genode/repos/base-codezero/include/base/ipc_pager.h
Stefan Kalkowski 786fe805da base: introduce caching attributes (fix #1184)
On ARM it's relevant to not only distinguish between ordinary cached memory
and write-combined one, but also having non-cached memory too. To insert the
appropriated page table entries e.g.: in the base-hw kernel, we need to preserve
the information about the kind of memory from allocation until the pager
resolves a page fault. Therefore, this commit introduces a new Cache_attribute
type, and replaces the write_combined boolean with the new type where necessary.
2014-06-26 10:57:26 +02:00

172 lines
3.5 KiB
C++

/*
* \brief Dummy pager support for Genode
* \author Norman Feske
* \date 2009-10-02
*/
/*
* Copyright (C) 2009-2013 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_PAGER_H_
#define _INCLUDE__BASE__IPC_PAGER_H_
#include <base/cache.h>
#include <base/ipc.h>
#include <base/stdint.h>
#include <base/native_types.h>
namespace Genode {
class Mapping
{
private:
addr_t _from_phys_addr;
addr_t _to_virt_addr;
size_t _num_pages;
bool _writeable;
enum { PAGE_SIZE_LOG2 = 12 };
public:
/**
* Constructor
*/
Mapping(addr_t dst_addr, addr_t src_addr,
Cache_attribute const cacheability, bool io_mem,
unsigned l2size = PAGE_SIZE_LOG2,
bool rw = true)
:
_from_phys_addr(src_addr),
_to_virt_addr(dst_addr),
_num_pages(1 << (l2size - PAGE_SIZE_LOG2)),
_writeable(rw)
{ }
/**
* Construct invalid mapping
*/
Mapping() : _num_pages(0) { }
/**
* Prepare map operation
*
* No preparations are needed on Codezero because all mapping
* originate from the physical address space.
*/
void prepare_map_operation() { }
addr_t from_phys() const { return _from_phys_addr; }
addr_t to_virt() const { return _to_virt_addr; }
size_t num_pages() const { return _num_pages; }
bool writeable() const { return _writeable; }
};
/**
* Special paging server class
*/
class Ipc_pager : public Native_capability
{
private:
Native_thread_id _last; /* faulted thread */
addr_t _pf_addr; /* page-fault address */
addr_t _pf_ip; /* instruction pointer of faulter */
bool _pf_write; /* true on write fault */
Mapping _reply_mapping;
// protected:
//
// /**
// * Wait for pagefault
// */
// void _wait();
//
// /**
// * Send page-fault reply and wait for next page fault
// */
// void _reply_and_wait();
public:
/**
* Constructor
*/
Ipc_pager();
/**
* Wait for a new page fault received as short message IPC
*/
void wait_for_fault();
/**
* Reply current page-fault and wait for a new one
*/
void reply_and_wait_for_fault();
/**
* Request instruction pointer of current page fault
*/
addr_t fault_ip() { return _pf_ip; }
/**
* Request fault address of current page fault
*/
addr_t fault_addr() { return _pf_addr; }
/**
* Set parameters for next reply
*/
void set_reply_mapping(Mapping m) { _reply_mapping = m; }
/**
* Set destination for next reply
*/
void set_reply_dst(Native_capability pager_object) {
_last = pager_object.local_name(); }
/**
* Answer call without sending a mapping
*
* This function is used to acknowledge local calls from one of
* core's region-manager sessions.
*/
void acknowledge_wakeup();
/**
* Return thread ID of last faulter
*/
Native_thread_id last() const { return _last; }
/**
* Return badge for faulting thread
*/
unsigned long badge() const { return _last; }
/**
* Return true if page fault was a write fault
*/
bool is_write_fault() const { return _pf_write; }
/**
* Return true if last fault was an exception
*/
bool is_exception() const
{
/*
* Reflection of exceptions is not supported on this platform.
*/
return false;
}
};
}
#endif /* _INCLUDE__BASE__IPC_PAGER_H_ */