freebsd-dev/sys/dev/dpaa/bman_portals.c
Jeff Roberson 686bcb5c14 schedlock 4/4
Don't hold the scheduler lock while doing context switches.  Instead we
unlock after selecting the new thread and switch within a spinlock
section leaving interrupts and preemption disabled to prevent local
concurrency.  This means that mi_switch() is entered with the thread
locked but returns without.  This dramatically simplifies scheduler
locking because we will not hold the schedlock while spinning on
blocked lock in switch.

This change has not been made to 4BSD but in principle it would be
more straightforward.

Discussed with:	markj
Reviewed by:	kib
Tested by:	pho
Differential Revision: https://reviews.freebsd.org/D22778
2019-12-15 21:26:50 +00:00

180 lines
4.4 KiB
C

/*-
* Copyright (c) 2012 Semihalf.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "opt_platform.h"
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/pcpu.h>
#include <sys/sched.h>
#include <machine/bus.h>
#include <machine/tlb.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <powerpc/mpc85xx/mpc85xx.h>
#include "bman.h"
#include "portals.h"
t_Handle bman_portal_setup(struct bman_softc *);
struct dpaa_portals_softc *bp_sc;
int
bman_portals_attach(device_t dev)
{
struct dpaa_portals_softc *sc;
sc = bp_sc = device_get_softc(dev);
/* Map bman portal to physical address space */
if (law_enable(OCP85XX_TGTIF_BMAN, sc->sc_dp_pa, sc->sc_dp_size)) {
bman_portals_detach(dev);
return (ENXIO);
}
/* Set portal properties for XX_VirtToPhys() */
XX_PortalSetInfo(dev);
return (bus_generic_attach(dev));
}
int
bman_portals_detach(device_t dev)
{
struct dpaa_portals_softc *sc;
int i;
bp_sc = NULL;
sc = device_get_softc(dev);
for (i = 0; i < ARRAY_SIZE(sc->sc_dp); i++) {
if (sc->sc_dp[i].dp_ph != NULL) {
thread_lock(curthread);
sched_bind(curthread, i);
thread_unlock(curthread);
BM_PORTAL_Free(sc->sc_dp[i].dp_ph);
thread_lock(curthread);
sched_unbind(curthread);
thread_unlock(curthread);
}
if (sc->sc_dp[i].dp_ires != NULL) {
XX_DeallocIntr((uintptr_t)sc->sc_dp[i].dp_ires);
bus_release_resource(dev, SYS_RES_IRQ,
sc->sc_dp[i].dp_irid, sc->sc_dp[i].dp_ires);
}
}
for (i = 0; i < ARRAY_SIZE(sc->sc_rres); i++) {
if (sc->sc_rres[i] != NULL)
bus_release_resource(dev, SYS_RES_MEMORY,
sc->sc_rrid[i],
sc->sc_rres[i]);
}
return (0);
}
t_Handle
bman_portal_setup(struct bman_softc *bsc)
{
struct dpaa_portals_softc *sc;
t_BmPortalParam bpp;
t_Handle portal;
unsigned int cpu;
uintptr_t p;
/* Return NULL if we're not ready or while detach */
if (bp_sc == NULL)
return (NULL);
sc = bp_sc;
sched_pin();
portal = NULL;
cpu = PCPU_GET(cpuid);
/* Check if portal is ready */
while (atomic_cmpset_acq_ptr((uintptr_t *)&sc->sc_dp[cpu].dp_ph,
0, -1) == 0) {
p = atomic_load_acq_ptr((uintptr_t *)&sc->sc_dp[cpu].dp_ph);
/* Return if portal is already initialized */
if (p != 0 && p != -1) {
sched_unpin();
return ((t_Handle)p);
}
/* Not inititialized and "owned" by another thread */
thread_lock(curthread);
mi_switch(SW_VOL);
}
/* Map portal registers */
dpaa_portal_map_registers(sc);
/* Configure and initialize portal */
bpp.ceBaseAddress = rman_get_bushandle(sc->sc_rres[0]);
bpp.ciBaseAddress = rman_get_bushandle(sc->sc_rres[1]);
bpp.h_Bm = bsc->sc_bh;
bpp.swPortalId = cpu;
bpp.irq = (uintptr_t)sc->sc_dp[cpu].dp_ires;
portal = BM_PORTAL_Config(&bpp);
if (portal == NULL)
goto err;
if (BM_PORTAL_Init(portal) != E_OK)
goto err;
atomic_store_rel_ptr((uintptr_t *)&sc->sc_dp[cpu].dp_ph, (uintptr_t)portal);
sched_unpin();
return (portal);
err:
if (portal != NULL)
BM_PORTAL_Free(portal);
atomic_store_rel_ptr((uintptr_t *)&sc->sc_dp[cpu].dp_ph, 0);
sched_unpin();
return (NULL);
}