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3 | ;; Copyright (C) KolibriOS team 2013-2015. All rights reserved. ;; |
3 | ;; Copyright (C) KolibriOS team 2013-2015. All rights reserved. ;; |
4 | ;; Distributed under terms of the GNU General Public License ;; |
4 | ;; Distributed under terms of the GNU General Public License ;; |
5 | ;; ;; |
5 | ;; ;; |
6 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; |
6 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; |
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7 | 7 | ||
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8 | $Revision: 5363 $ |
8 | $Revision: 8037 $ |
9 | - | ||
10 | ; Memory management for USB structures. |
9 | |
11 | ; Protocol layer uses the common kernel heap malloc/free. |
10 | ; Memory management for slab structures. |
12 | ; Hardware layer has special requirements: |
11 | ; The allocator meets special requirements: |
13 | ; * memory blocks should be properly aligned |
12 | ; * memory blocks are properly aligned |
14 | ; * memory blocks should not cross page boundary |
13 | ; * memory blocks do not cross page boundary |
15 | ; Hardware layer allocates fixed-size blocks. |
14 | ; The allocator manages fixed-size blocks. |
16 | ; Thus, the specific allocator is quite easy to write: |
15 | ; Thus, the specific allocator works as follows: |
Line 17... | Line 16... | ||
17 | ; allocate one page, split into blocks, maintain the single-linked |
16 | ; allocate one page, split into blocks, maintain the single-linked |
Line 18... | Line 17... | ||
18 | ; list of all free blocks in each page. |
17 | ; list of all free blocks in each page. |
Line 19... | Line 18... | ||
19 | 18 | ||
20 | ; Note: size must be a multiple of required alignment. |
19 | ; Note: size must be a multiple of required alignment. |
21 | 20 | ||
22 | ; Data for one pool: dd pointer to the first page, MUTEX lock. |
21 | ; Data for one pool: dd pointer to the first page, MUTEX lock. |
23 | 22 | ||
24 | ; Allocator for fixed-size blocks: allocate a block. |
23 | ; Allocator for fixed-size blocks: allocate a block. |
25 | ; [ebx-4] = pointer to the first page, ebx = pointer to MUTEX structure. |
24 | ; [ebx-4] = pointer to the first page, ebx = pointer to MUTEX structure. |
26 | proc usb_allocate_common |
25 | proc slab_alloc |
Line 53... | Line 52... | ||
53 | ; 2e. Get the pointer to the next free block. |
52 | ; 2e. Get the pointer to the next free block. |
54 | mov ecx, [eax] |
53 | mov ecx, [eax] |
55 | ; 2f. Update the pointer to the first free block from eax to ecx. |
54 | ; 2f. Update the pointer to the first free block from eax to ecx. |
56 | ; Normally [edx-8] still contains eax, if so, atomically set it to ecx |
55 | ; Normally [edx-8] still contains eax, if so, atomically set it to ecx |
57 | ; and proceed to 3. |
56 | ; and proceed to 3. |
58 | ; However, the price of simplicity of usb_free_common (in particular, it |
57 | ; However, the price of simplicity of slab_free (in particular, it doesn't take |
59 | ; doesn't take the lock) is that [edx-8] could (rarely) be changed while |
58 | ; the lock) is that [edx-8] could (rarely) be changed while we processed steps |
60 | ; we processed steps 2d+2e. If so, return to 2d and retry. |
59 | ; 2d+2e. If so, return to 2d and retry. |
61 | lock cmpxchg [edx-8], ecx |
60 | lock cmpxchg [edx-8], ecx |
62 | jnz @b |
61 | jnz @b |
63 | .return: |
62 | .return: |
64 | ; 3. Release the lock taken in step 1 and return. |
63 | ; 3. Release the lock taken in step 1 and return. |
65 | push eax |
64 | push eax |
Line 97... | Line 96... | ||
97 | sub ecx, [.size] |
96 | sub ecx, [.size] |
98 | and dword [ecx], 0 |
97 | and dword [ecx], 0 |
99 | ; 8. Return (start of page). |
98 | ; 8. Return (start of page). |
100 | jmp .return |
99 | jmp .return |
101 | .nomemory: |
100 | .nomemory: |
102 | dbgstr 'no memory for USB descriptor' |
101 | dbgstr 'no memory for slab allocation' |
103 | xor eax, eax |
102 | xor eax, eax |
104 | jmp .return |
103 | jmp .return |
105 | endp |
104 | endp |
Line 106... | Line 105... | ||
106 | 105 | ||
107 | ; Allocator for fixed-size blocks: free a block. |
106 | ; Allocator for fixed-size blocks: free a block. |
108 | proc usb_free_common |
107 | proc slab_free |
109 | push ecx edx |
108 | push ecx edx |
110 | virtual at esp |
109 | virtual at esp |
111 | rd 2 ; saved registers |
110 | rd 2 ; saved registers |
112 | dd ? ; return address |
111 | dd ? ; return address |
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122 | lock cmpxchg [edx+1-8], ecx |
121 | lock cmpxchg [edx+1-8], ecx |
123 | jnz @b |
122 | jnz @b |
124 | pop edx ecx |
123 | pop edx ecx |
125 | ret 4 |
124 | ret 4 |
126 | endp |
125 | endp |
127 | - | ||
128 | ; Helper procedure: translate physical address in ecx |
- | |
129 | ; of some transfer descriptor to linear address. |
- | |
130 | ; in: eax = address of first page |
- | |
131 | proc usb_td_to_virt |
- | |
132 | ; Traverse all pages used for transfer descriptors, looking for the one |
- | |
133 | ; with physical address as in ecx. |
- | |
134 | @@: |
- | |
135 | test eax, eax |
- | |
136 | jz .zero |
- | |
137 | push eax |
- | |
138 | call get_pg_addr |
- | |
139 | sub eax, ecx |
- | |
140 | jz .found |
- | |
141 | cmp eax, -0x1000 |
- | |
142 | ja .found |
- | |
143 | pop eax |
- | |
144 | mov eax, [eax+0x1000-4] |
- | |
145 | jmp @b |
- | |
146 | .found: |
- | |
147 | ; When found, combine page address from eax with page offset from ecx. |
- | |
148 | pop eax |
- | |
149 | and ecx, 0xFFF |
- | |
150 | add eax, ecx |
- | |
151 | .zero: |
- | |
152 | ret |
- | |
153 | endp |
- |