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4b1bf81c | 1 | /** @file\r |
2 | PEIM to produce gPeiUsb2HostControllerPpiGuid based on gPeiUsbControllerPpiGuid\r | |
3 | which is used to enable recovery function from USB Drivers.\r | |
4 | \r | |
2c656af0 | 5 | Copyright (c) 2010 - 2017, Intel Corporation. All rights reserved.<BR>\r |
4b1bf81c | 6 | \r |
7 | This program and the accompanying materials\r | |
8 | are licensed and made available under the terms and conditions\r | |
9 | of the BSD License which accompanies this distribution. The\r | |
10 | full text of the license may be found at\r | |
11 | http://opensource.org/licenses/bsd-license.php\r | |
12 | \r | |
13 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
14 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
15 | \r | |
16 | **/\r | |
17 | \r | |
18 | #include "EhcPeim.h"\r | |
19 | \r | |
20 | /**\r | |
21 | Allocate a block of memory to be used by the buffer pool.\r | |
22 | \r | |
23 | @param Ehc The EHCI device.\r | |
24 | @param Pool The buffer pool to allocate memory for.\r | |
25 | @param Pages How many pages to allocate.\r | |
26 | \r | |
27 | @return The allocated memory block or NULL if failed.\r | |
28 | \r | |
29 | **/\r | |
30 | USBHC_MEM_BLOCK *\r | |
31 | UsbHcAllocMemBlock (\r | |
32 | IN PEI_USB2_HC_DEV *Ehc,\r | |
33 | IN USBHC_MEM_POOL *Pool,\r | |
34 | IN UINTN Pages\r | |
35 | )\r | |
36 | {\r | |
37 | USBHC_MEM_BLOCK *Block;\r | |
38 | VOID *BufHost;\r | |
39 | VOID *Mapping;\r | |
40 | EFI_PHYSICAL_ADDRESS MappedAddr;\r | |
41 | EFI_STATUS Status;\r | |
42 | UINTN PageNumber;\r | |
43 | EFI_PHYSICAL_ADDRESS TempPtr;\r | |
44 | \r | |
45 | Mapping = NULL;\r | |
46 | PageNumber = sizeof(USBHC_MEM_BLOCK)/PAGESIZE +1;\r | |
47 | Status = PeiServicesAllocatePages (\r | |
48 | EfiBootServicesCode,\r | |
49 | PageNumber,\r | |
50 | &TempPtr\r | |
51 | );\r | |
52 | \r | |
53 | if (EFI_ERROR (Status)) {\r | |
54 | return NULL;\r | |
55 | }\r | |
56 | ZeroMem ((VOID *)(UINTN)TempPtr, PageNumber*EFI_PAGE_SIZE);\r | |
57 | \r | |
58 | //\r | |
59 | // each bit in the bit array represents USBHC_MEM_UNIT\r | |
60 | // bytes of memory in the memory block.\r | |
61 | //\r | |
62 | ASSERT (USBHC_MEM_UNIT * 8 <= EFI_PAGE_SIZE);\r | |
63 | \r | |
64 | Block = (USBHC_MEM_BLOCK*)(UINTN)TempPtr;\r | |
65 | Block->BufLen = EFI_PAGES_TO_SIZE (Pages);\r | |
66 | Block->BitsLen = Block->BufLen / (USBHC_MEM_UNIT * 8);\r | |
67 | \r | |
68 | PageNumber = (Block->BitsLen)/PAGESIZE +1;\r | |
69 | Status = PeiServicesAllocatePages (\r | |
70 | EfiBootServicesCode,\r | |
71 | PageNumber,\r | |
72 | &TempPtr\r | |
73 | );\r | |
74 | \r | |
75 | if (EFI_ERROR (Status)) {\r | |
76 | return NULL;\r | |
77 | }\r | |
78 | ZeroMem ((VOID *)(UINTN)TempPtr, PageNumber*EFI_PAGE_SIZE); \r | |
79 | \r | |
80 | Block->Bits = (UINT8 *)(UINTN)TempPtr;\r | |
81 | \r | |
2c656af0 SZ |
82 | Status = IoMmuAllocateBuffer (\r |
83 | Ehc->IoMmu,\r | |
4b1bf81c | 84 | Pages,\r |
2c656af0 SZ |
85 | (VOID **) &BufHost,\r |
86 | &MappedAddr,\r | |
87 | &Mapping\r | |
4b1bf81c | 88 | );\r |
2c656af0 SZ |
89 | if (EFI_ERROR (Status)) {\r |
90 | return NULL;\r | |
91 | }\r | |
92 | ZeroMem (BufHost, Pages*EFI_PAGE_SIZE);\r | |
4b1bf81c | 93 | \r |
4b1bf81c | 94 | //\r |
95 | // Check whether the data structure used by the host controller\r | |
96 | // should be restricted into the same 4G\r | |
97 | //\r | |
98 | if (Pool->Check4G && (Pool->Which4G != USB_HC_HIGH_32BIT (MappedAddr))) {\r | |
99 | return NULL;\r | |
100 | }\r | |
101 | \r | |
102 | Block->BufHost = BufHost;\r | |
103 | Block->Buf = (UINT8 *) ((UINTN) MappedAddr);\r | |
104 | Block->Mapping = Mapping;\r | |
105 | Block->Next = NULL;\r | |
106 | \r | |
107 | return Block;\r | |
108 | \r | |
109 | }\r | |
110 | \r | |
111 | /**\r | |
112 | Free the memory block from the memory pool.\r | |
113 | \r | |
2c656af0 | 114 | @param Ehc The EHCI device.\r |
4b1bf81c | 115 | @param Pool The memory pool to free the block from.\r |
116 | @param Block The memory block to free.\r | |
117 | \r | |
118 | **/\r | |
119 | VOID\r | |
120 | UsbHcFreeMemBlock (\r | |
2c656af0 | 121 | IN PEI_USB2_HC_DEV *Ehc,\r |
4b1bf81c | 122 | IN USBHC_MEM_POOL *Pool,\r |
123 | IN USBHC_MEM_BLOCK *Block\r | |
124 | )\r | |
125 | {\r | |
126 | ASSERT ((Pool != NULL) && (Block != NULL));\r | |
2c656af0 SZ |
127 | \r |
128 | IoMmuFreeBuffer (Ehc->IoMmu, EFI_SIZE_TO_PAGES (Block->BufLen), Block->BufHost, Block->Mapping);\r | |
4b1bf81c | 129 | }\r |
130 | \r | |
131 | /**\r | |
132 | Alloc some memory from the block.\r | |
133 | \r | |
134 | @param Block The memory block to allocate memory from.\r | |
135 | @param Units Number of memory units to allocate.\r | |
136 | \r | |
137 | @return The pointer to the allocated memory. If couldn't allocate the needed memory,\r | |
138 | the return value is NULL.\r | |
139 | \r | |
140 | **/\r | |
141 | VOID *\r | |
142 | UsbHcAllocMemFromBlock (\r | |
143 | IN USBHC_MEM_BLOCK *Block,\r | |
144 | IN UINTN Units\r | |
145 | )\r | |
146 | {\r | |
147 | UINTN Byte;\r | |
148 | UINT8 Bit;\r | |
149 | UINTN StartByte;\r | |
150 | UINT8 StartBit;\r | |
151 | UINTN Available;\r | |
152 | UINTN Count;\r | |
153 | \r | |
154 | ASSERT ((Block != 0) && (Units != 0));\r | |
155 | \r | |
156 | StartByte = 0;\r | |
157 | StartBit = 0;\r | |
158 | Available = 0;\r | |
159 | \r | |
160 | for (Byte = 0, Bit = 0; Byte < Block->BitsLen;) {\r | |
161 | //\r | |
162 | // If current bit is zero, the corresponding memory unit is\r | |
163 | // available, otherwise we need to restart our searching.\r | |
164 | // Available counts the consective number of zero bit.\r | |
165 | //\r | |
166 | if (!USB_HC_BIT_IS_SET (Block->Bits[Byte], Bit)) {\r | |
167 | Available++;\r | |
168 | \r | |
169 | if (Available >= Units) {\r | |
170 | break;\r | |
171 | }\r | |
172 | \r | |
173 | NEXT_BIT (Byte, Bit);\r | |
174 | \r | |
175 | } else {\r | |
176 | NEXT_BIT (Byte, Bit);\r | |
177 | \r | |
178 | Available = 0;\r | |
179 | StartByte = Byte;\r | |
180 | StartBit = Bit;\r | |
181 | }\r | |
182 | }\r | |
183 | \r | |
184 | if (Available < Units) {\r | |
185 | return NULL;\r | |
186 | }\r | |
187 | \r | |
188 | //\r | |
189 | // Mark the memory as allocated\r | |
190 | //\r | |
191 | Byte = StartByte;\r | |
192 | Bit = StartBit;\r | |
193 | \r | |
194 | for (Count = 0; Count < Units; Count++) {\r | |
195 | ASSERT (!USB_HC_BIT_IS_SET (Block->Bits[Byte], Bit));\r | |
196 | \r | |
197 | Block->Bits[Byte] = (UINT8) (Block->Bits[Byte] | (UINT8) USB_HC_BIT (Bit));\r | |
198 | NEXT_BIT (Byte, Bit);\r | |
199 | }\r | |
200 | \r | |
201 | return Block->Buf + (StartByte * 8 + StartBit) * USBHC_MEM_UNIT;\r | |
202 | }\r | |
203 | \r | |
2c656af0 SZ |
204 | /**\r |
205 | Calculate the corresponding pci bus address according to the Mem parameter.\r | |
206 | \r | |
207 | @param Pool The memory pool of the host controller.\r | |
208 | @param Mem The pointer to host memory.\r | |
209 | @param Size The size of the memory region.\r | |
210 | \r | |
211 | @return the pci memory address\r | |
212 | **/\r | |
213 | EFI_PHYSICAL_ADDRESS\r | |
214 | UsbHcGetPciAddressForHostMem (\r | |
215 | IN USBHC_MEM_POOL *Pool,\r | |
216 | IN VOID *Mem,\r | |
217 | IN UINTN Size\r | |
218 | )\r | |
219 | {\r | |
220 | USBHC_MEM_BLOCK *Head;\r | |
221 | USBHC_MEM_BLOCK *Block;\r | |
222 | UINTN AllocSize;\r | |
223 | EFI_PHYSICAL_ADDRESS PhyAddr;\r | |
224 | UINTN Offset;\r | |
225 | \r | |
226 | Head = Pool->Head;\r | |
227 | AllocSize = USBHC_MEM_ROUND (Size);\r | |
228 | \r | |
229 | if (Mem == NULL) {\r | |
230 | return 0;\r | |
231 | }\r | |
232 | \r | |
233 | for (Block = Head; Block != NULL; Block = Block->Next) {\r | |
234 | //\r | |
235 | // scan the memory block list for the memory block that\r | |
236 | // completely contains the allocated memory.\r | |
237 | //\r | |
238 | if ((Block->BufHost <= (UINT8 *) Mem) && (((UINT8 *) Mem + AllocSize) <= (Block->BufHost + Block->BufLen))) {\r | |
239 | break;\r | |
240 | }\r | |
241 | }\r | |
242 | \r | |
243 | ASSERT ((Block != NULL));\r | |
244 | //\r | |
245 | // calculate the pci memory address for host memory address.\r | |
246 | //\r | |
247 | Offset = (UINT8 *)Mem - Block->BufHost;\r | |
248 | PhyAddr = (EFI_PHYSICAL_ADDRESS)(UINTN) (Block->Buf + Offset);\r | |
249 | return PhyAddr;\r | |
250 | }\r | |
251 | \r | |
4b1bf81c | 252 | /**\r |
253 | Insert the memory block to the pool's list of the blocks.\r | |
254 | \r | |
255 | @param Head The head of the memory pool's block list.\r | |
256 | @param Block The memory block to insert.\r | |
257 | \r | |
258 | **/\r | |
259 | VOID\r | |
260 | UsbHcInsertMemBlockToPool (\r | |
261 | IN USBHC_MEM_BLOCK *Head,\r | |
262 | IN USBHC_MEM_BLOCK *Block\r | |
263 | )\r | |
264 | {\r | |
265 | ASSERT ((Head != NULL) && (Block != NULL));\r | |
266 | Block->Next = Head->Next;\r | |
267 | Head->Next = Block;\r | |
268 | }\r | |
269 | \r | |
270 | /**\r | |
271 | Is the memory block empty?\r | |
272 | \r | |
273 | @param Block The memory block to check.\r | |
274 | \r | |
275 | @retval TRUE The memory block is empty.\r | |
276 | @retval FALSE The memory block isn't empty.\r | |
277 | \r | |
278 | **/\r | |
279 | BOOLEAN\r | |
280 | UsbHcIsMemBlockEmpty (\r | |
281 | IN USBHC_MEM_BLOCK *Block\r | |
282 | )\r | |
283 | {\r | |
284 | UINTN Index;\r | |
285 | \r | |
286 | \r | |
287 | for (Index = 0; Index < Block->BitsLen; Index++) {\r | |
288 | if (Block->Bits[Index] != 0) {\r | |
289 | return FALSE;\r | |
290 | }\r | |
291 | }\r | |
292 | \r | |
293 | return TRUE;\r | |
294 | }\r | |
295 | \r | |
296 | /**\r | |
297 | Unlink the memory block from the pool's list.\r | |
298 | \r | |
299 | @param Head The block list head of the memory's pool.\r | |
300 | @param BlockToUnlink The memory block to unlink.\r | |
301 | \r | |
302 | **/\r | |
303 | VOID\r | |
304 | UsbHcUnlinkMemBlock (\r | |
305 | IN USBHC_MEM_BLOCK *Head,\r | |
306 | IN USBHC_MEM_BLOCK *BlockToUnlink\r | |
307 | )\r | |
308 | {\r | |
309 | USBHC_MEM_BLOCK *Block;\r | |
310 | \r | |
311 | ASSERT ((Head != NULL) && (BlockToUnlink != NULL));\r | |
312 | \r | |
313 | for (Block = Head; Block != NULL; Block = Block->Next) {\r | |
314 | if (Block->Next == BlockToUnlink) {\r | |
315 | Block->Next = BlockToUnlink->Next;\r | |
316 | BlockToUnlink->Next = NULL;\r | |
317 | break;\r | |
318 | }\r | |
319 | }\r | |
320 | }\r | |
321 | \r | |
322 | /**\r | |
323 | Initialize the memory management pool for the host controller.\r | |
324 | \r | |
325 | @param Ehc The EHCI device.\r | |
326 | @param Check4G Whether the host controller requires allocated memory.\r | |
327 | from one 4G address space.\r | |
328 | @param Which4G The 4G memory area each memory allocated should be from.\r | |
329 | \r | |
330 | @retval EFI_SUCCESS The memory pool is initialized.\r | |
331 | @retval EFI_OUT_OF_RESOURCE Fail to init the memory pool.\r | |
332 | \r | |
333 | **/\r | |
334 | USBHC_MEM_POOL *\r | |
335 | UsbHcInitMemPool (\r | |
336 | IN PEI_USB2_HC_DEV *Ehc,\r | |
337 | IN BOOLEAN Check4G,\r | |
338 | IN UINT32 Which4G\r | |
339 | )\r | |
340 | {\r | |
341 | USBHC_MEM_POOL *Pool;\r | |
342 | UINTN PageNumber;\r | |
343 | EFI_STATUS Status;\r | |
344 | EFI_PHYSICAL_ADDRESS TempPtr;\r | |
345 | \r | |
346 | PageNumber = sizeof(USBHC_MEM_POOL)/PAGESIZE +1;\r | |
347 | Status = PeiServicesAllocatePages (\r | |
348 | EfiBootServicesCode,\r | |
349 | PageNumber,\r | |
350 | &TempPtr\r | |
351 | );\r | |
352 | \r | |
353 | if (EFI_ERROR (Status)) {\r | |
354 | return NULL;\r | |
355 | }\r | |
356 | ZeroMem ((VOID *)(UINTN)TempPtr, PageNumber*EFI_PAGE_SIZE); \r | |
357 | \r | |
358 | Pool = (USBHC_MEM_POOL *) ((UINTN) TempPtr); \r | |
359 | \r | |
360 | Pool->Check4G = Check4G;\r | |
361 | Pool->Which4G = Which4G;\r | |
362 | Pool->Head = UsbHcAllocMemBlock (Ehc, Pool, USBHC_MEM_DEFAULT_PAGES);\r | |
363 | \r | |
364 | if (Pool->Head == NULL) {\r | |
365 | Pool = NULL;\r | |
366 | }\r | |
367 | \r | |
368 | return Pool;\r | |
369 | }\r | |
370 | \r | |
371 | /**\r | |
372 | Release the memory management pool.\r | |
2c656af0 SZ |
373 | \r |
374 | @param Ehc The EHCI device.\r | |
4b1bf81c | 375 | @param Pool The USB memory pool to free.\r |
376 | \r | |
377 | @retval EFI_DEVICE_ERROR Fail to free the memory pool.\r | |
378 | @retval EFI_SUCCESS The memory pool is freed.\r | |
379 | \r | |
380 | **/\r | |
381 | EFI_STATUS\r | |
382 | UsbHcFreeMemPool (\r | |
2c656af0 | 383 | IN PEI_USB2_HC_DEV *Ehc,\r |
4b1bf81c | 384 | IN USBHC_MEM_POOL *Pool\r |
385 | )\r | |
386 | {\r | |
387 | USBHC_MEM_BLOCK *Block;\r | |
388 | \r | |
389 | ASSERT (Pool->Head != NULL);\r | |
390 | \r | |
391 | //\r | |
392 | // Unlink all the memory blocks from the pool, then free them.\r | |
393 | // UsbHcUnlinkMemBlock can't be used to unlink and free the\r | |
394 | // first block.\r | |
395 | //\r | |
2c656af0 SZ |
396 | for (Block = Pool->Head->Next; Block != NULL; Block = Block->Next) {\r |
397 | UsbHcFreeMemBlock (Ehc, Pool, Block);\r | |
4b1bf81c | 398 | }\r |
399 | \r | |
2c656af0 | 400 | UsbHcFreeMemBlock (Ehc, Pool, Pool->Head);\r |
4b1bf81c | 401 | \r |
402 | return EFI_SUCCESS;\r | |
403 | }\r | |
404 | \r | |
405 | /**\r | |
406 | Allocate some memory from the host controller's memory pool\r | |
407 | which can be used to communicate with host controller.\r | |
408 | \r | |
409 | @param Ehc The EHCI device.\r | |
410 | @param Pool The host controller's memory pool.\r | |
411 | @param Size Size of the memory to allocate.\r | |
412 | \r | |
413 | @return The allocated memory or NULL.\r | |
414 | \r | |
415 | **/\r | |
416 | VOID *\r | |
417 | UsbHcAllocateMem (\r | |
418 | IN PEI_USB2_HC_DEV *Ehc,\r | |
419 | IN USBHC_MEM_POOL *Pool,\r | |
420 | IN UINTN Size\r | |
421 | )\r | |
422 | {\r | |
423 | USBHC_MEM_BLOCK *Head;\r | |
424 | USBHC_MEM_BLOCK *Block;\r | |
425 | USBHC_MEM_BLOCK *NewBlock;\r | |
426 | VOID *Mem;\r | |
427 | UINTN AllocSize;\r | |
428 | UINTN Pages;\r | |
429 | \r | |
430 | Mem = NULL;\r | |
431 | AllocSize = USBHC_MEM_ROUND (Size);\r | |
432 | Head = Pool->Head;\r | |
433 | ASSERT (Head != NULL);\r | |
434 | \r | |
435 | //\r | |
436 | // First check whether current memory blocks can satisfy the allocation.\r | |
437 | //\r | |
438 | for (Block = Head; Block != NULL; Block = Block->Next) {\r | |
439 | Mem = UsbHcAllocMemFromBlock (Block, AllocSize / USBHC_MEM_UNIT);\r | |
440 | \r | |
441 | if (Mem != NULL) {\r | |
442 | ZeroMem (Mem, Size);\r | |
443 | break;\r | |
444 | }\r | |
445 | }\r | |
446 | \r | |
447 | if (Mem != NULL) {\r | |
448 | return Mem;\r | |
449 | }\r | |
450 | \r | |
451 | //\r | |
452 | // Create a new memory block if there is not enough memory\r | |
453 | // in the pool. If the allocation size is larger than the\r | |
454 | // default page number, just allocate a large enough memory\r | |
455 | // block. Otherwise allocate default pages.\r | |
456 | //\r | |
457 | if (AllocSize > EFI_PAGES_TO_SIZE (USBHC_MEM_DEFAULT_PAGES)) {\r | |
458 | Pages = EFI_SIZE_TO_PAGES (AllocSize) + 1;\r | |
459 | } else {\r | |
460 | Pages = USBHC_MEM_DEFAULT_PAGES;\r | |
461 | }\r | |
462 | NewBlock = UsbHcAllocMemBlock (Ehc,Pool, Pages);\r | |
463 | \r | |
464 | if (NewBlock == NULL) {\r | |
465 | return NULL;\r | |
466 | }\r | |
467 | \r | |
468 | //\r | |
469 | // Add the new memory block to the pool, then allocate memory from it\r | |
470 | //\r | |
471 | UsbHcInsertMemBlockToPool (Head, NewBlock);\r | |
472 | Mem = UsbHcAllocMemFromBlock (NewBlock, AllocSize / USBHC_MEM_UNIT);\r | |
473 | \r | |
474 | if (Mem != NULL) {\r | |
475 | ZeroMem (Mem, Size);\r | |
476 | }\r | |
477 | \r | |
478 | return Mem;\r | |
479 | }\r | |
480 | \r | |
481 | /**\r | |
482 | Free the allocated memory back to the memory pool.\r | |
483 | \r | |
2c656af0 | 484 | @param Ehc The EHCI device.\r |
4b1bf81c | 485 | @param Pool The memory pool of the host controller.\r |
486 | @param Mem The memory to free.\r | |
487 | @param Size The size of the memory to free.\r | |
488 | \r | |
489 | **/\r | |
490 | VOID\r | |
491 | UsbHcFreeMem (\r | |
2c656af0 | 492 | IN PEI_USB2_HC_DEV *Ehc,\r |
4b1bf81c | 493 | IN USBHC_MEM_POOL *Pool,\r |
494 | IN VOID *Mem,\r | |
495 | IN UINTN Size\r | |
496 | )\r | |
497 | {\r | |
498 | USBHC_MEM_BLOCK *Head;\r | |
499 | USBHC_MEM_BLOCK *Block;\r | |
500 | UINT8 *ToFree;\r | |
501 | UINTN AllocSize;\r | |
502 | UINTN Byte;\r | |
503 | UINTN Bit;\r | |
504 | UINTN Count;\r | |
505 | \r | |
506 | Head = Pool->Head;\r | |
507 | AllocSize = USBHC_MEM_ROUND (Size);\r | |
508 | ToFree = (UINT8 *) Mem;\r | |
509 | \r | |
510 | for (Block = Head; Block != NULL; Block = Block->Next) {\r | |
511 | //\r | |
512 | // scan the memory block list for the memory block that\r | |
513 | // completely contains the memory to free.\r | |
514 | //\r | |
515 | if ((Block->Buf <= ToFree) && ((ToFree + AllocSize) <= (Block->Buf + Block->BufLen))) {\r | |
516 | //\r | |
517 | // compute the start byte and bit in the bit array\r | |
518 | //\r | |
519 | Byte = ((ToFree - Block->Buf) / USBHC_MEM_UNIT) / 8;\r | |
520 | Bit = ((ToFree - Block->Buf) / USBHC_MEM_UNIT) % 8;\r | |
521 | \r | |
522 | //\r | |
2048c585 | 523 | // reset associated bits in bit array\r |
4b1bf81c | 524 | //\r |
525 | for (Count = 0; Count < (AllocSize / USBHC_MEM_UNIT); Count++) {\r | |
526 | ASSERT (USB_HC_BIT_IS_SET (Block->Bits[Byte], Bit));\r | |
527 | \r | |
528 | Block->Bits[Byte] = (UINT8) (Block->Bits[Byte] ^ USB_HC_BIT (Bit));\r | |
529 | NEXT_BIT (Byte, Bit);\r | |
530 | }\r | |
531 | \r | |
532 | break;\r | |
533 | }\r | |
534 | }\r | |
535 | \r | |
536 | //\r | |
537 | // If Block == NULL, it means that the current memory isn't\r | |
538 | // in the host controller's pool. This is critical because\r | |
539 | // the caller has passed in a wrong memory point\r | |
540 | //\r | |
541 | ASSERT (Block != NULL);\r | |
542 | \r | |
543 | //\r | |
544 | // Release the current memory block if it is empty and not the head\r | |
545 | //\r | |
546 | if ((Block != Head) && UsbHcIsMemBlockEmpty (Block)) {\r | |
2c656af0 | 547 | UsbHcFreeMemBlock (Ehc, Pool, Block);\r |
4b1bf81c | 548 | }\r |
549 | \r | |
550 | return ;\r | |
551 | }\r |