kernel/eka/nkernsmp/nkern.cpp
changeset 177 a232af6b0b1f
parent 90 947f0dc9f7a8
equal deleted inserted replaced
176:af6ec97d9189 177:a232af6b0b1f
  2844 	mb();
  2844 	mb();
  2845 	}
  2845 	}
  2846 
  2846 
  2847 /**	Stop all other CPUs
  2847 /**	Stop all other CPUs
  2848 
  2848 
  2849 	Call with kernel locked
  2849 Call with kernel unlocked, returns with kernel locked.
  2850 */
  2850 Returns mask of CPUs halted plus current CPU.
  2851 void TStopIPI::StopCPUs()
  2851 */
  2852 	{
  2852 TUint32 TStopIPI::StopCPUs()
       
  2853 	{
       
  2854 	CHECK_PRECONDITIONS(MASK_THREAD_STANDARD,"TStopIPI::StopCPUs()");
       
  2855 	TScheduler& s = TheScheduler;
  2853 	iFlag = 0;
  2856 	iFlag = 0;
       
  2857 	NKern::ThreadEnterCS();
       
  2858 
       
  2859 	// Stop any cores powering up or down for now
       
  2860 	// A core already on the way down will stop just before the transition to SHUTDOWN_FINAL
       
  2861 	// A core already on the way up will carry on powering up
       
  2862 	TInt irq = s.iGenIPILock.LockIrqSave();
       
  2863 	++s.iCCDeferCount;	// stops bits in iIpiAcceptCpus being cleared, but doesn't stop them being set
       
  2864 						// but iIpiAcceptCpus | s.iCpusComingUp is constant
       
  2865 	TUint32 act2 = s.iIpiAcceptCpus;		// CPUs still accepting IPIs
       
  2866 	TUint32 cu = s.iCpusComingUp;			// CPUs powering up
       
  2867 	s.iGenIPILock.UnlockIrqRestore(irq);
       
  2868 	TUint32 cores = act2 | cu;
       
  2869 	if (cu)
       
  2870 		{
       
  2871 		// wait for CPUs coming up to start accepting IPIs
       
  2872 		while (cores & ~s.iIpiAcceptCpus)
       
  2873 			{
       
  2874 			__snooze();	// snooze until cores have come up
       
  2875 			}
       
  2876 		}
       
  2877 	NKern::Lock();
  2854 	QueueAllOther(&Isr);	// send IPIs to all other CPUs
  2878 	QueueAllOther(&Isr);	// send IPIs to all other CPUs
  2855 	WaitEntry();			// wait for other CPUs to reach the ISR
  2879 	WaitEntry();			// wait for other CPUs to reach the ISR
  2856 	}
  2880 	return cores;
  2857 
  2881 	}
       
  2882 
       
  2883 
       
  2884 /**	Release the stopped CPUs
       
  2885 
       
  2886 Call with kernel locked, returns with kernel unlocked.
       
  2887 */
  2858 void TStopIPI::ReleaseCPUs()
  2888 void TStopIPI::ReleaseCPUs()
  2859 	{
  2889 	{
  2860 	iFlag = 1;				// allow other CPUs to proceed
  2890 	__e32_atomic_store_rel32(&iFlag, 1);	// allow other CPUs to proceed
  2861 	WaitCompletion();		// wait for them to finish with this IPI
  2891 	WaitCompletion();		// wait for them to finish with this IPI
       
  2892 	NKern::Unlock();
       
  2893 	TheScheduler.CCUnDefer();
       
  2894 	NKern::ThreadLeaveCS();
  2862 	}
  2895 	}
  2863 
  2896 
  2864 void TStopIPI::Isr(TGenericIPI* a)
  2897 void TStopIPI::Isr(TGenericIPI* a)
  2865 	{
  2898 	{
  2866 	TStopIPI* s = (TStopIPI*)a;
  2899 	TStopIPI* s = (TStopIPI*)a;
  2867 	while (!s->iFlag)
  2900 	while (!__e32_atomic_load_acq32(&s->iFlag))
  2868 		{
  2901 		{
  2869 		__chill();
  2902 		__chill();
  2870 		}
  2903 		}
       
  2904 	__e32_io_completion_barrier();
  2871 	}
  2905 	}
  2872 
  2906 
  2873 
  2907 
  2874 /******************************************************************************
  2908 /******************************************************************************
  2875  * TCoreCycler - general method to execute something on all active cores
  2909  * TCoreCycler - general method to execute something on all active cores