genode/base-foc/include/base/ipc_msgbuf.h
2013-01-10 21:44:47 +01:00

161 lines
3.3 KiB
C++

/*
* \brief IPC message buffer layout for Fiasco.OC
* \author Stefan Kalkowski
* \date 2010-11-30
*
* On Fiasco.OC, IPC is used to transmit plain data and capabilities.
* Therefore the message buffer contains both categories of payload.
*/
/*
* Copyright (C) 2010-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _INCLUDE__BASE__IPC_MSGBUF_H_
#define _INCLUDE__BASE__IPC_MSGBUF_H_
/* Genode includes */
#include <base/cap_map.h>
/* Fiasco.OC includes */
namespace Fiasco {
#include <l4/sys/types.h>
#include <l4/sys/utcb.h>
}
namespace Genode {
class Msgbuf_base
{
public:
enum { MAX_CAP_ARGS_LOG2 = 2, MAX_CAP_ARGS = 1 << MAX_CAP_ARGS_LOG2 };
protected:
size_t _size;
/**
* Number of capability selectors to send.
*/
size_t _snd_cap_sel_cnt;
/**
* Capability selectors to delegate.
*/
addr_t _snd_cap_sel[MAX_CAP_ARGS];
/**
* Base of capability receive window.
*/
Cap_index* _rcv_idx_base;
/**
* Read counter for unmarshalling portal capability selectors
*/
addr_t _rcv_cap_sel_cnt;
unsigned long _label;
char _msg_start[]; /* symbol marks start of message */
public:
/**
* Constructor
*/
Msgbuf_base()
: _rcv_idx_base(cap_idx_alloc()->alloc_range(MAX_CAP_ARGS)), _label(0)
{
rcv_reset();
snd_reset();
}
~Msgbuf_base() {
cap_idx_alloc()->free(_rcv_idx_base, MAX_CAP_ARGS); }
/*
* Begin of actual message buffer
*/
char buf[];
/**
* Return size of message buffer
*/
inline size_t size() const { return _size; };
/**
* Return address of message buffer
*/
inline void *addr() { return &_msg_start[0]; };
/**
* Reset portal capability selector payload
*/
inline void snd_reset() { _snd_cap_sel_cnt = 0; }
/**
* Append capability selector to message buffer
*/
inline bool snd_append_cap_sel(addr_t cap_sel)
{
if (_snd_cap_sel_cnt >= MAX_CAP_ARGS)
return false;
_snd_cap_sel[_snd_cap_sel_cnt++] = cap_sel;
return true;
}
/**
* Return number of marshalled capability selectors
*/
inline size_t snd_cap_sel_cnt() { return _snd_cap_sel_cnt; }
/**
* Return capability selector to send.
*
* \param i index (0 ... 'snd_cap_sel_cnt()' - 1)
* \return capability selector, or 0 if index is invalid
*/
addr_t snd_cap_sel(unsigned i) {
return i < _snd_cap_sel_cnt ? _snd_cap_sel[i] : 0; }
/**
* Return address of capability receive window.
*/
addr_t rcv_cap_sel_base() { return _rcv_idx_base->kcap(); }
/**
* Reset capability receive window
*/
void rcv_reset() { _rcv_cap_sel_cnt = 0; }
/**
* Return next received capability selector.
*
* \return capability selector, or 0 if index is invalid
*/
addr_t rcv_cap_sel() {
return rcv_cap_sel_base() + _rcv_cap_sel_cnt++ * Fiasco::L4_CAP_SIZE; }
void label(unsigned long label) { _label = label; }
unsigned long label() { return _label & (~0UL << 2); }
};
template <unsigned BUF_SIZE>
class Msgbuf : public Msgbuf_base
{
public:
char buf[BUF_SIZE];
Msgbuf() { _size = BUF_SIZE; }
};
}
#endif /* _INCLUDE__BASE__IPC_MSGBUF_H_ */