Author: avg
Date: Sun May 13 17:15:30 2012
New Revision: 235411
URL: http://svn.freebsd.org/changeset/base/235411
Log:
MFC r228765: ukbd: adjust for SCHEDULER_STOPPED() and overhaul locking code
Modified:
stable/9/sys/dev/usb/input/ukbd.c
Directory Properties:
stable/9/sys/ (props changed)
stable/9/sys/amd64/include/xen/ (props changed)
stable/9/sys/boot/ (props changed)
stable/9/sys/boot/i386/efi/ (props changed)
stable/9/sys/boot/ia64/efi/ (props changed)
stable/9/sys/boot/ia64/ski/ (props changed)
stable/9/sys/boot/powerpc/boot1.chrp/ (props changed)
stable/9/sys/boot/powerpc/ofw/ (props changed)
stable/9/sys/cddl/contrib/opensolaris/ (props changed)
stable/9/sys/conf/ (props changed)
stable/9/sys/contrib/dev/acpica/ (props changed)
stable/9/sys/contrib/octeon-sdk/ (props changed)
stable/9/sys/contrib/pf/ (props changed)
stable/9/sys/contrib/x86emu/ (props changed)
stable/9/sys/fs/ (props changed)
stable/9/sys/fs/ntfs/ (props changed)
stable/9/sys/i386/conf/XENHVM (props changed)
stable/9/sys/kern/subr_witness.c (props changed)
Modified: stable/9/sys/dev/usb/input/ukbd.c
==============================================================================
--- stable/9/sys/dev/usb/input/ukbd.c Sun May 13 17:14:26 2012
(r235410)
+++ stable/9/sys/dev/usb/input/ukbd.c Sun May 13 17:15:30 2012
(r235411)
@@ -198,7 +198,6 @@ struct ukbd_softc {
int sc_mode; /* input mode (K_XLATE,K_RAW,K_CODE) */
int sc_state; /* shift/lock key state */
int sc_accents; /* accent key index (> 0) */
- int sc_poll_tick_last;
int sc_led_size;
int sc_kbd_size;
@@ -227,7 +226,6 @@ struct ukbd_softc {
uint8_t sc_id_events;
uint8_t sc_kbd_id;
- uint8_t sc_poll_detected;
uint8_t sc_buffer[UKBD_BUFFER_SIZE];
};
@@ -247,6 +245,33 @@ struct ukbd_softc {
SCAN_PREFIX_CTL | SCAN_PREFIX_SHIFT)
#define SCAN_CHAR(c) ((c) & 0x7f)
+#define UKBD_LOCK() mtx_lock(&Giant)
+#define UKBD_UNLOCK() mtx_unlock(&Giant)
+
+#ifdef INVARIANTS
+
+/*
+ * Assert that the lock is held in all contexts
+ * where the code can be executed.
+ */
+#define UKBD_LOCK_ASSERT() mtx_assert(&Giant, MA_OWNED)
+
+/*
+ * Assert that the lock is held in the contexts
+ * where it really has to be so.
+ */
+#define UKBD_CTX_LOCK_ASSERT() \
+ do { \
+ if (!kdb_active && panicstr == NULL) \
+ mtx_assert(&Giant, MA_OWNED); \
+ } while (0)
+#else
+
+#define UKBD_LOCK_ASSERT() (void)0
+#define UKBD_CTX_LOCK_ASSERT() (void)0
+
+#endif
+
struct ukbd_mods {
uint32_t mask, key;
};
@@ -339,8 +364,6 @@ static int ukbd_ioctl(keyboard_t *, u_lo
static int ukbd_enable(keyboard_t *);
static int ukbd_disable(keyboard_t *);
static void ukbd_interrupt(struct ukbd_softc *);
-static int ukbd_is_polling(struct ukbd_softc *);
-static int ukbd_polls_other_thread(struct ukbd_softc *);
static void ukbd_event_keyinput(struct ukbd_softc *);
static device_probe_t ukbd_probe;
@@ -370,7 +393,8 @@ ukbd_start_timer(struct ukbd_softc *sc)
static void
ukbd_put_key(struct ukbd_softc *sc, uint32_t key)
{
- mtx_assert(&Giant, MA_OWNED);
+
+ UKBD_CTX_LOCK_ASSERT();
DPRINTF("0x%02x (%d) %s\n", key, key,
(key & KEY_RELEASE) ? "released" : "pressed");
@@ -388,52 +412,32 @@ ukbd_put_key(struct ukbd_softc *sc, uint
}
static void
-ukbd_yield(void)
-{
- struct thread *td = curthread;
- uint32_t old_prio;
-
- DROP_GIANT();
-
- thread_lock(td);
-
- /* get current priority */
- old_prio = td->td_base_pri;
-
- /* set new priority */
- sched_prio(td, td->td_user_pri);
-
- /* cause a task switch */
- mi_switch(SW_INVOL | SWT_RELINQUISH, NULL);
-
- /* restore priority */
- sched_prio(td, old_prio);
-
- thread_unlock(td);
-
- PICKUP_GIANT();
-}
-
-static void
ukbd_do_poll(struct ukbd_softc *sc, uint8_t wait)
{
- DPRINTFN(2, "polling\n");
- /* update stats about last polling event */
- sc->sc_poll_tick_last = ticks;
- sc->sc_poll_detected = 1;
+ UKBD_CTX_LOCK_ASSERT();
+ KASSERT((sc->sc_flags & UKBD_FLAG_POLLING) != 0,
+ ("ukbd_do_poll called when not polling\n"));
+ DPRINTFN(2, "polling\n");
- if (kdb_active == 0) {
+ if (!kdb_active && !SCHEDULER_STOPPED()) {
+ /*
+ * In this context the kernel is polling for input,
+ * but the USB subsystem works in normal interrupt-driven
+ * mode, so we just wait on the USB threads to do the job.
+ * Note that we currently hold the Giant, but it's also used
+ * as the transfer mtx, so we must release it while waiting.
+ */
while (sc->sc_inputs == 0) {
-
- /* give USB threads a chance to run */
- ukbd_yield();
-
- /* check if we should wait */
+ /*
+ * Give USB threads a chance to run. Note that
+ * kern_yield performs DROP_GIANT + PICKUP_GIANT.
+ */
+ kern_yield(PRI_UNCHANGED);
if (!wait)
break;
}
- return; /* Only poll if KDB is active */
+ return;
}
while (sc->sc_inputs == 0) {
@@ -441,7 +445,6 @@ ukbd_do_poll(struct ukbd_softc *sc, uint
usbd_transfer_poll(sc->sc_xfer, UKBD_N_TRANSFER);
/* Delay-optimised support for repetition of keys */
-
if (ukbd_any_key_pressed(sc)) {
/* a key is pressed - need timekeeping */
DELAY(1000);
@@ -462,16 +465,16 @@ ukbd_get_key(struct ukbd_softc *sc, uint
{
int32_t c;
- mtx_assert(&Giant, MA_OWNED);
+ UKBD_CTX_LOCK_ASSERT();
+ KASSERT((!kdb_active && !SCHEDULER_STOPPED())
+ || (sc->sc_flags & UKBD_FLAG_POLLING) != 0,
+ ("not polling in kdb or panic\n"));
if (sc->sc_inputs == 0) {
/* start transfer, if not already started */
usbd_transfer_start(sc->sc_xfer[UKBD_INTR_DT]);
}
- if (ukbd_polls_other_thread(sc))
- return (-1);
-
if (sc->sc_flags & UKBD_FLAG_POLLING)
ukbd_do_poll(sc, wait);
@@ -499,6 +502,8 @@ ukbd_interrupt(struct ukbd_softc *sc)
uint8_t i;
uint8_t j;
+ UKBD_CTX_LOCK_ASSERT();
+
if (sc->sc_ndata.keycode[0] == KEY_ERROR)
return;
@@ -584,7 +589,9 @@ ukbd_event_keyinput(struct ukbd_softc *s
{
int c;
- if (ukbd_is_polling(sc))
+ UKBD_CTX_LOCK_ASSERT();
+
+ if ((sc->sc_flags & UKBD_FLAG_POLLING) != 0)
return;
if (sc->sc_inputs == 0)
@@ -608,7 +615,7 @@ ukbd_timeout(void *arg)
{
struct ukbd_softc *sc = arg;
- mtx_assert(&Giant, MA_OWNED);
+ UKBD_LOCK_ASSERT();
sc->sc_time_ms += 25; /* milliseconds */
@@ -656,6 +663,8 @@ ukbd_intr_callback(struct usb_xfer *xfer
uint8_t id;
int len;
+ UKBD_LOCK_ASSERT();
+
usbd_xfer_status(xfer, &len, NULL, NULL, NULL);
pc = usbd_xfer_get_frame(xfer, 0);
@@ -842,6 +851,8 @@ ukbd_set_leds_callback(struct usb_xfer *
uint8_t any;
int len;
+ UKBD_LOCK_ASSERT();
+
#ifdef USB_DEBUG
if (ukbd_no_leds)
return;
@@ -972,6 +983,7 @@ ukbd_probe(device_t dev)
int error;
uint16_t d_len;
+ UKBD_LOCK_ASSERT();
DPRINTFN(11, "\n");
if (sw == NULL) {
@@ -998,7 +1010,7 @@ ukbd_probe(device_t dev)
if (error)
return (ENXIO);
- /*
+ /*
* NOTE: we currently don't support USB mouse and USB keyboard
* on the same USB endpoint.
*/
@@ -1165,6 +1177,8 @@ ukbd_attach(device_t dev)
uint16_t n;
uint16_t hid_len;
+ UKBD_LOCK_ASSERT();
+
kbd_init_struct(kbd, UKBD_DRIVER_NAME, KB_OTHER, unit, 0, 0, 0);
kbd->kb_data = (void *)sc;
@@ -1241,14 +1255,10 @@ ukbd_attach(device_t dev)
/* ignore if SETIDLE fails, hence it is not crucial */
usbd_req_set_idle(sc->sc_udev, NULL, sc->sc_iface_index, 0, 0);
- mtx_lock(&Giant);
-
ukbd_ioctl(kbd, KDSETLED, (caddr_t)&sc->sc_state);
KBD_INIT_DONE(kbd);
- mtx_unlock(&Giant);
-
if (kbd_register(kbd) < 0) {
goto detach;
}
@@ -1266,15 +1276,10 @@ ukbd_attach(device_t dev)
if (bootverbose) {
genkbd_diag(kbd, bootverbose);
}
- /* lock keyboard mutex */
-
- mtx_lock(&Giant);
/* start the keyboard */
-
usbd_transfer_start(sc->sc_xfer[UKBD_INTR_DT]);
- mtx_unlock(&Giant);
return (0); /* success */
detach:
@@ -1288,9 +1293,9 @@ ukbd_detach(device_t dev)
struct ukbd_softc *sc = device_get_softc(dev);
int error;
- DPRINTF("\n");
+ UKBD_LOCK_ASSERT();
- mtx_lock(&Giant);
+ DPRINTF("\n");
sc->sc_flags |= UKBD_FLAG_GONE;
@@ -1318,8 +1323,6 @@ ukbd_detach(device_t dev)
}
sc->sc_kbd.kb_flags = 0;
- mtx_unlock(&Giant);
-
usbd_transfer_unsetup(sc->sc_xfer, UKBD_N_TRANSFER);
usb_callout_drain(&sc->sc_callout);
@@ -1335,12 +1338,10 @@ ukbd_resume(device_t dev)
{
struct ukbd_softc *sc = device_get_softc(dev);
- mtx_lock(&Giant);
+ UKBD_LOCK_ASSERT();
ukbd_clear_state(&sc->sc_kbd);
- mtx_unlock(&Giant);
-
return (0);
}
@@ -1400,15 +1401,11 @@ ukbd_lock(keyboard_t *kbd, int lock)
static int
ukbd_enable(keyboard_t *kbd)
{
- if (!mtx_owned(&Giant)) {
- /* XXX cludge */
- int retval;
- mtx_lock(&Giant);
- retval = ukbd_enable(kbd);
- mtx_unlock(&Giant);
- return (retval);
- }
+
+ UKBD_LOCK();
KBD_ACTIVATE(kbd);
+ UKBD_UNLOCK();
+
return (0);
}
@@ -1416,44 +1413,24 @@ ukbd_enable(keyboard_t *kbd)
static int
ukbd_disable(keyboard_t *kbd)
{
- if (!mtx_owned(&Giant)) {
- /* XXX cludge */
- int retval;
- mtx_lock(&Giant);
- retval = ukbd_disable(kbd);
- mtx_unlock(&Giant);
- return (retval);
- }
+
+ UKBD_LOCK();
KBD_DEACTIVATE(kbd);
+ UKBD_UNLOCK();
+
return (0);
}
/* check if data is waiting */
+/* Currently unused. */
static int
ukbd_check(keyboard_t *kbd)
{
struct ukbd_softc *sc = kbd->kb_data;
- if (!KBD_IS_ACTIVE(kbd))
- return (0);
+ UKBD_CTX_LOCK_ASSERT();
- if (sc->sc_flags & UKBD_FLAG_POLLING) {
- if (!mtx_owned(&Giant)) {
- /* XXX cludge */
- int retval;
- mtx_lock(&Giant);
- retval = ukbd_check(kbd);
- mtx_unlock(&Giant);
- return (retval);
- }
- } else {
- /* XXX the keyboard layer requires Giant */
- if (!mtx_owned(&Giant))
- return (0);
- }
-
- /* check if key belongs to this thread */
- if (ukbd_polls_other_thread(sc))
+ if (!KBD_IS_ACTIVE(kbd))
return (0);
if (sc->sc_flags & UKBD_FLAG_POLLING)
@@ -1472,30 +1449,13 @@ ukbd_check(keyboard_t *kbd)
/* check if char is waiting */
static int
-ukbd_check_char(keyboard_t *kbd)
+ukbd_check_char_locked(keyboard_t *kbd)
{
struct ukbd_softc *sc = kbd->kb_data;
- if (!KBD_IS_ACTIVE(kbd))
- return (0);
+ UKBD_CTX_LOCK_ASSERT();
- if (sc->sc_flags & UKBD_FLAG_POLLING) {
- if (!mtx_owned(&Giant)) {
- /* XXX cludge */
- int retval;
- mtx_lock(&Giant);
- retval = ukbd_check_char(kbd);
- mtx_unlock(&Giant);
- return (retval);
- }
- } else {
- /* XXX the keyboard layer requires Giant */
- if (!mtx_owned(&Giant))
- return (0);
- }
-
- /* check if key belongs to this thread */
- if (ukbd_polls_other_thread(sc))
+ if (!KBD_IS_ACTIVE(kbd))
return (0);
if ((sc->sc_composed_char > 0) &&
@@ -1505,39 +1465,34 @@ ukbd_check_char(keyboard_t *kbd)
return (ukbd_check(kbd));
}
+static int
+ukbd_check_char(keyboard_t *kbd)
+{
+ int result;
+
+ UKBD_LOCK();
+ result = ukbd_check_char_locked(kbd);
+ UKBD_UNLOCK();
+
+ return (result);
+}
/* read one byte from the keyboard if it's allowed */
+/* Currently unused. */
static int
ukbd_read(keyboard_t *kbd, int wait)
{
struct ukbd_softc *sc = kbd->kb_data;
int32_t usbcode;
-
#ifdef UKBD_EMULATE_ATSCANCODE
uint32_t keycode;
uint32_t scancode;
#endif
- if (!KBD_IS_ACTIVE(kbd))
- return (-1);
- if (sc->sc_flags & UKBD_FLAG_POLLING) {
- if (!mtx_owned(&Giant)) {
- /* XXX cludge */
- int retval;
- mtx_lock(&Giant);
- retval = ukbd_read(kbd, wait);
- mtx_unlock(&Giant);
- return (retval);
- }
- } else {
- /* XXX the keyboard layer requires Giant */
- if (!mtx_owned(&Giant))
- return (-1);
- }
+ UKBD_CTX_LOCK_ASSERT();
- /* check if key belongs to this thread */
- if (ukbd_polls_other_thread(sc))
+ if (!KBD_IS_ACTIVE(kbd))
return (-1);
#ifdef UKBD_EMULATE_ATSCANCODE
@@ -1574,38 +1529,19 @@ ukbd_read(keyboard_t *kbd, int wait)
/* read char from the keyboard */
static uint32_t
-ukbd_read_char(keyboard_t *kbd, int wait)
+ukbd_read_char_locked(keyboard_t *kbd, int wait)
{
struct ukbd_softc *sc = kbd->kb_data;
uint32_t action;
uint32_t keycode;
int32_t usbcode;
-
#ifdef UKBD_EMULATE_ATSCANCODE
uint32_t scancode;
-
#endif
- if (!KBD_IS_ACTIVE(kbd))
- return (NOKEY);
-
- if (sc->sc_flags & UKBD_FLAG_POLLING) {
- if (!mtx_owned(&Giant)) {
- /* XXX cludge */
- int retval;
- mtx_lock(&Giant);
- retval = ukbd_read_char(kbd, wait);
- mtx_unlock(&Giant);
- return (retval);
- }
- } else {
- /* XXX the keyboard layer requires Giant */
- if (!mtx_owned(&Giant))
- return (NOKEY);
- }
+ UKBD_CTX_LOCK_ASSERT();
- /* check if key belongs to this thread */
- if (ukbd_polls_other_thread(sc))
+ if (!KBD_IS_ACTIVE(kbd))
return (NOKEY);
next_code:
@@ -1782,39 +1718,32 @@ errkey:
return (ERRKEY);
}
+/* Currently wait is always false. */
+static uint32_t
+ukbd_read_char(keyboard_t *kbd, int wait)
+{
+ uint32_t keycode;
+
+ UKBD_LOCK();
+ keycode = ukbd_read_char_locked(kbd, wait);
+ UKBD_UNLOCK();
+
+ return (keycode);
+}
+
/* some useful control functions */
static int
-ukbd_ioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)
+ukbd_ioctl_locked(keyboard_t *kbd, u_long cmd, caddr_t arg)
{
struct ukbd_softc *sc = kbd->kb_data;
int i;
-
#if defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD5) || \
defined(COMPAT_FREEBSD4) || defined(COMPAT_43)
int ival;
#endif
- if (!mtx_owned(&Giant)) {
- /*
- * XXX big problem: If scroll lock is pressed and "printf()"
- * is called, the CPU will get here, to un-scroll lock the
- * keyboard. But if "printf()" acquires the "Giant" lock,
- * there will be a locking order reversal problem, so the
- * keyboard system must get out of "Giant" first, before the
- * CPU can proceed here ...
- */
- switch (cmd) {
- case KDGKBMODE:
- case KDSKBMODE:
- /* workaround for Geli */
- mtx_lock(&Giant);
- i = ukbd_ioctl(kbd, cmd, arg);
- mtx_unlock(&Giant);
- return (i);
- default:
- return (EINVAL);
- }
- }
+
+ UKBD_LOCK_ASSERT();
switch (cmd) {
case KDGKBMODE: /* get keyboard mode */
@@ -1839,7 +1768,7 @@ ukbd_ioctl(keyboard_t *kbd, u_long cmd,
case K_RAW:
case K_CODE:
if (sc->sc_mode != *(int *)arg) {
- if (ukbd_is_polling(sc) == 0)
+ if ((sc->sc_flags & UKBD_FLAG_POLLING) == 0)
ukbd_clear_state(kbd);
sc->sc_mode = *(int *)arg;
}
@@ -1943,19 +1872,44 @@ ukbd_ioctl(keyboard_t *kbd, u_long cmd,
return (0);
}
+static int
+ukbd_ioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)
+{
+ int result;
+
+ /*
+ * XXX KDGKBSTATE, KDSKBSTATE and KDSETLED can be called from any
+ * context where printf(9) can be called, which among other things
+ * includes interrupt filters and threads with any kinds of locks
+ * already held. For this reason it would be dangerous to acquire
+ * the Giant here unconditionally. On the other hand we have to
+ * have it to handle the ioctl.
+ * So we make our best effort to auto-detect whether we can grab
+ * the Giant or not. Blame syscons(4) for this.
+ */
+ switch (cmd) {
+ case KDGKBSTATE:
+ case KDSKBSTATE:
+ case KDSETLED:
+ if (!mtx_owned(&Giant) && !SCHEDULER_STOPPED())
+ return (EDEADLK); /* best I could come up with */
+ /* FALLTHROUGH */
+ default:
+ UKBD_LOCK();
+ result = ukbd_ioctl_locked(kbd, cmd, arg);
+ UKBD_UNLOCK();
+ return (result);
+ }
+}
+
+
/* clear the internal state of the keyboard */
static void
ukbd_clear_state(keyboard_t *kbd)
{
struct ukbd_softc *sc = kbd->kb_data;
- if (!mtx_owned(&Giant)) {
- /* XXX cludge */
- mtx_lock(&Giant);
- ukbd_clear_state(kbd);
- mtx_unlock(&Giant);
- return;
- }
+ UKBD_CTX_LOCK_ASSERT();
sc->sc_flags &= ~(UKBD_FLAG_COMPOSE | UKBD_FLAG_POLLING);
sc->sc_state &= LOCK_MASK; /* preserve locking key state */
@@ -1986,43 +1940,11 @@ ukbd_set_state(keyboard_t *kbd, void *bu
}
static int
-ukbd_is_polling(struct ukbd_softc *sc)
-{
- int delta;
-
- if (sc->sc_flags & UKBD_FLAG_POLLING)
- return (1); /* polling */
-
- delta = ticks - sc->sc_poll_tick_last;
- if ((delta < 0) || (delta >= hz)) {
- sc->sc_poll_detected = 0;
- return (0); /* not polling */
- }
-
- return (sc->sc_poll_detected);
-}
-
-static int
-ukbd_polls_other_thread(struct ukbd_softc *sc)
-{
- return (ukbd_is_polling(sc) &&
- (sc->sc_poll_thread != curthread));
-}
-
-static int
ukbd_poll(keyboard_t *kbd, int on)
{
struct ukbd_softc *sc = kbd->kb_data;
- if (!mtx_owned(&Giant)) {
- /* XXX cludge */
- int retval;
- mtx_lock(&Giant);
- retval = ukbd_poll(kbd, on);
- mtx_unlock(&Giant);
- return (retval);
- }
-
+ UKBD_LOCK();
if (on) {
sc->sc_flags |= UKBD_FLAG_POLLING;
sc->sc_poll_thread = curthread;
@@ -2030,6 +1952,8 @@ ukbd_poll(keyboard_t *kbd, int on)
sc->sc_flags &= ~UKBD_FLAG_POLLING;
ukbd_start_timer(sc); /* start timer */
}
+ UKBD_UNLOCK();
+
return (0);
}
@@ -2038,6 +1962,8 @@ ukbd_poll(keyboard_t *kbd, int on)
static void
ukbd_set_leds(struct ukbd_softc *sc, uint8_t leds)
{
+
+ UKBD_LOCK_ASSERT();
DPRINTF("leds=0x%02x\n", leds);
sc->sc_leds = leds;
_______________________________________________
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"
