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14cf11af PM |
1 | /* |
2 | * arch/ppc/kernel/head_44x.S | |
3 | * | |
4 | * Kernel execution entry point code. | |
5 | * | |
6 | * Copyright (c) 1995-1996 Gary Thomas <gdt@linuxppc.org> | |
7 | * Initial PowerPC version. | |
8 | * Copyright (c) 1996 Cort Dougan <cort@cs.nmt.edu> | |
9 | * Rewritten for PReP | |
10 | * Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au> | |
11 | * Low-level exception handers, MMU support, and rewrite. | |
12 | * Copyright (c) 1997 Dan Malek <dmalek@jlc.net> | |
13 | * PowerPC 8xx modifications. | |
14 | * Copyright (c) 1998-1999 TiVo, Inc. | |
15 | * PowerPC 403GCX modifications. | |
16 | * Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu> | |
17 | * PowerPC 403GCX/405GP modifications. | |
18 | * Copyright 2000 MontaVista Software Inc. | |
19 | * PPC405 modifications | |
20 | * PowerPC 403GCX/405GP modifications. | |
21 | * Author: MontaVista Software, Inc. | |
22 | * frank_rowand@mvista.com or source@mvista.com | |
23 | * debbie_chu@mvista.com | |
24 | * Copyright 2002-2005 MontaVista Software, Inc. | |
25 | * PowerPC 44x support, Matt Porter <mporter@kernel.crashing.org> | |
26 | * | |
27 | * This program is free software; you can redistribute it and/or modify it | |
28 | * under the terms of the GNU General Public License as published by the | |
29 | * Free Software Foundation; either version 2 of the License, or (at your | |
30 | * option) any later version. | |
31 | */ | |
32 | ||
33 | #include <linux/config.h> | |
34 | #include <asm/processor.h> | |
35 | #include <asm/page.h> | |
36 | #include <asm/mmu.h> | |
37 | #include <asm/pgtable.h> | |
38 | #include <asm/ibm4xx.h> | |
39 | #include <asm/ibm44x.h> | |
40 | #include <asm/cputable.h> | |
41 | #include <asm/thread_info.h> | |
42 | #include <asm/ppc_asm.h> | |
43 | #include <asm/asm-offsets.h> | |
44 | #include "head_booke.h" | |
45 | ||
46 | ||
47 | /* As with the other PowerPC ports, it is expected that when code | |
48 | * execution begins here, the following registers contain valid, yet | |
49 | * optional, information: | |
50 | * | |
51 | * r3 - Board info structure pointer (DRAM, frequency, MAC address, etc.) | |
52 | * r4 - Starting address of the init RAM disk | |
53 | * r5 - Ending address of the init RAM disk | |
54 | * r6 - Start of kernel command line string (e.g. "mem=128") | |
55 | * r7 - End of kernel command line string | |
56 | * | |
57 | */ | |
58 | .text | |
59 | _GLOBAL(_stext) | |
60 | _GLOBAL(_start) | |
61 | /* | |
62 | * Reserve a word at a fixed location to store the address | |
63 | * of abatron_pteptrs | |
64 | */ | |
65 | nop | |
66 | /* | |
67 | * Save parameters we are passed | |
68 | */ | |
69 | mr r31,r3 | |
70 | mr r30,r4 | |
71 | mr r29,r5 | |
72 | mr r28,r6 | |
73 | mr r27,r7 | |
74 | li r24,0 /* CPU number */ | |
75 | ||
76 | /* | |
77 | * Set up the initial MMU state | |
78 | * | |
79 | * We are still executing code at the virtual address | |
80 | * mappings set by the firmware for the base of RAM. | |
81 | * | |
82 | * We first invalidate all TLB entries but the one | |
83 | * we are running from. We then load the KERNELBASE | |
84 | * mappings so we can begin to use kernel addresses | |
85 | * natively and so the interrupt vector locations are | |
86 | * permanently pinned (necessary since Book E | |
87 | * implementations always have translation enabled). | |
88 | * | |
89 | * TODO: Use the known TLB entry we are running from to | |
90 | * determine which physical region we are located | |
91 | * in. This can be used to determine where in RAM | |
92 | * (on a shared CPU system) or PCI memory space | |
93 | * (on a DRAMless system) we are located. | |
94 | * For now, we assume a perfect world which means | |
95 | * we are located at the base of DRAM (physical 0). | |
96 | */ | |
97 | ||
98 | /* | |
99 | * Search TLB for entry that we are currently using. | |
100 | * Invalidate all entries but the one we are using. | |
101 | */ | |
102 | /* Load our current PID->MMUCR TID and MSR IS->MMUCR STS */ | |
103 | mfspr r3,SPRN_PID /* Get PID */ | |
104 | mfmsr r4 /* Get MSR */ | |
105 | andi. r4,r4,MSR_IS@l /* TS=1? */ | |
106 | beq wmmucr /* If not, leave STS=0 */ | |
107 | oris r3,r3,PPC44x_MMUCR_STS@h /* Set STS=1 */ | |
108 | wmmucr: mtspr SPRN_MMUCR,r3 /* Put MMUCR */ | |
109 | sync | |
110 | ||
111 | bl invstr /* Find our address */ | |
112 | invstr: mflr r5 /* Make it accessible */ | |
113 | tlbsx r23,0,r5 /* Find entry we are in */ | |
114 | li r4,0 /* Start at TLB entry 0 */ | |
115 | li r3,0 /* Set PAGEID inval value */ | |
116 | 1: cmpw r23,r4 /* Is this our entry? */ | |
117 | beq skpinv /* If so, skip the inval */ | |
118 | tlbwe r3,r4,PPC44x_TLB_PAGEID /* If not, inval the entry */ | |
119 | skpinv: addi r4,r4,1 /* Increment */ | |
120 | cmpwi r4,64 /* Are we done? */ | |
121 | bne 1b /* If not, repeat */ | |
122 | isync /* If so, context change */ | |
123 | ||
124 | /* | |
125 | * Configure and load pinned entry into TLB slot 63. | |
126 | */ | |
127 | ||
128 | lis r3,KERNELBASE@h /* Load the kernel virtual address */ | |
129 | ori r3,r3,KERNELBASE@l | |
130 | ||
131 | /* Kernel is at the base of RAM */ | |
132 | li r4, 0 /* Load the kernel physical address */ | |
133 | ||
134 | /* Load the kernel PID = 0 */ | |
135 | li r0,0 | |
136 | mtspr SPRN_PID,r0 | |
137 | sync | |
138 | ||
139 | /* Initialize MMUCR */ | |
140 | li r5,0 | |
141 | mtspr SPRN_MMUCR,r5 | |
142 | sync | |
143 | ||
144 | /* pageid fields */ | |
145 | clrrwi r3,r3,10 /* Mask off the effective page number */ | |
146 | ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_256M | |
147 | ||
148 | /* xlat fields */ | |
149 | clrrwi r4,r4,10 /* Mask off the real page number */ | |
150 | /* ERPN is 0 for first 4GB page */ | |
151 | ||
152 | /* attrib fields */ | |
153 | /* Added guarded bit to protect against speculative loads/stores */ | |
154 | li r5,0 | |
155 | ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G) | |
156 | ||
157 | li r0,63 /* TLB slot 63 */ | |
158 | ||
159 | tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */ | |
160 | tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */ | |
161 | tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Load the attrib/access fields */ | |
162 | ||
163 | /* Force context change */ | |
164 | mfmsr r0 | |
165 | mtspr SPRN_SRR1, r0 | |
166 | lis r0,3f@h | |
167 | ori r0,r0,3f@l | |
168 | mtspr SPRN_SRR0,r0 | |
169 | sync | |
170 | rfi | |
171 | ||
172 | /* If necessary, invalidate original entry we used */ | |
173 | 3: cmpwi r23,63 | |
174 | beq 4f | |
175 | li r6,0 | |
176 | tlbwe r6,r23,PPC44x_TLB_PAGEID | |
177 | isync | |
178 | ||
179 | 4: | |
180 | #ifdef CONFIG_SERIAL_TEXT_DEBUG | |
181 | /* | |
182 | * Add temporary UART mapping for early debug. | |
183 | * We can map UART registers wherever we want as long as they don't | |
184 | * interfere with other system mappings (e.g. with pinned entries). | |
185 | * For an example of how we handle this - see ocotea.h. --ebs | |
186 | */ | |
187 | /* pageid fields */ | |
188 | lis r3,UART0_IO_BASE@h | |
189 | ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_4K | |
190 | ||
191 | /* xlat fields */ | |
192 | lis r4,UART0_PHYS_IO_BASE@h /* RPN depends on SoC */ | |
193 | #ifndef CONFIG_440EP | |
194 | ori r4,r4,0x0001 /* ERPN is 1 for second 4GB page */ | |
195 | #endif | |
196 | ||
197 | /* attrib fields */ | |
198 | li r5,0 | |
199 | ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_I | PPC44x_TLB_G) | |
200 | ||
201 | li r0,0 /* TLB slot 0 */ | |
202 | ||
203 | tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */ | |
204 | tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */ | |
205 | tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Load the attrib/access fields */ | |
206 | ||
207 | /* Force context change */ | |
208 | isync | |
209 | #endif /* CONFIG_SERIAL_TEXT_DEBUG */ | |
210 | ||
211 | /* Establish the interrupt vector offsets */ | |
212 | SET_IVOR(0, CriticalInput); | |
213 | SET_IVOR(1, MachineCheck); | |
214 | SET_IVOR(2, DataStorage); | |
215 | SET_IVOR(3, InstructionStorage); | |
216 | SET_IVOR(4, ExternalInput); | |
217 | SET_IVOR(5, Alignment); | |
218 | SET_IVOR(6, Program); | |
219 | SET_IVOR(7, FloatingPointUnavailable); | |
220 | SET_IVOR(8, SystemCall); | |
221 | SET_IVOR(9, AuxillaryProcessorUnavailable); | |
222 | SET_IVOR(10, Decrementer); | |
223 | SET_IVOR(11, FixedIntervalTimer); | |
224 | SET_IVOR(12, WatchdogTimer); | |
225 | SET_IVOR(13, DataTLBError); | |
226 | SET_IVOR(14, InstructionTLBError); | |
227 | SET_IVOR(15, Debug); | |
228 | ||
229 | /* Establish the interrupt vector base */ | |
230 | lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */ | |
231 | mtspr SPRN_IVPR,r4 | |
232 | ||
233 | #ifdef CONFIG_440EP | |
234 | /* Clear DAPUIB flag in CCR0 (enable APU between CPU and FPU) */ | |
235 | mfspr r2,SPRN_CCR0 | |
236 | lis r3,0xffef | |
237 | ori r3,r3,0xffff | |
238 | and r2,r2,r3 | |
239 | mtspr SPRN_CCR0,r2 | |
240 | isync | |
241 | #endif | |
242 | ||
243 | /* | |
244 | * This is where the main kernel code starts. | |
245 | */ | |
246 | ||
247 | /* ptr to current */ | |
248 | lis r2,init_task@h | |
249 | ori r2,r2,init_task@l | |
250 | ||
251 | /* ptr to current thread */ | |
252 | addi r4,r2,THREAD /* init task's THREAD */ | |
253 | mtspr SPRN_SPRG3,r4 | |
254 | ||
255 | /* stack */ | |
256 | lis r1,init_thread_union@h | |
257 | ori r1,r1,init_thread_union@l | |
258 | li r0,0 | |
259 | stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1) | |
260 | ||
261 | bl early_init | |
262 | ||
263 | /* | |
264 | * Decide what sort of machine this is and initialize the MMU. | |
265 | */ | |
266 | mr r3,r31 | |
267 | mr r4,r30 | |
268 | mr r5,r29 | |
269 | mr r6,r28 | |
270 | mr r7,r27 | |
271 | bl machine_init | |
272 | bl MMU_init | |
273 | ||
274 | /* Setup PTE pointers for the Abatron bdiGDB */ | |
275 | lis r6, swapper_pg_dir@h | |
276 | ori r6, r6, swapper_pg_dir@l | |
277 | lis r5, abatron_pteptrs@h | |
278 | ori r5, r5, abatron_pteptrs@l | |
279 | lis r4, KERNELBASE@h | |
280 | ori r4, r4, KERNELBASE@l | |
281 | stw r5, 0(r4) /* Save abatron_pteptrs at a fixed location */ | |
282 | stw r6, 0(r5) | |
283 | ||
284 | /* Let's move on */ | |
285 | lis r4,start_kernel@h | |
286 | ori r4,r4,start_kernel@l | |
287 | lis r3,MSR_KERNEL@h | |
288 | ori r3,r3,MSR_KERNEL@l | |
289 | mtspr SPRN_SRR0,r4 | |
290 | mtspr SPRN_SRR1,r3 | |
291 | rfi /* change context and jump to start_kernel */ | |
292 | ||
293 | /* | |
294 | * Interrupt vector entry code | |
295 | * | |
296 | * The Book E MMUs are always on so we don't need to handle | |
297 | * interrupts in real mode as with previous PPC processors. In | |
298 | * this case we handle interrupts in the kernel virtual address | |
299 | * space. | |
300 | * | |
301 | * Interrupt vectors are dynamically placed relative to the | |
302 | * interrupt prefix as determined by the address of interrupt_base. | |
303 | * The interrupt vectors offsets are programmed using the labels | |
304 | * for each interrupt vector entry. | |
305 | * | |
306 | * Interrupt vectors must be aligned on a 16 byte boundary. | |
307 | * We align on a 32 byte cache line boundary for good measure. | |
308 | */ | |
309 | ||
310 | interrupt_base: | |
311 | /* Critical Input Interrupt */ | |
dc1c1ca3 | 312 | CRITICAL_EXCEPTION(0x0100, CriticalInput, unknown_exception) |
14cf11af PM |
313 | |
314 | /* Machine Check Interrupt */ | |
315 | #ifdef CONFIG_440A | |
dc1c1ca3 | 316 | MCHECK_EXCEPTION(0x0200, MachineCheck, machine_check_exception) |
14cf11af | 317 | #else |
dc1c1ca3 | 318 | CRITICAL_EXCEPTION(0x0200, MachineCheck, machine_check_exception) |
14cf11af PM |
319 | #endif |
320 | ||
321 | /* Data Storage Interrupt */ | |
322 | START_EXCEPTION(DataStorage) | |
323 | mtspr SPRN_SPRG0, r10 /* Save some working registers */ | |
324 | mtspr SPRN_SPRG1, r11 | |
325 | mtspr SPRN_SPRG4W, r12 | |
326 | mtspr SPRN_SPRG5W, r13 | |
327 | mfcr r11 | |
328 | mtspr SPRN_SPRG7W, r11 | |
329 | ||
330 | /* | |
331 | * Check if it was a store fault, if not then bail | |
332 | * because a user tried to access a kernel or | |
333 | * read-protected page. Otherwise, get the | |
334 | * offending address and handle it. | |
335 | */ | |
336 | mfspr r10, SPRN_ESR | |
337 | andis. r10, r10, ESR_ST@h | |
338 | beq 2f | |
339 | ||
340 | mfspr r10, SPRN_DEAR /* Get faulting address */ | |
341 | ||
342 | /* If we are faulting a kernel address, we have to use the | |
343 | * kernel page tables. | |
344 | */ | |
345 | lis r11, TASK_SIZE@h | |
346 | cmplw r10, r11 | |
347 | blt+ 3f | |
348 | lis r11, swapper_pg_dir@h | |
349 | ori r11, r11, swapper_pg_dir@l | |
350 | ||
351 | mfspr r12,SPRN_MMUCR | |
352 | rlwinm r12,r12,0,0,23 /* Clear TID */ | |
353 | ||
354 | b 4f | |
355 | ||
356 | /* Get the PGD for the current thread */ | |
357 | 3: | |
358 | mfspr r11,SPRN_SPRG3 | |
359 | lwz r11,PGDIR(r11) | |
360 | ||
361 | /* Load PID into MMUCR TID */ | |
362 | mfspr r12,SPRN_MMUCR /* Get MMUCR */ | |
363 | mfspr r13,SPRN_PID /* Get PID */ | |
364 | rlwimi r12,r13,0,24,31 /* Set TID */ | |
365 | ||
366 | 4: | |
367 | mtspr SPRN_MMUCR,r12 | |
368 | ||
369 | rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */ | |
370 | lwzx r11, r12, r11 /* Get pgd/pmd entry */ | |
371 | rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */ | |
372 | beq 2f /* Bail if no table */ | |
373 | ||
374 | rlwimi r12, r10, 23, 20, 28 /* Compute pte address */ | |
375 | lwz r11, 4(r12) /* Get pte entry */ | |
376 | ||
377 | andi. r13, r11, _PAGE_RW /* Is it writeable? */ | |
378 | beq 2f /* Bail if not */ | |
379 | ||
380 | /* Update 'changed'. | |
381 | */ | |
382 | ori r11, r11, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE | |
383 | stw r11, 4(r12) /* Update Linux page table */ | |
384 | ||
385 | li r13, PPC44x_TLB_SR@l /* Set SR */ | |
386 | rlwimi r13, r11, 29, 29, 29 /* SX = _PAGE_HWEXEC */ | |
387 | rlwimi r13, r11, 0, 30, 30 /* SW = _PAGE_RW */ | |
388 | rlwimi r13, r11, 29, 28, 28 /* UR = _PAGE_USER */ | |
389 | rlwimi r12, r11, 31, 26, 26 /* (_PAGE_USER>>1)->r12 */ | |
390 | rlwimi r12, r11, 29, 30, 30 /* (_PAGE_USER>>3)->r12 */ | |
391 | and r12, r12, r11 /* HWEXEC/RW & USER */ | |
392 | rlwimi r13, r12, 0, 26, 26 /* UX = HWEXEC & USER */ | |
393 | rlwimi r13, r12, 3, 27, 27 /* UW = RW & USER */ | |
394 | ||
395 | rlwimi r11,r13,0,26,31 /* Insert static perms */ | |
396 | ||
397 | rlwinm r11,r11,0,20,15 /* Clear U0-U3 */ | |
398 | ||
399 | /* find the TLB index that caused the fault. It has to be here. */ | |
400 | tlbsx r10, 0, r10 | |
401 | ||
402 | tlbwe r11, r10, PPC44x_TLB_ATTRIB /* Write ATTRIB */ | |
403 | ||
404 | /* Done...restore registers and get out of here. | |
405 | */ | |
406 | mfspr r11, SPRN_SPRG7R | |
407 | mtcr r11 | |
408 | mfspr r13, SPRN_SPRG5R | |
409 | mfspr r12, SPRN_SPRG4R | |
410 | ||
411 | mfspr r11, SPRN_SPRG1 | |
412 | mfspr r10, SPRN_SPRG0 | |
413 | rfi /* Force context change */ | |
414 | ||
415 | 2: | |
416 | /* | |
417 | * The bailout. Restore registers to pre-exception conditions | |
418 | * and call the heavyweights to help us out. | |
419 | */ | |
420 | mfspr r11, SPRN_SPRG7R | |
421 | mtcr r11 | |
422 | mfspr r13, SPRN_SPRG5R | |
423 | mfspr r12, SPRN_SPRG4R | |
424 | ||
425 | mfspr r11, SPRN_SPRG1 | |
426 | mfspr r10, SPRN_SPRG0 | |
427 | b data_access | |
428 | ||
429 | /* Instruction Storage Interrupt */ | |
430 | INSTRUCTION_STORAGE_EXCEPTION | |
431 | ||
432 | /* External Input Interrupt */ | |
433 | EXCEPTION(0x0500, ExternalInput, do_IRQ, EXC_XFER_LITE) | |
434 | ||
435 | /* Alignment Interrupt */ | |
436 | ALIGNMENT_EXCEPTION | |
437 | ||
438 | /* Program Interrupt */ | |
439 | PROGRAM_EXCEPTION | |
440 | ||
441 | /* Floating Point Unavailable Interrupt */ | |
442 | #ifdef CONFIG_PPC_FPU | |
443 | FP_UNAVAILABLE_EXCEPTION | |
444 | #else | |
dc1c1ca3 | 445 | EXCEPTION(0x2010, FloatingPointUnavailable, unknown_exception, EXC_XFER_EE) |
14cf11af PM |
446 | #endif |
447 | ||
448 | /* System Call Interrupt */ | |
449 | START_EXCEPTION(SystemCall) | |
450 | NORMAL_EXCEPTION_PROLOG | |
451 | EXC_XFER_EE_LITE(0x0c00, DoSyscall) | |
452 | ||
453 | /* Auxillary Processor Unavailable Interrupt */ | |
dc1c1ca3 | 454 | EXCEPTION(0x2020, AuxillaryProcessorUnavailable, unknown_exception, EXC_XFER_EE) |
14cf11af PM |
455 | |
456 | /* Decrementer Interrupt */ | |
457 | DECREMENTER_EXCEPTION | |
458 | ||
459 | /* Fixed Internal Timer Interrupt */ | |
460 | /* TODO: Add FIT support */ | |
dc1c1ca3 | 461 | EXCEPTION(0x1010, FixedIntervalTimer, unknown_exception, EXC_XFER_EE) |
14cf11af PM |
462 | |
463 | /* Watchdog Timer Interrupt */ | |
464 | /* TODO: Add watchdog support */ | |
465 | #ifdef CONFIG_BOOKE_WDT | |
466 | CRITICAL_EXCEPTION(0x1020, WatchdogTimer, WatchdogException) | |
467 | #else | |
dc1c1ca3 | 468 | CRITICAL_EXCEPTION(0x1020, WatchdogTimer, unknown_exception) |
14cf11af PM |
469 | #endif |
470 | ||
471 | /* Data TLB Error Interrupt */ | |
472 | START_EXCEPTION(DataTLBError) | |
473 | mtspr SPRN_SPRG0, r10 /* Save some working registers */ | |
474 | mtspr SPRN_SPRG1, r11 | |
475 | mtspr SPRN_SPRG4W, r12 | |
476 | mtspr SPRN_SPRG5W, r13 | |
477 | mfcr r11 | |
478 | mtspr SPRN_SPRG7W, r11 | |
479 | mfspr r10, SPRN_DEAR /* Get faulting address */ | |
480 | ||
481 | /* If we are faulting a kernel address, we have to use the | |
482 | * kernel page tables. | |
483 | */ | |
484 | lis r11, TASK_SIZE@h | |
485 | cmplw r10, r11 | |
486 | blt+ 3f | |
487 | lis r11, swapper_pg_dir@h | |
488 | ori r11, r11, swapper_pg_dir@l | |
489 | ||
490 | mfspr r12,SPRN_MMUCR | |
491 | rlwinm r12,r12,0,0,23 /* Clear TID */ | |
492 | ||
493 | b 4f | |
494 | ||
495 | /* Get the PGD for the current thread */ | |
496 | 3: | |
497 | mfspr r11,SPRN_SPRG3 | |
498 | lwz r11,PGDIR(r11) | |
499 | ||
500 | /* Load PID into MMUCR TID */ | |
501 | mfspr r12,SPRN_MMUCR | |
502 | mfspr r13,SPRN_PID /* Get PID */ | |
503 | rlwimi r12,r13,0,24,31 /* Set TID */ | |
504 | ||
505 | 4: | |
506 | mtspr SPRN_MMUCR,r12 | |
507 | ||
508 | rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */ | |
509 | lwzx r11, r12, r11 /* Get pgd/pmd entry */ | |
510 | rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */ | |
511 | beq 2f /* Bail if no table */ | |
512 | ||
513 | rlwimi r12, r10, 23, 20, 28 /* Compute pte address */ | |
514 | lwz r11, 4(r12) /* Get pte entry */ | |
515 | andi. r13, r11, _PAGE_PRESENT /* Is the page present? */ | |
516 | beq 2f /* Bail if not present */ | |
517 | ||
518 | ori r11, r11, _PAGE_ACCESSED | |
519 | stw r11, 4(r12) | |
520 | ||
521 | /* Jump to common tlb load */ | |
522 | b finish_tlb_load | |
523 | ||
524 | 2: | |
525 | /* The bailout. Restore registers to pre-exception conditions | |
526 | * and call the heavyweights to help us out. | |
527 | */ | |
528 | mfspr r11, SPRN_SPRG7R | |
529 | mtcr r11 | |
530 | mfspr r13, SPRN_SPRG5R | |
531 | mfspr r12, SPRN_SPRG4R | |
532 | mfspr r11, SPRN_SPRG1 | |
533 | mfspr r10, SPRN_SPRG0 | |
534 | b data_access | |
535 | ||
536 | /* Instruction TLB Error Interrupt */ | |
537 | /* | |
538 | * Nearly the same as above, except we get our | |
539 | * information from different registers and bailout | |
540 | * to a different point. | |
541 | */ | |
542 | START_EXCEPTION(InstructionTLBError) | |
543 | mtspr SPRN_SPRG0, r10 /* Save some working registers */ | |
544 | mtspr SPRN_SPRG1, r11 | |
545 | mtspr SPRN_SPRG4W, r12 | |
546 | mtspr SPRN_SPRG5W, r13 | |
547 | mfcr r11 | |
548 | mtspr SPRN_SPRG7W, r11 | |
549 | mfspr r10, SPRN_SRR0 /* Get faulting address */ | |
550 | ||
551 | /* If we are faulting a kernel address, we have to use the | |
552 | * kernel page tables. | |
553 | */ | |
554 | lis r11, TASK_SIZE@h | |
555 | cmplw r10, r11 | |
556 | blt+ 3f | |
557 | lis r11, swapper_pg_dir@h | |
558 | ori r11, r11, swapper_pg_dir@l | |
559 | ||
560 | mfspr r12,SPRN_MMUCR | |
561 | rlwinm r12,r12,0,0,23 /* Clear TID */ | |
562 | ||
563 | b 4f | |
564 | ||
565 | /* Get the PGD for the current thread */ | |
566 | 3: | |
567 | mfspr r11,SPRN_SPRG3 | |
568 | lwz r11,PGDIR(r11) | |
569 | ||
570 | /* Load PID into MMUCR TID */ | |
571 | mfspr r12,SPRN_MMUCR | |
572 | mfspr r13,SPRN_PID /* Get PID */ | |
573 | rlwimi r12,r13,0,24,31 /* Set TID */ | |
574 | ||
575 | 4: | |
576 | mtspr SPRN_MMUCR,r12 | |
577 | ||
578 | rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */ | |
579 | lwzx r11, r12, r11 /* Get pgd/pmd entry */ | |
580 | rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */ | |
581 | beq 2f /* Bail if no table */ | |
582 | ||
583 | rlwimi r12, r10, 23, 20, 28 /* Compute pte address */ | |
584 | lwz r11, 4(r12) /* Get pte entry */ | |
585 | andi. r13, r11, _PAGE_PRESENT /* Is the page present? */ | |
586 | beq 2f /* Bail if not present */ | |
587 | ||
588 | ori r11, r11, _PAGE_ACCESSED | |
589 | stw r11, 4(r12) | |
590 | ||
591 | /* Jump to common TLB load point */ | |
592 | b finish_tlb_load | |
593 | ||
594 | 2: | |
595 | /* The bailout. Restore registers to pre-exception conditions | |
596 | * and call the heavyweights to help us out. | |
597 | */ | |
598 | mfspr r11, SPRN_SPRG7R | |
599 | mtcr r11 | |
600 | mfspr r13, SPRN_SPRG5R | |
601 | mfspr r12, SPRN_SPRG4R | |
602 | mfspr r11, SPRN_SPRG1 | |
603 | mfspr r10, SPRN_SPRG0 | |
604 | b InstructionStorage | |
605 | ||
606 | /* Debug Interrupt */ | |
607 | DEBUG_EXCEPTION | |
608 | ||
609 | /* | |
610 | * Local functions | |
611 | */ | |
612 | /* | |
613 | * Data TLB exceptions will bail out to this point | |
614 | * if they can't resolve the lightweight TLB fault. | |
615 | */ | |
616 | data_access: | |
617 | NORMAL_EXCEPTION_PROLOG | |
618 | mfspr r5,SPRN_ESR /* Grab the ESR, save it, pass arg3 */ | |
619 | stw r5,_ESR(r11) | |
620 | mfspr r4,SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */ | |
621 | EXC_XFER_EE_LITE(0x0300, handle_page_fault) | |
622 | ||
623 | /* | |
624 | ||
625 | * Both the instruction and data TLB miss get to this | |
626 | * point to load the TLB. | |
627 | * r10 - EA of fault | |
628 | * r11 - available to use | |
629 | * r12 - Pointer to the 64-bit PTE | |
630 | * r13 - available to use | |
631 | * MMUCR - loaded with proper value when we get here | |
632 | * Upon exit, we reload everything and RFI. | |
633 | */ | |
634 | finish_tlb_load: | |
635 | /* | |
636 | * We set execute, because we don't have the granularity to | |
637 | * properly set this at the page level (Linux problem). | |
638 | * If shared is set, we cause a zero PID->TID load. | |
639 | * Many of these bits are software only. Bits we don't set | |
640 | * here we (properly should) assume have the appropriate value. | |
641 | */ | |
642 | ||
643 | /* Load the next available TLB index */ | |
644 | lis r13, tlb_44x_index@ha | |
645 | lwz r13, tlb_44x_index@l(r13) | |
646 | /* Load the TLB high watermark */ | |
647 | lis r11, tlb_44x_hwater@ha | |
648 | lwz r11, tlb_44x_hwater@l(r11) | |
649 | ||
650 | /* Increment, rollover, and store TLB index */ | |
651 | addi r13, r13, 1 | |
652 | cmpw 0, r13, r11 /* reserve entries */ | |
653 | ble 7f | |
654 | li r13, 0 | |
655 | 7: | |
656 | /* Store the next available TLB index */ | |
657 | lis r11, tlb_44x_index@ha | |
658 | stw r13, tlb_44x_index@l(r11) | |
659 | ||
660 | lwz r11, 0(r12) /* Get MS word of PTE */ | |
661 | lwz r12, 4(r12) /* Get LS word of PTE */ | |
662 | rlwimi r11, r12, 0, 0 , 19 /* Insert RPN */ | |
663 | tlbwe r11, r13, PPC44x_TLB_XLAT /* Write XLAT */ | |
664 | ||
665 | /* | |
666 | * Create PAGEID. This is the faulting address, | |
667 | * page size, and valid flag. | |
668 | */ | |
669 | li r11, PPC44x_TLB_VALID | PPC44x_TLB_4K | |
670 | rlwimi r10, r11, 0, 20, 31 /* Insert valid and page size */ | |
671 | tlbwe r10, r13, PPC44x_TLB_PAGEID /* Write PAGEID */ | |
672 | ||
673 | li r10, PPC44x_TLB_SR@l /* Set SR */ | |
674 | rlwimi r10, r12, 0, 30, 30 /* Set SW = _PAGE_RW */ | |
675 | rlwimi r10, r12, 29, 29, 29 /* SX = _PAGE_HWEXEC */ | |
676 | rlwimi r10, r12, 29, 28, 28 /* UR = _PAGE_USER */ | |
677 | rlwimi r11, r12, 31, 26, 26 /* (_PAGE_USER>>1)->r12 */ | |
678 | and r11, r12, r11 /* HWEXEC & USER */ | |
679 | rlwimi r10, r11, 0, 26, 26 /* UX = HWEXEC & USER */ | |
680 | ||
681 | rlwimi r12, r10, 0, 26, 31 /* Insert static perms */ | |
682 | rlwinm r12, r12, 0, 20, 15 /* Clear U0-U3 */ | |
683 | tlbwe r12, r13, PPC44x_TLB_ATTRIB /* Write ATTRIB */ | |
684 | ||
685 | /* Done...restore registers and get out of here. | |
686 | */ | |
687 | mfspr r11, SPRN_SPRG7R | |
688 | mtcr r11 | |
689 | mfspr r13, SPRN_SPRG5R | |
690 | mfspr r12, SPRN_SPRG4R | |
691 | mfspr r11, SPRN_SPRG1 | |
692 | mfspr r10, SPRN_SPRG0 | |
693 | rfi /* Force context change */ | |
694 | ||
695 | /* | |
696 | * Global functions | |
697 | */ | |
698 | ||
699 | /* | |
700 | * extern void giveup_altivec(struct task_struct *prev) | |
701 | * | |
702 | * The 44x core does not have an AltiVec unit. | |
703 | */ | |
704 | _GLOBAL(giveup_altivec) | |
705 | blr | |
706 | ||
707 | /* | |
708 | * extern void giveup_fpu(struct task_struct *prev) | |
709 | * | |
710 | * The 44x core does not have an FPU. | |
711 | */ | |
712 | #ifndef CONFIG_PPC_FPU | |
713 | _GLOBAL(giveup_fpu) | |
714 | blr | |
715 | #endif | |
716 | ||
717 | /* | |
718 | * extern void abort(void) | |
719 | * | |
720 | * At present, this routine just applies a system reset. | |
721 | */ | |
722 | _GLOBAL(abort) | |
723 | mfspr r13,SPRN_DBCR0 | |
724 | oris r13,r13,DBCR0_RST_SYSTEM@h | |
725 | mtspr SPRN_DBCR0,r13 | |
726 | ||
727 | _GLOBAL(set_context) | |
728 | ||
729 | #ifdef CONFIG_BDI_SWITCH | |
730 | /* Context switch the PTE pointer for the Abatron BDI2000. | |
731 | * The PGDIR is the second parameter. | |
732 | */ | |
733 | lis r5, abatron_pteptrs@h | |
734 | ori r5, r5, abatron_pteptrs@l | |
735 | stw r4, 0x4(r5) | |
736 | #endif | |
737 | mtspr SPRN_PID,r3 | |
738 | isync /* Force context change */ | |
739 | blr | |
740 | ||
741 | /* | |
742 | * We put a few things here that have to be page-aligned. This stuff | |
743 | * goes at the beginning of the data segment, which is page-aligned. | |
744 | */ | |
745 | .data | |
746 | _GLOBAL(sdata) | |
747 | _GLOBAL(empty_zero_page) | |
748 | .space 4096 | |
749 | ||
750 | /* | |
751 | * To support >32-bit physical addresses, we use an 8KB pgdir. | |
752 | */ | |
753 | _GLOBAL(swapper_pg_dir) | |
754 | .space 8192 | |
755 | ||
756 | /* Reserved 4k for the critical exception stack & 4k for the machine | |
757 | * check stack per CPU for kernel mode exceptions */ | |
758 | .section .bss | |
759 | .align 12 | |
760 | exception_stack_bottom: | |
761 | .space BOOKE_EXCEPTION_STACK_SIZE | |
762 | _GLOBAL(exception_stack_top) | |
763 | ||
764 | /* | |
765 | * This space gets a copy of optional info passed to us by the bootstrap | |
766 | * which is used to pass parameters into the kernel like root=/dev/sda1, etc. | |
767 | */ | |
768 | _GLOBAL(cmd_line) | |
769 | .space 512 | |
770 | ||
771 | /* | |
772 | * Room for two PTE pointers, usually the kernel and current user pointers | |
773 | * to their respective root page table. | |
774 | */ | |
775 | abatron_pteptrs: | |
776 | .space 8 | |
777 | ||
778 |