|
1 // Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies). |
|
2 // All rights reserved. |
|
3 // This component and the accompanying materials are made available |
|
4 // under the terms of the License "Eclipse Public License v1.0" |
|
5 // which accompanies this distribution, and is available |
|
6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
|
7 // |
|
8 // Initial Contributors: |
|
9 // Nokia Corporation - initial contribution. |
|
10 // |
|
11 // Contributors: |
|
12 // |
|
13 // Description: |
|
14 // |
|
15 |
|
16 /** |
|
17 @file |
|
18 @internalComponent |
|
19 */ |
|
20 |
|
21 #ifndef MVALLOC_H |
|
22 #define MVALLOC_H |
|
23 |
|
24 |
|
25 class RVirtualAllocSlabSet; |
|
26 |
|
27 /** |
|
28 Allocator for virtual addresses. |
|
29 |
|
30 The allocator has the concept of addresses having a 'slab type' (#TVirtualSlabType). |
|
31 It ensures that addresses of different slab types will not overlap in the same 'chunk' |
|
32 (the region covered by a single MMU page table). |
|
33 |
|
34 Addresses will be allocated from lower address regions first, subject to slab type |
|
35 and allocation algorithm constraints. See #RBackwardsVirtualAllocator. |
|
36 */ |
|
37 class RVirtualAllocator |
|
38 { |
|
39 public: |
|
40 RVirtualAllocator(); |
|
41 ~RVirtualAllocator(); |
|
42 |
|
43 /** |
|
44 Second phase constructor. |
|
45 |
|
46 @param aStart The starting virtual address of the region to be covered |
|
47 by this allocator. |
|
48 Must be an integer multiple of #KVirtualAllocSlabSize. |
|
49 @param aEnd The end virtual address (last valid address plus one) of the region |
|
50 to be covered by this allocator. |
|
51 Must be an integer multiple of #KVirtualAllocSlabSize. |
|
52 @param aNumSlabTypes The number of different 'slab types' to be allocated. |
|
53 This will normally be #ENumVirtualAllocTypes. |
|
54 @param aWriteLock Reference to the mutex which is being used to protect allocations |
|
55 with this object. This is only used for debug checks and may be |
|
56 a mutex assigned by #DMutexPool. In practice, this will usually be an |
|
57 address space lock DAddressSpace::iLock. |
|
58 |
|
59 @return KErrNone if successful, otherwise one of the system wide error codes. |
|
60 */ |
|
61 TInt Construct(TLinAddr aStart, TLinAddr aEnd, TUint aNumSlabTypes, DMutex*& aWriteLock); |
|
62 |
|
63 /** |
|
64 Allocate a region of virtual addresses. |
|
65 |
|
66 The returned region may have a start address and/or size which is different to |
|
67 those requested due to various alignment requirements in the implementation. |
|
68 However the returned region will always include all addresses requested. |
|
69 |
|
70 @param[out] aAddr Returns the start address of the region which was allocated. |
|
71 @param[out] aSize Returns the size, in bytes, of the region which was allocated. |
|
72 This will always be aligned to a multiple of the page colouring |
|
73 size: #KPageColourCount*#KPageSize. |
|
74 @param aRequestedAddr The requested start address of the region to allocate, |
|
75 or zero if no specific address is required. |
|
76 @param aRequestedSize The requested size, in bytes, of the region to allocate. |
|
77 @param aSlabType The 'slab type' of the address to be allocated. |
|
78 Addresses of different slab types will not overlap in the |
|
79 same 'chunk' (region covered by a single MMU page table). |
|
80 This value must be less than the \a aNumSlabTypes argument |
|
81 used in #Construct. |
|
82 |
|
83 @return KErrNone if successful. |
|
84 KErrAlreadyExists if a specific address was supplied and this was already |
|
85 allocated, or exists in a slab already used for a different slab type. |
|
86 Otherwise, one of the system wide error codes. |
|
87 |
|
88 @pre The write lock must be held. (See \a aWriteLock argument for #Construct.) |
|
89 */ |
|
90 TInt Alloc(TLinAddr& aAddr, TUint& aSize, TLinAddr aRequestedAddr, TUint aRequestedSize, TUint aSlabType); |
|
91 |
|
92 /** |
|
93 Free a virtual addresses region which was allocated with #Alloc. |
|
94 The region supplied to this function must either be one supplied to a |
|
95 previous call to #Alloc or be one returned by that function. |
|
96 |
|
97 @param aAddr Start address of the region to be freed. |
|
98 @param aSize Size, in bytes, of the region to be freed. |
|
99 |
|
100 @pre The write lock must be held. (See \a aWriteLock argument for #Construct.) |
|
101 */ |
|
102 void Free(TLinAddr aAddr, TUint aSize); |
|
103 |
|
104 /** |
|
105 Return true if the the address region specified by \a aAddr and \a aSize is |
|
106 entirely within the region of addresses covered by this allocator. |
|
107 */ |
|
108 TBool InRange(TLinAddr aAddr, TUint aSize); |
|
109 |
|
110 /** |
|
111 Return true if the the address region specified by \a aAddr and \a aSize was |
|
112 allocated by this allocator using the specified \a aSlabType. |
|
113 |
|
114 @pre The write lock must be held. (See \a aWriteLock argument for #Construct.) |
|
115 */ |
|
116 TBool CheckSlabType(TLinAddr aAddr, TUint aSize, TUint aSlabType); |
|
117 |
|
118 private: |
|
119 /** |
|
120 If required, expand the region specified by \a aAddr and \a aSize |
|
121 to meet size and alignment requirements of the allocator. |
|
122 This also returns log2 of the address alignment required. |
|
123 */ |
|
124 static TUint AdjustRegion(TLinAddr& aAddr, TUint& aSize); |
|
125 |
|
126 protected: |
|
127 /** |
|
128 The starting virtual address of the region covered by this allocator. |
|
129 */ |
|
130 TLinAddr iBase; |
|
131 |
|
132 /** |
|
133 The size, in bytes, of the virtual address of the region covered by this allocator. |
|
134 */ |
|
135 TUint iSize; |
|
136 |
|
137 private: |
|
138 /** |
|
139 Bitmap of used virtual address regions, each a 'slab' size (#KVirtualAllocSlabSize). |
|
140 */ |
|
141 TBitMapAllocator* iAllocator; |
|
142 |
|
143 /** |
|
144 Pointer to allocator object used for sizes less than #KVirtualAllocSlabSize. |
|
145 */ |
|
146 RVirtualAllocSlabSet* iSlabSet; |
|
147 }; |
|
148 |
|
149 |
|
150 inline TBool RVirtualAllocator::InRange(TLinAddr aAddr, TUint aSize) |
|
151 { |
|
152 aAddr -= iBase; |
|
153 return aAddr<iSize && aAddr+aSize>=aAddr && aAddr+aSize<=iSize; |
|
154 } |
|
155 |
|
156 |
|
157 |
|
158 /** |
|
159 Allocator for virtual addresses which is identical to #RVirtualAllocator |
|
160 except that addresses will be allocated from higher address regions first. |
|
161 (Subject to 'slab type' and allocation algorithm constraints). |
|
162 */ |
|
163 class RBackwardsVirtualAllocator : public RVirtualAllocator |
|
164 { |
|
165 public: |
|
166 // overriding RVirtualAllocator... |
|
167 TInt Alloc(TLinAddr& aAddr, TUint& aSize, TLinAddr aRequestedAddr, TUint aRequestedSize, TUint aSlabType); |
|
168 void Free(TLinAddr aAddr, TUint aSize); |
|
169 }; |
|
170 |
|
171 |
|
172 /** |
|
173 Enumeration of the different virtual address allocation types which may not |
|
174 overlap in the same 'chunk' (region covered by a single MMU page table). |
|
175 |
|
176 This includes all #TPdeType values, plus addition address types. |
|
177 */ |
|
178 enum TVirtualSlabType |
|
179 { |
|
180 /** |
|
181 Bit flag used to distinguish common virtual addresses allocated with |
|
182 DAddressSpace::AllocateUserCommonVirtualMemory. |
|
183 |
|
184 It is important that these addresses reside in their own slab type, |
|
185 otherwise normal local address allocation would tend to get allocated |
|
186 adjacent to them; clogging up the 'common' address region. |
|
187 */ |
|
188 EVirtualSlabTypeCommonVirtual = ENumPdeTypes<<0, |
|
189 |
|
190 /** |
|
191 Bit flag used to distinguish virtual addresses allocated for use in |
|
192 mapping demand paged memory. |
|
193 |
|
194 This ensures that page tables used for demand paged memory are not |
|
195 used for other memory types and means they may be freed once the |
|
196 memory is paged out. |
|
197 */ |
|
198 EVirtualSlabTypeDemandPaged = ENumPdeTypes<<1, |
|
199 |
|
200 /** |
|
201 Total number of different 'kinds' of virtual address which may need to be allocated. |
|
202 */ |
|
203 ENumVirtualAllocTypes = ENumPdeTypes<<2 |
|
204 }; |
|
205 |
|
206 |
|
207 #endif |