genode/repos/base-hw/src/core/kernel/cpu.h

/*
 * \brief   Class for kernel data that is needed to manage a specific CPU
 * \author  Martin Stein
 * \author  Stefan Kalkowski
 * \date    2014-01-14
 */

/*
 * Copyright (C) 2014-2017 Genode Labs GmbH
 *
 * This file is part of the Genode OS framework, which is distributed
 * under the terms of the GNU Affero General Public License version 3.
 */

#ifndef _CORE__KERNEL__CPU_H_
#define _CORE__KERNEL__CPU_H_

/* core includes */
#include <kernel/cpu_context.h>
#include <kernel/irq.h>
#include <kernel/thread.h>

namespace Kernel
{
	/**
	 * Class for kernel data that is needed to manage a specific CPU
	 */
	class Cpu;

	/**
	 * Provides a CPU object for every available CPU
	 */
	class Cpu_pool;

	/**
	 * Return singleton of CPU pool
	 */
	Cpu_pool * cpu_pool();
}

class Kernel::Cpu : public Genode::Cpu, public Irq::Pool, private Timeout
{
	private:

		typedef Cpu_job Job;

		/**
		 * Inter-processor-interrupt object of the cpu
		 */
		struct Ipi : Irq
		{
			bool pending = false;


			/*********************
			 **  Irq interface  **
			 *********************/

			void occurred();

			/**
			 * Constructor
			 *
			 * \param p  interrupt pool this irq shall reside in
			 */
			Ipi(Irq::Pool &p);

			/**
			 * Trigger the ipi
			 *
			 * \param cpu_id  id of the cpu this ipi object is related to
			 */
			void trigger(unsigned const cpu_id);
		};


		struct Idle_thread : Kernel::Thread
		{
			/**
			 * Construct idle context for CPU 'cpu'
			 */
			Idle_thread(Cpu * const cpu);
		};


		unsigned const _id;
		Timer          _timer;
		Cpu_scheduler  _scheduler;
		Idle_thread    _idle;
		Ipi            _ipi_irq;
		Irq            _timer_irq; /* timer IRQ implemented as empty event */

		unsigned _quota() const { return _timer.us_to_ticks(cpu_quota_us); }
		unsigned _fill() const  { return _timer.us_to_ticks(cpu_fill_us); }

	public:

		enum { KERNEL_STACK_SIZE = 16 * 1024 * sizeof(Genode::addr_t) };

		/**
		 * Construct object for CPU 'id'
		 */
		Cpu(unsigned const id);

		/**
		 * Initialize primary cpu object
		 *
		 * \param pic      interrupt controller object
		 * \param core_pd  core's pd object
		 * \param board    object encapsulating board specifics
		 */
		void init(Pic &pic/*, Kernel::Pd &core_pd, Genode::Board & board*/);

		/**
		 * Raise the IPI of the CPU
		 */
		void trigger_ip_interrupt() { _ipi_irq.trigger(_id); }

		/**
		 * Deliver interrupt to the CPU
		 *
		 * \param irq_id  id of the interrupt that occured
		 * \returns true if the interrupt belongs to this CPU, otherwise false
		 */
		bool interrupt(unsigned const irq_id);

		/**
		 * Schedule 'job' at this CPU
		 */
		void schedule(Job * const job);

		/**
		 * Return the job that should be executed at next
		 */
		Cpu_job& schedule();

		void set_timeout(Timeout * const timeout, time_t const duration_us);

		time_t timeout_age_us(Timeout const * const timeout) const;

		time_t timeout_max_us() const;

		time_t time() const { return _timer.time(); }

		/***************
		 ** Accessors **
		 ***************/

		/**
		 * Returns the currently active job
		 */
		Job & scheduled_job() const {
			return *static_cast<Job *>(_scheduler.head())->helping_sink(); }

		unsigned id() const { return _id; }
		Cpu_scheduler * scheduler() { return &_scheduler; }

		time_t us_to_ticks(time_t const us) const { return _timer.us_to_ticks(us); };

		unsigned timer_interrupt_id() const { return _timer.interrupt_id(); }
};

class Kernel::Cpu_pool
{
	private:

		/*
		 * Align to machine word size, otherwise load/stores might fail on some
		 * platforms.
		 */
		char _cpus[NR_OF_CPUS][sizeof(Cpu)]
		     __attribute__((aligned(sizeof(addr_t))));

	public:

		Cpu_pool();

		/**
		 * Return object of CPU 'id'
		 */
		Cpu * cpu(unsigned const id) const;

		/**
		 * Return object of primary CPU
		 */
		Cpu * primary_cpu() const { return cpu(Cpu::primary_id()); }

		/**
		 * Return object of current CPU
		 */
		Cpu * executing_cpu() const { return cpu(Cpu::executing_id()); }

		template <typename FUNC>
		void for_each_cpu(FUNC const &func) const
		{
			for (unsigned i = 0; i < sizeof(_cpus)/sizeof(_cpus[i]); i++) {
				func(*cpu(i));
			}
		}
};

#endif /* _CORE__KERNEL__CPU_H_ */