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1/*
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
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>
40#include <asm/asm-offsets.h>
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 */
105wmmucr: mtspr SPRN_MMUCR,r3 /* Put MMUCR */
106 sync
107
108 bl invstr /* Find our address */
109invstr: 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 */
1131: 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 */
116skpinv: 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 */
1703: cmpwi r23,63
171 beq 4f
172 li r6,0
173 tlbwe r6,r23,PPC44x_TLB_PAGEID
174 isync
175
1764:
177#ifdef CONFIG_SERIAL_TEXT_DEBUG
178 /*
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
183 */
184 /* pageid fields */
185 lis r3,UART0_IO_BASE@h
186 ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_4K
187
188 /* xlat fields */
189 lis r4,UART0_PHYS_IO_BASE@h /* RPN depends on SoC */
190#ifdef UART0_PHYS_ERPN
191 ori r4,r4,UART0_PHYS_ERPN /* Add ERPN if above 4GB */
192#endif
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
198 li r0,62 /* TLB slot 62 */
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
297interrupt_base:
298 /* Critical Input Interrupt */
299 CRITICAL_EXCEPTION(0x0100, CriticalInput, unknown_exception)
300
301 /* Machine Check Interrupt */
302#ifdef CONFIG_440A
303 MCHECK_EXCEPTION(0x0200, MachineCheck, machine_check_exception)
304#else
305 CRITICAL_EXCEPTION(0x0200, MachineCheck, machine_check_exception)
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 */
332 lis r11, TASK_SIZE@h
333 cmplw r10, r11
334 blt+ 3f
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 */
3443:
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
3534:
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
4022:
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 */
429#ifdef CONFIG_PPC_FPU
430 FP_UNAVAILABLE_EXCEPTION
431#else
432 EXCEPTION(0x2010, FloatingPointUnavailable, unknown_exception, EXC_XFER_EE)
433#endif
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 */
441 EXCEPTION(0x2020, AuxillaryProcessorUnavailable, unknown_exception, EXC_XFER_EE)
442
443 /* Decrementer Interrupt */
444 DECREMENTER_EXCEPTION
445
446 /* Fixed Internal Timer Interrupt */
447 /* TODO: Add FIT support */
448 EXCEPTION(0x1010, FixedIntervalTimer, unknown_exception, EXC_XFER_EE)
449
450 /* Watchdog Timer Interrupt */
451 /* TODO: Add watchdog support */
452#ifdef CONFIG_BOOKE_WDT
453 CRITICAL_EXCEPTION(0x1020, WatchdogTimer, WatchdogException)
454#else
455 CRITICAL_EXCEPTION(0x1020, WatchdogTimer, unknown_exception)
456#endif
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 */
471 lis r11, TASK_SIZE@h
472 cmplw r10, r11
473 blt+ 3f
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 */
4833:
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
4924:
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
5112:
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 */
541 lis r11, TASK_SIZE@h
542 cmplw r10, r11
543 blt+ 3f
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 */
5533:
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
5624:
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
5812:
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 */
603data_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 */
621finish_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
6427:
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 */
699#ifndef CONFIG_PPC_FPU
700_GLOBAL(giveup_fpu)
701 blr
702#endif
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
733 .align 12
734 .globl sdata
735sdata:
736 .globl empty_zero_page
737empty_zero_page:
738 .space 4096
739
740/*
741 * To support >32-bit physical addresses, we use an 8KB pgdir.
742 */
743 .globl swapper_pg_dir
744swapper_pg_dir:
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
751exception_stack_bottom:
752 .space BOOKE_EXCEPTION_STACK_SIZE
753 .globl exception_stack_top
754exception_stack_top:
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 */
760 .globl cmd_line
761cmd_line:
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 */
768abatron_pteptrs:
769 .space 8
generated by cgit v1.2.2 (git 2.25.0) at 2025-02-08 02:59:50 -0500