622959ede4
Prior this patch the startup lock was not released if the call of '_associate()' failed. In this condition, the caller of the constructor was infinitely blocked.
270 lines
5.4 KiB
C++
270 lines
5.4 KiB
C++
/**
|
|
* \brief Shared-interrupt support
|
|
* \author Christian Helmuth
|
|
* \author Sebastian Sumpf
|
|
* \date 2009-12-15
|
|
*/
|
|
|
|
#ifndef _CORE__INCLUDE__IRQ_PROXY_H_
|
|
#define _CORE__INCLUDE__IRQ_PROXY_H_
|
|
|
|
#include <base/env.h>
|
|
#include <util.h>
|
|
#include <base/thread.h>
|
|
|
|
|
|
namespace Genode {
|
|
class Irq_blocker;
|
|
template <typename THREAD> class Irq_proxy;
|
|
class Irq_thread_dummy;
|
|
class Irq_proxy_single;
|
|
}
|
|
|
|
|
|
class Genode::Irq_blocker : public Genode::List<Genode::Irq_blocker>::Element
|
|
{
|
|
private:
|
|
|
|
Lock _wait_lock;
|
|
|
|
public:
|
|
|
|
Irq_blocker() : _wait_lock(Lock::LOCKED) { }
|
|
|
|
void block() { _wait_lock.lock(); }
|
|
void unblock() { _wait_lock.unlock(); }
|
|
};
|
|
|
|
|
|
/*
|
|
* Proxy thread that associates to the interrupt and unblocks waiting irqctrl
|
|
* threads. Maybe, we should utilize our signals for interrupt delivery...
|
|
*
|
|
* XXX resources are not accounted as the interrupt is shared
|
|
*/
|
|
template <typename THREAD>
|
|
class Genode::Irq_proxy : public THREAD,
|
|
public Genode::List<Genode::Irq_proxy<THREAD> >::Element
|
|
{
|
|
protected:
|
|
|
|
char _name[32];
|
|
Lock _startup_lock;
|
|
|
|
long _irq_number;
|
|
|
|
Lock _mutex; /* protects this object */
|
|
int _num_sharers; /* number of clients sharing this IRQ */
|
|
Semaphore _sleep; /* wake me up if aspired blockers return */
|
|
List<Irq_blocker> _blocker_list;
|
|
int _num_blockers; /* number of currently blocked clients */
|
|
bool _woken_up; /* client decided to wake me up -
|
|
this prevents multiple wakeups
|
|
to happen during initialization */
|
|
|
|
|
|
/***************
|
|
** Interface **
|
|
***************/
|
|
|
|
/**
|
|
* Request interrupt
|
|
*
|
|
* \return true on success
|
|
*/
|
|
virtual bool _associate() = 0;
|
|
|
|
/**
|
|
* Wait for associated interrupt
|
|
*/
|
|
virtual void _wait_for_irq() = 0;
|
|
|
|
/**
|
|
* Acknowledge interrupt
|
|
*/
|
|
virtual void _ack_irq() = 0;
|
|
|
|
/********************
|
|
** Implementation **
|
|
********************/
|
|
|
|
const char *_construct_name(long irq_number)
|
|
{
|
|
snprintf(_name, sizeof(_name), "irqproxy%02lx", irq_number);
|
|
return _name;
|
|
}
|
|
|
|
void _loop()
|
|
{
|
|
/* wait for first blocker */
|
|
_sleep.down();
|
|
|
|
while (1) {
|
|
_wait_for_irq();
|
|
|
|
{
|
|
Lock::Guard lock_guard(_mutex);
|
|
|
|
/* inform blocked clients */
|
|
Irq_blocker *b;
|
|
while ((b = _blocker_list.first())) {
|
|
_blocker_list.remove(b);
|
|
b->unblock();
|
|
}
|
|
|
|
/* reset blocker state */
|
|
_num_blockers = 0;
|
|
_woken_up = false;
|
|
}
|
|
|
|
/*
|
|
* We must wait for all clients to ack their interrupt,
|
|
* otherwise level-triggered interrupts will occur immediately
|
|
* after acknowledgement. That's an inherent security problem
|
|
* with shared IRQs and induces problems with dynamic driver
|
|
* load and unload.
|
|
*/
|
|
_sleep.down();
|
|
|
|
/* acknowledge previous interrupt */
|
|
_ack_irq();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Start this thread, should be called externally from derived class
|
|
*/
|
|
virtual void _start()
|
|
{
|
|
THREAD::start();
|
|
_startup_lock.lock();
|
|
}
|
|
|
|
public:
|
|
|
|
Irq_proxy(long irq_number)
|
|
:
|
|
THREAD(_construct_name(irq_number)),
|
|
_startup_lock(Lock::LOCKED), _irq_number(irq_number),
|
|
_mutex(Lock::UNLOCKED), _num_sharers(0), _num_blockers(0), _woken_up(false)
|
|
{ }
|
|
|
|
/**
|
|
* Thread interface
|
|
*/
|
|
void entry()
|
|
{
|
|
bool const associate_suceeded = _associate();
|
|
|
|
_startup_lock.unlock();
|
|
|
|
if (associate_suceeded)
|
|
_loop();
|
|
}
|
|
|
|
/**
|
|
* Block until interrupt occured
|
|
*/
|
|
virtual void wait_for_irq()
|
|
{
|
|
Irq_blocker blocker;
|
|
{
|
|
Lock::Guard lock_guard(_mutex);
|
|
|
|
_blocker_list.insert(&blocker);
|
|
_num_blockers++;
|
|
|
|
/*
|
|
* The proxy thread is woken up if no client woke it up before
|
|
* and this client is the last aspired blocker.
|
|
*/
|
|
if (!_woken_up && _num_blockers == _num_sharers) {
|
|
_sleep.up();
|
|
_woken_up = true;
|
|
}
|
|
}
|
|
blocker.block();
|
|
}
|
|
|
|
|
|
long irq_number() const { return _irq_number; }
|
|
|
|
virtual bool add_sharer()
|
|
{
|
|
Lock::Guard lock_guard(_mutex);
|
|
++_num_sharers;
|
|
return true;
|
|
}
|
|
|
|
template <typename PROXY>
|
|
static PROXY *get_irq_proxy(long irq_number, Range_allocator *irq_alloc = 0)
|
|
{
|
|
static List<Irq_proxy> proxies;
|
|
static Lock proxies_lock;
|
|
|
|
Lock::Guard lock_guard(proxies_lock);
|
|
|
|
/* lookup proxy in database */
|
|
for (Irq_proxy *p = proxies.first(); p; p = p->next())
|
|
if (p->irq_number() == irq_number)
|
|
return static_cast<PROXY *>(p);
|
|
|
|
/* try to create proxy */
|
|
if (!irq_alloc || irq_alloc->alloc_addr(1, irq_number).is_error())
|
|
return 0;
|
|
|
|
PROXY *new_proxy = new (env()->heap()) PROXY(irq_number);
|
|
proxies.insert(new_proxy);
|
|
return new_proxy;
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Dummy thread
|
|
*/
|
|
class Genode::Irq_thread_dummy
|
|
{
|
|
public:
|
|
|
|
Irq_thread_dummy(char const *name) { }
|
|
void start() { }
|
|
};
|
|
|
|
|
|
/**
|
|
* Non-threaded proxy that disables shared interrupts
|
|
*/
|
|
class Genode::Irq_proxy_single : public Genode::Irq_proxy<Genode::Irq_thread_dummy>
|
|
{
|
|
protected:
|
|
|
|
void _start()
|
|
{
|
|
_associate();
|
|
}
|
|
|
|
public:
|
|
|
|
Irq_proxy_single(long irq_number) : Irq_proxy(irq_number) { }
|
|
|
|
bool add_sharer()
|
|
{
|
|
Lock::Guard lock_guard(_mutex);
|
|
|
|
if (_num_sharers)
|
|
return false;
|
|
|
|
_num_sharers = 1;
|
|
return true;
|
|
}
|
|
|
|
void wait_for_irq()
|
|
{
|
|
_wait_for_irq();
|
|
_ack_irq();
|
|
}
|
|
};
|
|
|
|
#endif /* _CORE__INCLUDE__IRQ_PROXY_H_ */
|