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878ddf1f | 1 | /*++ \r |
2 | \r | |
3 | Copyright (c) 2006, Intel Corporation \r | |
4 | All rights reserved. This program and the accompanying materials \r | |
5 | are licensed and made available under the terms and conditions of the BSD License \r | |
6 | which accompanies this distribution. The full text of the license may be found at \r | |
7 | http://opensource.org/licenses/bsd-license.php \r | |
8 | \r | |
9 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r | |
10 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r | |
11 | \r | |
12 | Module Name:\r | |
13 | \r | |
14 | dependency.c\r | |
15 | \r | |
16 | Abstract:\r | |
17 | \r | |
18 | DXE Dispatcher Dependency Evaluator\r | |
19 | \r | |
20 | This routine evaluates a dependency expression (DEPENDENCY_EXPRESSION) to determine\r | |
21 | if a driver can be scheduled for execution. The criteria for\r | |
22 | schedulability is that the dependency expression is satisfied.\r | |
23 | \r | |
24 | --*/\r | |
25 | \r | |
26 | #include <DxeMain.h>\r | |
27 | \r | |
28 | //\r | |
29 | // Global stack used to evaluate dependency expressions\r | |
30 | //\r | |
31 | BOOLEAN *mDepexEvaluationStack = NULL;\r | |
32 | BOOLEAN *mDepexEvaluationStackEnd = NULL;\r | |
33 | BOOLEAN *mDepexEvaluationStackPointer = NULL;\r | |
34 | \r | |
35 | //\r | |
36 | // Worker functions\r | |
37 | //\r | |
38 | \r | |
39 | STATIC\r | |
40 | EFI_STATUS\r | |
41 | GrowDepexStack (\r | |
42 | VOID\r | |
43 | )\r | |
44 | /*++\r | |
45 | \r | |
46 | Routine Description:\r | |
47 | \r | |
48 | Grow size of the Depex stack\r | |
49 | \r | |
50 | Arguments:\r | |
51 | \r | |
52 | Stack - Old stack on the way in and new stack on the way out\r | |
53 | \r | |
54 | StackSize - New size of the stack\r | |
55 | \r | |
56 | Returns:\r | |
57 | \r | |
58 | EFI_SUCCESS - Stack successfully growed.\r | |
59 | \r | |
60 | EFI_OUT_OF_RESOURCES - There is not enough system memory to grow the stack.\r | |
61 | \r | |
62 | \r | |
63 | \r | |
64 | --*/\r | |
65 | {\r | |
66 | BOOLEAN *NewStack;\r | |
67 | UINTN Size;\r | |
68 | \r | |
69 | Size = DEPEX_STACK_SIZE_INCREMENT;\r | |
70 | if (mDepexEvaluationStack != NULL) {\r | |
71 | Size = Size + (mDepexEvaluationStackEnd - mDepexEvaluationStack);\r | |
72 | }\r | |
73 | \r | |
74 | NewStack = CoreAllocateBootServicesPool (Size * sizeof (BOOLEAN));\r | |
75 | if (NewStack == NULL) {\r | |
76 | return EFI_OUT_OF_RESOURCES;\r | |
77 | }\r | |
78 | \r | |
79 | if (mDepexEvaluationStack != NULL) {\r | |
80 | //\r | |
81 | // Copy to Old Stack to the New Stack\r | |
82 | //\r | |
83 | CopyMem (\r | |
84 | NewStack, \r | |
85 | mDepexEvaluationStack, \r | |
86 | (mDepexEvaluationStackEnd - mDepexEvaluationStack) * sizeof (BOOLEAN)\r | |
87 | );\r | |
88 | \r | |
89 | //\r | |
90 | // Free The Old Stack\r | |
91 | //\r | |
92 | CoreFreePool (mDepexEvaluationStack);\r | |
93 | }\r | |
94 | \r | |
95 | //\r | |
96 | // Make the Stack pointer point to the old data in the new stack\r | |
97 | //\r | |
98 | mDepexEvaluationStackPointer = NewStack + (mDepexEvaluationStackPointer - mDepexEvaluationStack);\r | |
99 | mDepexEvaluationStack = NewStack;\r | |
100 | mDepexEvaluationStackEnd = NewStack + Size;\r | |
101 | \r | |
102 | return EFI_SUCCESS;\r | |
103 | }\r | |
104 | \r | |
105 | \r | |
106 | STATIC\r | |
107 | EFI_STATUS\r | |
108 | PushBool (\r | |
109 | IN BOOLEAN Value\r | |
110 | )\r | |
111 | /*++\r | |
112 | \r | |
113 | Routine Description:\r | |
114 | \r | |
115 | Push an element onto the Boolean Stack\r | |
116 | \r | |
117 | Arguments:\r | |
118 | \r | |
119 | Value - BOOLEAN to push.\r | |
120 | \r | |
121 | Returns:\r | |
122 | \r | |
123 | EFI_SUCCESS - The value was pushed onto the stack.\r | |
124 | \r | |
125 | EFI_OUT_OF_RESOURCES - There is not enough system memory to grow the stack.\r | |
126 | \r | |
127 | --*/\r | |
128 | {\r | |
129 | EFI_STATUS Status;\r | |
130 | \r | |
131 | //\r | |
132 | // Check for a stack overflow condition\r | |
133 | //\r | |
134 | if (mDepexEvaluationStackPointer == mDepexEvaluationStackEnd) {\r | |
135 | //\r | |
136 | // Grow the stack\r | |
137 | //\r | |
138 | Status = GrowDepexStack ();\r | |
139 | if (EFI_ERROR (Status)) {\r | |
140 | return Status;\r | |
141 | }\r | |
142 | }\r | |
143 | \r | |
144 | //\r | |
145 | // Push the item onto the stack\r | |
146 | //\r | |
147 | *mDepexEvaluationStackPointer = Value;\r | |
148 | mDepexEvaluationStackPointer++;\r | |
149 | \r | |
150 | return EFI_SUCCESS;\r | |
151 | }\r | |
152 | \r | |
153 | \r | |
154 | STATIC\r | |
155 | EFI_STATUS \r | |
156 | PopBool (\r | |
157 | OUT BOOLEAN *Value\r | |
158 | )\r | |
159 | /*++\r | |
160 | \r | |
161 | Routine Description:\r | |
162 | \r | |
163 | Pop an element from the Boolean stack.\r | |
164 | \r | |
165 | Arguments:\r | |
166 | \r | |
167 | Value - BOOLEAN to pop.\r | |
168 | \r | |
169 | Returns:\r | |
170 | \r | |
171 | EFI_SUCCESS - The value was popped onto the stack.\r | |
172 | \r | |
173 | EFI_ACCESS_DENIED - The pop operation underflowed the stack\r | |
174 | \r | |
175 | --*/\r | |
176 | {\r | |
177 | //\r | |
178 | // Check for a stack underflow condition\r | |
179 | //\r | |
180 | if (mDepexEvaluationStackPointer == mDepexEvaluationStack) {\r | |
181 | return EFI_ACCESS_DENIED;\r | |
182 | }\r | |
183 | \r | |
184 | //\r | |
185 | // Pop the item off the stack\r | |
186 | //\r | |
187 | mDepexEvaluationStackPointer--;\r | |
188 | *Value = *mDepexEvaluationStackPointer;\r | |
189 | return EFI_SUCCESS; \r | |
190 | }\r | |
191 | \r | |
192 | \r | |
193 | EFI_STATUS\r | |
194 | CorePreProcessDepex (\r | |
195 | IN EFI_CORE_DRIVER_ENTRY *DriverEntry \r | |
196 | )\r | |
197 | /*++\r | |
198 | \r | |
199 | Routine Description:\r | |
200 | \r | |
201 | Preprocess dependency expression and update DriverEntry to reflect the\r | |
202 | state of Before, After, and SOR dependencies. If DriverEntry->Before\r | |
203 | or DriverEntry->After is set it will never be cleared. If SOR is set\r | |
204 | it will be cleared by CoreSchedule(), and then the driver can be \r | |
205 | dispatched.\r | |
206 | \r | |
207 | Arguments:\r | |
208 | \r | |
209 | DriverEntry - DriverEntry element to update\r | |
210 | \r | |
211 | Returns:\r | |
212 | \r | |
213 | EFI_SUCCESS - It always works.\r | |
214 | \r | |
215 | --*/\r | |
216 | {\r | |
217 | UINT8 *Iterator;\r | |
218 | \r | |
219 | Iterator = DriverEntry->Depex;\r | |
220 | if (*Iterator == EFI_DEP_SOR) {\r | |
221 | DriverEntry->Unrequested = TRUE;\r | |
222 | } else {\r | |
223 | DriverEntry->Dependent = TRUE;\r | |
224 | }\r | |
225 | \r | |
226 | if (*Iterator == EFI_DEP_BEFORE) {\r | |
227 | DriverEntry->Before = TRUE;\r | |
228 | } else if (*Iterator == EFI_DEP_AFTER) {\r | |
229 | DriverEntry->After = TRUE;\r | |
230 | } \r | |
231 | \r | |
232 | if (DriverEntry->Before || DriverEntry->After) {\r | |
233 | CopyMem (&DriverEntry->BeforeAfterGuid, Iterator + 1, sizeof (EFI_GUID));\r | |
234 | }\r | |
235 | \r | |
236 | return EFI_SUCCESS;\r | |
237 | }\r | |
238 | \r | |
239 | \r | |
240 | BOOLEAN\r | |
241 | CoreIsSchedulable (\r | |
242 | IN EFI_CORE_DRIVER_ENTRY *DriverEntry \r | |
243 | )\r | |
244 | /*++\r | |
245 | \r | |
246 | Routine Description:\r | |
247 | \r | |
248 | This is the POSTFIX version of the dependency evaluator. This code does \r | |
249 | not need to handle Before or After, as it is not valid to call this \r | |
250 | routine in this case. The SOR is just ignored and is a nop in the grammer.\r | |
251 | \r | |
252 | POSTFIX means all the math is done on top of the stack.\r | |
253 | \r | |
254 | Arguments:\r | |
255 | \r | |
256 | DriverEntry - DriverEntry element to update\r | |
257 | \r | |
258 | Returns:\r | |
259 | \r | |
260 | TRUE - If driver is ready to run.\r | |
261 | \r | |
262 | FALSE - If driver is not ready to run or some fatal error was found.\r | |
263 | \r | |
264 | --*/\r | |
265 | {\r | |
266 | EFI_STATUS Status;\r | |
267 | UINT8 *Iterator;\r | |
268 | BOOLEAN Operator;\r | |
269 | BOOLEAN Operator2;\r | |
270 | EFI_GUID DriverGuid;\r | |
271 | VOID *Interface;\r | |
272 | \r | |
273 | if (DriverEntry->After || DriverEntry->Before) {\r | |
274 | //\r | |
275 | // If Before or After Depex skip as CoreInsertOnScheduledQueueWhileProcessingBeforeAndAfter ()\r | |
276 | // processes them.\r | |
277 | //\r | |
278 | return FALSE;\r | |
279 | }\r | |
280 | \r | |
281 | if (DriverEntry->Depex == NULL) {\r | |
282 | //\r | |
283 | // A NULL Depex means treat the driver like an EFI 1.0 thing.\r | |
284 | //\r | |
285 | Status = CoreAllEfiServicesAvailable ();\r | |
286 | if (EFI_ERROR (Status)) {\r | |
287 | return FALSE;\r | |
288 | }\r | |
289 | return TRUE;\r | |
290 | }\r | |
291 | \r | |
292 | //\r | |
293 | // Clean out memory leaks in Depex Boolean stack. Leaks are only caused by\r | |
294 | // incorrectly formed DEPEX expressions\r | |
295 | //\r | |
296 | mDepexEvaluationStackPointer = mDepexEvaluationStack;\r | |
297 | \r | |
298 | \r | |
299 | Iterator = DriverEntry->Depex;\r | |
300 | \r | |
301 | while (TRUE) {\r | |
302 | //\r | |
303 | // Check to see if we are attempting to fetch dependency expression instructions\r | |
304 | // past the end of the dependency expression.\r | |
305 | //\r | |
306 | if (((UINTN)Iterator - (UINTN)DriverEntry->Depex) > DriverEntry->DepexSize) {\r | |
307 | return FALSE;\r | |
308 | }\r | |
309 | \r | |
310 | //\r | |
311 | // Look at the opcode of the dependency expression instruction.\r | |
312 | //\r | |
313 | switch (*Iterator) {\r | |
314 | case EFI_DEP_BEFORE:\r | |
315 | case EFI_DEP_AFTER:\r | |
316 | //\r | |
317 | // For a well-formed Dependency Expression, the code should never get here.\r | |
318 | // The BEFORE and AFTER are processed prior to this routine's invocation.\r | |
319 | // If the code flow arrives at this point, there was a BEFORE or AFTER\r | |
320 | // that were not the first opcodes.\r | |
321 | //\r | |
322 | ASSERT (FALSE);\r | |
323 | case EFI_DEP_SOR:\r | |
324 | //\r | |
325 | // These opcodes can only appear once as the first opcode. If it is found \r | |
326 | // at any other location, then the dependency expression evaluates to FALSE\r | |
327 | //\r | |
328 | if (Iterator != DriverEntry->Depex) {\r | |
329 | return FALSE;\r | |
330 | }\r | |
331 | //\r | |
332 | // Otherwise, it is the first opcode and should be treated as a NOP.\r | |
333 | //\r | |
334 | break;\r | |
335 | \r | |
336 | case EFI_DEP_PUSH: \r | |
337 | //\r | |
338 | // Push operator is followed by a GUID. Test to see if the GUID protocol\r | |
339 | // is installed and push the boolean result on the stack.\r | |
340 | //\r | |
341 | CopyMem (&DriverGuid, Iterator + 1, sizeof (EFI_GUID));\r | |
342 | \r | |
343 | Status = CoreLocateProtocol (&DriverGuid, NULL, &Interface);\r | |
344 | \r | |
345 | if (EFI_ERROR (Status)) {\r | |
346 | Status = PushBool (FALSE);\r | |
347 | } else {\r | |
348 | *Iterator = EFI_DEP_REPLACE_TRUE;\r | |
349 | Status = PushBool (TRUE);\r | |
350 | }\r | |
351 | if (EFI_ERROR (Status)) {\r | |
352 | return FALSE;\r | |
353 | }\r | |
354 | \r | |
355 | Iterator += sizeof (EFI_GUID);\r | |
356 | break;\r | |
357 | \r | |
358 | case EFI_DEP_AND: \r | |
359 | Status = PopBool (&Operator);\r | |
360 | if (EFI_ERROR (Status)) {\r | |
361 | return FALSE;\r | |
362 | }\r | |
363 | \r | |
364 | Status = PopBool (&Operator2);\r | |
365 | if (EFI_ERROR (Status)) {\r | |
366 | return FALSE;\r | |
367 | }\r | |
368 | \r | |
369 | Status = PushBool ((BOOLEAN)(Operator && Operator2));\r | |
370 | if (EFI_ERROR (Status)) {\r | |
371 | return FALSE;\r | |
372 | }\r | |
373 | break;\r | |
374 | \r | |
375 | case EFI_DEP_OR: \r | |
376 | Status = PopBool (&Operator);\r | |
377 | if (EFI_ERROR (Status)) {\r | |
378 | return FALSE;\r | |
379 | }\r | |
380 | \r | |
381 | Status = PopBool (&Operator2);\r | |
382 | if (EFI_ERROR (Status)) {\r | |
383 | return FALSE;\r | |
384 | }\r | |
385 | \r | |
386 | Status = PushBool ((BOOLEAN)(Operator || Operator2));\r | |
387 | if (EFI_ERROR (Status)) {\r | |
388 | return FALSE;\r | |
389 | }\r | |
390 | break;\r | |
391 | \r | |
392 | case EFI_DEP_NOT: \r | |
393 | Status = PopBool (&Operator);\r | |
394 | if (EFI_ERROR (Status)) {\r | |
395 | return FALSE;\r | |
396 | }\r | |
397 | \r | |
398 | Status = PushBool ((BOOLEAN)(!Operator));\r | |
399 | if (EFI_ERROR (Status)) {\r | |
400 | return FALSE;\r | |
401 | }\r | |
402 | break;\r | |
403 | \r | |
404 | case EFI_DEP_TRUE: \r | |
405 | Status = PushBool (TRUE);\r | |
406 | if (EFI_ERROR (Status)) {\r | |
407 | return FALSE;\r | |
408 | }\r | |
409 | break;\r | |
410 | \r | |
411 | case EFI_DEP_FALSE: \r | |
412 | Status = PushBool (FALSE);\r | |
413 | if (EFI_ERROR (Status)) {\r | |
414 | return FALSE;\r | |
415 | }\r | |
416 | break;\r | |
417 | \r | |
418 | case EFI_DEP_END: \r | |
419 | Status = PopBool (&Operator);\r | |
420 | if (EFI_ERROR (Status)) {\r | |
421 | return FALSE;\r | |
422 | }\r | |
423 | return Operator;\r | |
424 | \r | |
425 | case EFI_DEP_REPLACE_TRUE:\r | |
426 | Status = PushBool (TRUE);\r | |
427 | if (EFI_ERROR (Status)) {\r | |
428 | return FALSE;\r | |
429 | }\r | |
430 | \r | |
431 | Iterator += sizeof (EFI_GUID);\r | |
432 | break;\r | |
433 | \r | |
434 | default: \r | |
435 | return FALSE;\r | |
436 | }\r | |
437 | \r | |
438 | //\r | |
439 | // Skip over the Dependency Op Code we just processed in the switch.\r | |
440 | // The math is done out of order, but it should not matter. That is\r | |
441 | // we may add in the sizeof (EFI_GUID) before we account for the OP Code.\r | |
442 | // This is not an issue, since we just need the correct end result. You\r | |
443 | // need to be careful using Iterator in the loop as it's intermediate value\r | |
444 | // may be strange.\r | |
445 | //\r | |
446 | Iterator++;\r | |
447 | }\r | |
448 | return FALSE;\r | |
449 | }\r | |
450 | \r |