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author	Ed Maste <emaste@FreeBSD.org>	2022-03-22 17:48:43 +0000
committer	Ed Maste <emaste@FreeBSD.org>	2022-04-15 16:29:02 +0000
commit	3ec2816ad7a19dc2ae21ccd2d2d2c236027e4572 (patch)
tree	8f37da292c46d18800845586b6f0e1f2d29c7f4d
parent	421c2f93a4e03da9c6ed36913916b15c170949e6 (diff)

kbd: replace vestigial spl calls with Giant assertions

The keyboard driver was initially protected via spl* interrupt priority calls but (as part of a comprehensive effort) migrated to use the Giant lock (mutex). The spl calls left behind became NOPs but they can be confusing as they have no bearing on the actual mutual exclusion that is now present. Remove them from kbd and add assertions that Giant is held. markj notes that there is conflation between the "bus topo" lock (which is Giant under the hood) and Giant. The assertions could either be addressed as a small item along with bus topology locking work or they'll be removed if kbd is decoupled from Giant. PR: 206680 Reviewed by: markj MFC after: 3 weeks Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D34645 (cherry picked from commit a0cd78bf2c148d7ab63454471771e3f4b572522f)

Diffstat

-rw-r--r--

sys/dev/kbd/kbd.c

1 files changed, 12 insertions, 55 deletions

diff --git a/sys/dev/kbd/kbd.c b/sys/dev/kbd/kbd.c
index 70c0ef15a56e..deb7672de7fa 100644
--- a/sys/dev/kbd/kbd.c
+++ b/sys/dev/kbd/kbd.c

@@ -35,7 +35,9 @@ __FBSDID("$FreeBSD$");

#include <sys/param.h>

#include <sys/systm.h>

#include <sys/kernel.h>

+#include <sys/lock.h>

#include <sys/malloc.h>

+#include <sys/mutex.h>

#include <sys/conf.h>

#include <sys/fcntl.h>

#include <sys/poll.h>

@@ -97,13 +99,11 @@ kbd_realloc_array(void)

{

keyboard_t **new_kbd;

int newsize;

- int s;

- s = spltty();

+ GIANT_REQUIRED;

newsize = rounddown(keyboards + ARRAY_DELTA, ARRAY_DELTA);

new_kbd = malloc(sizeof(*new_kbd)*newsize, M_DEVBUF, M_NOWAIT|M_ZERO);

if (new_kbd == NULL) {

- splx(s);

return (ENOMEM);

}

bcopy(keyboard, new_kbd, sizeof(*keyboard)*keyboards);

@@ -111,7 +111,6 @@ kbd_realloc_array(void)

free(keyboard, M_DEVBUF);

keyboard = new_kbd;

keyboards = newsize;

- splx(s);

if (bootverbose)

printf("kbd: new array size %d\n", keyboards);

@@ -245,30 +244,26 @@ int

kbd_unregister(keyboard_t *kbd)

{

int error;

- int s;

+ GIANT_REQUIRED;

if ((kbd->kb_index < 0) || (kbd->kb_index >= keyboards))

return (ENOENT);

if (keyboard[kbd->kb_index] != kbd)

return (ENOENT);

- s = spltty();

if (KBD_IS_BUSY(kbd)) {

error = (*kbd->kb_callback.kc_func)(kbd, KBDIO_UNLOADING,

kbd->kb_callback.kc_arg);

if (error) {

- splx(s);

return (error);

}

if (KBD_IS_BUSY(kbd)) {

- splx(s);

return (EBUSY);

}

KBD_INVALID(kbd);

keyboard[kbd->kb_index] = NULL;

- splx(s);

return (0);

}

@@ -333,16 +328,14 @@ kbd_allocate(char *driver, int unit, void *id, kbd_callback_func_t *func,

void *arg)

{

int index;

- int s;

+ GIANT_REQUIRED;

if (func == NULL)

return (-1);

- s = spltty();

index = kbd_find_keyboard(driver, unit);

if (index >= 0) {

if (KBD_IS_BUSY(keyboard[index])) {

- splx(s);

return (-1);

}

keyboard[index]->kb_token = id;

@@ -351,7 +344,6 @@ kbd_allocate(char *driver, int unit, void *id, kbd_callback_func_t *func,

keyboard[index]->kb_callback.kc_arg = arg;

kbdd_clear_state(keyboard[index]);

}

- splx(s);

return (index);

}

@@ -359,9 +351,8 @@ int

kbd_release(keyboard_t *kbd, void *id)

{

int error;

- int s;

- s = spltty();

+ GIANT_REQUIRED;

if (!KBD_IS_VALID(kbd) || !KBD_IS_BUSY(kbd)) {

error = EINVAL;

} else if (kbd->kb_token != id) {

@@ -374,7 +365,6 @@ kbd_release(keyboard_t *kbd, void *id)

kbdd_clear_state(kbd);

error = 0;

}

- splx(s);

return (error);

}

@@ -383,9 +373,8 @@ kbd_change_callback(keyboard_t *kbd, void *id, kbd_callback_func_t *func,

void *arg)

{

int error;

- int s;

- s = spltty();

+ GIANT_REQUIRED;

if (!KBD_IS_VALID(kbd) || !KBD_IS_BUSY(kbd)) {

error = EINVAL;

} else if (kbd->kb_token != id) {

@@ -397,7 +386,6 @@ kbd_change_callback(keyboard_t *kbd, void *id, kbd_callback_func_t *func,

kbd->kb_callback.kc_arg = arg;

error = 0;

}

- splx(s);

return (error);

}

@@ -542,20 +530,17 @@ genkbdopen(struct cdev *dev, int mode, int flag, struct thread *td)

{

keyboard_t *kbd;

genkbd_softc_t *sc;

- int s;

int i;

- s = spltty();

+ GIANT_REQUIRED;

sc = dev->si_drv1;

kbd = kbd_get_keyboard(KBD_INDEX(dev));

if ((sc == NULL) || (kbd == NULL) || !KBD_IS_VALID(kbd)) {

- splx(s);

return (ENXIO);

}

i = kbd_allocate(kbd->kb_name, kbd->kb_unit, sc,

genkbd_event, (void *)sc);

if (i < 0) {

- splx(s);

return (EBUSY);

}

/* assert(i == kbd->kb_index) */

@@ -567,7 +552,6 @@ genkbdopen(struct cdev *dev, int mode, int flag, struct thread *td)

sc->gkb_q_length = 0;

- splx(s);

return (0);

}

@@ -577,13 +561,12 @@ genkbdclose(struct cdev *dev, int mode, int flag, struct thread *td)

{

keyboard_t *kbd;

genkbd_softc_t *sc;

- int s;

+ GIANT_REQUIRED;

* NOTE: the device may have already become invalid.

* kbd == NULL || !KBD_IS_VALID(kbd)

- s = spltty();

sc = dev->si_drv1;

kbd = kbd_get_keyboard(KBD_INDEX(dev));

if ((sc == NULL) || (kbd == NULL) || !KBD_IS_VALID(kbd)) {

@@ -591,7 +574,6 @@ genkbdclose(struct cdev *dev, int mode, int flag, struct thread *td)

} else {

kbd_release(kbd, (void *)sc);

}

- splx(s);

return (0);

}

@@ -603,35 +585,29 @@ genkbdread(struct cdev *dev, struct uio *uio, int flag)

u_char buffer[KB_BUFSIZE];

int len;

int error;

- int s;

+ GIANT_REQUIRED;

/* wait for input */

- s = spltty();

sc = dev->si_drv1;

kbd = kbd_get_keyboard(KBD_INDEX(dev));

if ((sc == NULL) || (kbd == NULL) || !KBD_IS_VALID(kbd)) {

- splx(s);

return (ENXIO);

}

while (sc->gkb_q_length == 0) {

if (flag & O_NONBLOCK) {

- splx(s);

return (EWOULDBLOCK);

}

sc->gkb_flags |= KB_ASLEEP;

error = tsleep(sc, PZERO | PCATCH, "kbdrea", 0);

kbd = kbd_get_keyboard(KBD_INDEX(dev));

if ((kbd == NULL) || !KBD_IS_VALID(kbd)) {

- splx(s);

return (ENXIO); /* our keyboard has gone... */

}

if (error) {

sc->gkb_flags &= ~KB_ASLEEP;

- splx(s);

return (error);

}

- splx(s);

/* copy as much input as possible */

error = 0;

@@ -680,10 +656,9 @@ genkbdpoll(struct cdev *dev, int events, struct thread *td)

keyboard_t *kbd;

genkbd_softc_t *sc;

int revents;

- int s;

+ GIANT_REQUIRED;

revents = 0;

- s = spltty();

sc = dev->si_drv1;

kbd = kbd_get_keyboard(KBD_INDEX(dev));

if ((sc == NULL) || (kbd == NULL) || !KBD_IS_VALID(kbd)) {

@@ -694,7 +669,6 @@ genkbdpoll(struct cdev *dev, int events, struct thread *td)

else

selrecord(td, &sc->gkb_rsel);

}

- splx(s);

return (revents);

}

@@ -818,11 +792,10 @@ genkbd_commonioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)

okeymap_t *omapp;

keyarg_t *keyp;

fkeyarg_t *fkeyp;

- int s;

int i, j;

int error;

- s = spltty();

+ GIANT_REQUIRED;

switch (cmd) {

case KDGKBINFO: /* get keyboard information */

@@ -848,7 +821,6 @@ genkbd_commonioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)

case GIO_KEYMAP: /* get keyboard translation table */

error = copyout(kbd->kb_keymap, *(void **)arg,

sizeof(keymap_t));

- splx(s);

return (error);

case OGIO_KEYMAP: /* get keyboard translation table (compat) */

mapp = kbd->kb_keymap;

@@ -879,7 +851,6 @@ genkbd_commonioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)

} else {

error = copyin(*(void **)arg, mapp, sizeof *mapp);

if (error != 0) {

- splx(s);

free(mapp, M_TEMP);

return (error);

}

@@ -887,7 +858,6 @@ genkbd_commonioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)

error = keymap_change_ok(kbd->kb_keymap, mapp, curthread);

if (error != 0) {

- splx(s);

free(mapp, M_TEMP);

return (error);

}

@@ -896,7 +866,6 @@ genkbd_commonioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)

free(mapp, M_TEMP);

break;

#else

- splx(s);

return (ENODEV);

#endif

@@ -904,7 +873,6 @@ genkbd_commonioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)

keyp = (keyarg_t *)arg;

if (keyp->keynum >= sizeof(kbd->kb_keymap->key) /

sizeof(kbd->kb_keymap->key[0])) {

- splx(s);

return (EINVAL);

}

bcopy(&kbd->kb_keymap->key[keyp->keynum], &keyp->key,

@@ -915,20 +883,17 @@ genkbd_commonioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)

keyp = (keyarg_t *)arg;

if (keyp->keynum >= sizeof(kbd->kb_keymap->key) /

sizeof(kbd->kb_keymap->key[0])) {

- splx(s);

return (EINVAL);

}

error = key_change_ok(&kbd->kb_keymap->key[keyp->keynum],

&keyp->key, curthread);

if (error != 0) {

- splx(s);

return (error);

}

bcopy(&keyp->key, &kbd->kb_keymap->key[keyp->keynum],

sizeof(keyp->key));

break;

#else

- splx(s);

return (ENODEV);

#endif

@@ -940,20 +905,17 @@ genkbd_commonioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)

error = accent_change_ok(kbd->kb_accentmap,

(accentmap_t *)arg, curthread);

if (error != 0) {

- splx(s);

return (error);

}

bcopy(arg, kbd->kb_accentmap, sizeof(*kbd->kb_accentmap));

break;

#else

- splx(s);

return (ENODEV);

#endif

case GETFKEY: /* get functionkey string */

fkeyp = (fkeyarg_t *)arg;

if (fkeyp->keynum >= kbd->kb_fkeytab_size) {

- splx(s);

return (EINVAL);

}

bcopy(kbd->kb_fkeytab[fkeyp->keynum].str, fkeyp->keydef,

@@ -964,13 +926,11 @@ genkbd_commonioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)

#ifndef KBD_DISABLE_KEYMAP_LOAD

fkeyp = (fkeyarg_t *)arg;

if (fkeyp->keynum >= kbd->kb_fkeytab_size) {

- splx(s);

return (EINVAL);

}

error = fkey_change_ok(&kbd->kb_fkeytab[fkeyp->keynum],

fkeyp, curthread);

if (error != 0) {

- splx(s);

return (error);

}

kbd->kb_fkeytab[fkeyp->keynum].len = min(fkeyp->flen, MAXFK);

@@ -978,16 +938,13 @@ genkbd_commonioctl(keyboard_t *kbd, u_long cmd, caddr_t arg)

kbd->kb_fkeytab[fkeyp->keynum].len);

break;

#else

- splx(s);

return (ENODEV);

#endif

default:

- splx(s);

return (ENOIOCTL);

}

- splx(s);

return (0);

}