]>
Commit | Line | Data |
---|---|---|
504214c4 | 1 | /** @file\r |
e94a9ff7 | 2 | DXE Dispatcher Dependency Evaluator.\r |
504214c4 LG |
3 | \r |
4 | This routine evaluates a dependency expression (DEPENDENCY_EXPRESSION) to determine\r | |
5 | if a driver can be scheduled for execution. The criteria for\r | |
6 | schedulability is that the dependency expression is satisfied.\r | |
7 | \r | |
23c98c94 | 8 | Copyright (c) 2006 - 2008, Intel Corporation. <BR>\r |
9 | All rights reserved. This program and the accompanying materials\r | |
10 | are licensed and made available under the terms and conditions of the BSD License\r | |
11 | which accompanies this distribution. The full text of the license may be found at\r | |
12 | http://opensource.org/licenses/bsd-license.php\r | |
13 | \r | |
14 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
15 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
28a00297 | 16 | \r |
504214c4 | 17 | **/\r |
28a00297 | 18 | \r |
19 | #include <DxeMain.h>\r | |
20 | \r | |
21 | //\r | |
22 | // Global stack used to evaluate dependency expressions\r | |
23 | //\r | |
24 | BOOLEAN *mDepexEvaluationStack = NULL;\r | |
25 | BOOLEAN *mDepexEvaluationStackEnd = NULL;\r | |
26 | BOOLEAN *mDepexEvaluationStackPointer = NULL;\r | |
27 | \r | |
28 | //\r | |
29 | // Worker functions\r | |
30 | //\r | |
31 | \r | |
162ed594 | 32 | \r |
33 | /**\r | |
34 | Grow size of the Depex stack\r | |
35 | \r | |
022c6d45 | 36 | @retval EFI_SUCCESS Stack successfully growed.\r |
e94a9ff7 | 37 | @retval EFI_OUT_OF_RESOURCES There is not enough system memory to grow the stack.\r |
162ed594 | 38 | \r |
39 | **/\r | |
28a00297 | 40 | EFI_STATUS\r |
41 | GrowDepexStack (\r | |
42 | VOID\r | |
43 | )\r | |
28a00297 | 44 | {\r |
45 | BOOLEAN *NewStack;\r | |
46 | UINTN Size;\r | |
47 | \r | |
48 | Size = DEPEX_STACK_SIZE_INCREMENT;\r | |
49 | if (mDepexEvaluationStack != NULL) {\r | |
50 | Size = Size + (mDepexEvaluationStackEnd - mDepexEvaluationStack);\r | |
51 | }\r | |
52 | \r | |
53 | NewStack = CoreAllocateBootServicesPool (Size * sizeof (BOOLEAN));\r | |
54 | if (NewStack == NULL) {\r | |
55 | return EFI_OUT_OF_RESOURCES;\r | |
56 | }\r | |
57 | \r | |
58 | if (mDepexEvaluationStack != NULL) {\r | |
59 | //\r | |
60 | // Copy to Old Stack to the New Stack\r | |
61 | //\r | |
62 | CopyMem (\r | |
022c6d45 | 63 | NewStack,\r |
64 | mDepexEvaluationStack,\r | |
28a00297 | 65 | (mDepexEvaluationStackEnd - mDepexEvaluationStack) * sizeof (BOOLEAN)\r |
66 | );\r | |
67 | \r | |
68 | //\r | |
69 | // Free The Old Stack\r | |
70 | //\r | |
71 | CoreFreePool (mDepexEvaluationStack);\r | |
72 | }\r | |
73 | \r | |
74 | //\r | |
75 | // Make the Stack pointer point to the old data in the new stack\r | |
76 | //\r | |
77 | mDepexEvaluationStackPointer = NewStack + (mDepexEvaluationStackPointer - mDepexEvaluationStack);\r | |
78 | mDepexEvaluationStack = NewStack;\r | |
79 | mDepexEvaluationStackEnd = NewStack + Size;\r | |
80 | \r | |
81 | return EFI_SUCCESS;\r | |
82 | }\r | |
83 | \r | |
84 | \r | |
28a00297 | 85 | \r |
162ed594 | 86 | /**\r |
e94a9ff7 | 87 | Push an element onto the Boolean Stack.\r |
28a00297 | 88 | \r |
022c6d45 | 89 | @param Value BOOLEAN to push.\r |
28a00297 | 90 | \r |
022c6d45 | 91 | @retval EFI_SUCCESS The value was pushed onto the stack.\r |
e94a9ff7 | 92 | @retval EFI_OUT_OF_RESOURCES There is not enough system memory to grow the stack.\r |
28a00297 | 93 | \r |
162ed594 | 94 | **/\r |
162ed594 | 95 | EFI_STATUS\r |
96 | PushBool (\r | |
97 | IN BOOLEAN Value\r | |
98 | )\r | |
28a00297 | 99 | {\r |
100 | EFI_STATUS Status;\r | |
101 | \r | |
102 | //\r | |
103 | // Check for a stack overflow condition\r | |
104 | //\r | |
105 | if (mDepexEvaluationStackPointer == mDepexEvaluationStackEnd) {\r | |
106 | //\r | |
107 | // Grow the stack\r | |
108 | //\r | |
109 | Status = GrowDepexStack ();\r | |
110 | if (EFI_ERROR (Status)) {\r | |
111 | return Status;\r | |
112 | }\r | |
113 | }\r | |
114 | \r | |
115 | //\r | |
116 | // Push the item onto the stack\r | |
117 | //\r | |
118 | *mDepexEvaluationStackPointer = Value;\r | |
119 | mDepexEvaluationStackPointer++;\r | |
120 | \r | |
121 | return EFI_SUCCESS;\r | |
122 | }\r | |
123 | \r | |
124 | \r | |
28a00297 | 125 | \r |
162ed594 | 126 | /**\r |
28a00297 | 127 | Pop an element from the Boolean stack.\r |
128 | \r | |
022c6d45 | 129 | @param Value BOOLEAN to pop.\r |
28a00297 | 130 | \r |
022c6d45 | 131 | @retval EFI_SUCCESS The value was popped onto the stack.\r |
e94a9ff7 | 132 | @retval EFI_ACCESS_DENIED The pop operation underflowed the stack.\r |
28a00297 | 133 | \r |
162ed594 | 134 | **/\r |
022c6d45 | 135 | EFI_STATUS\r |
162ed594 | 136 | PopBool (\r |
137 | OUT BOOLEAN *Value\r | |
138 | )\r | |
28a00297 | 139 | {\r |
140 | //\r | |
141 | // Check for a stack underflow condition\r | |
142 | //\r | |
143 | if (mDepexEvaluationStackPointer == mDepexEvaluationStack) {\r | |
144 | return EFI_ACCESS_DENIED;\r | |
145 | }\r | |
146 | \r | |
147 | //\r | |
148 | // Pop the item off the stack\r | |
149 | //\r | |
150 | mDepexEvaluationStackPointer--;\r | |
151 | *Value = *mDepexEvaluationStackPointer;\r | |
022c6d45 | 152 | return EFI_SUCCESS;\r |
28a00297 | 153 | }\r |
154 | \r | |
155 | \r | |
28a00297 | 156 | \r |
162ed594 | 157 | /**\r |
28a00297 | 158 | Preprocess dependency expression and update DriverEntry to reflect the\r |
159 | state of Before, After, and SOR dependencies. If DriverEntry->Before\r | |
160 | or DriverEntry->After is set it will never be cleared. If SOR is set\r | |
162ed594 | 161 | it will be cleared by CoreSchedule(), and then the driver can be\r |
28a00297 | 162 | dispatched.\r |
163 | \r | |
e94a9ff7 | 164 | @param DriverEntry DriverEntry element to update .\r |
28a00297 | 165 | \r |
162ed594 | 166 | @retval EFI_SUCCESS It always works.\r |
28a00297 | 167 | \r |
162ed594 | 168 | **/\r |
169 | EFI_STATUS\r | |
170 | CorePreProcessDepex (\r | |
022c6d45 | 171 | IN EFI_CORE_DRIVER_ENTRY *DriverEntry\r |
162ed594 | 172 | )\r |
28a00297 | 173 | {\r |
174 | UINT8 *Iterator;\r | |
022c6d45 | 175 | \r |
28a00297 | 176 | Iterator = DriverEntry->Depex;\r |
177 | if (*Iterator == EFI_DEP_SOR) {\r | |
178 | DriverEntry->Unrequested = TRUE;\r | |
179 | } else {\r | |
180 | DriverEntry->Dependent = TRUE;\r | |
181 | }\r | |
022c6d45 | 182 | \r |
28a00297 | 183 | if (*Iterator == EFI_DEP_BEFORE) {\r |
184 | DriverEntry->Before = TRUE;\r | |
185 | } else if (*Iterator == EFI_DEP_AFTER) {\r | |
186 | DriverEntry->After = TRUE;\r | |
022c6d45 | 187 | }\r |
28a00297 | 188 | \r |
189 | if (DriverEntry->Before || DriverEntry->After) {\r | |
190 | CopyMem (&DriverEntry->BeforeAfterGuid, Iterator + 1, sizeof (EFI_GUID));\r | |
191 | }\r | |
192 | \r | |
193 | return EFI_SUCCESS;\r | |
194 | }\r | |
195 | \r | |
196 | \r | |
28a00297 | 197 | \r |
162ed594 | 198 | /**\r |
199 | This is the POSTFIX version of the dependency evaluator. This code does\r | |
200 | not need to handle Before or After, as it is not valid to call this\r | |
28a00297 | 201 | routine in this case. The SOR is just ignored and is a nop in the grammer.\r |
28a00297 | 202 | POSTFIX means all the math is done on top of the stack.\r |
203 | \r | |
022c6d45 | 204 | @param DriverEntry DriverEntry element to update.\r |
28a00297 | 205 | \r |
022c6d45 | 206 | @retval TRUE If driver is ready to run.\r |
207 | @retval FALSE If driver is not ready to run or some fatal error\r | |
162ed594 | 208 | was found.\r |
28a00297 | 209 | \r |
162ed594 | 210 | **/\r |
211 | BOOLEAN\r | |
212 | CoreIsSchedulable (\r | |
022c6d45 | 213 | IN EFI_CORE_DRIVER_ENTRY *DriverEntry\r |
162ed594 | 214 | )\r |
28a00297 | 215 | {\r |
216 | EFI_STATUS Status;\r | |
217 | UINT8 *Iterator;\r | |
218 | BOOLEAN Operator;\r | |
219 | BOOLEAN Operator2;\r | |
220 | EFI_GUID DriverGuid;\r | |
221 | VOID *Interface;\r | |
222 | \r | |
223 | if (DriverEntry->After || DriverEntry->Before) {\r | |
224 | //\r | |
225 | // If Before or After Depex skip as CoreInsertOnScheduledQueueWhileProcessingBeforeAndAfter ()\r | |
226 | // processes them.\r | |
227 | //\r | |
228 | return FALSE;\r | |
229 | }\r | |
230 | \r | |
231 | if (DriverEntry->Depex == NULL) {\r | |
232 | //\r | |
8a7d75b0 | 233 | // A NULL Depex means treat the driver like an UEFI 2.0 thing.\r |
28a00297 | 234 | //\r |
235 | Status = CoreAllEfiServicesAvailable ();\r | |
236 | if (EFI_ERROR (Status)) {\r | |
237 | return FALSE;\r | |
238 | }\r | |
239 | return TRUE;\r | |
240 | }\r | |
241 | \r | |
242 | //\r | |
243 | // Clean out memory leaks in Depex Boolean stack. Leaks are only caused by\r | |
e94a9ff7 | 244 | // incorrectly formed DEPEX expressions\r |
28a00297 | 245 | //\r |
246 | mDepexEvaluationStackPointer = mDepexEvaluationStack;\r | |
247 | \r | |
248 | \r | |
249 | Iterator = DriverEntry->Depex;\r | |
022c6d45 | 250 | \r |
28a00297 | 251 | while (TRUE) {\r |
252 | //\r | |
253 | // Check to see if we are attempting to fetch dependency expression instructions\r | |
254 | // past the end of the dependency expression.\r | |
255 | //\r | |
256 | if (((UINTN)Iterator - (UINTN)DriverEntry->Depex) >= DriverEntry->DepexSize) {\r | |
257 | return FALSE;\r | |
258 | }\r | |
259 | \r | |
260 | //\r | |
261 | // Look at the opcode of the dependency expression instruction.\r | |
262 | //\r | |
263 | switch (*Iterator) {\r | |
264 | case EFI_DEP_BEFORE:\r | |
265 | case EFI_DEP_AFTER:\r | |
266 | //\r | |
267 | // For a well-formed Dependency Expression, the code should never get here.\r | |
268 | // The BEFORE and AFTER are processed prior to this routine's invocation.\r | |
269 | // If the code flow arrives at this point, there was a BEFORE or AFTER\r | |
270 | // that were not the first opcodes.\r | |
271 | //\r | |
272 | ASSERT (FALSE);\r | |
273 | case EFI_DEP_SOR:\r | |
274 | //\r | |
022c6d45 | 275 | // These opcodes can only appear once as the first opcode. If it is found\r |
28a00297 | 276 | // at any other location, then the dependency expression evaluates to FALSE\r |
277 | //\r | |
278 | if (Iterator != DriverEntry->Depex) {\r | |
279 | return FALSE;\r | |
280 | }\r | |
281 | //\r | |
282 | // Otherwise, it is the first opcode and should be treated as a NOP.\r | |
283 | //\r | |
284 | break;\r | |
285 | \r | |
022c6d45 | 286 | case EFI_DEP_PUSH:\r |
28a00297 | 287 | //\r |
288 | // Push operator is followed by a GUID. Test to see if the GUID protocol\r | |
289 | // is installed and push the boolean result on the stack.\r | |
290 | //\r | |
291 | CopyMem (&DriverGuid, Iterator + 1, sizeof (EFI_GUID));\r | |
292 | \r | |
293 | Status = CoreLocateProtocol (&DriverGuid, NULL, &Interface);\r | |
294 | \r | |
295 | if (EFI_ERROR (Status)) {\r | |
296 | Status = PushBool (FALSE);\r | |
297 | } else {\r | |
298 | *Iterator = EFI_DEP_REPLACE_TRUE;\r | |
299 | Status = PushBool (TRUE);\r | |
300 | }\r | |
301 | if (EFI_ERROR (Status)) {\r | |
302 | return FALSE;\r | |
303 | }\r | |
304 | \r | |
305 | Iterator += sizeof (EFI_GUID);\r | |
306 | break;\r | |
307 | \r | |
022c6d45 | 308 | case EFI_DEP_AND:\r |
28a00297 | 309 | Status = PopBool (&Operator);\r |
310 | if (EFI_ERROR (Status)) {\r | |
311 | return FALSE;\r | |
312 | }\r | |
313 | \r | |
314 | Status = PopBool (&Operator2);\r | |
315 | if (EFI_ERROR (Status)) {\r | |
316 | return FALSE;\r | |
317 | }\r | |
318 | \r | |
319 | Status = PushBool ((BOOLEAN)(Operator && Operator2));\r | |
320 | if (EFI_ERROR (Status)) {\r | |
321 | return FALSE;\r | |
322 | }\r | |
323 | break;\r | |
324 | \r | |
022c6d45 | 325 | case EFI_DEP_OR:\r |
28a00297 | 326 | Status = PopBool (&Operator);\r |
327 | if (EFI_ERROR (Status)) {\r | |
328 | return FALSE;\r | |
329 | }\r | |
330 | \r | |
331 | Status = PopBool (&Operator2);\r | |
332 | if (EFI_ERROR (Status)) {\r | |
333 | return FALSE;\r | |
334 | }\r | |
335 | \r | |
336 | Status = PushBool ((BOOLEAN)(Operator || Operator2));\r | |
337 | if (EFI_ERROR (Status)) {\r | |
338 | return FALSE;\r | |
339 | }\r | |
340 | break;\r | |
341 | \r | |
022c6d45 | 342 | case EFI_DEP_NOT:\r |
28a00297 | 343 | Status = PopBool (&Operator);\r |
344 | if (EFI_ERROR (Status)) {\r | |
345 | return FALSE;\r | |
346 | }\r | |
347 | \r | |
348 | Status = PushBool ((BOOLEAN)(!Operator));\r | |
349 | if (EFI_ERROR (Status)) {\r | |
350 | return FALSE;\r | |
351 | }\r | |
352 | break;\r | |
353 | \r | |
022c6d45 | 354 | case EFI_DEP_TRUE:\r |
28a00297 | 355 | Status = PushBool (TRUE);\r |
356 | if (EFI_ERROR (Status)) {\r | |
357 | return FALSE;\r | |
358 | }\r | |
359 | break;\r | |
360 | \r | |
022c6d45 | 361 | case EFI_DEP_FALSE:\r |
28a00297 | 362 | Status = PushBool (FALSE);\r |
363 | if (EFI_ERROR (Status)) {\r | |
364 | return FALSE;\r | |
365 | }\r | |
366 | break;\r | |
367 | \r | |
022c6d45 | 368 | case EFI_DEP_END:\r |
28a00297 | 369 | Status = PopBool (&Operator);\r |
370 | if (EFI_ERROR (Status)) {\r | |
371 | return FALSE;\r | |
372 | }\r | |
373 | return Operator;\r | |
374 | \r | |
375 | case EFI_DEP_REPLACE_TRUE:\r | |
376 | Status = PushBool (TRUE);\r | |
377 | if (EFI_ERROR (Status)) {\r | |
378 | return FALSE;\r | |
379 | }\r | |
380 | \r | |
381 | Iterator += sizeof (EFI_GUID);\r | |
382 | break;\r | |
383 | \r | |
022c6d45 | 384 | default:\r |
28a00297 | 385 | goto Done;\r |
386 | }\r | |
022c6d45 | 387 | \r |
28a00297 | 388 | //\r |
389 | // Skip over the Dependency Op Code we just processed in the switch.\r | |
390 | // The math is done out of order, but it should not matter. That is\r | |
391 | // we may add in the sizeof (EFI_GUID) before we account for the OP Code.\r | |
392 | // This is not an issue, since we just need the correct end result. You\r | |
393 | // need to be careful using Iterator in the loop as it's intermediate value\r | |
394 | // may be strange.\r | |
395 | //\r | |
396 | Iterator++;\r | |
397 | }\r | |
398 | \r | |
399 | Done:\r | |
400 | return FALSE;\r | |
401 | }\r | |
402 | \r | |
162ed594 | 403 | \r |