haiku/src/system/kernel/cpu.c
Axel Dörfler df213cedbc * CPUs can now be disabled - that is, they will keep idling.
* Added syscalls _kern_set_cpu_enabled() and _kern_cpu_enabled().
* scheduler.c::sRunQueue::tail was not maintained at all; changed sRunQueue to
  be a simple thread pointer instead of a struct thread_queue.
* Turns out we're monitoring CPU activity incorrectly when we've got more
  than one CPU.
* Renamed the global CPU array from "cpu" to gCPU.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16186 a95241bf-73f2-0310-859d-f6bbb57e9c96
2006-02-01 16:09:05 +00:00

123 lines
2.0 KiB
C

/*
* Copyright 2002-2006, Axel Dörfler, axeld@pinc-software.de.
* Distributed under the terms of the MIT License.
*
* Copyright 2002, Travis Geiselbrecht. All rights reserved.
* Distributed under the terms of the NewOS License.
*/
/* This file contains the cpu functions (init, etc). */
#include <kernel.h>
#include <cpu.h>
#include <vm.h>
#include <arch/cpu.h>
#include <boot/kernel_args.h>
#include <string.h>
/* global per-cpu structure */
cpu_ent gCPU[MAX_BOOT_CPUS];
static spinlock sSetCpuLock;
status_t
cpu_init(kernel_args *args)
{
int i;
memset(gCPU, 0, sizeof(gCPU));
for (i = 0; i < MAX_BOOT_CPUS; i++) {
gCPU[i].info.cpu_num = i;
}
return arch_cpu_init(args);
}
status_t
cpu_init_post_vm(kernel_args *args)
{
return arch_cpu_init_post_vm(args);
}
status_t
cpu_init_post_modules(kernel_args *args)
{
return arch_cpu_init_post_modules(args);
}
status_t
cpu_preboot_init(kernel_args *args)
{
return arch_cpu_preboot_init(args);
}
void
clear_caches(void *address, size_t length, uint32 flags)
{
// ToDo: implement me!
}
// #pragma mark -
void
_user_clear_caches(void *address, size_t length, uint32 flags)
{
clear_caches(address, length, flags);
}
bool
_user_cpu_enabled(int32 cpu)
{
if (cpu < 0 || cpu >= smp_get_num_cpus())
return B_BAD_VALUE;
return !gCPU[cpu].info.disabled;
}
status_t
_user_set_cpu_enabled(int32 cpu, bool enabled)
{
status_t status = B_OK;
cpu_status state;
int32 i, count;
if (cpu < 0 || cpu >= smp_get_num_cpus())
return B_BAD_VALUE;
// We need to lock here to make sure that no one can disable
// the last CPU
state = disable_interrupts();
acquire_spinlock(&sSetCpuLock);
if (!enabled) {
// check if this is the last CPU to be disabled
for (i = 0, count = 0; i < smp_get_num_cpus(); i++) {
if (!gCPU[i].info.disabled)
count++;
}
if (count == 1)
status = B_NOT_ALLOWED;
}
if (status == B_OK)
gCPU[cpu].info.disabled = !enabled;
release_spinlock(&sSetCpuLock);
restore_interrupts(state);
return status;
}