 0)
+ break;
+ bind->port = evtchn->port;
+ break;
+ }
+
+ case IOCTL_EVTCHN_BIND_UNBOUND_PORT: {
+ struct ioctl_evtchn_bind_unbound_port *bind;
+ struct user_evtchn *evtchn;
+
+ evtchn = malloc(sizeof(*evtchn), M_EVTCHN, M_WAITOK | M_ZERO);
+
+ bind = (struct ioctl_evtchn_bind_unbound_port *)arg;
+
+ error = xen_intr_alloc_and_bind_local_port(evtchn_dev,
+ bind->remote_domain, NULL, NULL, NULL, 0, &evtchn->handle);
+ if (error != 0) {
+ free(evtchn, M_EVTCHN);
+ break;
+ }
+ error = evtchn_bind_user_port(u, evtchn);
+ if (error != 0)
+ break;
+ bind->port = evtchn->port;
+ break;
+ }
+
+ case IOCTL_EVTCHN_UNBIND: {
+ struct ioctl_evtchn_unbind *unbind;
+ struct user_evtchn *evtchn;
+
+ unbind = (struct ioctl_evtchn_unbind *)arg;
+
+ mtx_lock(&u->bind_mutex);
+ evtchn = find_evtchn(u, unbind->port);
+ if (evtchn == NULL) {
+ error = ENOTCONN;
+ break;
+ }
+
+ xen_intr_unbind(&evtchn->handle);
+ RB_REMOVE(evtchn_tree, &u->evtchns, evtchn);
+ mtx_unlock(&u->bind_mutex);
+ free(evtchn, M_EVTCHN);
+ error = 0;
+ break;
+ }
+
+ case IOCTL_EVTCHN_NOTIFY: {
+ struct ioctl_evtchn_notify *notify;
+ struct user_evtchn *evtchn;
+
+ notify = (struct ioctl_evtchn_notify *)arg;
+
+ mtx_lock(&u->bind_mutex);
+ evtchn = find_evtchn(u, notify->port);
+ if (evtchn == NULL) {
+ error = ENOTCONN;
+ break;
+ }
+
+ xen_intr_signal(evtchn->handle);
+ mtx_unlock(&u->bind_mutex);
+ error = 0;
+ break;
+ }
+
+ case IOCTL_EVTCHN_RESET: {
+ /* Initialise the ring to empty. Clear errors. */
+ sx_xlock(&u->ring_cons_mutex);
+ mtx_lock(&u->ring_prod_mutex);
+ u->ring_cons = u->ring_prod = u->ring_overflow = 0;
+ mtx_unlock(&u->ring_prod_mutex);
+ sx_xunlock(&u->ring_cons_mutex);
+ error = 0;
+ break;
+ }
+
+ case FIONBIO:
+ case FIOASYNC:
+ /* Handled in an upper layer */
+ error = 0;
+ break;
+
+ default:
+ error = ENOTTY;
+ break;
+ }
+
+ return (error);
+}
+
+static int
+evtchn_poll(struct cdev *dev, int events, struct thread *td)
+{
+ struct per_user_data *u;
+ int error, mask;
+
+ error = devfs_get_cdevpriv((void **)&u);
+ if (error != 0)
+ return (POLLERR);
+
+ /* we can always write */
+ mask = events & (POLLOUT | POLLWRNORM);
+
+ mtx_lock(&u->ring_prod_mutex);
+ if (events & (POLLIN | POLLRDNORM)) {
+ if (u->ring_cons != u->ring_prod) {
+ mask |= events & (POLLIN | POLLRDNORM);
+ } else {
+ /* Record that someone is waiting */
+ selrecord(td, &u->ev_rsel);
+ }
+ }
+ mtx_unlock(&u->ring_prod_mutex);
+
+ return (mask);
+}
+
+/*------------------ Private Device Attachment Functions
--------------------*/
+static void
+evtchn_identify(driver_t *driver, device_t parent)
+{
+
+ KASSERT((xen_domain()),
+ ("Trying to attach evtchn device on non Xen domain"));
+
+ evtchn_dev = BUS_ADD_CHILD(parent, 0, "evtchn", 0);
+ if (evtchn_dev == NULL)
+ panic("unable to attach evtchn user-space device");
+}
+
+static int
+evtchn_probe(device_t dev)
+{
+
+ device_set_desc(dev, "Xen event channel user-space device");
+ return (BUS_PROBE_NOWILDCARD);
+}
+
+static int
+evtchn_attach(device_t dev)
+{
+
+ make_dev_credf(MAKEDEV_ETERNAL, &evtchn_devsw, 0, NULL, UID_ROOT,
+ GID_WHEEL, 0600, "xen/evtchn");
+ return (0);
+}
+
+/*-------------------- Private Device Attachment Data
-----------------------*/
+static device_method_t evtchn_methods[] = {
+ DEVMETHOD(device_identify, evtchn_identify),
+ DEVMETHOD(device_probe, evtchn_probe),
+ DEVMETHOD(device_attach, evtchn_attach),
+
+ DEVMETHOD_END
+};
+
+static driver_t evtchn_driver = {
+ "evtchn",
+ evtchn_methods,
+ 0,
+};
+
+devclass_t evtchn_devclass;
+
+DRIVER_MODULE(evtchn, xenpv, evtchn_driver, evtchn_devclass, 0, 0);
+MODULE_DEPEND(evtchn, xenpv, 1, 1, 1);
_______________________________________________
svn-src-all@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
