Rev 3520 | Rev 4850 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
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3520 | clevermous | 1 | ; Memory management for USB structures. |
2 | ; Protocol layer uses the common kernel heap malloc/free. |
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3 | ; Hardware layer has special requirements: |
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4 | ; * memory blocks should be properly aligned |
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5 | ; * memory blocks should not cross page boundary |
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6 | ; Hardware layer allocates fixed-size blocks. |
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7 | ; Thus, the specific allocator is quite easy to write: |
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8 | ; allocate one page, split into blocks, maintain the single-linked |
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9 | ; list of all free blocks in each page. |
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10 | |||
11 | ; Note: size must be a multiple of required alignment. |
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12 | |||
13 | ; Data for one pool: dd pointer to the first page, MUTEX lock. |
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14 | |||
15 | uglobal |
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16 | ; Structures in UHCI and OHCI have equal sizes. |
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17 | ; Thus, functions and data for allocating/freeing can be shared; |
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18 | ; we keep them here rather than in controller-specific files. |
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19 | align 4 |
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20 | ; Data for UHCI and OHCI endpoints pool. |
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21 | usb1_ep_first_page dd ? |
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22 | usb1_ep_mutex MUTEX |
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23 | ; Data for UHCI and OHCI general transfer descriptors pool. |
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24 | usb_gtd_first_page dd ? |
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25 | usb_gtd_mutex MUTEX |
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26 | endg |
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27 | |||
28 | ; sanity check: structures in UHCI and OHCI should be the same for allocation |
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3653 | clevermous | 29 | if (sizeof.ohci_pipe = sizeof.uhci_pipe) |
3520 | clevermous | 30 | |
31 | ; Allocates one endpoint structure for UHCI/OHCI. |
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32 | ; Returns pointer to software part (usb_pipe) in eax. |
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33 | proc usb1_allocate_endpoint |
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34 | push ebx |
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35 | mov ebx, usb1_ep_mutex |
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3653 | clevermous | 36 | stdcall usb_allocate_common, (sizeof.ohci_pipe + sizeof.usb_pipe + 0Fh) and not 0Fh |
3520 | clevermous | 37 | test eax, eax |
38 | jz @f |
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3653 | clevermous | 39 | add eax, sizeof.ohci_pipe |
3520 | clevermous | 40 | @@: |
41 | pop ebx |
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42 | ret |
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43 | endp |
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44 | |||
45 | ; Free one endpoint structure for UHCI/OHCI. |
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46 | ; Stdcall with one argument, pointer to software part (usb_pipe). |
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47 | proc usb1_free_endpoint |
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3653 | clevermous | 48 | sub dword [esp+4], sizeof.ohci_pipe |
3520 | clevermous | 49 | jmp usb_free_common |
50 | endp |
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51 | |||
52 | else |
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53 | ; sanity check continued |
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54 | .err allocate_endpoint/free_endpoint must be different for OHCI and UHCI |
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55 | end if |
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56 | |||
57 | ; sanity check: structures in UHCI and OHCI should be the same for allocation |
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3653 | clevermous | 58 | if (sizeof.ohci_gtd = sizeof.uhci_gtd) |
3520 | clevermous | 59 | |
60 | ; Allocates one general transfer descriptor structure for UHCI/OHCI. |
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61 | ; Returns pointer to software part (usb_gtd) in eax. |
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62 | proc usb1_allocate_general_td |
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63 | push ebx |
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64 | mov ebx, usb_gtd_mutex |
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3653 | clevermous | 65 | stdcall usb_allocate_common, (sizeof.ohci_gtd + sizeof.usb_gtd + 0Fh) and not 0Fh |
3520 | clevermous | 66 | test eax, eax |
67 | jz @f |
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3653 | clevermous | 68 | add eax, sizeof.ohci_gtd |
3520 | clevermous | 69 | @@: |
70 | pop ebx |
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71 | ret |
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72 | endp |
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73 | |||
74 | ; Free one general transfer descriptor structure for UHCI/OHCI. |
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75 | ; Stdcall with one argument, pointer to software part (usb_gtd). |
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76 | proc usb1_free_general_td |
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3653 | clevermous | 77 | sub dword [esp+4], sizeof.ohci_gtd |
3520 | clevermous | 78 | jmp usb_free_common |
79 | endp |
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80 | |||
81 | else |
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82 | ; sanity check continued |
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83 | .err allocate_general_td/free_general_td must be different for OHCI and UHCI |
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84 | end if |
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85 | |||
86 | ; Allocator for fixed-size blocks: allocate a block. |
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87 | ; [ebx-4] = pointer to the first page, ebx = pointer to MUTEX structure. |
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88 | proc usb_allocate_common |
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89 | push edi ; save used register to be stdcall |
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90 | virtual at esp |
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91 | dd ? ; saved edi |
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92 | dd ? ; return address |
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93 | .size dd ? |
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94 | end virtual |
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95 | ; 1. Take the lock. |
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96 | mov ecx, ebx |
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97 | call mutex_lock |
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98 | ; 2. Find the first allocated page with a free block, if any. |
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99 | ; 2a. Initialize for the loop. |
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100 | mov edx, ebx |
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101 | .pageloop: |
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102 | ; 2b. Get the next page, keeping the current in eax. |
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103 | mov eax, edx |
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104 | mov edx, [edx-4] |
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105 | ; 2c. If there is no next page, we're out of luck; go to 4. |
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106 | test edx, edx |
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107 | jz .newpage |
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108 | add edx, 0x1000 |
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109 | @@: |
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110 | ; 2d. Get the pointer to the first free block on this page. |
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111 | ; If there is no free block, continue to 2b. |
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112 | mov eax, [edx-8] |
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113 | test eax, eax |
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114 | jz .pageloop |
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115 | ; 2e. Get the pointer to the next free block. |
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116 | mov ecx, [eax] |
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117 | ; 2f. Update the pointer to the first free block from eax to ecx. |
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118 | ; Normally [edx-8] still contains eax, if so, atomically set it to ecx |
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119 | ; and proceed to 3. |
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120 | ; However, the price of simplicity of usb_free_common (in particular, it |
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121 | ; doesn't take the lock) is that [edx-8] could (rarely) be changed while |
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122 | ; we processed steps 2d+2e. If so, return to 2d and retry. |
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123 | lock cmpxchg [edx-8], ecx |
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124 | jnz @b |
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125 | .return: |
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126 | ; 3. Release the lock taken in step 1 and return. |
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127 | push eax |
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128 | mov ecx, ebx |
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129 | call mutex_unlock |
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130 | pop eax |
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131 | pop edi ; restore used register to be stdcall |
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132 | ret 4 |
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133 | .newpage: |
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134 | ; 4. Allocate a new page. |
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135 | push eax |
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136 | stdcall kernel_alloc, 0x1000 |
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137 | pop edx |
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138 | ; If failed, say something to the debug board and return zero. |
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139 | test eax, eax |
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140 | jz .nomemory |
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141 | ; 5. Add the new page to the tail of list of allocated pages. |
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142 | mov [edx-4], eax |
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143 | ; 6. Initialize two service dwords in the end of page: |
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144 | ; first free block is (start of page) + (block size) |
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145 | ; (we will return first block at (start of page), so consider it allocated), |
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146 | ; no next page. |
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147 | mov edx, eax |
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148 | lea edi, [eax+0x1000-8] |
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149 | add edx, [.size] |
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150 | mov [edi], edx |
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151 | and dword [edi+4], 0 |
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152 | ; 7. All blocks starting from edx are free; join them in a single-linked list. |
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153 | @@: |
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154 | mov ecx, edx |
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155 | add edx, [.size] |
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156 | mov [ecx], edx |
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157 | cmp edx, edi |
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158 | jbe @b |
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159 | sub ecx, [.size] |
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160 | and dword [ecx], 0 |
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161 | ; 8. Return (start of page). |
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162 | jmp .return |
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163 | .nomemory: |
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164 | dbgstr 'no memory for USB descriptor' |
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165 | xor eax, eax |
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166 | jmp .return |
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167 | endp |
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168 | |||
169 | ; Allocator for fixed-size blocks: free a block. |
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170 | proc usb_free_common |
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171 | push ecx edx |
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172 | virtual at esp |
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173 | rd 2 ; saved registers |
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174 | dd ? ; return address |
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175 | .block dd ? |
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176 | end virtual |
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177 | ; Insert the given block to the head of free blocks in this page. |
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178 | mov ecx, [.block] |
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179 | mov edx, ecx |
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180 | or edx, 0xFFF |
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181 | @@: |
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182 | mov eax, [edx+1-8] |
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183 | mov [ecx], eax |
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184 | lock cmpxchg [edx+1-8], ecx |
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185 | jnz @b |
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186 | pop edx ecx |
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187 | ret 4 |
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188 | endp |
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189 | |||
190 | ; Helper procedure for OHCI: translate physical address in ecx |
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191 | ; of some transfer descriptor to linear address. |
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192 | proc usb_td_to_virt |
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193 | ; Traverse all pages used for transfer descriptors, looking for the one |
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194 | ; with physical address as in ecx. |
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195 | mov eax, [usb_gtd_first_page] |
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196 | @@: |
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197 | test eax, eax |
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198 | jz .zero |
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199 | push eax |
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200 | call get_pg_addr |
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201 | sub eax, ecx |
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202 | jz .found |
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203 | cmp eax, -0x1000 |
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204 | ja .found |
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205 | pop eax |
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206 | mov eax, [eax+0x1000-4] |
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207 | jmp @b |
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208 | .found: |
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209 | ; When found, combine page address from eax with page offset from ecx. |
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210 | pop eax |
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211 | and ecx, 0xFFF |
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212 | add eax, ecx |
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213 | .zero: |
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214 | ret |
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215 | endp |