6b289a1423
This patch replaces the former prominent use of pointers by references wherever feasible. This has the following benefits: * The contract between caller and callee becomes more obvious. When passing a reference, the contract says that the argument cannot be a null pointer. The caller is responsible to ensure that. Therefore, the use of reference eliminates the need to add defensive null-pointer checks at the callee site, which sometimes merely exist to be on the safe side. The bottom line is that the code becomes easier to follow. * Reference members must be initialized via an object initializer, which promotes a programming style that avoids intermediate object- construction states. Within core, there are still a few pointers as member variables left though. E.g., caused by the late association of 'Platform_thread' objects with their 'Platform_pd' objects. * If no pointers are present as member variables, we don't need to manually provide declarations of a private copy constructor and an assignment operator to avoid -Weffc++ errors "class ... has pointer data members [-Werror=effc++]". This patch also changes a few system bindings on NOVA and Fiasco.OC, e.g., the return value of the global 'cap_map' accessor has become a reference. Hence, the patch touches a few places outside of core. Fixes #3135
215 lines
5.1 KiB
C++
215 lines
5.1 KiB
C++
/*
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* \brief Fiasco.OC pager support
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* \author Christian Helmuth
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* \author Stefan Kalkowski
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* \date 2006-06-14
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*/
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/*
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* Copyright (C) 2006-2017 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU Affero General Public License version 3.
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*/
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#ifndef _CORE__INCLUDE__IPC_PAGER_H_
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#define _CORE__INCLUDE__IPC_PAGER_H_
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/* Genode includes */
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#include <base/cache.h>
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#include <base/ipc.h>
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#include <base/stdint.h>
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#include <base/native_capability.h>
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#include <base/thread_state.h>
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#include <util/touch.h>
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#include <foc/native_capability.h>
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#include <foc/thread_state.h>
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/* base-internal includes */
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#include <base/internal/native_thread.h>
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/* Fiasco includes */
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namespace Fiasco {
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#include <l4/sys/types.h>
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}
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namespace Genode {
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class Mapping;
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class Ipc_pager;
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}
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class Genode::Mapping
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{
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private:
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addr_t _dst_addr;
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Fiasco::l4_fpage_t _fpage { };
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Cache_attribute _cacheability;
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bool _iomem;
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public:
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/**
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* Constructor
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*/
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Mapping(addr_t dst_addr, addr_t src_addr,
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Cache_attribute c, bool io_mem,
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unsigned log2size, bool write, bool executable)
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: _dst_addr(dst_addr), _cacheability(c), _iomem(io_mem)
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{
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typedef Fiasco::L4_fpage_rights Rights;
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Rights rights = (write && executable) ? Fiasco::L4_FPAGE_RWX :
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(write && !executable) ? Fiasco::L4_FPAGE_RW :
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(!write && !executable) ? Fiasco::L4_FPAGE_RO :
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Fiasco::L4_FPAGE_RX;
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_fpage = Fiasco::l4_fpage(src_addr, log2size, rights);
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}
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/**
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* Construct invalid flexpage
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*/
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Mapping() : _dst_addr(0), _fpage(Fiasco::l4_fpage_invalid()),
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_cacheability(UNCACHED), _iomem(false) { }
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Fiasco::l4_umword_t dst_addr() const { return _dst_addr; }
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bool grant() const { return false; }
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Fiasco::l4_fpage_t fpage() const { return _fpage; }
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Cache_attribute cacheability() const { return _cacheability; }
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bool iomem() const { return _iomem; }
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/**
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* Prepare map operation is not needed on Fiasco.OC, since we clear the
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* dataspace before this function is called.
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*/
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void prepare_map_operation() { }
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};
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/**
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* Special paging server class
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*/
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class Genode::Ipc_pager : public Native_capability
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{
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public:
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enum Msg_type { PAGEFAULT, WAKE_UP, PAUSE, EXCEPTION };
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private:
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Native_thread _last { }; /* origin of last fault */
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addr_t _pf_addr { 0 }; /* page-fault address */
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addr_t _pf_ip { 0 }; /* ip of faulter */
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Mapping _reply_mapping { }; /* page-fault answer */
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unsigned long _badge; /* badge of faulting thread */
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Fiasco::l4_msgtag_t _tag { }; /* receive message tag */
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Fiasco::l4_exc_regs_t _regs { }; /* exception registers */
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Msg_type _type { PAGEFAULT };
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void _parse_msg_type(void);
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void _parse_exception(void);
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void _parse_pagefault(void);
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void _parse(unsigned long label);
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public:
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/**
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* Constructor
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*/
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Ipc_pager();
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/**
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* Wait for a new page fault received as short message IPC
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*/
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void wait_for_fault();
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/**
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* Reply current page-fault and wait for a new one
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*
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* Send short flex page and wait for next short-message (register)
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* IPC -- pagefault
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*/
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void reply_and_wait_for_fault();
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/**
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* Request instruction pointer of current page fault
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*/
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addr_t fault_ip() { return _pf_ip; }
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/**
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* Request fault address of current page fault. Lower 3 bits are used
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* to encode error codes.
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*/
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addr_t fault_addr() { return _pf_addr & ~7UL; }
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/**
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* Set parameters for next reply
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*/
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void set_reply_mapping(Mapping m) { _reply_mapping = m; }
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/**
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* Set destination for next reply
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*/
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void set_reply_dst(Native_thread t) { _last = t; }
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/**
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* Answer call without sending a flex-page mapping
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*
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* This function is used to acknowledge local calls from one of
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* core's region-manager sessions.
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*/
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void acknowledge_wakeup();
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/**
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* Reply to an exception IPC
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*/
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void acknowledge_exception();
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/**
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* Return thread ID of last faulter
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*/
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Native_thread last() const { return _last; }
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/**
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* Return badge for faulting thread
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*/
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unsigned long badge() { return _badge; }
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/**
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* Return true if fault was a write fault
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*/
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bool write_fault() const { return (_pf_addr & 2); }
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/**
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* Return true if fault was caused by execution on non executable memory
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*/
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bool exec_fault() const;
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/**
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* Return true if last fault was an exception
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*/
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bool exception() const
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{
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return _type == Ipc_pager::EXCEPTION;
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}
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/**
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* Return the type of ipc we received at last.
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*/
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Msg_type msg_type() { return _type; };
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/**
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* Copy the exception registers from the last exception
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* to the given Thread_state object.
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*/
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void get_regs(Foc_thread_state &state) const;
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/*
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* Copy the exception reply registers from the given
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* Thread_state object
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*/
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void set_regs(Foc_thread_state const &state);
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};
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#endif /* _CORE__INCLUDE__IPC_PAGER_H_ */
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