freebsd-src/sys/mips/include/smp.h
Attilio Rao dc6fbf6545 * Completely Remove the option STOP_NMI from the kernel. This option
has proven to have a good effect when entering KDB by using a NMI,
but it completely violates all the good rules about interrupts
disabled while holding a spinlock in other occasions.  This can be the
cause of deadlocks on events where a normal IPI_STOP is expected.
* Adds an new IPI called IPI_STOP_HARD on all the supported architectures.
This IPI is responsible for sending a stop message among CPUs using a
privileged channel when disponible. In other cases it just does match a
normal IPI_STOP.
Right now the IPI_STOP_HARD functionality uses a NMI on ia32 and amd64
architectures, while on the other has a normal IPI_STOP effect. It is
responsibility of maintainers to eventually implement an hard stop
when necessary and possible.
* Use the new IPI facility in order to implement a new userend SMP kernel
function called stop_cpus_hard(). That is specular to stop_cpu() but
it does use the privileged channel for the stopping facility.
* Let KDB use the newly introduced function stop_cpus_hard() and leave
stop_cpus() for all the other cases
* Disable interrupts on CPU0 when starting the process of APs suspension.
* Style cleanup and comments adding

This patch should fix the reboot/shutdown deadlocks many users are
constantly reporting on mailing lists.

Please don't forget to update your config file with the STOP_NMI
option removal

Reviewed by:	jhb
Tested by:	pho, bz, rink
Approved by:	re (kib)
2009-08-13 17:09:45 +00:00

43 lines
1.1 KiB
C

/*-
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <phk@FreeBSD.org> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*
* from: src/sys/alpha/include/smp.h,v 1.8 2005/01/05 20:05:50 imp
* JNPR: smp.h,v 1.3 2006/12/02 09:53:41 katta
* $FreeBSD$
*
*/
#ifndef _MACHINE_SMP_H_
#define _MACHINE_SMP_H_
#ifdef _KERNEL
/*
* Interprocessor interrupts for SMP.
*/
#define IPI_INVLTLB 0x0001
#define IPI_RENDEZVOUS 0x0002
#define IPI_AST 0x0004
#define IPI_STOP 0x0008
#define IPI_STOP_HARD 0x0008
#ifndef LOCORE
extern u_int32_t boot_cpu_id;
void ipi_selected(u_int cpus, u_int32_t ipi);
void ipi_all_but_self(u_int32_t ipi);
intrmask_t smp_handle_ipi(struct trapframe *frame);
void smp_init_secondary(u_int32_t cpuid);
void mips_ipi_send(int thread_id);
#endif /* !LOCORE */
#endif /* _KERNEL */
#endif /* _MACHINE_SMP_H_ */