path: root/src/kernel/cpumgr.C

/* IBM_PROLOG_BEGIN_TAG                                                   */
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/* $Source: src/kernel/cpumgr.C $                                         */
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/* IBM CONFIDENTIAL                                                       */
/*                                                                        */
/* COPYRIGHT International Business Machines Corp. 2010,2012              */
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/* p1                                                                     */
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/* Object Code Only (OCO) source materials                                */
/* Licensed Internal Code Source Materials                                */
/* IBM HostBoot Licensed Internal Code                                    */
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/* The source code for this program is not published or otherwise         */
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/* Origin: 30                                                             */
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/* IBM_PROLOG_END_TAG                                                     */
#include <assert.h>
#include <kernel/cpumgr.H>
#include <kernel/task.H>
#include <kernel/cpu.H>
#include <kernel/scheduler.H>
#include <kernel/taskmgr.H>
#include <kernel/pagemgr.H>
#include <kernel/console.H>
#include <util/singleton.H>
#include <arch/ppc.H>
#include <kernel/timemgr.H>
#include <sys/sync.h>
#include <kernel/cpuid.H>
#include <kernel/ptmgr.H>
#include <kernel/heapmgr.H>
#include <kernel/intmsghandler.H>
#include <errno.h>
#include <kernel/deferred.H>
#include <kernel/misc.H>

cpu_t** CpuManager::cv_cpus[KERNEL_MAX_SUPPORTED_NODES];
bool CpuManager::cv_shutdown_requested = false;
uint64_t CpuManager::cv_shutdown_status = 0;
size_t CpuManager::cv_cpuSeq = 0;
bool CpuManager::cv_forcedMemPeriodic = false;
InteractiveDebug CpuManager::cv_interactive_debug;

CpuManager::CpuManager() : iv_lastStartTimebase(0)
{
    for (int i = 0; i < KERNEL_MAX_SUPPORTED_NODES; i++)
        cv_cpus[i] = NULL;

    memset(&cv_interactive_debug, '\0', sizeof(cv_interactive_debug));
}

cpu_t* CpuManager::getMasterCPU()
{
    for (int i = 0; i < KERNEL_MAX_SUPPORTED_NODES; i++)
    {
        if (NULL == cv_cpus[i])
        {
            continue;
        }

        for (int j = 0; j < KERNEL_MAX_SUPPORTED_CPUS_PER_NODE; j++)
        {
            if ((cv_cpus[i][j] != NULL) && (cv_cpus[i][j]->master))
            {
                return cv_cpus[i][j];
            }
        }
    }
    return NULL;
}

void CpuManager::init()
{
    // For the initial boot we only want to set up CPU objects for the threads
    // on this core.  Otherwise we waste memory with kernel / idle task stacks.
    //
    // As long as the CPU object pointer is NULL, the start.S code won't
    // enter the kernel, so we skip initializing all the other CPUs for now.

    // Determine number of threads on this core.
    size_t threads = getThreadCount();

    // Set up CPU structure.
    cv_cpus[getPIR() / KERNEL_MAX_SUPPORTED_CPUS_PER_NODE] =
        new cpu_t*[KERNEL_MAX_SUPPORTED_CPUS_PER_NODE];

    // Create CPU objects starting at the thread-0 for this core.
    size_t baseCpu = getCpuId() & ~(threads-1);
    for (size_t i = 0; i < threads; i++)
        Singleton<CpuManager>::instance().startCPU(i + baseCpu);
}

void CpuManager::init_slave_smp(cpu_t* cpu)
{
    Singleton<CpuManager>::instance().startSlaveCPU(cpu);
}

void CpuManager::requestShutdown(uint64_t i_status)
{
    cv_shutdown_status = i_status;
    __sync_synchronize();
    cv_shutdown_requested = true;

    class ExecuteShutdown : public DeferredWork
    {
        public:
            void masterPreWork()
            {
                // The stats can be retrieved from global variables as needed.
                // This can be uncommented for debug if desired
                #ifdef __MEMSTATS__
                if(c->master)
                    HeapManager::stats();
                #endif
            }

            void activeMainWork()
            {
                KernelMisc::shutdown();
            }

            void nonactiveMainWork()
            {
                // Something wasn't synchronized correctly if we got to here.
                // Should not have CPUs coming online while trying to execute
                // a shutdown.
                kassert(false);
            }
    };

    DeferredQueue::insert(new ExecuteShutdown());
}

void CpuManager::startCPU(ssize_t i)
{
    // Save away the current timebase for TB synchronization.
    iv_lastStartTimebase = getTB();

    bool currentCPU = false;
    if (i < 0)
    {
        i = getCpuId();
        currentCPU = true;
    }
    else if (getCpuId() == (uint64_t)i)
    {
        currentCPU = true;
    }

    size_t nodeId = i / KERNEL_MAX_SUPPORTED_CPUS_PER_NODE;
    size_t cpuId = i % KERNEL_MAX_SUPPORTED_CPUS_PER_NODE;

    // Initialize node structure.
    if (NULL == cv_cpus[nodeId])
    {
        cv_cpus[nodeId] = new cpu_t*[KERNEL_MAX_SUPPORTED_CPUS_PER_NODE];
    }

    // Initialize CPU structure.
    if (NULL == cv_cpus[nodeId][cpuId])
    {
        printk("Starting CPU %ld...", i);
        cpu_t* cpu = cv_cpus[nodeId][cpuId] = new cpu_t;

        // Initialize CPU.
        cpu->cpu = i;
        if (currentCPU)
        {
            cpu->master = true;
        }
        else
        {
            cpu->master = false;
        }
        cpu->scheduler = &Singleton<Scheduler>::instance();
        cpu->scheduler_extra = NULL;

        const size_t kernel_page_count = 4;
        const size_t kernel_page_offset = kernel_page_count * PAGESIZE -
                                          8 * sizeof(uint64_t);
        cpu->kernel_stack_bottom = PageManager::allocatePage(kernel_page_count);
        cpu->kernel_stack = reinterpret_cast<void*>(
            reinterpret_cast<uintptr_t>(cpu->kernel_stack_bottom) +
            kernel_page_offset);

        cpu->xscom_mutex = (mutex_t)MUTEX_INITIALIZER;

        // Create idle task.
        cpu->idle_task = TaskManager::createIdleTask();
        cpu->idle_task->cpu = cpu;
        cpu->periodic_count = 0;

        // Call TimeManager setup for a CPU.
        TimeManager::init_cpu(cpu);

        printk("done\n");
    }

    if (currentCPU)
    {
        setDEC(TimeManager::getTimeSliceCount());
        activateCPU(getCpu(i));
    }
    return;
}

void CpuManager::startSlaveCPU(cpu_t* cpu)
{
    // Activate CPU.
    activateCPU(cpu);

    // Sync timebase with master.
    while(getTB() < iv_lastStartTimebase)
    {
        class SyncTimebase : public DeferredWork
        {
            public:
                void masterPreWork()
                {
                    iv_timebase = getTB();
                }

                void activeMainWork()
                {
                    if (getTB() < iv_timebase)
                    {
                        setTB(iv_timebase);
                    }
                }

            private:
                uint64_t iv_timebase;
        };

        SyncTimebase* deferred = new SyncTimebase();
        DeferredQueue::insert(deferred);
        DeferredQueue::execute();
    }

    // Update decrementer.
    setDEC(TimeManager::getTimeSliceCount());

    return;
}

void CpuManager::activateCPU(cpu_t * i_cpu)
{
    // Set active.
    i_cpu->active = true;

    // Update sequence ID.
    do
    {
        uint64_t old_seq = cv_cpuSeq;
        i_cpu->cpu_start_seqid = old_seq + 1 + (1ull << 32);

        if (__sync_bool_compare_and_swap(&cv_cpuSeq, old_seq,
                                         i_cpu->cpu_start_seqid))
        {
            break;
        }
    } while (1);
    i_cpu->cpu_start_seqid >>= 32;

    // Verify / set SPRs.
    uint64_t msr = getMSR();
    kassert(WAKEUP_MSR_VALUE == msr);
    setLPCR(WAKEUP_LPCR_VALUE);
}

void CpuManager::deactivateCPU(cpu_t * i_cpu)
{
    // Set inactive.
    i_cpu->active = false;

    // Update sequence ID.
    do
    {
        uint64_t old_seq = cv_cpuSeq;
        uint64_t new_seq = old_seq - 1 + (1ull << 32);

        if (__sync_bool_compare_and_swap(&cv_cpuSeq, old_seq, new_seq))
        {
            break;
        }
    } while(1);
}

void CpuManager::executePeriodics(cpu_t * i_cpu)
{
    if(i_cpu->master)
    {
        if (cv_interactive_debug.isReady())
        {
            cv_interactive_debug.startDebugTask();
        }

        bool forceMemoryPeriodic = __sync_fetch_and_and(&cv_forcedMemPeriodic,
                                                        false);

        ++(i_cpu->periodic_count);
        if((0 == (i_cpu->periodic_count % CPU_PERIODIC_CHECK_MEMORY)) ||
           (forceMemoryPeriodic))
        {
            uint64_t pcntAvail = PageManager::queryAvail();
            if((pcntAvail < PageManager::LOWMEM_NORM_LIMIT) ||
               (forceMemoryPeriodic))
            {
                VmmManager::flushPageTable();
                ++(i_cpu->periodic_count);   // prevent another flush below
                if(pcntAvail < PageManager::LOWMEM_CRIT_LIMIT)
                {
                    VmmManager::castOutPages(VmmManager::CRITICAL);
                }
                else
                {
                    VmmManager::castOutPages(VmmManager::NORMAL);
                }
            }
        }
        if(0 == (i_cpu->periodic_count % CPU_PERIODIC_FLUSH_PAGETABLE))
        {
            VmmManager::flushPageTable();
        }
        if((0 == (i_cpu->periodic_count % CPU_PERIODIC_DEFRAG)) ||
           (forceMemoryPeriodic))
        {
            class MemoryCoalesce : public DeferredWork
            {
                public:
                    void masterPreWork()
                    {
                        HeapManager::coalesce();
                        PageManager::coalesce();
                    }
            };

            DeferredQueue::insert(new MemoryCoalesce());
        }
    }

    DeferredQueue::execute();

}

int CpuManager::startCore(uint64_t pir)
{
    size_t threads = getThreadCount();
    pir = pir & ~(threads-1);

    if (pir >=
        (KERNEL_MAX_SUPPORTED_NODES * KERNEL_MAX_SUPPORTED_CPUS_PER_NODE))
    {
        return -ENXIO;
    }

    for(size_t i = 0; i < threads; i++)
    {
        Singleton<CpuManager>::instance().startCPU(pir + i);
    }
    __sync_synchronize();

    InterruptMsgHdlr::addCpuCore(pir);

    return 0;
};

size_t CpuManager::getThreadCount()
{
    size_t threads = 0;
    switch (CpuID::getCpuType())
    {
        case CORE_POWER8_VENICE:
        case CORE_POWER8_MURANO:
            threads = 8;
            break;

        case CORE_UNKNOWN:
        default:
            kassert(false);
            break;
    }

    return threads;
}

void CpuManager::forceMemoryPeriodic()
{
    cv_forcedMemPeriodic = true;
}