/* * Copyright 2008-2009, Ingo Weinhold, ingo_weinhold@gmx.de. * Copyright 2003-2007, Axel Dörfler, axeld@pinc-software.de. * Distributed under the terms of the MIT License. * * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved. * Distributed under the terms of the NewOS License. */ #ifndef _KERNEL_VM_VM_CACHE_H #define _KERNEL_VM_VM_CACHE_H #include #include #include #include #include "kernel_debug_config.h" struct kernel_args; enum { CACHE_TYPE_RAM = 0, CACHE_TYPE_VNODE, CACHE_TYPE_DEVICE, CACHE_TYPE_NULL }; enum { PAGE_EVENT_NOT_BUSY = 0x01 // page not busy anymore }; struct VMCachePagesTreeDefinition { typedef page_num_t KeyType; typedef vm_page NodeType; static page_num_t GetKey(const NodeType* node) { return node->cache_offset; } static SplayTreeLink* GetLink(NodeType* node) { return &node->cache_link; } static int Compare(page_num_t key, const NodeType* node) { return key == node->cache_offset ? 0 : (key < node->cache_offset ? -1 : 1); } static NodeType** GetListLink(NodeType* node) { return &node->cache_next; } }; typedef IteratableSplayTree VMCachePagesTree; struct VMCache { public: VMCache(); virtual ~VMCache(); status_t Init(uint32 cacheType, uint32 allocationFlags); virtual void Delete(); inline bool Lock(); inline bool TryLock(); inline bool SwitchLock(mutex* from); inline bool SwitchFromReadLock(rw_lock* from); void Unlock(bool consumerLocked = false); inline void AssertLocked(); inline void AcquireRefLocked(); inline void AcquireRef(); inline void ReleaseRefLocked(); inline void ReleaseRef(); inline void ReleaseRefAndUnlock( bool consumerLocked = false); inline VMCacheRef* CacheRef() const { return fCacheRef; } void WaitForPageEvents(vm_page* page, uint32 events, bool relock); void NotifyPageEvents(vm_page* page, uint32 events) { if (fPageEventWaiters != NULL) _NotifyPageEvents(page, events); } inline void MarkPageUnbusy(vm_page* page); vm_page* LookupPage(off_t offset); void InsertPage(vm_page* page, off_t offset); void RemovePage(vm_page* page); void MovePage(vm_page* page); void MoveAllPages(VMCache* fromCache); void AddConsumer(VMCache* consumer); status_t InsertAreaLocked(VMArea* area); status_t RemoveArea(VMArea* area); void TransferAreas(VMCache* fromCache); uint32 CountWritableAreas(VMArea* ignoreArea) const; status_t WriteModified(); status_t SetMinimalCommitment(off_t commitment, int priority); status_t Resize(off_t newSize, int priority); status_t FlushAndRemoveAllPages(); void* UserData() { return fUserData; } void SetUserData(void* data) { fUserData = data; } // Settable by the lock owner and valid as // long as the lock is owned. // for debugging only mutex* GetLock() { return &fLock; } int32 RefCount() const { return fRefCount; } // backing store operations virtual status_t Commit(off_t size, int priority); virtual bool HasPage(off_t offset); virtual status_t Read(off_t offset, const iovec *vecs, size_t count,uint32 flags, size_t *_numBytes); virtual status_t Write(off_t offset, const iovec *vecs, size_t count, uint32 flags, size_t *_numBytes); virtual status_t WriteAsync(off_t offset, const iovec* vecs, size_t count, size_t numBytes, uint32 flags, AsyncIOCallback* callback); virtual bool CanWritePage(off_t offset); virtual int32 MaxPagesPerWrite() const { return -1; } // no restriction virtual int32 MaxPagesPerAsyncWrite() const { return -1; } // no restriction virtual status_t Fault(struct VMAddressSpace *aspace, off_t offset); virtual void Merge(VMCache* source); virtual status_t AcquireUnreferencedStoreRef(); virtual void AcquireStoreRef(); virtual void ReleaseStoreRef(); public: VMArea* areas; list_link consumer_link; list consumers; // list of caches that use this cache as a source VMCachePagesTree pages; VMCache* source; off_t virtual_base; off_t virtual_end; off_t committed_size; // TODO: Remove! uint32 page_count; uint32 temporary : 1; uint32 scan_skip : 1; uint32 type : 6; #if DEBUG_CACHE_LIST VMCache* debug_previous; VMCache* debug_next; #endif private: struct PageEventWaiter; friend struct VMCacheRef; private: void _NotifyPageEvents(vm_page* page, uint32 events); inline bool _IsMergeable() const; void _MergeWithOnlyConsumer(bool consumerLocked); void _RemoveConsumer(VMCache* consumer); private: int32 fRefCount; mutex fLock; PageEventWaiter* fPageEventWaiters; void* fUserData; VMCacheRef* fCacheRef; }; #if DEBUG_CACHE_LIST extern VMCache* gDebugCacheList; #endif class VMCacheFactory { public: static status_t CreateAnonymousCache(VMCache*& cache, bool canOvercommit, int32 numPrecommittedPages, int32 numGuardPages, bool swappable, int priority); static status_t CreateVnodeCache(VMCache*& cache, struct vnode* vnode); static status_t CreateDeviceCache(VMCache*& cache, addr_t baseAddress); static status_t CreateNullCache(int priority, VMCache*& cache); }; bool VMCache::Lock() { return mutex_lock(&fLock) == B_OK; } bool VMCache::TryLock() { return mutex_trylock(&fLock) == B_OK; } bool VMCache::SwitchLock(mutex* from) { return mutex_switch_lock(from, &fLock) == B_OK; } bool VMCache::SwitchFromReadLock(rw_lock* from) { return mutex_switch_from_read_lock(from, &fLock) == B_OK; } void VMCache::AssertLocked() { ASSERT_LOCKED_MUTEX(&fLock); } void VMCache::AcquireRefLocked() { ASSERT_LOCKED_MUTEX(&fLock); fRefCount++; } void VMCache::AcquireRef() { Lock(); fRefCount++; Unlock(); } void VMCache::ReleaseRefLocked() { ASSERT_LOCKED_MUTEX(&fLock); fRefCount--; } void VMCache::ReleaseRef() { Lock(); fRefCount--; Unlock(); } void VMCache::ReleaseRefAndUnlock(bool consumerLocked) { ReleaseRefLocked(); Unlock(consumerLocked); } void VMCache::MarkPageUnbusy(vm_page* page) { ASSERT(page->busy); page->busy = false; NotifyPageEvents(page, PAGE_EVENT_NOT_BUSY); } #ifdef __cplusplus extern "C" { #endif status_t vm_cache_init(struct kernel_args *args); void vm_cache_init_post_heap(); struct VMCache *vm_cache_acquire_locked_page_cache(struct vm_page *page, bool dontWait); #ifdef __cplusplus } #endif #endif /* _KERNEL_VM_VM_CACHE_H */