[src/jmcneill-usbmp]: src/sys/dev/usb convert usb event code to using a mutex...

[mrg <mrg%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/c5bec3fc5601
branches:  jmcneill-usbmp
changeset: 771796:c5bec3fc5601
user:      mrg <mrg%NetBSD.org@localhost>
date:      Mon Feb 20 03:27:07 2012 +0000

description:
convert usb event code to using a mutex and condvar.

diffstat:

 sys/dev/usb/usb.c |  71 ++++++++++++++++++++++++++++++------------------------
 1 files changed, 40 insertions(+), 31 deletions(-)

diffs (243 lines):

diff -r 85ed87585898 -r c5bec3fc5601 sys/dev/usb/usb.c
--- a/sys/dev/usb/usb.c Mon Feb 20 03:25:33 2012 +0000
+++ b/sys/dev/usb/usb.c Mon Feb 20 03:27:07 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: usb.c,v 1.125.6.6 2012/02/20 02:12:24 mrg Exp $        */
+/*     $NetBSD: usb.c,v 1.125.6.7 2012/02/20 03:27:07 mrg Exp $        */
 
 /*
  * Copyright (c) 1998, 2002, 2008 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usb.c,v 1.125.6.6 2012/02/20 02:12:24 mrg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usb.c,v 1.125.6.7 2012/02/20 03:27:07 mrg Exp $");
 
 #include "opt_compat_netbsd.h"
 #include "opt_usb.h"
@@ -57,19 +57,19 @@
 #include <sys/signalvar.h>
 #include <sys/intr.h>
 #include <sys/module.h>
+#include <sys/mutex.h>
+#include <sys/bus.h>
+#include <sys/once.h>
 
 #include <dev/usb/usb.h>
 #include <dev/usb/usbdi.h>
 #include <dev/usb/usbdi_util.h>
+#include <dev/usb/usbdivar.h>
 #include <dev/usb/usb_verbose.h>
+#include <dev/usb/usb_quirks.h>
 
 #define USB_DEV_MINOR 255
 
-#include <sys/bus.h>
-
-#include <dev/usb/usbdivar.h>
-#include <dev/usb/usb_quirks.h>
-
 #ifdef USB_DEBUG
 #define DPRINTF(x)     if (usbdebug) printf x
 #define DPRINTFN(n,x)  if (usbdebug>(n)) printf x
@@ -135,6 +135,8 @@
        SIMPLEQ_HEAD_INITIALIZER(usb_events);
 Static int usb_nevents = 0;
 Static struct selinfo usb_selevent;
+Static kmutex_t usb_event_lock;
+Static kcondvar_t usb_event_cv;
 Static proc_t *usb_async_proc;  /* process that wants USB SIGIO */
 Static void *usb_async_sih;
 Static int usb_dev_open = 0;
@@ -156,6 +158,7 @@
 static int usb_detach(device_t, int);
 static int usb_activate(device_t, enum devact);
 static void usb_childdet(device_t, device_t);
+static int usb_once_init(void);
 static void usb_doattach(device_t);
 
 extern struct cfdriver usb_cd;
@@ -174,6 +177,7 @@
 void
 usb_attach(device_t parent, device_t self, void *aux)
 {
+       static ONCE_DECL(init_control);
        struct usb_softc *sc = device_private(self);
        int usbrev;
 
@@ -194,13 +198,23 @@
        }
        aprint_normal("\n");
 
+       RUN_ONCE(&init_control, usb_once_init);
        config_interrupts(self, usb_doattach);
 }
 
+static int
+usb_once_init(void)
+{
+
+       selinit(&usb_selevent);
+       mutex_init(&usb_event_lock, MUTEX_DEFAULT, IPL_NONE);
+       cv_init(&usb_event_cv, "usbrea");
+       return 0;
+}
+
 static void
 usb_doattach(device_t self)
 {
-       static bool usb_selevent_init;  /* XXX */
        struct usb_softc *sc = device_private(self);
        usbd_device_handle dev;
        usbd_status err;
@@ -208,10 +222,6 @@
        struct usb_event *ue;
        bool mpsafe = sc->sc_bus->methods->get_locks ? true : false;
 
-       if (!usb_selevent_init) {
-               selinit(&usb_selevent);
-               usb_selevent_init = true;
-       }
        DPRINTF(("usbd_doattach\n"));
 
        sc->sc_bus->usbctl = self;
@@ -485,7 +495,7 @@
 #ifdef COMPAT_30
        struct usb_event_old *ueo = NULL;       /* XXXGCC */
 #endif
-       int s, error, n, useold;
+       int error, n, useold;
 
        if (minor(dev) != USB_DEV_MINOR)
                return (ENXIO);
@@ -507,7 +517,7 @@
        }
 
        error = 0;
-       s = splusb();
+       mutex_enter(&usb_event_lock);
        for (;;) {
                n = usb_get_next_event(ue);
                if (n != 0)
@@ -516,11 +526,11 @@
                        error = EWOULDBLOCK;
                        break;
                }
-               error = tsleep(&usb_events, PZERO | PCATCH, "usbrea", 0);
+               error = cv_wait_sig(&usb_event_cv, &usb_event_lock);
                if (error)
                        break;
        }
-       splx(s);
+       mutex_exit(&usb_event_lock);
        if (!error) {
 #ifdef COMPAT_30
                if (useold) { /* copy fields to old struct */
@@ -721,18 +731,18 @@
 int
 usbpoll(dev_t dev, int events, struct lwp *l)
 {
-       int revents, mask, s;
+       int revents, mask;
 
        if (minor(dev) == USB_DEV_MINOR) {
                revents = 0;
                mask = POLLIN | POLLRDNORM;
 
-               s = splusb();
+               mutex_enter(&usb_event_lock);
                if (events & mask && usb_nevents > 0)
                        revents |= events & mask;
                if (revents == 0 && events & mask)
                        selrecord(l, &usb_selevent);
-               splx(s);
+               mutex_exit(&usb_event_lock);
 
                return (revents);
        } else {
@@ -743,11 +753,10 @@
 static void
 filt_usbrdetach(struct knote *kn)
 {
-       int s;
 
-       s = splusb();
+       mutex_enter(&usb_event_lock);
        SLIST_REMOVE(&usb_selevent.sel_klist, kn, knote, kn_selnext);
-       splx(s);
+       mutex_exit(&usb_event_lock);
 }
 
 static int
@@ -768,7 +777,6 @@
 usbkqfilter(dev_t dev, struct knote *kn)
 {
        struct klist *klist;
-       int s;
 
        switch (kn->kn_filter) {
        case EVFILT_READ:
@@ -784,9 +792,9 @@
 
        kn->kn_hook = NULL;
 
-       s = splusb();
+       mutex_enter(&usb_event_lock);
        SLIST_INSERT_HEAD(klist, kn, kn_selnext);
-       splx(s);
+       mutex_exit(&usb_event_lock);
 
        return (0);
 }
@@ -847,12 +855,14 @@
                wakeup(&dev->bus->needs_explore);
 }
 
-/* Called at splusb() */
+/* Called at with usb_event_lock held. */
 int
 usb_get_next_event(struct usb_event *ue)
 {
        struct usb_event_q *ueq;
 
+       KASSERT(mutex_owned(&usb_event_lock));
+
        if (usb_nevents <= 0)
                return (0);
        ueq = SIMPLEQ_FIRST(&usb_events);
@@ -909,30 +919,29 @@
 {
        struct usb_event_q *ueq;
        struct timeval thetime;
-       int s;
 
        microtime(&thetime);
-       /* Don't want to wait here inside splusb() */
+       /* Don't want to wait here with usb_event_lock held */
        ueq = (struct usb_event_q *)(void *)uep;
        ueq->ue = *uep;
        ueq->ue.ue_type = type;
        TIMEVAL_TO_TIMESPEC(&thetime, &ueq->ue.ue_time);
 
-       s = splusb();
+       mutex_enter(&usb_event_lock);
        if (++usb_nevents >= USB_MAX_EVENTS) {
                /* Too many queued events, drop an old one. */
                DPRINTFN(-1,("usb: event dropped\n"));
                (void)usb_get_next_event(0);
        }
        SIMPLEQ_INSERT_TAIL(&usb_events, ueq, next);
-       wakeup(&usb_events);
+       cv_signal(&usb_event_cv);
        selnotify(&usb_selevent, 0, 0);
        if (usb_async_proc != NULL) {
                kpreempt_disable();
                softint_schedule(usb_async_sih);
                kpreempt_enable();
        }
-       splx(s);
+       mutex_exit(&usb_event_lock);
 }
 
 Static void