minix/kernel/smp.h
Tomas Hruby 0a55e63413 SMP - fixed IPI livelock
- two CPUs can issue IPI to each other now without any hazzard

- we must be able to handle synchronous scheduling IPIs from
  other CPUs when we are waiting for attention from another one.
  Otherwise we might livelock.

- necessary barriers to prevent reordering
2012-01-13 11:30:00 +00:00

83 lines
2.5 KiB
C

#ifndef __SMP_H__
#define __SMP_H__
#ifdef CONFIG_SMP
#ifndef __ASSEMBLY__
#include "kernel.h"
#include "arch_smp.h"
#include "spinlock.h"
/* number of CPUs (execution strands in the system */
EXTERN unsigned ncpus;
/* Number of virtual strands per physical core */
EXTERN unsigned ht_per_core;
/* which cpu is bootstraping */
EXTERN unsigned bsp_cpu_id;
#define cpu_is_bsp(cpu) (bsp_cpu_id == cpu)
/*
* SMP initialization is largely architecture dependent and each architecture
* must provide a method how to do it. If initiating SMP fails the function does
* not report it. However it must put the system in such a state that it falls
* back to a uniprocessor system. Although the uniprocessor configuration may be
* suboptimal, the system must be able to run on the bootstrap processor as if
* it was the only processor in the system
*/
_PROTOTYPE(void smp_init, (void));
#define CPU_IS_BSP 1
#define CPU_IS_READY 2
struct cpu {
u32_t flags;
};
EXTERN struct cpu cpus[CONFIG_MAX_CPUS];
#define cpu_set_flag(cpu, flag) do { cpus[cpu].flags |= (flag); } while(0)
#define cpu_clear_flag(cpu, flag) do { cpus[cpu].flags &= ~(flag); } while(0)
#define cpu_test_flag(cpu, flag) (cpus[cpu].flags & (flag))
#define cpu_is_ready(cpu) cpu_test_flag(cpu, CPU_IS_READY)
/*
* Big Kernel Lock prevents more then one cpu executing the kernel code
*/
SPINLOCK_DECLARE(big_kernel_lock)
/*
* to sync the booting APs
*/
SPINLOCK_DECLARE(boot_lock)
_PROTOTYPE(void wait_for_APs_to_finish_booting, (void));
_PROTOTYPE(void ap_boot_finished, (unsigned cpu));
_PROTOTYPE(void smp_shutdown_aps, (void ));
/* IPI handlers */
_PROTOTYPE(void smp_ipi_halt_handler, (void));
_PROTOTYPE(void smp_ipi_sched_handler, (void));
_PROTOTYPE(void smp_schedule, (unsigned cpu));
/* stop a processes on a different cpu */
_PROTOTYPE(void smp_schedule_stop_proc, (struct proc * p));
/* stop a process on a different cpu because its adress space is being changed */
_PROTOTYPE(void smp_schedule_vminhibit, (struct proc * p));
/* stop the process and for saving its full context */
_PROTOTYPE(void smp_schedule_stop_proc_save_ctx, (struct proc * p));
/* migrate the full context of a process to the destination CPU */
_PROTOTYPE(void smp_schedule_migrate_proc,
(struct proc * p, unsigned dest_cpu));
_PROTOTYPE(void arch_send_smp_schedule_ipi, (unsigned cpu));
_PROTOTYPE(void arch_smp_halt_cpu, (void));
/* deal with x-cpu scheduling event */
_PROTOTYPE(void smp_sched_handler, (void));
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_SMP */
#endif /* __SMP_H__ */