Mapdb Class Reference

The mapping database. More...

#include <mapdb.h>

List of all members.

Public Member Functions
	Mapdb (Address start, Address end)
	Constructor.
	~Mapdb ()
	Destructor.
Mapping *	lookup (unsigned space, Address va, Address phys)
	Lookup a mapping and lock the corresponding mapping tree.
void	free (Mapping *mapping_of_tree)
	Unlock the mapping tree to which the mapping belongs.
void	grant (Mapping *m, unsigned new_space, Address va)
	Change ownership of a mapping.
Static Public Member Functions
static Mapping *	insert (Mapping *parent, unsigned space, Address va, size_t size, Mapping_type type)
	Insert a new mapping entry with the given values as child of "parent".
static void	flush (Mapping *m, bool me_too)
	Delete mappings from a tree.
static bool	valid_address (Address phys)
Private Attributes
Physframe *	physframe
Address	_start
Friends
class	Jdb_mapdb

---

Detailed Description

The mapping database.

---

Constructor & Destructor Documentation

Mapdb::Mapdb (  Address  start, Address  end )

Constructor. Parameters: start  physical start address of RAM end  physical end address of RAM.

Mapdb::~Mapdb (   )

Destructor.

---

Member Function Documentation

void Mapdb::flush (  Mapping *  m, bool  me_too )  [static]

Delete mappings from a tree. This function deleted mappings recusively. Parameters: m  Mapping that denotes the subtree that should be deleted. me_too  If true, delete m as well; otherwise, delete only submappings.

void Mapdb::free (  Mapping *  mapping_of_tree  )

Unlock the mapping tree to which the mapping belongs. Once a tree has been unlocked, all Mapping instances pointing into it become invalid. A mapping tree is locked during lookup(). When the tree is locked, the tree may be traversed (using member functions of Mapping, which serves as an iterator over the tree) or manipulated (using insert(), free(), flush(), grant()). Note that only one insert() is allowed during each locking cycle. Parameters: mapping_of_tree  Any mapping belonging to a mapping tree.

void Mapdb::grant (  Mapping *  m, unsigned  new_space, Address  va )

Change ownership of a mapping. Parameters: m  Mapping to be modified. new_space  Number of address space the mapping should be transferred to va  Virtual address of the mapping in the new address space

Mapping * Mapdb::insert (  Mapping *  parent, unsigned  space, Address  va, size_t  size, Mapping_type  type )  [static]

Insert a new mapping entry with the given values as child of "parent". We assume that there is at least one free entry at the end of the array so that at least one insert() operation can succeed between a lookup()/free() pair of calls. This is guaranteed by the free() operation which allocates a larger tree if the current one becomes to small. Parameters: parent  Parent mapping of the new mapping. space  Number of the address space into which the mapping is entered va  Virtual address of the mapped page. size  Size of the mapping. For memory mappings, 4K or 4M. type  Type of the mapping (Map_mem or Map_io). Returns: If successful, new mapping. If out of memory or mapping tree full, 0. Postcondition: All Mapping* pointers pointing into this mapping tree, except "parent" and its parents, will be invalidated.

Mapping * Mapdb::lookup (  unsigned  space, Address  va, Address  phys )

Lookup a mapping and lock the corresponding mapping tree. The returned mapping pointer, and all other mapping pointers derived from it, remain valid until free() is called on one of them. We guarantee that at most one insert() operation succeeds between one lookup()/free() pair of calls (it succeeds unless the mapping tree is full). Parameters: space  Number of virtual address space in which the mapping was entered va  Virtual address of the mapping phys  Physical address of the mapped pag frame type  Type of the mapping (Map_mem or Map_io). Returns: mapping, if found; otherwise, 0

bool Mapdb::valid_address (  Address  phys  )  [inline, static]

---

Friends And Related Function Documentation

friend class Jdb_mapdb [friend]

---

Member Data Documentation

Address Mapdb::_start [private]

Physframe* Mapdb::physframe [private]

---

The documentation for this class was generated from the following files:

• mapdb.h
• mapdb.cc

---