Commit | Line | Data |
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1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Kernel execution entry point code. |
3 | * | |
4 | * Copyright (c) 1995-1996 Gary Thomas <gdt@linuxppc.org> | |
5 | * Initial PowerPC version. | |
6 | * Copyright (c) 1996 Cort Dougan <cort@cs.nmt.edu> | |
7 | * Rewritten for PReP | |
8 | * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au> | |
9 | * Low-level exception handers, MMU support, and rewrite. | |
10 | * Copyright (c) 1997 Dan Malek <dmalek@jlc.net> | |
11 | * PowerPC 8xx modifications. | |
12 | * Copyright (c) 1998-1999 TiVo, Inc. | |
13 | * PowerPC 403GCX modifications. | |
14 | * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu> | |
15 | * PowerPC 403GCX/405GP modifications. | |
16 | * Copyright 2000 MontaVista Software Inc. | |
17 | * PPC405 modifications | |
18 | * PowerPC 403GCX/405GP modifications. | |
19 | * Author: MontaVista Software, Inc. | |
20 | * frank_rowand@mvista.com or source@mvista.com | |
21 | * debbie_chu@mvista.com | |
22 | * Copyright 2002-2005 MontaVista Software, Inc. | |
23 | * PowerPC 44x support, Matt Porter <mporter@kernel.crashing.org> | |
24 | * | |
25 | * This program is free software; you can redistribute it and/or modify it | |
26 | * under the terms of the GNU General Public License as published by the | |
27 | * Free Software Foundation; either version 2 of the License, or (at your | |
28 | * option) any later version. | |
29 | */ | |
30 | ||
1da177e4 LT |
31 | #include <asm/processor.h> |
32 | #include <asm/page.h> | |
33 | #include <asm/mmu.h> | |
34 | #include <asm/pgtable.h> | |
35 | #include <asm/ibm4xx.h> | |
36 | #include <asm/ibm44x.h> | |
37 | #include <asm/cputable.h> | |
38 | #include <asm/thread_info.h> | |
39 | #include <asm/ppc_asm.h> | |
0013a854 | 40 | #include <asm/asm-offsets.h> |
1da177e4 LT |
41 | #include "head_booke.h" |
42 | ||
43 | ||
44 | /* As with the other PowerPC ports, it is expected that when code | |
45 | * execution begins here, the following registers contain valid, yet | |
46 | * optional, information: | |
47 | * | |
48 | * r3 - Board info structure pointer (DRAM, frequency, MAC address, etc.) | |
49 | * r4 - Starting address of the init RAM disk | |
50 | * r5 - Ending address of the init RAM disk | |
51 | * r6 - Start of kernel command line string (e.g. "mem=128") | |
52 | * r7 - End of kernel command line string | |
53 | * | |
54 | */ | |
55 | .text | |
56 | _GLOBAL(_stext) | |
57 | _GLOBAL(_start) | |
58 | /* | |
59 | * Reserve a word at a fixed location to store the address | |
60 | * of abatron_pteptrs | |
61 | */ | |
62 | nop | |
63 | /* | |
64 | * Save parameters we are passed | |
65 | */ | |
66 | mr r31,r3 | |
67 | mr r30,r4 | |
68 | mr r29,r5 | |
69 | mr r28,r6 | |
70 | mr r27,r7 | |
71 | li r24,0 /* CPU number */ | |
72 | ||
73 | /* | |
74 | * Set up the initial MMU state | |
75 | * | |
76 | * We are still executing code at the virtual address | |
77 | * mappings set by the firmware for the base of RAM. | |
78 | * | |
79 | * We first invalidate all TLB entries but the one | |
80 | * we are running from. We then load the KERNELBASE | |
81 | * mappings so we can begin to use kernel addresses | |
82 | * natively and so the interrupt vector locations are | |
83 | * permanently pinned (necessary since Book E | |
84 | * implementations always have translation enabled). | |
85 | * | |
86 | * TODO: Use the known TLB entry we are running from to | |
87 | * determine which physical region we are located | |
88 | * in. This can be used to determine where in RAM | |
89 | * (on a shared CPU system) or PCI memory space | |
90 | * (on a DRAMless system) we are located. | |
91 | * For now, we assume a perfect world which means | |
92 | * we are located at the base of DRAM (physical 0). | |
93 | */ | |
94 | ||
95 | /* | |
96 | * Search TLB for entry that we are currently using. | |
97 | * Invalidate all entries but the one we are using. | |
98 | */ | |
99 | /* Load our current PID->MMUCR TID and MSR IS->MMUCR STS */ | |
100 | mfspr r3,SPRN_PID /* Get PID */ | |
101 | mfmsr r4 /* Get MSR */ | |
102 | andi. r4,r4,MSR_IS@l /* TS=1? */ | |
103 | beq wmmucr /* If not, leave STS=0 */ | |
104 | oris r3,r3,PPC44x_MMUCR_STS@h /* Set STS=1 */ | |
105 | wmmucr: mtspr SPRN_MMUCR,r3 /* Put MMUCR */ | |
106 | sync | |
107 | ||
108 | bl invstr /* Find our address */ | |
109 | invstr: mflr r5 /* Make it accessible */ | |
110 | tlbsx r23,0,r5 /* Find entry we are in */ | |
111 | li r4,0 /* Start at TLB entry 0 */ | |
112 | li r3,0 /* Set PAGEID inval value */ | |
113 | 1: cmpw r23,r4 /* Is this our entry? */ | |
114 | beq skpinv /* If so, skip the inval */ | |
115 | tlbwe r3,r4,PPC44x_TLB_PAGEID /* If not, inval the entry */ | |
116 | skpinv: addi r4,r4,1 /* Increment */ | |
117 | cmpwi r4,64 /* Are we done? */ | |
118 | bne 1b /* If not, repeat */ | |
119 | isync /* If so, context change */ | |
120 | ||
121 | /* | |
122 | * Configure and load pinned entry into TLB slot 63. | |
123 | */ | |
124 | ||
125 | lis r3,KERNELBASE@h /* Load the kernel virtual address */ | |
126 | ori r3,r3,KERNELBASE@l | |
127 | ||
128 | /* Kernel is at the base of RAM */ | |
129 | li r4, 0 /* Load the kernel physical address */ | |
130 | ||
131 | /* Load the kernel PID = 0 */ | |
132 | li r0,0 | |
133 | mtspr SPRN_PID,r0 | |
134 | sync | |
135 | ||
136 | /* Initialize MMUCR */ | |
137 | li r5,0 | |
138 | mtspr SPRN_MMUCR,r5 | |
139 | sync | |
140 | ||
141 | /* pageid fields */ | |
142 | clrrwi r3,r3,10 /* Mask off the effective page number */ | |
143 | ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_256M | |
144 | ||
145 | /* xlat fields */ | |
146 | clrrwi r4,r4,10 /* Mask off the real page number */ | |
147 | /* ERPN is 0 for first 4GB page */ | |
148 | ||
149 | /* attrib fields */ | |
150 | /* Added guarded bit to protect against speculative loads/stores */ | |
151 | li r5,0 | |
152 | ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G) | |
153 | ||
154 | li r0,63 /* TLB slot 63 */ | |
155 | ||
156 | tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */ | |
157 | tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */ | |
158 | tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Load the attrib/access fields */ | |
159 | ||
160 | /* Force context change */ | |
161 | mfmsr r0 | |
162 | mtspr SPRN_SRR1, r0 | |
163 | lis r0,3f@h | |
164 | ori r0,r0,3f@l | |
165 | mtspr SPRN_SRR0,r0 | |
166 | sync | |
167 | rfi | |
168 | ||
169 | /* If necessary, invalidate original entry we used */ | |
170 | 3: cmpwi r23,63 | |
171 | beq 4f | |
172 | li r6,0 | |
173 | tlbwe r6,r23,PPC44x_TLB_PAGEID | |
174 | isync | |
175 | ||
176 | 4: | |
177 | #ifdef CONFIG_SERIAL_TEXT_DEBUG | |
178 | /* | |
5ce17b18 ES |
179 | * Add temporary UART mapping for early debug. |
180 | * We can map UART registers wherever we want as long as they don't | |
181 | * interfere with other system mappings (e.g. with pinned entries). | |
182 | * For an example of how we handle this - see ocotea.h. --ebs | |
1da177e4 LT |
183 | */ |
184 | /* pageid fields */ | |
185 | lis r3,UART0_IO_BASE@h | |
5ce17b18 | 186 | ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_4K |
1da177e4 LT |
187 | |
188 | /* xlat fields */ | |
189 | lis r4,UART0_PHYS_IO_BASE@h /* RPN depends on SoC */ | |
fcc188e7 RD |
190 | #ifdef UART0_PHYS_ERPN |
191 | ori r4,r4,UART0_PHYS_ERPN /* Add ERPN if above 4GB */ | |
c9cf73ae | 192 | #endif |
1da177e4 LT |
193 | |
194 | /* attrib fields */ | |
195 | li r5,0 | |
196 | ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_I | PPC44x_TLB_G) | |
197 | ||
5ce17b18 | 198 | li r0,0 /* TLB slot 0 */ |
1da177e4 LT |
199 | |
200 | tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */ | |
201 | tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */ | |
202 | tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Load the attrib/access fields */ | |
203 | ||
204 | /* Force context change */ | |
205 | isync | |
206 | #endif /* CONFIG_SERIAL_TEXT_DEBUG */ | |
207 | ||
208 | /* Establish the interrupt vector offsets */ | |
209 | SET_IVOR(0, CriticalInput); | |
210 | SET_IVOR(1, MachineCheck); | |
211 | SET_IVOR(2, DataStorage); | |
212 | SET_IVOR(3, InstructionStorage); | |
213 | SET_IVOR(4, ExternalInput); | |
214 | SET_IVOR(5, Alignment); | |
215 | SET_IVOR(6, Program); | |
216 | SET_IVOR(7, FloatingPointUnavailable); | |
217 | SET_IVOR(8, SystemCall); | |
218 | SET_IVOR(9, AuxillaryProcessorUnavailable); | |
219 | SET_IVOR(10, Decrementer); | |
220 | SET_IVOR(11, FixedIntervalTimer); | |
221 | SET_IVOR(12, WatchdogTimer); | |
222 | SET_IVOR(13, DataTLBError); | |
223 | SET_IVOR(14, InstructionTLBError); | |
224 | SET_IVOR(15, Debug); | |
225 | ||
226 | /* Establish the interrupt vector base */ | |
227 | lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */ | |
228 | mtspr SPRN_IVPR,r4 | |
229 | ||
230 | /* | |
231 | * This is where the main kernel code starts. | |
232 | */ | |
233 | ||
234 | /* ptr to current */ | |
235 | lis r2,init_task@h | |
236 | ori r2,r2,init_task@l | |
237 | ||
238 | /* ptr to current thread */ | |
239 | addi r4,r2,THREAD /* init task's THREAD */ | |
240 | mtspr SPRN_SPRG3,r4 | |
241 | ||
242 | /* stack */ | |
243 | lis r1,init_thread_union@h | |
244 | ori r1,r1,init_thread_union@l | |
245 | li r0,0 | |
246 | stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1) | |
247 | ||
248 | bl early_init | |
249 | ||
250 | /* | |
251 | * Decide what sort of machine this is and initialize the MMU. | |
252 | */ | |
253 | mr r3,r31 | |
254 | mr r4,r30 | |
255 | mr r5,r29 | |
256 | mr r6,r28 | |
257 | mr r7,r27 | |
258 | bl machine_init | |
259 | bl MMU_init | |
260 | ||
261 | /* Setup PTE pointers for the Abatron bdiGDB */ | |
262 | lis r6, swapper_pg_dir@h | |
263 | ori r6, r6, swapper_pg_dir@l | |
264 | lis r5, abatron_pteptrs@h | |
265 | ori r5, r5, abatron_pteptrs@l | |
266 | lis r4, KERNELBASE@h | |
267 | ori r4, r4, KERNELBASE@l | |
268 | stw r5, 0(r4) /* Save abatron_pteptrs at a fixed location */ | |
269 | stw r6, 0(r5) | |
270 | ||
271 | /* Let's move on */ | |
272 | lis r4,start_kernel@h | |
273 | ori r4,r4,start_kernel@l | |
274 | lis r3,MSR_KERNEL@h | |
275 | ori r3,r3,MSR_KERNEL@l | |
276 | mtspr SPRN_SRR0,r4 | |
277 | mtspr SPRN_SRR1,r3 | |
278 | rfi /* change context and jump to start_kernel */ | |
279 | ||
280 | /* | |
281 | * Interrupt vector entry code | |
282 | * | |
283 | * The Book E MMUs are always on so we don't need to handle | |
284 | * interrupts in real mode as with previous PPC processors. In | |
285 | * this case we handle interrupts in the kernel virtual address | |
286 | * space. | |
287 | * | |
288 | * Interrupt vectors are dynamically placed relative to the | |
289 | * interrupt prefix as determined by the address of interrupt_base. | |
290 | * The interrupt vectors offsets are programmed using the labels | |
291 | * for each interrupt vector entry. | |
292 | * | |
293 | * Interrupt vectors must be aligned on a 16 byte boundary. | |
294 | * We align on a 32 byte cache line boundary for good measure. | |
295 | */ | |
296 | ||
297 | interrupt_base: | |
298 | /* Critical Input Interrupt */ | |
dc1c1ca3 | 299 | CRITICAL_EXCEPTION(0x0100, CriticalInput, unknown_exception) |
1da177e4 LT |
300 | |
301 | /* Machine Check Interrupt */ | |
302 | #ifdef CONFIG_440A | |
dc1c1ca3 | 303 | MCHECK_EXCEPTION(0x0200, MachineCheck, machine_check_exception) |
1da177e4 | 304 | #else |
dc1c1ca3 | 305 | CRITICAL_EXCEPTION(0x0200, MachineCheck, machine_check_exception) |
1da177e4 LT |
306 | #endif |
307 | ||
308 | /* Data Storage Interrupt */ | |
309 | START_EXCEPTION(DataStorage) | |
310 | mtspr SPRN_SPRG0, r10 /* Save some working registers */ | |
311 | mtspr SPRN_SPRG1, r11 | |
312 | mtspr SPRN_SPRG4W, r12 | |
313 | mtspr SPRN_SPRG5W, r13 | |
314 | mfcr r11 | |
315 | mtspr SPRN_SPRG7W, r11 | |
316 | ||
317 | /* | |
318 | * Check if it was a store fault, if not then bail | |
319 | * because a user tried to access a kernel or | |
320 | * read-protected page. Otherwise, get the | |
321 | * offending address and handle it. | |
322 | */ | |
323 | mfspr r10, SPRN_ESR | |
324 | andis. r10, r10, ESR_ST@h | |
325 | beq 2f | |
326 | ||
327 | mfspr r10, SPRN_DEAR /* Get faulting address */ | |
328 | ||
329 | /* If we are faulting a kernel address, we have to use the | |
330 | * kernel page tables. | |
331 | */ | |
b2665f92 MP |
332 | lis r11, TASK_SIZE@h |
333 | cmplw r10, r11 | |
334 | blt+ 3f | |
1da177e4 LT |
335 | lis r11, swapper_pg_dir@h |
336 | ori r11, r11, swapper_pg_dir@l | |
337 | ||
338 | mfspr r12,SPRN_MMUCR | |
339 | rlwinm r12,r12,0,0,23 /* Clear TID */ | |
340 | ||
341 | b 4f | |
342 | ||
343 | /* Get the PGD for the current thread */ | |
344 | 3: | |
345 | mfspr r11,SPRN_SPRG3 | |
346 | lwz r11,PGDIR(r11) | |
347 | ||
348 | /* Load PID into MMUCR TID */ | |
349 | mfspr r12,SPRN_MMUCR /* Get MMUCR */ | |
350 | mfspr r13,SPRN_PID /* Get PID */ | |
351 | rlwimi r12,r13,0,24,31 /* Set TID */ | |
352 | ||
353 | 4: | |
354 | mtspr SPRN_MMUCR,r12 | |
355 | ||
356 | rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */ | |
357 | lwzx r11, r12, r11 /* Get pgd/pmd entry */ | |
358 | rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */ | |
359 | beq 2f /* Bail if no table */ | |
360 | ||
361 | rlwimi r12, r10, 23, 20, 28 /* Compute pte address */ | |
362 | lwz r11, 4(r12) /* Get pte entry */ | |
363 | ||
364 | andi. r13, r11, _PAGE_RW /* Is it writeable? */ | |
365 | beq 2f /* Bail if not */ | |
366 | ||
367 | /* Update 'changed'. | |
368 | */ | |
369 | ori r11, r11, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE | |
370 | stw r11, 4(r12) /* Update Linux page table */ | |
371 | ||
372 | li r13, PPC44x_TLB_SR@l /* Set SR */ | |
373 | rlwimi r13, r11, 29, 29, 29 /* SX = _PAGE_HWEXEC */ | |
374 | rlwimi r13, r11, 0, 30, 30 /* SW = _PAGE_RW */ | |
375 | rlwimi r13, r11, 29, 28, 28 /* UR = _PAGE_USER */ | |
376 | rlwimi r12, r11, 31, 26, 26 /* (_PAGE_USER>>1)->r12 */ | |
377 | rlwimi r12, r11, 29, 30, 30 /* (_PAGE_USER>>3)->r12 */ | |
378 | and r12, r12, r11 /* HWEXEC/RW & USER */ | |
379 | rlwimi r13, r12, 0, 26, 26 /* UX = HWEXEC & USER */ | |
380 | rlwimi r13, r12, 3, 27, 27 /* UW = RW & USER */ | |
381 | ||
382 | rlwimi r11,r13,0,26,31 /* Insert static perms */ | |
383 | ||
384 | rlwinm r11,r11,0,20,15 /* Clear U0-U3 */ | |
385 | ||
386 | /* find the TLB index that caused the fault. It has to be here. */ | |
387 | tlbsx r10, 0, r10 | |
388 | ||
389 | tlbwe r11, r10, PPC44x_TLB_ATTRIB /* Write ATTRIB */ | |
390 | ||
391 | /* Done...restore registers and get out of here. | |
392 | */ | |
393 | mfspr r11, SPRN_SPRG7R | |
394 | mtcr r11 | |
395 | mfspr r13, SPRN_SPRG5R | |
396 | mfspr r12, SPRN_SPRG4R | |
397 | ||
398 | mfspr r11, SPRN_SPRG1 | |
399 | mfspr r10, SPRN_SPRG0 | |
400 | rfi /* Force context change */ | |
401 | ||
402 | 2: | |
403 | /* | |
404 | * The bailout. Restore registers to pre-exception conditions | |
405 | * and call the heavyweights to help us out. | |
406 | */ | |
407 | mfspr r11, SPRN_SPRG7R | |
408 | mtcr r11 | |
409 | mfspr r13, SPRN_SPRG5R | |
410 | mfspr r12, SPRN_SPRG4R | |
411 | ||
412 | mfspr r11, SPRN_SPRG1 | |
413 | mfspr r10, SPRN_SPRG0 | |
414 | b data_access | |
415 | ||
416 | /* Instruction Storage Interrupt */ | |
417 | INSTRUCTION_STORAGE_EXCEPTION | |
418 | ||
419 | /* External Input Interrupt */ | |
420 | EXCEPTION(0x0500, ExternalInput, do_IRQ, EXC_XFER_LITE) | |
421 | ||
422 | /* Alignment Interrupt */ | |
423 | ALIGNMENT_EXCEPTION | |
424 | ||
425 | /* Program Interrupt */ | |
426 | PROGRAM_EXCEPTION | |
427 | ||
428 | /* Floating Point Unavailable Interrupt */ | |
443a848c PM |
429 | #ifdef CONFIG_PPC_FPU |
430 | FP_UNAVAILABLE_EXCEPTION | |
431 | #else | |
dc1c1ca3 | 432 | EXCEPTION(0x2010, FloatingPointUnavailable, unknown_exception, EXC_XFER_EE) |
443a848c | 433 | #endif |
1da177e4 LT |
434 | |
435 | /* System Call Interrupt */ | |
436 | START_EXCEPTION(SystemCall) | |
437 | NORMAL_EXCEPTION_PROLOG | |
438 | EXC_XFER_EE_LITE(0x0c00, DoSyscall) | |
439 | ||
440 | /* Auxillary Processor Unavailable Interrupt */ | |
dc1c1ca3 | 441 | EXCEPTION(0x2020, AuxillaryProcessorUnavailable, unknown_exception, EXC_XFER_EE) |
1da177e4 LT |
442 | |
443 | /* Decrementer Interrupt */ | |
444 | DECREMENTER_EXCEPTION | |
445 | ||
446 | /* Fixed Internal Timer Interrupt */ | |
447 | /* TODO: Add FIT support */ | |
dc1c1ca3 | 448 | EXCEPTION(0x1010, FixedIntervalTimer, unknown_exception, EXC_XFER_EE) |
1da177e4 LT |
449 | |
450 | /* Watchdog Timer Interrupt */ | |
451 | /* TODO: Add watchdog support */ | |
a2f40ccd KG |
452 | #ifdef CONFIG_BOOKE_WDT |
453 | CRITICAL_EXCEPTION(0x1020, WatchdogTimer, WatchdogException) | |
454 | #else | |
dc1c1ca3 | 455 | CRITICAL_EXCEPTION(0x1020, WatchdogTimer, unknown_exception) |
a2f40ccd | 456 | #endif |
1da177e4 LT |
457 | |
458 | /* Data TLB Error Interrupt */ | |
459 | START_EXCEPTION(DataTLBError) | |
460 | mtspr SPRN_SPRG0, r10 /* Save some working registers */ | |
461 | mtspr SPRN_SPRG1, r11 | |
462 | mtspr SPRN_SPRG4W, r12 | |
463 | mtspr SPRN_SPRG5W, r13 | |
464 | mfcr r11 | |
465 | mtspr SPRN_SPRG7W, r11 | |
466 | mfspr r10, SPRN_DEAR /* Get faulting address */ | |
467 | ||
468 | /* If we are faulting a kernel address, we have to use the | |
469 | * kernel page tables. | |
470 | */ | |
b2665f92 MP |
471 | lis r11, TASK_SIZE@h |
472 | cmplw r10, r11 | |
473 | blt+ 3f | |
1da177e4 LT |
474 | lis r11, swapper_pg_dir@h |
475 | ori r11, r11, swapper_pg_dir@l | |
476 | ||
477 | mfspr r12,SPRN_MMUCR | |
478 | rlwinm r12,r12,0,0,23 /* Clear TID */ | |
479 | ||
480 | b 4f | |
481 | ||
482 | /* Get the PGD for the current thread */ | |
483 | 3: | |
484 | mfspr r11,SPRN_SPRG3 | |
485 | lwz r11,PGDIR(r11) | |
486 | ||
487 | /* Load PID into MMUCR TID */ | |
488 | mfspr r12,SPRN_MMUCR | |
489 | mfspr r13,SPRN_PID /* Get PID */ | |
490 | rlwimi r12,r13,0,24,31 /* Set TID */ | |
491 | ||
492 | 4: | |
493 | mtspr SPRN_MMUCR,r12 | |
494 | ||
495 | rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */ | |
496 | lwzx r11, r12, r11 /* Get pgd/pmd entry */ | |
497 | rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */ | |
498 | beq 2f /* Bail if no table */ | |
499 | ||
500 | rlwimi r12, r10, 23, 20, 28 /* Compute pte address */ | |
501 | lwz r11, 4(r12) /* Get pte entry */ | |
502 | andi. r13, r11, _PAGE_PRESENT /* Is the page present? */ | |
503 | beq 2f /* Bail if not present */ | |
504 | ||
505 | ori r11, r11, _PAGE_ACCESSED | |
506 | stw r11, 4(r12) | |
507 | ||
508 | /* Jump to common tlb load */ | |
509 | b finish_tlb_load | |
510 | ||
511 | 2: | |
512 | /* The bailout. Restore registers to pre-exception conditions | |
513 | * and call the heavyweights to help us out. | |
514 | */ | |
515 | mfspr r11, SPRN_SPRG7R | |
516 | mtcr r11 | |
517 | mfspr r13, SPRN_SPRG5R | |
518 | mfspr r12, SPRN_SPRG4R | |
519 | mfspr r11, SPRN_SPRG1 | |
520 | mfspr r10, SPRN_SPRG0 | |
521 | b data_access | |
522 | ||
523 | /* Instruction TLB Error Interrupt */ | |
524 | /* | |
525 | * Nearly the same as above, except we get our | |
526 | * information from different registers and bailout | |
527 | * to a different point. | |
528 | */ | |
529 | START_EXCEPTION(InstructionTLBError) | |
530 | mtspr SPRN_SPRG0, r10 /* Save some working registers */ | |
531 | mtspr SPRN_SPRG1, r11 | |
532 | mtspr SPRN_SPRG4W, r12 | |
533 | mtspr SPRN_SPRG5W, r13 | |
534 | mfcr r11 | |
535 | mtspr SPRN_SPRG7W, r11 | |
536 | mfspr r10, SPRN_SRR0 /* Get faulting address */ | |
537 | ||
538 | /* If we are faulting a kernel address, we have to use the | |
539 | * kernel page tables. | |
540 | */ | |
b2665f92 MP |
541 | lis r11, TASK_SIZE@h |
542 | cmplw r10, r11 | |
543 | blt+ 3f | |
1da177e4 LT |
544 | lis r11, swapper_pg_dir@h |
545 | ori r11, r11, swapper_pg_dir@l | |
546 | ||
547 | mfspr r12,SPRN_MMUCR | |
548 | rlwinm r12,r12,0,0,23 /* Clear TID */ | |
549 | ||
550 | b 4f | |
551 | ||
552 | /* Get the PGD for the current thread */ | |
553 | 3: | |
554 | mfspr r11,SPRN_SPRG3 | |
555 | lwz r11,PGDIR(r11) | |
556 | ||
557 | /* Load PID into MMUCR TID */ | |
558 | mfspr r12,SPRN_MMUCR | |
559 | mfspr r13,SPRN_PID /* Get PID */ | |
560 | rlwimi r12,r13,0,24,31 /* Set TID */ | |
561 | ||
562 | 4: | |
563 | mtspr SPRN_MMUCR,r12 | |
564 | ||
565 | rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */ | |
566 | lwzx r11, r12, r11 /* Get pgd/pmd entry */ | |
567 | rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */ | |
568 | beq 2f /* Bail if no table */ | |
569 | ||
570 | rlwimi r12, r10, 23, 20, 28 /* Compute pte address */ | |
571 | lwz r11, 4(r12) /* Get pte entry */ | |
572 | andi. r13, r11, _PAGE_PRESENT /* Is the page present? */ | |
573 | beq 2f /* Bail if not present */ | |
574 | ||
575 | ori r11, r11, _PAGE_ACCESSED | |
576 | stw r11, 4(r12) | |
577 | ||
578 | /* Jump to common TLB load point */ | |
579 | b finish_tlb_load | |
580 | ||
581 | 2: | |
582 | /* The bailout. Restore registers to pre-exception conditions | |
583 | * and call the heavyweights to help us out. | |
584 | */ | |
585 | mfspr r11, SPRN_SPRG7R | |
586 | mtcr r11 | |
587 | mfspr r13, SPRN_SPRG5R | |
588 | mfspr r12, SPRN_SPRG4R | |
589 | mfspr r11, SPRN_SPRG1 | |
590 | mfspr r10, SPRN_SPRG0 | |
591 | b InstructionStorage | |
592 | ||
593 | /* Debug Interrupt */ | |
594 | DEBUG_EXCEPTION | |
595 | ||
596 | /* | |
597 | * Local functions | |
598 | */ | |
599 | /* | |
600 | * Data TLB exceptions will bail out to this point | |
601 | * if they can't resolve the lightweight TLB fault. | |
602 | */ | |
603 | data_access: | |
604 | NORMAL_EXCEPTION_PROLOG | |
605 | mfspr r5,SPRN_ESR /* Grab the ESR, save it, pass arg3 */ | |
606 | stw r5,_ESR(r11) | |
607 | mfspr r4,SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */ | |
608 | EXC_XFER_EE_LITE(0x0300, handle_page_fault) | |
609 | ||
610 | /* | |
611 | ||
612 | * Both the instruction and data TLB miss get to this | |
613 | * point to load the TLB. | |
614 | * r10 - EA of fault | |
615 | * r11 - available to use | |
616 | * r12 - Pointer to the 64-bit PTE | |
617 | * r13 - available to use | |
618 | * MMUCR - loaded with proper value when we get here | |
619 | * Upon exit, we reload everything and RFI. | |
620 | */ | |
621 | finish_tlb_load: | |
622 | /* | |
623 | * We set execute, because we don't have the granularity to | |
624 | * properly set this at the page level (Linux problem). | |
625 | * If shared is set, we cause a zero PID->TID load. | |
626 | * Many of these bits are software only. Bits we don't set | |
627 | * here we (properly should) assume have the appropriate value. | |
628 | */ | |
629 | ||
630 | /* Load the next available TLB index */ | |
631 | lis r13, tlb_44x_index@ha | |
632 | lwz r13, tlb_44x_index@l(r13) | |
633 | /* Load the TLB high watermark */ | |
634 | lis r11, tlb_44x_hwater@ha | |
635 | lwz r11, tlb_44x_hwater@l(r11) | |
636 | ||
637 | /* Increment, rollover, and store TLB index */ | |
638 | addi r13, r13, 1 | |
639 | cmpw 0, r13, r11 /* reserve entries */ | |
640 | ble 7f | |
641 | li r13, 0 | |
642 | 7: | |
643 | /* Store the next available TLB index */ | |
644 | lis r11, tlb_44x_index@ha | |
645 | stw r13, tlb_44x_index@l(r11) | |
646 | ||
647 | lwz r11, 0(r12) /* Get MS word of PTE */ | |
648 | lwz r12, 4(r12) /* Get LS word of PTE */ | |
649 | rlwimi r11, r12, 0, 0 , 19 /* Insert RPN */ | |
650 | tlbwe r11, r13, PPC44x_TLB_XLAT /* Write XLAT */ | |
651 | ||
652 | /* | |
653 | * Create PAGEID. This is the faulting address, | |
654 | * page size, and valid flag. | |
655 | */ | |
656 | li r11, PPC44x_TLB_VALID | PPC44x_TLB_4K | |
657 | rlwimi r10, r11, 0, 20, 31 /* Insert valid and page size */ | |
658 | tlbwe r10, r13, PPC44x_TLB_PAGEID /* Write PAGEID */ | |
659 | ||
660 | li r10, PPC44x_TLB_SR@l /* Set SR */ | |
661 | rlwimi r10, r12, 0, 30, 30 /* Set SW = _PAGE_RW */ | |
662 | rlwimi r10, r12, 29, 29, 29 /* SX = _PAGE_HWEXEC */ | |
663 | rlwimi r10, r12, 29, 28, 28 /* UR = _PAGE_USER */ | |
664 | rlwimi r11, r12, 31, 26, 26 /* (_PAGE_USER>>1)->r12 */ | |
665 | and r11, r12, r11 /* HWEXEC & USER */ | |
666 | rlwimi r10, r11, 0, 26, 26 /* UX = HWEXEC & USER */ | |
667 | ||
668 | rlwimi r12, r10, 0, 26, 31 /* Insert static perms */ | |
669 | rlwinm r12, r12, 0, 20, 15 /* Clear U0-U3 */ | |
670 | tlbwe r12, r13, PPC44x_TLB_ATTRIB /* Write ATTRIB */ | |
671 | ||
672 | /* Done...restore registers and get out of here. | |
673 | */ | |
674 | mfspr r11, SPRN_SPRG7R | |
675 | mtcr r11 | |
676 | mfspr r13, SPRN_SPRG5R | |
677 | mfspr r12, SPRN_SPRG4R | |
678 | mfspr r11, SPRN_SPRG1 | |
679 | mfspr r10, SPRN_SPRG0 | |
680 | rfi /* Force context change */ | |
681 | ||
682 | /* | |
683 | * Global functions | |
684 | */ | |
685 | ||
686 | /* | |
687 | * extern void giveup_altivec(struct task_struct *prev) | |
688 | * | |
689 | * The 44x core does not have an AltiVec unit. | |
690 | */ | |
691 | _GLOBAL(giveup_altivec) | |
692 | blr | |
693 | ||
694 | /* | |
695 | * extern void giveup_fpu(struct task_struct *prev) | |
696 | * | |
697 | * The 44x core does not have an FPU. | |
698 | */ | |
443a848c | 699 | #ifndef CONFIG_PPC_FPU |
1da177e4 LT |
700 | _GLOBAL(giveup_fpu) |
701 | blr | |
443a848c | 702 | #endif |
1da177e4 LT |
703 | |
704 | /* | |
705 | * extern void abort(void) | |
706 | * | |
707 | * At present, this routine just applies a system reset. | |
708 | */ | |
709 | _GLOBAL(abort) | |
710 | mfspr r13,SPRN_DBCR0 | |
711 | oris r13,r13,DBCR0_RST_SYSTEM@h | |
712 | mtspr SPRN_DBCR0,r13 | |
713 | ||
714 | _GLOBAL(set_context) | |
715 | ||
716 | #ifdef CONFIG_BDI_SWITCH | |
717 | /* Context switch the PTE pointer for the Abatron BDI2000. | |
718 | * The PGDIR is the second parameter. | |
719 | */ | |
720 | lis r5, abatron_pteptrs@h | |
721 | ori r5, r5, abatron_pteptrs@l | |
722 | stw r4, 0x4(r5) | |
723 | #endif | |
724 | mtspr SPRN_PID,r3 | |
725 | isync /* Force context change */ | |
726 | blr | |
727 | ||
728 | /* | |
729 | * We put a few things here that have to be page-aligned. This stuff | |
730 | * goes at the beginning of the data segment, which is page-aligned. | |
731 | */ | |
732 | .data | |
3d904eef KG |
733 | .align 12 |
734 | .globl sdata | |
735 | sdata: | |
736 | .globl empty_zero_page | |
737 | empty_zero_page: | |
1da177e4 LT |
738 | .space 4096 |
739 | ||
740 | /* | |
741 | * To support >32-bit physical addresses, we use an 8KB pgdir. | |
742 | */ | |
3d904eef KG |
743 | .globl swapper_pg_dir |
744 | swapper_pg_dir: | |
1da177e4 LT |
745 | .space 8192 |
746 | ||
747 | /* Reserved 4k for the critical exception stack & 4k for the machine | |
748 | * check stack per CPU for kernel mode exceptions */ | |
749 | .section .bss | |
750 | .align 12 | |
751 | exception_stack_bottom: | |
752 | .space BOOKE_EXCEPTION_STACK_SIZE | |
3d904eef KG |
753 | .globl exception_stack_top |
754 | exception_stack_top: | |
1da177e4 LT |
755 | |
756 | /* | |
757 | * This space gets a copy of optional info passed to us by the bootstrap | |
758 | * which is used to pass parameters into the kernel like root=/dev/sda1, etc. | |
759 | */ | |
3d904eef KG |
760 | .globl cmd_line |
761 | cmd_line: | |
1da177e4 LT |
762 | .space 512 |
763 | ||
764 | /* | |
765 | * Room for two PTE pointers, usually the kernel and current user pointers | |
766 | * to their respective root page table. | |
767 | */ | |
768 | abatron_pteptrs: | |
769 | .space 8 |