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.
This commit is contained in:
Roger Pau Monné
parent
6d54cab1fe
commit
5779d8ad57
@ -2647,6 +2647,7 @@ dev/xen/pvcpu/pvcpu.c optional xen | xenhvm
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dev/xen/xenstore/xenstore.c optional xen | xenhvm
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dev/xen/xenstore/xenstore_dev.c optional xen | xenhvm
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dev/xen/xenstore/xenstored_dev.c optional xen | xenhvm
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dev/xen/evtchn/evtchn_dev.c optional xen | xenhvm
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dev/xl/if_xl.c optional xl pci
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dev/xl/xlphy.c optional xl pci
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fs/autofs/autofs.c optional autofs
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607
sys/dev/xen/evtchn/evtchn_dev.c
Normal file
607
sys/dev/xen/evtchn/evtchn_dev.c
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@ -0,0 +1,607 @@
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/******************************************************************************
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* evtchn.c
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*
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* Driver for receiving and demuxing event-channel signals.
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*
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* Copyright (c) 2004-2005, K A Fraser
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* Multi-process extensions Copyright (c) 2004, Steven Smith
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* FreeBSD port Copyright (c) 2014, Roger Pau Monné
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* Fetched from git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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* File: drivers/xen/evtchn.c
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* Git commit: 0dc0064add422bc0ef5165ebe9ece3052bbd457d
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation; or, when distributed
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* separately from the Linux kernel or incorporated into other
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* software packages, subject to the following license:
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this source file (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy, modify,
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* merge, publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/uio.h>
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#include <sys/bus.h>
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#include <sys/malloc.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/sx.h>
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#include <sys/selinfo.h>
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#include <sys/poll.h>
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#include <sys/conf.h>
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#include <sys/fcntl.h>
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#include <sys/ioccom.h>
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#include <sys/rman.h>
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#include <sys/tree.h>
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#include <sys/module.h>
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#include <sys/filio.h>
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#include <sys/vnode.h>
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#include <machine/intr_machdep.h>
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#include <machine/xen/synch_bitops.h>
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#include <xen/xen-os.h>
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#include <xen/evtchn.h>
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#include <xen/xen_intr.h>
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#include <xen/evtchn/evtchnvar.h>
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MALLOC_DEFINE(M_EVTCHN, "evtchn_dev", "Xen event channel user-space device");
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struct user_evtchn;
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static int evtchn_cmp(struct user_evtchn *u1, struct user_evtchn *u2);
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RB_HEAD(evtchn_tree, user_evtchn);
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struct per_user_data {
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struct mtx bind_mutex; /* serialize bind/unbind operations */
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struct evtchn_tree evtchns;
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/* Notification ring, accessed via /dev/xen/evtchn. */
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#define EVTCHN_RING_SIZE (PAGE_SIZE / sizeof(evtchn_port_t))
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#define EVTCHN_RING_MASK(_i) ((_i)&(EVTCHN_RING_SIZE-1))
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evtchn_port_t *ring;
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unsigned int ring_cons, ring_prod, ring_overflow;
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struct sx ring_cons_mutex; /* protect against concurrent readers */
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struct mtx ring_prod_mutex; /* product against concurrent interrupts */
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struct selinfo ev_rsel;
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};
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struct user_evtchn {
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RB_ENTRY(user_evtchn) node;
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struct per_user_data *user;
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evtchn_port_t port;
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xen_intr_handle_t handle;
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bool enabled;
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};
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RB_GENERATE_STATIC(evtchn_tree, user_evtchn, node, evtchn_cmp);
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static device_t evtchn_dev;
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static d_read_t evtchn_read;
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static d_write_t evtchn_write;
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static d_ioctl_t evtchn_ioctl;
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static d_poll_t evtchn_poll;
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static d_open_t evtchn_open;
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static void evtchn_release(void *arg);
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static struct cdevsw evtchn_devsw = {
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.d_version = D_VERSION,
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.d_open = evtchn_open,
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.d_read = evtchn_read,
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.d_write = evtchn_write,
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.d_ioctl = evtchn_ioctl,
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.d_poll = evtchn_poll,
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.d_name = "evtchn",
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};
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/*------------------------- Red-black tree helpers ---------------------------*/
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static int
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evtchn_cmp(struct user_evtchn *u1, struct user_evtchn *u2)
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{
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return (u1->port - u2->port);
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}
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static struct user_evtchn *
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find_evtchn(struct per_user_data *u, evtchn_port_t port)
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{
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struct user_evtchn tmp = {
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.port = port,
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};
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return (RB_FIND(evtchn_tree, &u->evtchns, &tmp));
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}
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/*--------------------------- Interrupt handlers -----------------------------*/
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static int
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evtchn_filter(void *arg)
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{
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struct user_evtchn *evtchn;
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evtchn = arg;
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if (!evtchn->enabled && bootverbose) {
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device_printf(evtchn_dev,
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"Received upcall for disabled event channel %d\n",
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evtchn->port);
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}
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evtchn_mask_port(evtchn->port);
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evtchn->enabled = false;
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return (FILTER_SCHEDULE_THREAD);
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}
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static void
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evtchn_interrupt(void *arg)
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{
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struct user_evtchn *evtchn;
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struct per_user_data *u;
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evtchn = arg;
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u = evtchn->user;
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/*
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* Protect against concurrent events using this handler
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* on different CPUs.
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*/
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mtx_lock(&u->ring_prod_mutex);
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if ((u->ring_prod - u->ring_cons) < EVTCHN_RING_SIZE) {
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u->ring[EVTCHN_RING_MASK(u->ring_prod)] = evtchn->port;
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wmb(); /* Ensure ring contents visible */
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if (u->ring_cons == u->ring_prod++) {
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wakeup(u);
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selwakeup(&u->ev_rsel);
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}
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} else
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u->ring_overflow = 1;
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mtx_unlock(&u->ring_prod_mutex);
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}
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/*------------------------- Character device methods -------------------------*/
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static int
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evtchn_open(struct cdev *dev, int flag, int otyp, struct thread *td)
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{
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struct per_user_data *u;
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int error;
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u = malloc(sizeof(*u), M_EVTCHN, M_WAITOK | M_ZERO);
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u->ring = malloc(PAGE_SIZE, M_EVTCHN, M_WAITOK | M_ZERO);
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/* Initialize locks */
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mtx_init(&u->bind_mutex, "evtchn_bind_mutex", NULL, MTX_DEF);
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sx_init(&u->ring_cons_mutex, "evtchn_ringc_sx");
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mtx_init(&u->ring_prod_mutex, "evtchn_ringp_mutex", NULL, MTX_DEF);
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/* Initialize red-black tree. */
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RB_INIT(&u->evtchns);
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/* Assign the allocated per_user_data to this open instance. */
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error = devfs_set_cdevpriv(u, evtchn_release);
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if (error != 0) {
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mtx_destroy(&u->bind_mutex);
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mtx_destroy(&u->ring_prod_mutex);
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sx_destroy(&u->ring_cons_mutex);
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free(u->ring, M_EVTCHN);
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free(u, M_EVTCHN);
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}
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return (error);
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}
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static void
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evtchn_release(void *arg)
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{
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struct per_user_data *u;
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struct user_evtchn *evtchn, *tmp;
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u = arg;
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seldrain(&u->ev_rsel);
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RB_FOREACH_SAFE(evtchn, evtchn_tree, &u->evtchns, tmp) {
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xen_intr_unbind(&evtchn->handle);
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RB_REMOVE(evtchn_tree, &u->evtchns, evtchn);
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free(evtchn, M_EVTCHN);
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}
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mtx_destroy(&u->bind_mutex);
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mtx_destroy(&u->ring_prod_mutex);
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sx_destroy(&u->ring_cons_mutex);
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free(u->ring, M_EVTCHN);
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free(u, M_EVTCHN);
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}
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static int
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evtchn_read(struct cdev *dev, struct uio *uio, int ioflag)
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{
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int error, count;
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unsigned int c, p, bytes1 = 0, bytes2 = 0;
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struct per_user_data *u;
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error = devfs_get_cdevpriv((void **)&u);
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if (error != 0)
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return (EINVAL);
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/* Whole number of ports. */
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count = uio->uio_resid;
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count &= ~(sizeof(evtchn_port_t)-1);
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if (count == 0)
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return (0);
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if (count > PAGE_SIZE)
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count = PAGE_SIZE;
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sx_xlock(&u->ring_cons_mutex);
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for (;;) {
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error = EFBIG;
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if (u->ring_overflow)
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goto unlock_out;
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c = u->ring_cons;
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p = u->ring_prod;
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if (c != p)
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break;
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if (ioflag & IO_NDELAY) {
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sx_xunlock(&u->ring_cons_mutex);
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return (EWOULDBLOCK);
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}
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error = sx_sleep(u, &u->ring_cons_mutex, PCATCH, "evtchw", 0);
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if ((error != 0) && (error != EWOULDBLOCK))
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return (error);
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}
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/* Byte lengths of two chunks. Chunk split (if any) is at ring wrap. */
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if (((c ^ p) & EVTCHN_RING_SIZE) != 0) {
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bytes1 = (EVTCHN_RING_SIZE - EVTCHN_RING_MASK(c)) *
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sizeof(evtchn_port_t);
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bytes2 = EVTCHN_RING_MASK(p) * sizeof(evtchn_port_t);
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} else {
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bytes1 = (p - c) * sizeof(evtchn_port_t);
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bytes2 = 0;
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}
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/* Truncate chunks according to caller's maximum byte count. */
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if (bytes1 > count) {
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bytes1 = count;
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bytes2 = 0;
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} else if ((bytes1 + bytes2) > count) {
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bytes2 = count - bytes1;
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}
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error = EFAULT;
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rmb(); /* Ensure that we see the port before we copy it. */
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if (uiomove(&u->ring[EVTCHN_RING_MASK(c)], bytes1, uio) ||
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((bytes2 != 0) && uiomove(&u->ring[0], bytes2, uio)))
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goto unlock_out;
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u->ring_cons += (bytes1 + bytes2) / sizeof(evtchn_port_t);
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error = 0;
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unlock_out:
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sx_xunlock(&u->ring_cons_mutex);
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return (error);
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}
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static int
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evtchn_write(struct cdev *dev, struct uio *uio, int ioflag)
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{
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int error, i, count;
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evtchn_port_t *kbuf;
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struct per_user_data *u;
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error = devfs_get_cdevpriv((void **)&u);
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if (error != 0)
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return (EINVAL);
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kbuf = malloc(PAGE_SIZE, M_EVTCHN, M_WAITOK);
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if (kbuf == NULL)
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return (ENOMEM);
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count = uio->uio_resid;
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/* Whole number of ports. */
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count &= ~(sizeof(evtchn_port_t)-1);
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error = 0;
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if (count == 0)
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goto out;
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if (count > PAGE_SIZE)
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count = PAGE_SIZE;
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error = uiomove(kbuf, count, uio);
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if (error != 0)
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goto out;
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mtx_lock(&u->bind_mutex);
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for (i = 0; i < (count/sizeof(evtchn_port_t)); i++) {
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evtchn_port_t port = kbuf[i];
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struct user_evtchn *evtchn;
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evtchn = find_evtchn(u, port);
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if (evtchn && !evtchn->enabled) {
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evtchn->enabled = true;
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evtchn_unmask_port(evtchn->port);
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}
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}
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mtx_unlock(&u->bind_mutex);
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error = 0;
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out:
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free(kbuf, M_EVTCHN);
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return (error);
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}
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static inline int
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evtchn_bind_user_port(struct per_user_data *u, struct user_evtchn *evtchn)
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{
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int error;
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evtchn->port = xen_intr_port(evtchn->handle);
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evtchn->user = u;
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evtchn->enabled = true;
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mtx_lock(&u->bind_mutex);
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RB_INSERT(evtchn_tree, &u->evtchns, evtchn);
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mtx_unlock(&u->bind_mutex);
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error = xen_intr_add_handler(evtchn_dev, evtchn_filter,
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evtchn_interrupt, evtchn, INTR_TYPE_MISC | INTR_MPSAFE,
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evtchn->handle);
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if (error != 0) {
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xen_intr_unbind(&evtchn->handle);
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mtx_lock(&u->bind_mutex);
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RB_REMOVE(evtchn_tree, &u->evtchns, evtchn);
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mtx_unlock(&u->bind_mutex);
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free(evtchn, M_EVTCHN);
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}
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return (error);
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}
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static int
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evtchn_ioctl(struct cdev *dev, unsigned long cmd, caddr_t arg,
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int mode, struct thread *td __unused)
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{
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struct per_user_data *u;
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int error;
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error = devfs_get_cdevpriv((void **)&u);
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if (error != 0)
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return (EINVAL);
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switch (cmd) {
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case IOCTL_EVTCHN_BIND_VIRQ: {
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struct ioctl_evtchn_bind_virq *bind;
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struct user_evtchn *evtchn;
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evtchn = malloc(sizeof(*evtchn), M_EVTCHN, M_WAITOK | M_ZERO);
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bind = (struct ioctl_evtchn_bind_virq *)arg;
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error = xen_intr_bind_virq(evtchn_dev, bind->virq, 0,
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NULL, NULL, NULL, 0, &evtchn->handle);
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if (error != 0) {
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free(evtchn, M_EVTCHN);
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break;
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}
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error = evtchn_bind_user_port(u, evtchn);
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if (error != 0)
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break;
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bind->port = evtchn->port;
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break;
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}
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case IOCTL_EVTCHN_BIND_INTERDOMAIN: {
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struct ioctl_evtchn_bind_interdomain *bind;
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struct user_evtchn *evtchn;
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evtchn = malloc(sizeof(*evtchn), M_EVTCHN, M_WAITOK | M_ZERO);
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bind = (struct ioctl_evtchn_bind_interdomain *)arg;
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error = xen_intr_bind_remote_port(evtchn_dev,
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bind->remote_domain, bind->remote_port, NULL,
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NULL, NULL, 0, &evtchn->handle);
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if (error != 0) {
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free(evtchn, M_EVTCHN);
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break;
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}
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error = evtchn_bind_user_port(u, evtchn);
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if (error != 0)
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break;
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||||
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);
|
||||
@ -1,358 +0,0 @@
|
||||
/******************************************************************************
|
||||
* evtchn.c
|
||||
*
|
||||
* Xenolinux driver for receiving and demuxing event-channel signals.
|
||||
*
|
||||
* Copyright (c) 2004, K A Fraser
|
||||
*/
|
||||
|
||||
#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/selinfo.h>
|
||||
#include <sys/poll.h>
|
||||
#include <sys/conf.h>
|
||||
#include <sys/fcntl.h>
|
||||
#include <sys/ioccom.h>
|
||||
#include <sys/rman.h>
|
||||
|
||||
#include <xen/xen-os.h>
|
||||
#include <xen/evtchn.h>
|
||||
#include <xen/xen_intr.h>
|
||||
|
||||
#include <machine/bus.h>
|
||||
#include <machine/resource.h>
|
||||
#include <machine/xen/synch_bitops.h>
|
||||
|
||||
#include <xen/evtchn/evtchnvar.h>
|
||||
|
||||
typedef struct evtchn_sotfc {
|
||||
|
||||
struct selinfo ev_rsel;
|
||||
} evtchn_softc_t;
|
||||
|
||||
/* Only one process may open /dev/xen/evtchn at any time. */
|
||||
static unsigned long evtchn_dev_inuse;
|
||||
|
||||
/* Notification ring, accessed via /dev/xen/evtchn. */
|
||||
|
||||
#define EVTCHN_RING_SIZE 2048 /* 2048 16-bit entries */
|
||||
|
||||
#define EVTCHN_RING_MASK(_i) ((_i)&(EVTCHN_RING_SIZE-1))
|
||||
static uint16_t *ring;
|
||||
static unsigned int ring_cons, ring_prod, ring_overflow;
|
||||
|
||||
/* Which ports is user-space bound to? */
|
||||
static uint32_t bound_ports[32];
|
||||
|
||||
/* Unique address for processes to sleep on */
|
||||
static void *evtchn_waddr = ˚
|
||||
|
||||
static struct mtx lock, upcall_lock;
|
||||
|
||||
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 d_close_t evtchn_close;
|
||||
|
||||
|
||||
void
|
||||
evtchn_device_upcall(evtchn_port_t port)
|
||||
{
|
||||
mtx_lock(&upcall_lock);
|
||||
|
||||
evtchn_mask_port(port);
|
||||
evtchn_clear_port(port);
|
||||
|
||||
if ( ring != NULL ) {
|
||||
if ( (ring_prod - ring_cons) < EVTCHN_RING_SIZE ) {
|
||||
ring[EVTCHN_RING_MASK(ring_prod)] = (uint16_t)port;
|
||||
if ( ring_cons == ring_prod++ ) {
|
||||
wakeup(evtchn_waddr);
|
||||
}
|
||||
}
|
||||
else {
|
||||
ring_overflow = 1;
|
||||
}
|
||||
}
|
||||
|
||||
mtx_unlock(&upcall_lock);
|
||||
}
|
||||
|
||||
static void
|
||||
__evtchn_reset_buffer_ring(void)
|
||||
{
|
||||
/* Initialise the ring to empty. Clear errors. */
|
||||
ring_cons = ring_prod = ring_overflow = 0;
|
||||
}
|
||||
|
||||
static int
|
||||
evtchn_read(struct cdev *dev, struct uio *uio, int ioflag)
|
||||
{
|
||||
int rc;
|
||||
unsigned int count, c, p, sst = 0, bytes1 = 0, bytes2 = 0;
|
||||
count = uio->uio_resid;
|
||||
|
||||
count &= ~1; /* even number of bytes */
|
||||
|
||||
if ( count == 0 )
|
||||
{
|
||||
rc = 0;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if ( count > PAGE_SIZE )
|
||||
count = PAGE_SIZE;
|
||||
|
||||
for ( ; ; ) {
|
||||
if ( (c = ring_cons) != (p = ring_prod) )
|
||||
break;
|
||||
|
||||
if ( ring_overflow ) {
|
||||
rc = EFBIG;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (sst != 0) {
|
||||
rc = EINTR;
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* PCATCH == check for signals before and after sleeping
|
||||
* PWAIT == priority of waiting on resource
|
||||
*/
|
||||
sst = tsleep(evtchn_waddr, PWAIT|PCATCH, "evchwt", 10);
|
||||
}
|
||||
|
||||
/* 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(uint16_t);
|
||||
bytes2 = EVTCHN_RING_MASK(p) * sizeof(uint16_t);
|
||||
}
|
||||
else {
|
||||
bytes1 = (p - c) * sizeof(uint16_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;
|
||||
}
|
||||
|
||||
if ( uiomove(&ring[EVTCHN_RING_MASK(c)], bytes1, uio) ||
|
||||
((bytes2 != 0) && uiomove(&ring[0], bytes2, uio)))
|
||||
/* keeping this around as its replacement is not equivalent
|
||||
* copyout(&ring[0], &buf[bytes1], bytes2)
|
||||
*/
|
||||
{
|
||||
rc = EFAULT;
|
||||
goto out;
|
||||
}
|
||||
|
||||
ring_cons += (bytes1 + bytes2) / sizeof(uint16_t);
|
||||
|
||||
rc = bytes1 + bytes2;
|
||||
|
||||
out:
|
||||
|
||||
return rc;
|
||||
}
|
||||
|
||||
static int
|
||||
evtchn_write(struct cdev *dev, struct uio *uio, int ioflag)
|
||||
{
|
||||
int rc, i, count;
|
||||
|
||||
count = uio->uio_resid;
|
||||
|
||||
uint16_t *kbuf = (uint16_t *)malloc(PAGE_SIZE, M_DEVBUF, M_WAITOK);
|
||||
|
||||
|
||||
if ( kbuf == NULL )
|
||||
return ENOMEM;
|
||||
|
||||
count &= ~1; /* even number of bytes */
|
||||
|
||||
if ( count == 0 ) {
|
||||
rc = 0;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if ( count > PAGE_SIZE )
|
||||
count = PAGE_SIZE;
|
||||
|
||||
if ( uiomove(kbuf, count, uio) != 0 ) {
|
||||
rc = EFAULT;
|
||||
goto out;
|
||||
}
|
||||
|
||||
mtx_lock_spin(&lock);
|
||||
for ( i = 0; i < (count/2); i++ )
|
||||
if ( test_bit(kbuf[i], &bound_ports[0]) )
|
||||
evtchn_unmask_port(kbuf[i]);
|
||||
mtx_unlock_spin(&lock);
|
||||
|
||||
rc = count;
|
||||
|
||||
out:
|
||||
free(kbuf, M_DEVBUF);
|
||||
return rc;
|
||||
}
|
||||
|
||||
static int
|
||||
evtchn_ioctl(struct cdev *dev, unsigned long cmd, caddr_t arg,
|
||||
int mode, struct thread *td __unused)
|
||||
{
|
||||
int rc = 0;
|
||||
|
||||
#ifdef NOTYET
|
||||
mtx_lock_spin(&lock);
|
||||
|
||||
switch ( cmd )
|
||||
{
|
||||
case EVTCHN_RESET:
|
||||
__evtchn_reset_buffer_ring();
|
||||
break;
|
||||
case EVTCHN_BIND:
|
||||
if ( !synch_test_and_set_bit((uintptr_t)arg, &bound_ports[0]) )
|
||||
unmask_evtchn((uintptr_t)arg);
|
||||
else
|
||||
rc = EINVAL;
|
||||
break;
|
||||
case EVTCHN_UNBIND:
|
||||
if ( synch_test_and_clear_bit((uintptr_t)arg, &bound_ports[0]) )
|
||||
mask_evtchn((uintptr_t)arg);
|
||||
else
|
||||
rc = EINVAL;
|
||||
break;
|
||||
default:
|
||||
rc = ENOSYS;
|
||||
break;
|
||||
}
|
||||
|
||||
mtx_unlock_spin(&lock);
|
||||
#endif
|
||||
|
||||
return rc;
|
||||
}
|
||||
|
||||
static int
|
||||
evtchn_poll(struct cdev *dev, int poll_events, struct thread *td)
|
||||
{
|
||||
|
||||
evtchn_softc_t *sc;
|
||||
unsigned int mask = POLLOUT | POLLWRNORM;
|
||||
|
||||
sc = dev->si_drv1;
|
||||
|
||||
if ( ring_cons != ring_prod )
|
||||
mask |= POLLIN | POLLRDNORM;
|
||||
else if ( ring_overflow )
|
||||
mask = POLLERR;
|
||||
else
|
||||
selrecord(td, &sc->ev_rsel);
|
||||
|
||||
|
||||
return mask;
|
||||
}
|
||||
|
||||
|
||||
static int
|
||||
evtchn_open(struct cdev *dev, int flag, int otyp, struct thread *td)
|
||||
{
|
||||
uint16_t *_ring;
|
||||
|
||||
if (flag & O_NONBLOCK)
|
||||
return EBUSY;
|
||||
|
||||
if ( synch_test_and_set_bit(0, &evtchn_dev_inuse) )
|
||||
return EBUSY;
|
||||
|
||||
if ( (_ring = (uint16_t *)malloc(PAGE_SIZE, M_DEVBUF, M_WAITOK)) == NULL )
|
||||
return ENOMEM;
|
||||
|
||||
mtx_lock_spin(&lock);
|
||||
ring = _ring;
|
||||
__evtchn_reset_buffer_ring();
|
||||
mtx_unlock_spin(&lock);
|
||||
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int
|
||||
evtchn_close(struct cdev *dev, int flag, int otyp, struct thread *td __unused)
|
||||
{
|
||||
int i;
|
||||
|
||||
if (ring != NULL) {
|
||||
free(ring, M_DEVBUF);
|
||||
ring = NULL;
|
||||
}
|
||||
mtx_lock_spin(&lock);
|
||||
for ( i = 0; i < NR_EVENT_CHANNELS; i++ )
|
||||
if ( synch_test_and_clear_bit(i, &bound_ports[0]) )
|
||||
evtchn_mask_port(i);
|
||||
mtx_unlock_spin(&lock);
|
||||
|
||||
evtchn_dev_inuse = 0;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct cdevsw evtchn_devsw = {
|
||||
.d_version = D_VERSION,
|
||||
.d_open = evtchn_open,
|
||||
.d_close = evtchn_close,
|
||||
.d_read = evtchn_read,
|
||||
.d_write = evtchn_write,
|
||||
.d_ioctl = evtchn_ioctl,
|
||||
.d_poll = evtchn_poll,
|
||||
.d_name = "evtchn",
|
||||
};
|
||||
|
||||
|
||||
/* XXX - if this device is ever supposed to support use by more than one process
|
||||
* this global static will have to go away
|
||||
*/
|
||||
static struct cdev *evtchn_dev;
|
||||
|
||||
|
||||
|
||||
static int
|
||||
evtchn_dev_init(void *dummy __unused)
|
||||
{
|
||||
/* XXX I believe we don't need these leaving them here for now until we
|
||||
* have some semblance of it working
|
||||
*/
|
||||
mtx_init(&upcall_lock, "evtchup", NULL, MTX_DEF);
|
||||
|
||||
/* (DEVFS) create '/dev/misc/evtchn'. */
|
||||
evtchn_dev = make_dev(&evtchn_devsw, 0, UID_ROOT, GID_WHEEL, 0600, "xen/evtchn");
|
||||
|
||||
mtx_init(&lock, "evch", NULL, MTX_SPIN | MTX_NOWITNESS);
|
||||
|
||||
evtchn_dev->si_drv1 = malloc(sizeof(evtchn_softc_t), M_DEVBUF, M_WAITOK);
|
||||
bzero(evtchn_dev->si_drv1, sizeof(evtchn_softc_t));
|
||||
|
||||
if (bootverbose)
|
||||
printf("Event-channel device installed.\n");
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
SYSINIT(evtchn_dev_init, SI_SUB_DRIVERS, SI_ORDER_FIRST, evtchn_dev_init, NULL);
|
||||
Loading…
Reference in New Issue
Block a user