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1/*
2 * PowerPC version
3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
4 *
5 * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
6 * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
7 * Adapted for Power Macintosh by Paul Mackerras.
8 * Low-level exception handlers and MMU support
9 * rewritten by Paul Mackerras.
10 * Copyright (C) 1996 Paul Mackerras.
11 * MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net).
12 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
13 *
14 * This file contains the low-level support and setup for the
15 * PowerPC platform, including trap and interrupt dispatch.
16 * (The PPC 8xx embedded CPUs use head_8xx.S instead.)
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 *
23 */
24
25#include <linux/config.h>
26#include <asm/processor.h>
27#include <asm/page.h>
28#include <asm/mmu.h>
29#include <asm/pgtable.h>
30#include <asm/cputable.h>
31#include <asm/cache.h>
32#include <asm/thread_info.h>
33#include <asm/ppc_asm.h>
34#include <asm/asm-offsets.h>
35
36#ifdef CONFIG_APUS
37#include <asm/amigappc.h>
38#endif
39
40/* 601 only have IBAT; cr0.eq is set on 601 when using this macro */
41#define LOAD_BAT(n, reg, RA, RB) \
42 /* see the comment for clear_bats() -- Cort */ \
43 li RA,0; \
44 mtspr SPRN_IBAT##n##U,RA; \
45 mtspr SPRN_DBAT##n##U,RA; \
46 lwz RA,(n*16)+0(reg); \
47 lwz RB,(n*16)+4(reg); \
48 mtspr SPRN_IBAT##n##U,RA; \
49 mtspr SPRN_IBAT##n##L,RB; \
50 beq 1f; \
51 lwz RA,(n*16)+8(reg); \
52 lwz RB,(n*16)+12(reg); \
53 mtspr SPRN_DBAT##n##U,RA; \
54 mtspr SPRN_DBAT##n##L,RB; \
551:
56
57 .text
58 .stabs "arch/ppc/kernel/",N_SO,0,0,0f
59 .stabs "head.S",N_SO,0,0,0f
600:
61 .globl _stext
62_stext:
63
64/*
65 * _start is defined this way because the XCOFF loader in the OpenFirmware
66 * on the powermac expects the entry point to be a procedure descriptor.
67 */
68 .text
69 .globl _start
70_start:
71 /*
72 * These are here for legacy reasons, the kernel used to
73 * need to look like a coff function entry for the pmac
74 * but we're always started by some kind of bootloader now.
75 * -- Cort
76 */
77 nop /* used by __secondary_hold on prep (mtx) and chrp smp */
78 nop /* used by __secondary_hold on prep (mtx) and chrp smp */
79 nop
80
81/* PMAC
82 * Enter here with the kernel text, data and bss loaded starting at
83 * 0, running with virtual == physical mapping.
84 * r5 points to the prom entry point (the client interface handler
85 * address). Address translation is turned on, with the prom
86 * managing the hash table. Interrupts are disabled. The stack
87 * pointer (r1) points to just below the end of the half-meg region
88 * from 0x380000 - 0x400000, which is mapped in already.
89 *
90 * If we are booted from MacOS via BootX, we enter with the kernel
91 * image loaded somewhere, and the following values in registers:
92 * r3: 'BooX' (0x426f6f58)
93 * r4: virtual address of boot_infos_t
94 * r5: 0
95 *
96 * APUS
97 * r3: 'APUS'
98 * r4: physical address of memory base
99 * Linux/m68k style BootInfo structure at &_end.
100 *
101 * PREP
102 * This is jumped to on prep systems right after the kernel is relocated
103 * to its proper place in memory by the boot loader. The expected layout
104 * of the regs is:
105 * r3: ptr to residual data
106 * r4: initrd_start or if no initrd then 0
107 * r5: initrd_end - unused if r4 is 0
108 * r6: Start of command line string
109 * r7: End of command line string
110 *
111 * This just gets a minimal mmu environment setup so we can call
112 * start_here() to do the real work.
113 * -- Cort
114 */
115
116 .globl __start
117__start:
118/*
119 * We have to do any OF calls before we map ourselves to KERNELBASE,
120 * because OF may have I/O devices mapped into that area
121 * (particularly on CHRP).
122 */
123 cmpwi 0,r5,0
124 beq 1f
125 bl prom_init
126 trap
127
1281: mr r31,r3 /* save parameters */
129 mr r30,r4
130 li r24,0 /* cpu # */
131
132/*
133 * early_init() does the early machine identification and does
134 * the necessary low-level setup and clears the BSS
135 * -- Cort <cort@fsmlabs.com>
136 */
137 bl early_init
138
139#ifdef CONFIG_APUS
140/* On APUS the __va/__pa constants need to be set to the correct
141 * values before continuing.
142 */
143 mr r4,r30
144 bl fix_mem_constants
145#endif /* CONFIG_APUS */
146
147/* Switch MMU off, clear BATs and flush TLB. At this point, r3 contains
148 * the physical address we are running at, returned by early_init()
149 */
150 bl mmu_off
151__after_mmu_off:
152 bl clear_bats
153 bl flush_tlbs
154
155 bl initial_bats
156#if !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT)
157 bl setup_disp_bat
158#endif
159
160/*
161 * Call setup_cpu for CPU 0 and initialize 6xx Idle
162 */
163 bl reloc_offset
164 li r24,0 /* cpu# */
165 bl call_setup_cpu /* Call setup_cpu for this CPU */
166#ifdef CONFIG_6xx
167 bl reloc_offset
168 bl init_idle_6xx
169#endif /* CONFIG_6xx */
170
171
172#ifndef CONFIG_APUS
173/*
174 * We need to run with _start at physical address 0.
175 * On CHRP, we are loaded at 0x10000 since OF on CHRP uses
176 * the exception vectors at 0 (and therefore this copy
177 * overwrites OF's exception vectors with our own).
178 * The MMU is off at this point.
179 */
180 bl reloc_offset
181 mr r26,r3
182 addis r4,r3,KERNELBASE@h /* current address of _start */
183 cmpwi 0,r4,0 /* are we already running at 0? */
184 bne relocate_kernel
185#endif /* CONFIG_APUS */
186/*
187 * we now have the 1st 16M of ram mapped with the bats.
188 * prep needs the mmu to be turned on here, but pmac already has it on.
189 * this shouldn't bother the pmac since it just gets turned on again
190 * as we jump to our code at KERNELBASE. -- Cort
191 * Actually no, pmac doesn't have it on any more. BootX enters with MMU
192 * off, and in other cases, we now turn it off before changing BATs above.
193 */
194turn_on_mmu:
195 mfmsr r0
196 ori r0,r0,MSR_DR|MSR_IR
197 mtspr SPRN_SRR1,r0
198 lis r0,start_here@h
199 ori r0,r0,start_here@l
200 mtspr SPRN_SRR0,r0
201 SYNC
202 RFI /* enables MMU */
203
204/*
205 * We need __secondary_hold as a place to hold the other cpus on
206 * an SMP machine, even when we are running a UP kernel.
207 */
208 . = 0xc0 /* for prep bootloader */
209 li r3,1 /* MTX only has 1 cpu */
210 .globl __secondary_hold
211__secondary_hold:
212 /* tell the master we're here */
213 stw r3,4(0)
214#ifdef CONFIG_SMP
215100: lwz r4,0(0)
216 /* wait until we're told to start */
217 cmpw 0,r4,r3
218 bne 100b
219 /* our cpu # was at addr 0 - go */
220 mr r24,r3 /* cpu # */
221 b __secondary_start
222#else
223 b .
224#endif /* CONFIG_SMP */
225
226/*
227 * Exception entry code. This code runs with address translation
228 * turned off, i.e. using physical addresses.
229 * We assume sprg3 has the physical address of the current
230 * task's thread_struct.
231 */
232#define EXCEPTION_PROLOG \
233 mtspr SPRN_SPRG0,r10; \
234 mtspr SPRN_SPRG1,r11; \
235 mfcr r10; \
236 EXCEPTION_PROLOG_1; \
237 EXCEPTION_PROLOG_2
238
239#define EXCEPTION_PROLOG_1 \
240 mfspr r11,SPRN_SRR1; /* check whether user or kernel */ \
241 andi. r11,r11,MSR_PR; \
242 tophys(r11,r1); /* use tophys(r1) if kernel */ \
243 beq 1f; \
244 mfspr r11,SPRN_SPRG3; \
245 lwz r11,THREAD_INFO-THREAD(r11); \
246 addi r11,r11,THREAD_SIZE; \
247 tophys(r11,r11); \
2481: subi r11,r11,INT_FRAME_SIZE /* alloc exc. frame */
249
250
251#define EXCEPTION_PROLOG_2 \
252 CLR_TOP32(r11); \
253 stw r10,_CCR(r11); /* save registers */ \
254 stw r12,GPR12(r11); \
255 stw r9,GPR9(r11); \
256 mfspr r10,SPRN_SPRG0; \
257 stw r10,GPR10(r11); \
258 mfspr r12,SPRN_SPRG1; \
259 stw r12,GPR11(r11); \
260 mflr r10; \
261 stw r10,_LINK(r11); \
262 mfspr r12,SPRN_SRR0; \
263 mfspr r9,SPRN_SRR1; \
264 stw r1,GPR1(r11); \
265 stw r1,0(r11); \
266 tovirt(r1,r11); /* set new kernel sp */ \
267 li r10,MSR_KERNEL & ~(MSR_IR|MSR_DR); /* can take exceptions */ \
268 MTMSRD(r10); /* (except for mach check in rtas) */ \
269 stw r0,GPR0(r11); \
270 SAVE_4GPRS(3, r11); \
271 SAVE_2GPRS(7, r11)
272
273/*
274 * Note: code which follows this uses cr0.eq (set if from kernel),
275 * r11, r12 (SRR0), and r9 (SRR1).
276 *
277 * Note2: once we have set r1 we are in a position to take exceptions
278 * again, and we could thus set MSR:RI at that point.
279 */
280
281/*
282 * Exception vectors.
283 */
284#define EXCEPTION(n, label, hdlr, xfer) \
285 . = n; \
286label: \
287 EXCEPTION_PROLOG; \
288 addi r3,r1,STACK_FRAME_OVERHEAD; \
289 xfer(n, hdlr)
290
291#define EXC_XFER_TEMPLATE(n, hdlr, trap, copyee, tfer, ret) \
292 li r10,trap; \
293 stw r10,TRAP(r11); \
294 li r10,MSR_KERNEL; \
295 copyee(r10, r9); \
296 bl tfer; \
297i##n: \
298 .long hdlr; \
299 .long ret
300
301#define COPY_EE(d, s) rlwimi d,s,0,16,16
302#define NOCOPY(d, s)
303
304#define EXC_XFER_STD(n, hdlr) \
305 EXC_XFER_TEMPLATE(n, hdlr, n, NOCOPY, transfer_to_handler_full, \
306 ret_from_except_full)
307
308#define EXC_XFER_LITE(n, hdlr) \
309 EXC_XFER_TEMPLATE(n, hdlr, n+1, NOCOPY, transfer_to_handler, \
310 ret_from_except)
311
312#define EXC_XFER_EE(n, hdlr) \
313 EXC_XFER_TEMPLATE(n, hdlr, n, COPY_EE, transfer_to_handler_full, \
314 ret_from_except_full)
315
316#define EXC_XFER_EE_LITE(n, hdlr) \
317 EXC_XFER_TEMPLATE(n, hdlr, n+1, COPY_EE, transfer_to_handler, \
318 ret_from_except)
319
320/* System reset */
321/* core99 pmac starts the seconary here by changing the vector, and
322 putting it back to what it was (unknown_exception) when done. */
323#if defined(CONFIG_GEMINI) && defined(CONFIG_SMP)
324 . = 0x100
325 b __secondary_start_gemini
326#else
327 EXCEPTION(0x100, Reset, unknown_exception, EXC_XFER_STD)
328#endif
329
330/* Machine check */
331/*
332 * On CHRP, this is complicated by the fact that we could get a
333 * machine check inside RTAS, and we have no guarantee that certain
334 * critical registers will have the values we expect. The set of
335 * registers that might have bad values includes all the GPRs
336 * and all the BATs. We indicate that we are in RTAS by putting
337 * a non-zero value, the address of the exception frame to use,
338 * in SPRG2. The machine check handler checks SPRG2 and uses its
339 * value if it is non-zero. If we ever needed to free up SPRG2,
340 * we could use a field in the thread_info or thread_struct instead.
341 * (Other exception handlers assume that r1 is a valid kernel stack
342 * pointer when we take an exception from supervisor mode.)
343 * -- paulus.
344 */
345 . = 0x200
346 mtspr SPRN_SPRG0,r10
347 mtspr SPRN_SPRG1,r11
348 mfcr r10
349#ifdef CONFIG_PPC_CHRP
350 mfspr r11,SPRN_SPRG2
351 cmpwi 0,r11,0
352 bne 7f
353#endif /* CONFIG_PPC_CHRP */
354 EXCEPTION_PROLOG_1
3557: EXCEPTION_PROLOG_2
356 addi r3,r1,STACK_FRAME_OVERHEAD
357#ifdef CONFIG_PPC_CHRP
358 mfspr r4,SPRN_SPRG2
359 cmpwi cr1,r4,0
360 bne cr1,1f
361#endif
362 EXC_XFER_STD(0x200, machine_check_exception)
363#ifdef CONFIG_PPC_CHRP
3641: b machine_check_in_rtas
365#endif
366
367/* Data access exception. */
368 . = 0x300
369DataAccess:
370 EXCEPTION_PROLOG
371 mfspr r10,SPRN_DSISR
372 andis. r0,r10,0xa470 /* weird error? */
373 bne 1f /* if not, try to put a PTE */
374 mfspr r4,SPRN_DAR /* into the hash table */
375 rlwinm r3,r10,32-15,21,21 /* DSISR_STORE -> _PAGE_RW */
376 bl hash_page
3771: stw r10,_DSISR(r11)
378 mr r5,r10
379 mfspr r4,SPRN_DAR
380 EXC_XFER_EE_LITE(0x300, handle_page_fault)
381
382
383/* Instruction access exception. */
384 . = 0x400
385InstructionAccess:
386 EXCEPTION_PROLOG
387 andis. r0,r9,0x4000 /* no pte found? */
388 beq 1f /* if so, try to put a PTE */
389 li r3,0 /* into the hash table */
390 mr r4,r12 /* SRR0 is fault address */
391 bl hash_page
3921: mr r4,r12
393 mr r5,r9
394 EXC_XFER_EE_LITE(0x400, handle_page_fault)
395
396/* External interrupt */
397 EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
398
399/* Alignment exception */
400 . = 0x600
401Alignment:
402 EXCEPTION_PROLOG
403 mfspr r4,SPRN_DAR
404 stw r4,_DAR(r11)
405 mfspr r5,SPRN_DSISR
406 stw r5,_DSISR(r11)
407 addi r3,r1,STACK_FRAME_OVERHEAD
408 EXC_XFER_EE(0x600, alignment_exception)
409
410/* Program check exception */
411 EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
412
413/* Floating-point unavailable */
414 . = 0x800
415FPUnavailable:
416 EXCEPTION_PROLOG
417 bne load_up_fpu /* if from user, just load it up */
418 addi r3,r1,STACK_FRAME_OVERHEAD
419 EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
420
421/* Decrementer */
422 EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
423
424 EXCEPTION(0xa00, Trap_0a, unknown_exception, EXC_XFER_EE)
425 EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_EE)
426
427/* System call */
428 . = 0xc00
429SystemCall:
430 EXCEPTION_PROLOG
431 EXC_XFER_EE_LITE(0xc00, DoSyscall)
432
433/* Single step - not used on 601 */
434 EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD)
435 EXCEPTION(0xe00, Trap_0e, unknown_exception, EXC_XFER_EE)
436
437/*
438 * The Altivec unavailable trap is at 0x0f20. Foo.
439 * We effectively remap it to 0x3000.
440 * We include an altivec unavailable exception vector even if
441 * not configured for Altivec, so that you can't panic a
442 * non-altivec kernel running on a machine with altivec just
443 * by executing an altivec instruction.
444 */
445 . = 0xf00
446 b Trap_0f
447
448 . = 0xf20
449 b AltiVecUnavailable
450
451Trap_0f:
452 EXCEPTION_PROLOG
453 addi r3,r1,STACK_FRAME_OVERHEAD
454 EXC_XFER_EE(0xf00, unknown_exception)
455
456/*
457 * Handle TLB miss for instruction on 603/603e.
458 * Note: we get an alternate set of r0 - r3 to use automatically.
459 */
460 . = 0x1000
461InstructionTLBMiss:
462/*
463 * r0: stored ctr
464 * r1: linux style pte ( later becomes ppc hardware pte )
465 * r2: ptr to linux-style pte
466 * r3: scratch
467 */
468 mfctr r0
469 /* Get PTE (linux-style) and check access */
470 mfspr r3,SPRN_IMISS
471 lis r1,KERNELBASE@h /* check if kernel address */
472 cmplw 0,r3,r1
473 mfspr r2,SPRN_SPRG3
474 li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
475 lwz r2,PGDIR(r2)
476 blt+ 112f
477 lis r2,swapper_pg_dir@ha /* if kernel address, use */
478 addi r2,r2,swapper_pg_dir@l /* kernel page table */
479 mfspr r1,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
480 rlwinm r1,r1,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
481112: tophys(r2,r2)
482 rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
483 lwz r2,0(r2) /* get pmd entry */
484 rlwinm. r2,r2,0,0,19 /* extract address of pte page */
485 beq- InstructionAddressInvalid /* return if no mapping */
486 rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
487 lwz r3,0(r2) /* get linux-style pte */
488 andc. r1,r1,r3 /* check access & ~permission */
489 bne- InstructionAddressInvalid /* return if access not permitted */
490 ori r3,r3,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
491 /*
492 * NOTE! We are assuming this is not an SMP system, otherwise
493 * we would need to update the pte atomically with lwarx/stwcx.
494 */
495 stw r3,0(r2) /* update PTE (accessed bit) */
496 /* Convert linux-style PTE to low word of PPC-style PTE */
497 rlwinm r1,r3,32-10,31,31 /* _PAGE_RW -> PP lsb */
498 rlwinm r2,r3,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
499 and r1,r1,r2 /* writable if _RW and _DIRTY */
500 rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
501 rlwimi r3,r3,32-1,31,31 /* _PAGE_USER -> PP lsb */
502 ori r1,r1,0xe14 /* clear out reserved bits and M */
503 andc r1,r3,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
504 mtspr SPRN_RPA,r1
505 mfspr r3,SPRN_IMISS
506 tlbli r3
507 mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
508 mtcrf 0x80,r3
509 rfi
510InstructionAddressInvalid:
511 mfspr r3,SPRN_SRR1
512 rlwinm r1,r3,9,6,6 /* Get load/store bit */
513
514 addis r1,r1,0x2000
515 mtspr SPRN_DSISR,r1 /* (shouldn't be needed) */
516 mtctr r0 /* Restore CTR */
517 andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
518 or r2,r2,r1
519 mtspr SPRN_SRR1,r2
520 mfspr r1,SPRN_IMISS /* Get failing address */
521 rlwinm. r2,r2,0,31,31 /* Check for little endian access */
522 rlwimi r2,r2,1,30,30 /* change 1 -> 3 */
523 xor r1,r1,r2
524 mtspr SPRN_DAR,r1 /* Set fault address */
525 mfmsr r0 /* Restore "normal" registers */
526 xoris r0,r0,MSR_TGPR>>16
527 mtcrf 0x80,r3 /* Restore CR0 */
528 mtmsr r0
529 b InstructionAccess
530
531/*
532 * Handle TLB miss for DATA Load operation on 603/603e
533 */
534 . = 0x1100
535DataLoadTLBMiss:
536/*
537 * r0: stored ctr
538 * r1: linux style pte ( later becomes ppc hardware pte )
539 * r2: ptr to linux-style pte
540 * r3: scratch
541 */
542 mfctr r0
543 /* Get PTE (linux-style) and check access */
544 mfspr r3,SPRN_DMISS
545 lis r1,KERNELBASE@h /* check if kernel address */
546 cmplw 0,r3,r1
547 mfspr r2,SPRN_SPRG3
548 li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
549 lwz r2,PGDIR(r2)
550 blt+ 112f
551 lis r2,swapper_pg_dir@ha /* if kernel address, use */
552 addi r2,r2,swapper_pg_dir@l /* kernel page table */
553 mfspr r1,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
554 rlwinm r1,r1,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
555112: tophys(r2,r2)
556 rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
557 lwz r2,0(r2) /* get pmd entry */
558 rlwinm. r2,r2,0,0,19 /* extract address of pte page */
559 beq- DataAddressInvalid /* return if no mapping */
560 rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
561 lwz r3,0(r2) /* get linux-style pte */
562 andc. r1,r1,r3 /* check access & ~permission */
563 bne- DataAddressInvalid /* return if access not permitted */
564 ori r3,r3,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
565 /*
566 * NOTE! We are assuming this is not an SMP system, otherwise
567 * we would need to update the pte atomically with lwarx/stwcx.
568 */
569 stw r3,0(r2) /* update PTE (accessed bit) */
570 /* Convert linux-style PTE to low word of PPC-style PTE */
571 rlwinm r1,r3,32-10,31,31 /* _PAGE_RW -> PP lsb */
572 rlwinm r2,r3,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
573 and r1,r1,r2 /* writable if _RW and _DIRTY */
574 rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
575 rlwimi r3,r3,32-1,31,31 /* _PAGE_USER -> PP lsb */
576 ori r1,r1,0xe14 /* clear out reserved bits and M */
577 andc r1,r3,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
578 mtspr SPRN_RPA,r1
579 mfspr r3,SPRN_DMISS
580 tlbld r3
581 mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
582 mtcrf 0x80,r3
583 rfi
584DataAddressInvalid:
585 mfspr r3,SPRN_SRR1
586 rlwinm r1,r3,9,6,6 /* Get load/store bit */
587 addis r1,r1,0x2000
588 mtspr SPRN_DSISR,r1
589 mtctr r0 /* Restore CTR */
590 andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
591 mtspr SPRN_SRR1,r2
592 mfspr r1,SPRN_DMISS /* Get failing address */
593 rlwinm. r2,r2,0,31,31 /* Check for little endian access */
594 beq 20f /* Jump if big endian */
595 xori r1,r1,3
59620: mtspr SPRN_DAR,r1 /* Set fault address */
597 mfmsr r0 /* Restore "normal" registers */
598 xoris r0,r0,MSR_TGPR>>16
599 mtcrf 0x80,r3 /* Restore CR0 */
600 mtmsr r0
601 b DataAccess
602
603/*
604 * Handle TLB miss for DATA Store on 603/603e
605 */
606 . = 0x1200
607DataStoreTLBMiss:
608/*
609 * r0: stored ctr
610 * r1: linux style pte ( later becomes ppc hardware pte )
611 * r2: ptr to linux-style pte
612 * r3: scratch
613 */
614 mfctr r0
615 /* Get PTE (linux-style) and check access */
616 mfspr r3,SPRN_DMISS
617 lis r1,KERNELBASE@h /* check if kernel address */
618 cmplw 0,r3,r1
619 mfspr r2,SPRN_SPRG3
620 li r1,_PAGE_RW|_PAGE_USER|_PAGE_PRESENT /* access flags */
621 lwz r2,PGDIR(r2)
622 blt+ 112f
623 lis r2,swapper_pg_dir@ha /* if kernel address, use */
624 addi r2,r2,swapper_pg_dir@l /* kernel page table */
625 mfspr r1,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
626 rlwinm r1,r1,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
627112: tophys(r2,r2)
628 rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
629 lwz r2,0(r2) /* get pmd entry */
630 rlwinm. r2,r2,0,0,19 /* extract address of pte page */
631 beq- DataAddressInvalid /* return if no mapping */
632 rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
633 lwz r3,0(r2) /* get linux-style pte */
634 andc. r1,r1,r3 /* check access & ~permission */
635 bne- DataAddressInvalid /* return if access not permitted */
636 ori r3,r3,_PAGE_ACCESSED|_PAGE_DIRTY
637 /*
638 * NOTE! We are assuming this is not an SMP system, otherwise
639 * we would need to update the pte atomically with lwarx/stwcx.
640 */
641 stw r3,0(r2) /* update PTE (accessed/dirty bits) */
642 /* Convert linux-style PTE to low word of PPC-style PTE */
643 rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
644 li r1,0xe15 /* clear out reserved bits and M */
645 andc r1,r3,r1 /* PP = user? 2: 0 */
646 mtspr SPRN_RPA,r1
647 mfspr r3,SPRN_DMISS
648 tlbld r3
649 mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
650 mtcrf 0x80,r3
651 rfi
652
653#ifndef CONFIG_ALTIVEC
654#define altivec_assist_exception unknown_exception
655#endif
656
657 EXCEPTION(0x1300, Trap_13, instruction_breakpoint_exception, EXC_XFER_EE)
658 EXCEPTION(0x1400, SMI, SMIException, EXC_XFER_EE)
659 EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
660 EXCEPTION(0x1600, Trap_16, altivec_assist_exception, EXC_XFER_EE)
661 EXCEPTION(0x1700, Trap_17, TAUException, EXC_XFER_STD)
662 EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_EE)
663 EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_EE)
664 EXCEPTION(0x1a00, Trap_1a, unknown_exception, EXC_XFER_EE)
665 EXCEPTION(0x1b00, Trap_1b, unknown_exception, EXC_XFER_EE)
666 EXCEPTION(0x1c00, Trap_1c, unknown_exception, EXC_XFER_EE)
667 EXCEPTION(0x1d00, Trap_1d, unknown_exception, EXC_XFER_EE)
668 EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_EE)
669 EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_EE)
670 EXCEPTION(0x2000, RunMode, RunModeException, EXC_XFER_EE)
671 EXCEPTION(0x2100, Trap_21, unknown_exception, EXC_XFER_EE)
672 EXCEPTION(0x2200, Trap_22, unknown_exception, EXC_XFER_EE)
673 EXCEPTION(0x2300, Trap_23, unknown_exception, EXC_XFER_EE)
674 EXCEPTION(0x2400, Trap_24, unknown_exception, EXC_XFER_EE)
675 EXCEPTION(0x2500, Trap_25, unknown_exception, EXC_XFER_EE)
676 EXCEPTION(0x2600, Trap_26, unknown_exception, EXC_XFER_EE)
677 EXCEPTION(0x2700, Trap_27, unknown_exception, EXC_XFER_EE)
678 EXCEPTION(0x2800, Trap_28, unknown_exception, EXC_XFER_EE)
679 EXCEPTION(0x2900, Trap_29, unknown_exception, EXC_XFER_EE)
680 EXCEPTION(0x2a00, Trap_2a, unknown_exception, EXC_XFER_EE)
681 EXCEPTION(0x2b00, Trap_2b, unknown_exception, EXC_XFER_EE)
682 EXCEPTION(0x2c00, Trap_2c, unknown_exception, EXC_XFER_EE)
683 EXCEPTION(0x2d00, Trap_2d, unknown_exception, EXC_XFER_EE)
684 EXCEPTION(0x2e00, Trap_2e, unknown_exception, EXC_XFER_EE)
685 EXCEPTION(0x2f00, MOLTrampoline, unknown_exception, EXC_XFER_EE_LITE)
686
687 .globl mol_trampoline
688 .set mol_trampoline, i0x2f00
689
690 . = 0x3000
691
692AltiVecUnavailable:
693 EXCEPTION_PROLOG
694#ifdef CONFIG_ALTIVEC
695 bne load_up_altivec /* if from user, just load it up */
696#endif /* CONFIG_ALTIVEC */
697 EXC_XFER_EE_LITE(0xf20, altivec_unavailable_exception)
698
699#ifdef CONFIG_ALTIVEC
700/* Note that the AltiVec support is closely modeled after the FP
701 * support. Changes to one are likely to be applicable to the
702 * other! */
703load_up_altivec:
704/*
705 * Disable AltiVec for the task which had AltiVec previously,
706 * and save its AltiVec registers in its thread_struct.
707 * Enables AltiVec for use in the kernel on return.
708 * On SMP we know the AltiVec units are free, since we give it up every
709 * switch. -- Kumar
710 */
711 mfmsr r5
712 oris r5,r5,MSR_VEC@h
713 MTMSRD(r5) /* enable use of AltiVec now */
714 isync
715/*
716 * For SMP, we don't do lazy AltiVec switching because it just gets too
717 * horrendously complex, especially when a task switches from one CPU
718 * to another. Instead we call giveup_altivec in switch_to.
719 */
720#ifndef CONFIG_SMP
721 tophys(r6,0)
722 addis r3,r6,last_task_used_altivec@ha
723 lwz r4,last_task_used_altivec@l(r3)
724 cmpwi 0,r4,0
725 beq 1f
726 add r4,r4,r6
727 addi r4,r4,THREAD /* want THREAD of last_task_used_altivec */
728 SAVE_32VRS(0,r10,r4)
729 mfvscr vr0
730 li r10,THREAD_VSCR
731 stvx vr0,r10,r4
732 lwz r5,PT_REGS(r4)
733 add r5,r5,r6
734 lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
735 lis r10,MSR_VEC@h
736 andc r4,r4,r10 /* disable altivec for previous task */
737 stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
7381:
739#endif /* CONFIG_SMP */
740 /* enable use of AltiVec after return */
741 oris r9,r9,MSR_VEC@h
742 mfspr r5,SPRN_SPRG3 /* current task's THREAD (phys) */
743 li r4,1
744 li r10,THREAD_VSCR
745 stw r4,THREAD_USED_VR(r5)
746 lvx vr0,r10,r5
747 mtvscr vr0
748 REST_32VRS(0,r10,r5)
749#ifndef CONFIG_SMP
750 subi r4,r5,THREAD
751 sub r4,r4,r6
752 stw r4,last_task_used_altivec@l(r3)
753#endif /* CONFIG_SMP */
754 /* restore registers and return */
755 /* we haven't used ctr or xer or lr */
756 b fast_exception_return
757
758/*
759 * AltiVec unavailable trap from kernel - print a message, but let
760 * the task use AltiVec in the kernel until it returns to user mode.
761 */
762KernelAltiVec:
763 lwz r3,_MSR(r1)
764 oris r3,r3,MSR_VEC@h
765 stw r3,_MSR(r1) /* enable use of AltiVec after return */
766 lis r3,87f@h
767 ori r3,r3,87f@l
768 mr r4,r2 /* current */
769 lwz r5,_NIP(r1)
770 bl printk
771 b ret_from_except
77287: .string "AltiVec used in kernel (task=%p, pc=%x) \n"
773 .align 4,0
774
775/*
776 * giveup_altivec(tsk)
777 * Disable AltiVec for the task given as the argument,
778 * and save the AltiVec registers in its thread_struct.
779 * Enables AltiVec for use in the kernel on return.
780 */
781
782 .globl giveup_altivec
783giveup_altivec:
784 mfmsr r5
785 oris r5,r5,MSR_VEC@h
786 SYNC
787 MTMSRD(r5) /* enable use of AltiVec now */
788 isync
789 cmpwi 0,r3,0
790 beqlr- /* if no previous owner, done */
791 addi r3,r3,THREAD /* want THREAD of task */
792 lwz r5,PT_REGS(r3)
793 cmpwi 0,r5,0
794 SAVE_32VRS(0, r4, r3)
795 mfvscr vr0
796 li r4,THREAD_VSCR
797 stvx vr0,r4,r3
798 beq 1f
799 lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
800 lis r3,MSR_VEC@h
801 andc r4,r4,r3 /* disable AltiVec for previous task */
802 stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
8031:
804#ifndef CONFIG_SMP
805 li r5,0
806 lis r4,last_task_used_altivec@ha
807 stw r5,last_task_used_altivec@l(r4)
808#endif /* CONFIG_SMP */
809 blr
810#endif /* CONFIG_ALTIVEC */
811
812/*
813 * This code is jumped to from the startup code to copy
814 * the kernel image to physical address 0.
815 */
816relocate_kernel:
817 addis r9,r26,klimit@ha /* fetch klimit */
818 lwz r25,klimit@l(r9)
819 addis r25,r25,-KERNELBASE@h
820 li r3,0 /* Destination base address */
821 li r6,0 /* Destination offset */
822 li r5,0x4000 /* # bytes of memory to copy */
823 bl copy_and_flush /* copy the first 0x4000 bytes */
824 addi r0,r3,4f@l /* jump to the address of 4f */
825 mtctr r0 /* in copy and do the rest. */
826 bctr /* jump to the copy */
8274: mr r5,r25
828 bl copy_and_flush /* copy the rest */
829 b turn_on_mmu
830
831/*
832 * Copy routine used to copy the kernel to start at physical address 0
833 * and flush and invalidate the caches as needed.
834 * r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset
835 * on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5.
836 */
837copy_and_flush:
838 addi r5,r5,-4
839 addi r6,r6,-4
8404: li r0,L1_CACHE_LINE_SIZE/4
841 mtctr r0
8423: addi r6,r6,4 /* copy a cache line */
843 lwzx r0,r6,r4
844 stwx r0,r6,r3
845 bdnz 3b
846 dcbst r6,r3 /* write it to memory */
847 sync
848 icbi r6,r3 /* flush the icache line */
849 cmplw 0,r6,r5
850 blt 4b
851 sync /* additional sync needed on g4 */
852 isync
853 addi r5,r5,4
854 addi r6,r6,4
855 blr
856
857#ifdef CONFIG_APUS
858/*
859 * On APUS the physical base address of the kernel is not known at compile
860 * time, which means the __pa/__va constants used are incorrect. In the
861 * __init section is recorded the virtual addresses of instructions using
862 * these constants, so all that has to be done is fix these before
863 * continuing the kernel boot.
864 *
865 * r4 = The physical address of the kernel base.
866 */
867fix_mem_constants:
868 mr r10,r4
869 addis r10,r10,-KERNELBASE@h /* virt_to_phys constant */
870 neg r11,r10 /* phys_to_virt constant */
871
872 lis r12,__vtop_table_begin@h
873 ori r12,r12,__vtop_table_begin@l
874 add r12,r12,r10 /* table begin phys address */
875 lis r13,__vtop_table_end@h
876 ori r13,r13,__vtop_table_end@l
877 add r13,r13,r10 /* table end phys address */
878 subi r12,r12,4
879 subi r13,r13,4
8801: lwzu r14,4(r12) /* virt address of instruction */
881 add r14,r14,r10 /* phys address of instruction */
882 lwz r15,0(r14) /* instruction, now insert top */
883 rlwimi r15,r10,16,16,31 /* half of vp const in low half */
884 stw r15,0(r14) /* of instruction and restore. */
885 dcbst r0,r14 /* write it to memory */
886 sync
887 icbi r0,r14 /* flush the icache line */
888 cmpw r12,r13
889 bne 1b
890 sync /* additional sync needed on g4 */
891 isync
892
893/*
894 * Map the memory where the exception handlers will
895 * be copied to when hash constants have been patched.
896 */
897#ifdef CONFIG_APUS_FAST_EXCEPT
898 lis r8,0xfff0
899#else
900 lis r8,0
901#endif
902 ori r8,r8,0x2 /* 128KB, supervisor */
903 mtspr SPRN_DBAT3U,r8
904 mtspr SPRN_DBAT3L,r8
905
906 lis r12,__ptov_table_begin@h
907 ori r12,r12,__ptov_table_begin@l
908 add r12,r12,r10 /* table begin phys address */
909 lis r13,__ptov_table_end@h
910 ori r13,r13,__ptov_table_end@l
911 add r13,r13,r10 /* table end phys address */
912 subi r12,r12,4
913 subi r13,r13,4
9141: lwzu r14,4(r12) /* virt address of instruction */
915 add r14,r14,r10 /* phys address of instruction */
916 lwz r15,0(r14) /* instruction, now insert top */
917 rlwimi r15,r11,16,16,31 /* half of pv const in low half*/
918 stw r15,0(r14) /* of instruction and restore. */
919 dcbst r0,r14 /* write it to memory */
920 sync
921 icbi r0,r14 /* flush the icache line */
922 cmpw r12,r13
923 bne 1b
924
925 sync /* additional sync needed on g4 */
926 isync /* No speculative loading until now */
927 blr
928
929/***********************************************************************
930 * Please note that on APUS the exception handlers are located at the
931 * physical address 0xfff0000. For this reason, the exception handlers
932 * cannot use relative branches to access the code below.
933 ***********************************************************************/
934#endif /* CONFIG_APUS */
935
936#ifdef CONFIG_SMP
937#ifdef CONFIG_GEMINI
938 .globl __secondary_start_gemini
939__secondary_start_gemini:
940 mfspr r4,SPRN_HID0
941 ori r4,r4,HID0_ICFI
942 li r3,0
943 ori r3,r3,HID0_ICE
944 andc r4,r4,r3
945 mtspr SPRN_HID0,r4
946 sync
947 b __secondary_start
948#endif /* CONFIG_GEMINI */
949
950 .globl __secondary_start_pmac_0
951__secondary_start_pmac_0:
952 /* NB the entries for cpus 0, 1, 2 must each occupy 8 bytes. */
953 li r24,0
954 b 1f
955 li r24,1
956 b 1f
957 li r24,2
958 b 1f
959 li r24,3
9601:
961 /* on powersurge, we come in here with IR=0 and DR=1, and DBAT 0
962 set to map the 0xf0000000 - 0xffffffff region */
963 mfmsr r0
964 rlwinm r0,r0,0,28,26 /* clear DR (0x10) */
965 SYNC
966 mtmsr r0
967 isync
968
969 .globl __secondary_start
970__secondary_start:
971 /* Copy some CPU settings from CPU 0 */
972 bl __restore_cpu_setup
973
974 lis r3,-KERNELBASE@h
975 mr r4,r24
976 bl call_setup_cpu /* Call setup_cpu for this CPU */
977#ifdef CONFIG_6xx
978 lis r3,-KERNELBASE@h
979 bl init_idle_6xx
980#endif /* CONFIG_6xx */
981
982 /* get current_thread_info and current */
983 lis r1,secondary_ti@ha
984 tophys(r1,r1)
985 lwz r1,secondary_ti@l(r1)
986 tophys(r2,r1)
987 lwz r2,TI_TASK(r2)
988
989 /* stack */
990 addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
991 li r0,0
992 tophys(r3,r1)
993 stw r0,0(r3)
994
995 /* load up the MMU */
996 bl load_up_mmu
997
998 /* ptr to phys current thread */
999 tophys(r4,r2)
1000 addi r4,r4,THREAD /* phys address of our thread_struct */
1001 CLR_TOP32(r4)
1002 mtspr SPRN_SPRG3,r4
1003 li r3,0
1004 mtspr SPRN_SPRG2,r3 /* 0 => not in RTAS */
1005
1006 /* enable MMU and jump to start_secondary */
1007 li r4,MSR_KERNEL
1008 FIX_SRR1(r4,r5)
1009 lis r3,start_secondary@h
1010 ori r3,r3,start_secondary@l
1011 mtspr SPRN_SRR0,r3
1012 mtspr SPRN_SRR1,r4
1013 SYNC
1014 RFI
1015#endif /* CONFIG_SMP */
1016
1017/*
1018 * Those generic dummy functions are kept for CPUs not
1019 * included in CONFIG_6xx
1020 */
1021#if !defined(CONFIG_6xx)
1022_GLOBAL(__save_cpu_setup)
1023 blr
1024_GLOBAL(__restore_cpu_setup)
1025 blr
1026#endif /* !defined(CONFIG_6xx) */
1027
1028
1029/*
1030 * Load stuff into the MMU. Intended to be called with
1031 * IR=0 and DR=0.
1032 */
1033load_up_mmu:
1034 sync /* Force all PTE updates to finish */
1035 isync
1036 tlbia /* Clear all TLB entries */
1037 sync /* wait for tlbia/tlbie to finish */
1038 TLBSYNC /* ... on all CPUs */
1039 /* Load the SDR1 register (hash table base & size) */
1040 lis r6,_SDR1@ha
1041 tophys(r6,r6)
1042 lwz r6,_SDR1@l(r6)
1043 mtspr SPRN_SDR1,r6
1044 li r0,16 /* load up segment register values */
1045 mtctr r0 /* for context 0 */
1046 lis r3,0x2000 /* Ku = 1, VSID = 0 */
1047 li r4,0
10483: mtsrin r3,r4
1049 addi r3,r3,0x111 /* increment VSID */
1050 addis r4,r4,0x1000 /* address of next segment */
1051 bdnz 3b
1052
1053/* Load the BAT registers with the values set up by MMU_init.
1054 MMU_init takes care of whether we're on a 601 or not. */
1055 mfpvr r3
1056 srwi r3,r3,16
1057 cmpwi r3,1
1058 lis r3,BATS@ha
1059 addi r3,r3,BATS@l
1060 tophys(r3,r3)
1061 LOAD_BAT(0,r3,r4,r5)
1062 LOAD_BAT(1,r3,r4,r5)
1063 LOAD_BAT(2,r3,r4,r5)
1064 LOAD_BAT(3,r3,r4,r5)
1065
1066 blr
1067
1068/*
1069 * This is where the main kernel code starts.
1070 */
1071start_here:
1072 /* ptr to current */
1073 lis r2,init_task@h
1074 ori r2,r2,init_task@l
1075 /* Set up for using our exception vectors */
1076 /* ptr to phys current thread */
1077 tophys(r4,r2)
1078 addi r4,r4,THREAD /* init task's THREAD */
1079 CLR_TOP32(r4)
1080 mtspr SPRN_SPRG3,r4
1081 li r3,0
1082 mtspr SPRN_SPRG2,r3 /* 0 => not in RTAS */
1083
1084 /* stack */
1085 lis r1,init_thread_union@ha
1086 addi r1,r1,init_thread_union@l
1087 li r0,0
1088 stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
1089/*
1090 * Do early platform-specific initialization,
1091 * and set up the MMU.
1092 */
1093 mr r3,r31
1094 mr r4,r30
1095 bl machine_init
1096 bl MMU_init
1097
1098#ifdef CONFIG_APUS
1099 /* Copy exception code to exception vector base on APUS. */
1100 lis r4,KERNELBASE@h
1101#ifdef CONFIG_APUS_FAST_EXCEPT
1102 lis r3,0xfff0 /* Copy to 0xfff00000 */
1103#else
1104 lis r3,0 /* Copy to 0x00000000 */
1105#endif
1106 li r5,0x4000 /* # bytes of memory to copy */
1107 li r6,0
1108 bl copy_and_flush /* copy the first 0x4000 bytes */
1109#endif /* CONFIG_APUS */
1110
1111/*
1112 * Go back to running unmapped so we can load up new values
1113 * for SDR1 (hash table pointer) and the segment registers
1114 * and change to using our exception vectors.
1115 */
1116 lis r4,2f@h
1117 ori r4,r4,2f@l
1118 tophys(r4,r4)
1119 li r3,MSR_KERNEL & ~(MSR_IR|MSR_DR)
1120 FIX_SRR1(r3,r5)
1121 mtspr SPRN_SRR0,r4
1122 mtspr SPRN_SRR1,r3
1123 SYNC
1124 RFI
1125/* Load up the kernel context */
11262: bl load_up_mmu
1127
1128#ifdef CONFIG_BDI_SWITCH
1129 /* Add helper information for the Abatron bdiGDB debugger.
1130 * We do this here because we know the mmu is disabled, and
1131 * will be enabled for real in just a few instructions.
1132 */
1133 lis r5, abatron_pteptrs@h
1134 ori r5, r5, abatron_pteptrs@l
1135 stw r5, 0xf0(r0) /* This much match your Abatron config */
1136 lis r6, swapper_pg_dir@h
1137 ori r6, r6, swapper_pg_dir@l
1138 tophys(r5, r5)
1139 stw r6, 0(r5)
1140#endif /* CONFIG_BDI_SWITCH */
1141
1142/* Now turn on the MMU for real! */
1143 li r4,MSR_KERNEL
1144 FIX_SRR1(r4,r5)
1145 lis r3,start_kernel@h
1146 ori r3,r3,start_kernel@l
1147 mtspr SPRN_SRR0,r3
1148 mtspr SPRN_SRR1,r4
1149 SYNC
1150 RFI
1151
1152/*
1153 * Set up the segment registers for a new context.
1154 */
1155_GLOBAL(set_context)
1156 mulli r3,r3,897 /* multiply context by skew factor */
1157 rlwinm r3,r3,4,8,27 /* VSID = (context & 0xfffff) << 4 */
1158 addis r3,r3,0x6000 /* Set Ks, Ku bits */
1159 li r0,NUM_USER_SEGMENTS
1160 mtctr r0
1161
1162#ifdef CONFIG_BDI_SWITCH
1163 /* Context switch the PTE pointer for the Abatron BDI2000.
1164 * The PGDIR is passed as second argument.
1165 */
1166 lis r5, KERNELBASE@h
1167 lwz r5, 0xf0(r5)
1168 stw r4, 0x4(r5)
1169#endif
1170 li r4,0
1171 isync
11723:
1173 mtsrin r3,r4
1174 addi r3,r3,0x111 /* next VSID */
1175 rlwinm r3,r3,0,8,3 /* clear out any overflow from VSID field */
1176 addis r4,r4,0x1000 /* address of next segment */
1177 bdnz 3b
1178 sync
1179 isync
1180 blr
1181
1182/*
1183 * An undocumented "feature" of 604e requires that the v bit
1184 * be cleared before changing BAT values.
1185 *
1186 * Also, newer IBM firmware does not clear bat3 and 4 so
1187 * this makes sure it's done.
1188 * -- Cort
1189 */
1190clear_bats:
1191 li r10,0
1192 mfspr r9,SPRN_PVR
1193 rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
1194 cmpwi r9, 1
1195 beq 1f
1196
1197 mtspr SPRN_DBAT0U,r10
1198 mtspr SPRN_DBAT0L,r10
1199 mtspr SPRN_DBAT1U,r10
1200 mtspr SPRN_DBAT1L,r10
1201 mtspr SPRN_DBAT2U,r10
1202 mtspr SPRN_DBAT2L,r10
1203 mtspr SPRN_DBAT3U,r10
1204 mtspr SPRN_DBAT3L,r10
12051:
1206 mtspr SPRN_IBAT0U,r10
1207 mtspr SPRN_IBAT0L,r10
1208 mtspr SPRN_IBAT1U,r10
1209 mtspr SPRN_IBAT1L,r10
1210 mtspr SPRN_IBAT2U,r10
1211 mtspr SPRN_IBAT2L,r10
1212 mtspr SPRN_IBAT3U,r10
1213 mtspr SPRN_IBAT3L,r10
1214BEGIN_FTR_SECTION
1215 /* Here's a tweak: at this point, CPU setup have
1216 * not been called yet, so HIGH_BAT_EN may not be
1217 * set in HID0 for the 745x processors. However, it
1218 * seems that doesn't affect our ability to actually
1219 * write to these SPRs.
1220 */
1221 mtspr SPRN_DBAT4U,r10
1222 mtspr SPRN_DBAT4L,r10
1223 mtspr SPRN_DBAT5U,r10
1224 mtspr SPRN_DBAT5L,r10
1225 mtspr SPRN_DBAT6U,r10
1226 mtspr SPRN_DBAT6L,r10
1227 mtspr SPRN_DBAT7U,r10
1228 mtspr SPRN_DBAT7L,r10
1229 mtspr SPRN_IBAT4U,r10
1230 mtspr SPRN_IBAT4L,r10
1231 mtspr SPRN_IBAT5U,r10
1232 mtspr SPRN_IBAT5L,r10
1233 mtspr SPRN_IBAT6U,r10
1234 mtspr SPRN_IBAT6L,r10
1235 mtspr SPRN_IBAT7U,r10
1236 mtspr SPRN_IBAT7L,r10
1237END_FTR_SECTION_IFSET(CPU_FTR_HAS_HIGH_BATS)
1238 blr
1239
1240flush_tlbs:
1241 lis r10, 0x40
12421: addic. r10, r10, -0x1000
1243 tlbie r10
1244 blt 1b
1245 sync
1246 blr
1247
1248mmu_off:
1249 addi r4, r3, __after_mmu_off - _start
1250 mfmsr r3
1251 andi. r0,r3,MSR_DR|MSR_IR /* MMU enabled? */
1252 beqlr
1253 andc r3,r3,r0
1254 mtspr SPRN_SRR0,r4
1255 mtspr SPRN_SRR1,r3
1256 sync
1257 RFI
1258
1259/*
1260 * Use the first pair of BAT registers to map the 1st 16MB
1261 * of RAM to KERNELBASE. From this point on we can't safely
1262 * call OF any more.
1263 */
1264initial_bats:
1265 lis r11,KERNELBASE@h
1266 mfspr r9,SPRN_PVR
1267 rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
1268 cmpwi 0,r9,1
1269 bne 4f
1270 ori r11,r11,4 /* set up BAT registers for 601 */
1271 li r8,0x7f /* valid, block length = 8MB */
1272 oris r9,r11,0x800000@h /* set up BAT reg for 2nd 8M */
1273 oris r10,r8,0x800000@h /* set up BAT reg for 2nd 8M */
1274 mtspr SPRN_IBAT0U,r11 /* N.B. 601 has valid bit in */
1275 mtspr SPRN_IBAT0L,r8 /* lower BAT register */
1276 mtspr SPRN_IBAT1U,r9
1277 mtspr SPRN_IBAT1L,r10
1278 isync
1279 blr
1280
12814: tophys(r8,r11)
1282#ifdef CONFIG_SMP
1283 ori r8,r8,0x12 /* R/W access, M=1 */
1284#else
1285 ori r8,r8,2 /* R/W access */
1286#endif /* CONFIG_SMP */
1287#ifdef CONFIG_APUS
1288 ori r11,r11,BL_8M<<2|0x2 /* set up 8MB BAT registers for 604 */
1289#else
1290 ori r11,r11,BL_256M<<2|0x2 /* set up BAT registers for 604 */
1291#endif /* CONFIG_APUS */
1292
1293 mtspr SPRN_DBAT0L,r8 /* N.B. 6xx (not 601) have valid */
1294 mtspr SPRN_DBAT0U,r11 /* bit in upper BAT register */
1295 mtspr SPRN_IBAT0L,r8
1296 mtspr SPRN_IBAT0U,r11
1297 isync
1298 blr
1299
1300#if !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT)
1301setup_disp_bat:
1302 /*
1303 * setup the display bat prepared for us in prom.c
1304 */
1305 mflr r8
1306 bl reloc_offset
1307 mtlr r8
1308 addis r8,r3,disp_BAT@ha
1309 addi r8,r8,disp_BAT@l
1310 lwz r11,0(r8)
1311 lwz r8,4(r8)
1312 mfspr r9,SPRN_PVR
1313 rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
1314 cmpwi 0,r9,1
1315 beq 1f
1316 mtspr SPRN_DBAT3L,r8
1317 mtspr SPRN_DBAT3U,r11
1318 blr
13191: mtspr SPRN_IBAT3L,r8
1320 mtspr SPRN_IBAT3U,r11
1321 blr
1322
1323#endif /* !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT) */
1324
1325
1326#ifdef CONFIG_8260
1327/* Jump into the system reset for the rom.
1328 * We first disable the MMU, and then jump to the ROM reset address.
1329 *
1330 * r3 is the board info structure, r4 is the location for starting.
1331 * I use this for building a small kernel that can load other kernels,
1332 * rather than trying to write or rely on a rom monitor that can tftp load.
1333 */
1334 .globl m8260_gorom
1335m8260_gorom:
1336 mfmsr r0
1337 rlwinm r0,r0,0,17,15 /* clear MSR_EE in r0 */
1338 sync
1339 mtmsr r0
1340 sync
1341 mfspr r11, SPRN_HID0
1342 lis r10, 0
1343 ori r10,r10,HID0_ICE|HID0_DCE
1344 andc r11, r11, r10
1345 mtspr SPRN_HID0, r11
1346 isync
1347 li r5, MSR_ME|MSR_RI
1348 lis r6,2f@h
1349 addis r6,r6,-KERNELBASE@h
1350 ori r6,r6,2f@l
1351 mtspr SPRN_SRR0,r6
1352 mtspr SPRN_SRR1,r5
1353 isync
1354 sync
1355 rfi
13562:
1357 mtlr r4
1358 blr
1359#endif
1360
1361
1362/*
1363 * We put a few things here that have to be page-aligned.
1364 * This stuff goes at the beginning of the data segment,
1365 * which is page-aligned.
1366 */
1367 .data
1368 .globl sdata
1369sdata:
1370 .globl empty_zero_page
1371empty_zero_page:
1372 .space 4096
1373
1374 .globl swapper_pg_dir
1375swapper_pg_dir:
1376 .space 4096
1377
1378/*
1379 * This space gets a copy of optional info passed to us by the bootstrap
1380 * Used to pass parameters into the kernel like root=/dev/sda1, etc.
1381 */
1382 .globl cmd_line
1383cmd_line:
1384 .space 512
1385
1386 .globl intercept_table
1387intercept_table:
1388 .long 0, 0, i0x200, i0x300, i0x400, 0, i0x600, i0x700
1389 .long i0x800, 0, 0, 0, 0, i0xd00, 0, 0
1390 .long 0, 0, 0, i0x1300, 0, 0, 0, 0
1391 .long 0, 0, 0, 0, 0, 0, 0, 0
1392 .long 0, 0, 0, 0, 0, 0, 0, 0
1393 .long 0, 0, 0, 0, 0, 0, 0, 0
1394
1395/* Room for two PTE pointers, usually the kernel and current user pointers
1396 * to their respective root page table.
1397 */
1398abatron_pteptrs:
1399 .space 8
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-20 04:26:51 -0500