Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix pad on systems with many cores/cpus: 

* Introduce a lock to serialize attach/detach of pad devices.
	* Forcefully detach children of pad on close.
	* Be more carefull in pad_open with regards to config_detach only
	  if new instances of the pad device are created and fail to open.

Addresses PR kern/52889.

These changes were developed with and tested by pgoyette@.
This commit is contained in:
nat 2018-01-09 04:23:59 +00:00
parent a29d76a139
commit 6a9f5fca12
1 changed files with 62 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

96
sys/dev/pad/pad.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: pad.c,v 1.49 2017/12/17 21:57:11 pgoyette Exp $ */
/* $NetBSD: pad.c,v 1.50 2018/01/09 04:23:59 nat Exp $ */
/*-
* Copyright (c) 2007 Jared D. McNeill <jmcneill@invisible.ca>
@ -27,7 +27,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pad.c,v 1.49 2017/12/17 21:57:11 pgoyette Exp $");
__KERNEL_RCSID(0, "$NetBSD: pad.c,v 1.50 2018/01/09 04:23:59 nat Exp $");
#include <sys/types.h>
#include <sys/param.h>
@ -67,6 +67,7 @@ __KERNEL_RCSID(0, "$NetBSD: pad.c,v 1.49 2017/12/17 21:57:11 pgoyette Exp $");
#define PADENC AUDIO_ENCODING_SLINEAR_LE
extern struct cfdriver pad_cd;
kmutex_t padconfig;
typedef struct pad_block {
uint8_t *pb_ptr;
@ -200,6 +201,7 @@ padattach(int n)
config_cfdriver_detach(&pad_cd);
return;
}
mutex_init(&padconfig, MUTEX_DEFAULT, IPL_NONE);
return;
}
@ -286,34 +288,13 @@ static int
pad_detach(device_t self, int flags)
{
pad_softc_t *sc;
int cmaj, mn, rc;
int cmaj, mn;
sc = device_private(self);
config_deactivate(sc->sc_audiodev);
/* Start draining existing accessors of the device. */
if ((rc = config_detach_children(self, flags)) != 0)
return rc;
mutex_enter(&sc->sc_lock);
sc->sc_dying = true;
cv_broadcast(&sc->sc_condvar);
mutex_exit(&sc->sc_lock);
KASSERT(sc->sc_open > 0);
sc->sc_open = 0;
cmaj = cdevsw_lookup_major(&pad_cdevsw);
mn = device_unit(sc->sc_dev);
vdevgone(cmaj, mn, mn, VCHR);
pmf_device_deregister(sc->sc_dev);
mutex_destroy(&sc->sc_lock);
mutex_destroy(&sc->sc_intr_lock);
cv_destroy(&sc->sc_condvar);
auconv_delete_encodings(sc->sc_encodings);
if (!sc->sc_dying)
vdevgone(cmaj, mn, mn, VCHR);
return 0;
}
@ -327,16 +308,17 @@ pad_open(dev_t dev, int flags, int fmt, struct lwp *l)
cfdata_t cf;
int error, fd, i;
mutex_enter(&padconfig);
if (PADUNIT(dev) == PADCLONER) {
for (i = 0; i < MAXDEVS; i++) {
if (device_lookup(&pad_cd, i) == NULL)
break;
}
if (i == MAXDEVS)
return ENXIO;
goto bad;
} else {
if (PADUNIT(dev) >= MAXDEVS)
return ENXIO;
goto bad;
i = PADUNIT(dev);
}
@ -346,18 +328,23 @@ pad_open(dev_t dev, int flags, int fmt, struct lwp *l)
cf->cf_unit = i;
cf->cf_fstate = FSTATE_STAR;
bool existing = false;
paddev = device_lookup(&pad_cd, minor(dev));
if (paddev == NULL)
paddev = config_attach_pseudo(cf);
else
existing = true;
if (paddev == NULL)
return ENXIO;
goto bad;
sc = device_private(paddev);
if (sc == NULL)
return ENXIO;
goto bad;
if (sc->sc_open == 1)
if (sc->sc_open == 1) {
mutex_exit(&padconfig);
return EBUSY;
}
sc->sc_dev = paddev;
sc->sc_dying = false;
@ -365,7 +352,9 @@ pad_open(dev_t dev, int flags, int fmt, struct lwp *l)
if (PADUNIT(dev) == PADCLONER) {
error = fd_allocfile(&fp, &fd);
if (error) {
config_detach(sc->sc_dev, 0);
if (existing == false)
config_detach(sc->sc_dev, 0);
mutex_exit(&padconfig);
return error;
}
}
@ -373,7 +362,9 @@ pad_open(dev_t dev, int flags, int fmt, struct lwp *l)
if (auconv_create_encodings(pad_formats, PAD_NFORMATS,
&sc->sc_encodings) != 0) {
aprint_error_dev(sc->sc_dev, "couldn't create encodings\n");
config_detach(sc->sc_dev, 0);
if (existing == false)
config_detach(sc->sc_dev, 0);
mutex_exit(&padconfig);
return EINVAL;
}
@ -394,17 +385,52 @@ pad_open(dev_t dev, int flags, int fmt, struct lwp *l)
KASSERT(error == EMOVEFD);
}
sc->sc_open = 1;
mutex_exit(&padconfig);
return error;
bad:
mutex_exit(&padconfig);
return ENXIO;
}
static int
pad_close(struct pad_softc *sc)
{
int rc;
if (sc == NULL)
return ENXIO;
return config_detach(sc->sc_dev, DETACH_FORCE);
mutex_enter(&padconfig);
config_deactivate(sc->sc_audiodev);
/* Start draining existing accessors of the device. */
if ((rc = config_detach_children(sc->sc_dev,
DETACH_SHUTDOWN|DETACH_FORCE)) != 0) {
mutex_exit(&padconfig);
return rc;
}
mutex_enter(&sc->sc_lock);
sc->sc_dying = true;
cv_broadcast(&sc->sc_condvar);
mutex_exit(&sc->sc_lock);
KASSERT(sc->sc_open > 0);
sc->sc_open = 0;
pmf_device_deregister(sc->sc_dev);
mutex_destroy(&sc->sc_lock);
mutex_destroy(&sc->sc_intr_lock);
cv_destroy(&sc->sc_condvar);
auconv_delete_encodings(sc->sc_encodings);
rc = config_detach(sc->sc_dev, 0);
mutex_exit(&padconfig);
return rc;
}
static int
@ -942,6 +968,7 @@ pad_modcmd(modcmd_t cmd, void *arg)
pad_cfattach, cfdata_ioconf_pad);
break;
}
mutex_init(&padconfig, MUTEX_DEFAULT, IPL_NONE);
#endif
break;
@ -959,6 +986,7 @@ pad_modcmd(modcmd_t cmd, void *arg)
&pad_cdevsw, &cmajor);
break;
}
mutex_destroy(&padconfig);
#endif
break;