/*
* \brief Paging-server framework
* \author Norman Feske
* \date 2006-04-28
*/
/*
* Copyright (C) 2006-2017 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__INCLUDE__PAGER_H_
#define _CORE__INCLUDE__PAGER_H_
/* Genode includes */
#include
#include
#include
#include
#include
#include
/* NOVA includes */
#include
/* core-local includes */
#include
#include
namespace Genode {
typedef Cpu_session::Thread_creation_failed Invalid_thread;
class Pager_entrypoint;
class Pager_object;
class Exception_handlers
{
private:
template
__attribute__((regparm(1))) static void _handler(Pager_object &);
public:
Exception_handlers(Pager_object &);
template
void register_handler(Pager_object &, Nova::Mtd,
void (__attribute__((regparm(1)))*)(Pager_object &) = nullptr);
};
class Pager_object : public Object_pool::Entry
{
private:
unsigned long _badge; /* used for debugging */
/**
* User-level signal handler registered for this pager object via
* 'Cpu_session::exception_handler()'.
*/
Signal_context_capability _exception_sigh { };
/**
* selectors for
* - cleanup portal
* - semaphore used by caller used to notify paused state
* - semaphore used to block during page fault handling or pausing
*/
addr_t _selectors;
addr_t _initial_esp = 0;
addr_t _initial_eip = 0;
addr_t _client_exc_pt_sel;
Lock _state_lock { };
struct
{
struct Thread_state thread;
addr_t sel_client_ec;
enum {
BLOCKED = 0x1U,
DEAD = 0x2U,
SINGLESTEP = 0x4U,
SIGNAL_SM = 0x8U,
DISSOLVED = 0x10U,
SUBMIT_SIGNAL = 0x20U,
BLOCKED_PAUSE_SM = 0x40U,
};
uint8_t _status;
bool modified;
/* convenience function to access pause/recall state */
inline bool blocked() { return _status & BLOCKED;}
inline void block() { _status |= BLOCKED; }
inline void unblock() { _status &= ~BLOCKED; }
inline bool blocked_pause_sm() { return _status & BLOCKED_PAUSE_SM;}
inline void block_pause_sm() { _status |= BLOCKED_PAUSE_SM; }
inline void unblock_pause_sm() { _status &= ~BLOCKED_PAUSE_SM; }
inline void mark_dead() { _status |= DEAD; }
inline bool is_dead() { return _status & DEAD; }
inline bool singlestep() { return _status & SINGLESTEP; }
inline void mark_signal_sm() { _status |= SIGNAL_SM; }
inline bool has_signal_sm() { return _status & SIGNAL_SM; }
inline void mark_dissolved() { _status |= DISSOLVED; }
inline bool dissolved() { return _status & DISSOLVED; }
inline bool to_submit() { return _status & SUBMIT_SIGNAL; }
inline void submit_signal() { _status |= SUBMIT_SIGNAL; }
inline void reset_submit() { _status &= ~SUBMIT_SIGNAL; }
} _state { };
Cpu_session_capability _cpu_session_cap;
Thread_capability _thread_cap;
Affinity::Location const _location;
Exception_handlers _exceptions;
addr_t _pd_target;
void _copy_state_from_utcb(Nova::Utcb const &utcb);
void _copy_state_to_utcb(Nova::Utcb &utcb) const;
uint8_t _unsynchronized_client_recall(bool get_state_and_block);
addr_t sel_pt_cleanup() const { return _selectors; }
addr_t sel_sm_block_pause() const { return _selectors + 1; }
addr_t sel_sm_block_oom() const { return _selectors + 2; }
addr_t sel_oom_portal() const { return _selectors + 3; }
__attribute__((regparm(1)))
static void _page_fault_handler(Pager_object &);
__attribute__((regparm(1)))
static void _startup_handler(Pager_object &);
__attribute__((regparm(1)))
static void _invoke_handler(Pager_object &);
__attribute__((regparm(1)))
static void _recall_handler(Pager_object &);
__attribute__((regparm(3)))
static void _oom_handler(addr_t, addr_t, addr_t);
public:
Pager_object(Cpu_session_capability cpu_session_cap,
Thread_capability thread_cap,
unsigned long badge, Affinity::Location location,
Genode::Session_label const &,
Cpu_session::Name const &);
virtual ~Pager_object();
unsigned long badge() const { return _badge; }
void reset_badge() { _badge = 0; }
const char * client_thread() const;
const char * client_pd() const;
virtual int pager(Ipc_pager &ps) = 0;
/**
* Assign user-level exception handler for the pager object
*/
void exception_handler(Signal_context_capability sigh)
{
_exception_sigh = sigh;
}
Affinity::Location location() const { return _location; }
/**
* Assign PD selector to PD
*/
void assign_pd(addr_t pd_sel) { _pd_target = pd_sel; }
addr_t pd_sel() const { return _pd_target; }
void exception(uint8_t exit_id);
/**
* Return base of initial portal window
*/
addr_t exc_pt_sel_client() { return _client_exc_pt_sel; }
/**
* Set initial stack pointer used by the startup handler
*/
addr_t initial_esp() { return _initial_esp; }
void initial_esp(addr_t esp) { _initial_esp = esp; }
/**
* Set initial instruction pointer used by the startup handler
*/
void initial_eip(addr_t eip) { _initial_eip = eip; }
/**
* Continue execution of pager object
*/
void wake_up();
/**
* Notify exception handler about the occurrence of an exception
*/
bool submit_exception_signal()
{
if (!_exception_sigh.valid()) return false;
_state.reset_submit();
Signal_transmitter transmitter(_exception_sigh);
transmitter.submit();
return true;
}
/**
* Copy thread state of recalled thread.
*/
bool copy_thread_state(Thread_state * state_dst)
{
Lock::Guard _state_lock_guard(_state_lock);
if (!state_dst || !_state.blocked())
return false;
*state_dst = _state.thread;
return true;
}
/*
* Copy thread state to recalled thread.
*/
bool copy_thread_state(Thread_state state_src)
{
Lock::Guard _state_lock_guard(_state_lock);
if (!_state.blocked())
return false;
_state.thread = state_src;
_state.modified = true;
return true;
}
/**
* Cancel blocking in a lock so that recall exception can take
* place.
*/
void client_cancel_blocking();
uint8_t client_recall(bool get_state_and_block);
void client_set_ec(addr_t ec) { _state.sel_client_ec = ec; }
inline void single_step(bool on)
{
_state_lock.lock();
if (_state.is_dead() || !_state.blocked() ||
(on && (_state._status & _state.SINGLESTEP)) ||
(!on && !(_state._status & _state.SINGLESTEP))) {
_state_lock.unlock();
return;
}
if (on)
_state._status |= _state.SINGLESTEP;
else
_state._status &= ~_state.SINGLESTEP;
_state_lock.unlock();
/* force client in exit and thereby apply single_step change */
client_recall(false);
}
/**
* Return CPU session that was used to created the thread
*/
Cpu_session_capability cpu_session_cap() const { return _cpu_session_cap; }
/**
* Return thread capability
*
* This function enables the destructor of the thread's
* address-space region map to kill the thread.
*/
Thread_capability thread_cap() const { return _thread_cap; }
/**
* Note in the thread state that an unresolved page
* fault occurred.
*/
void unresolved_page_fault_occurred()
{
_state.thread.unresolved_page_fault = true;
}
/**
* Make sure nobody is in the handler anymore by doing an IPC to a
* local cap pointing to same serving thread (if not running in the
* context of the serving thread). When the call returns
* we know that nobody is handled by this object anymore, because
* all remotely available portals had been revoked beforehand.
*/
void cleanup_call();
/**
* Portal called by thread that causes a out of memory in kernel.
*/
addr_t get_oom_portal();
enum Policy {
STOP = 1,
UPGRADE_CORE_TO_DST = 2,
UPGRADE_PREFER_SRC_TO_DST = 3,
};
enum Oom {
SEND = 1, REPLY = 2, SELF = 4,
SRC_CORE_PD = ~0UL, SRC_PD_UNKNOWN = 0,
NO_NOTIFICATION = 0
};
/**
* Implements policy on how to react on out of memory in kernel.
*
* Used solely inside core. On Genode core creates all the out
* of memory portals per EC. If the PD of a EC runs out of kernel
* memory it causes a OOM portal traversal, which is handled
* by the pager object of the causing thread.
*
* /param pd_sel PD selector from where to transfer kernel memory
* resources. The PD of this pager_object is the
* target PD.
* /param pd debug feature - string of PD (transfer_from)
* /param thread debug feature - string of EC (transfer_from)
*/
uint8_t handle_oom(addr_t pd_sel = SRC_CORE_PD,
const char * pd = "core",
const char * thread = "unknown",
Policy = Policy::UPGRADE_CORE_TO_DST);
static uint8_t handle_oom(addr_t pd_from, addr_t pd_to,
char const * src_pd,
char const * src_thread,
Policy policy,
addr_t sm_notify = NO_NOTIFICATION,
char const * dst_pd = "unknown",
char const * dst_thread = "unknown");
void print(Output &out) const;
};
/**
* A 'Pager_activation' processes one page fault of a 'Pager_object' at a time.
*/
class Pager_entrypoint;
class Pager_activation_base: public Thread
{
private:
Native_capability _cap;
Pager_entrypoint *_ep; /* entry point to which the
activation belongs */
/**
* Lock used for blocking until '_cap' is initialized
*/
Lock _cap_valid;
/*
* Noncopyable
*/
Pager_activation_base(Pager_activation_base const &);
Pager_activation_base &operator = (Pager_activation_base const &);
public:
/**
* Constructor
*
* \param name name of the new thread
* \param stack_size stack size of the new thread
*/
Pager_activation_base(char const * const name,
size_t const stack_size);
/**
* Thread interface
*/
void entry() override;
/**
* Return capability to this activation
*
* This function should only be called from 'Pager_entrypoint'
*/
Native_capability cap()
{
/* ensure that the initialization of our 'Ipc_pager' is done */
if (!_cap.valid())
_cap_valid.lock();
return _cap;
}
};
/**
* Paging entry point
*
* For a paging entry point can hold only one activation. So, paging is
* strictly serialized for one entry point.
*/
class Pager_entrypoint : public Object_pool
{
public:
/**
* Constructor
*
* \param cap_factory factory for creating capabilities
* for the pager objects managed by this
* entry point
*/
Pager_entrypoint(Rpc_cap_factory &cap_factory);
/**
* Associate Pager_object with the entry point
*/
Pager_capability manage(Pager_object &) {
return Pager_capability(); }
/**
* Dissolve Pager_object from entry point
*/
void dissolve(Pager_object &obj);
};
template
class Pager_activation : public Pager_activation_base
{
public:
Pager_activation() : Pager_activation_base("pager", STACK_SIZE)
{ }
};
}
#endif /* _CORE__INCLUDE__PAGER_H_ */