3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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).
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.)
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.
25 #include <asm/processor.h>
28 #include <asm/pgtable.h>
29 #include <asm/cputable.h>
30 #include <asm/cache.h>
31 #include <asm/thread_info.h>
32 #include <asm/ppc_asm.h>
33 #include <asm/asm-offsets.h>
35 /* 601 only have IBAT; cr0.eq is set on 601 when using this macro */
36 #define LOAD_BAT(n, reg, RA, RB) \
37 /* see the comment for clear_bats() -- Cort */ \
39 mtspr SPRN_IBAT##n##U,RA; \
40 mtspr SPRN_DBAT##n##U,RA; \
41 lwz RA,(n*16)+0(reg); \
42 lwz RB,(n*16)+4(reg); \
43 mtspr SPRN_IBAT##n##U,RA; \
44 mtspr SPRN_IBAT##n##L,RB; \
46 lwz RA,(n*16)+8(reg); \
47 lwz RB,(n*16)+12(reg); \
48 mtspr SPRN_DBAT##n##U,RA; \
49 mtspr SPRN_DBAT##n##L,RB; \
53 .stabs "arch/ppc/kernel/",N_SO,0,0,0f
54 .stabs "head.S",N_SO,0,0,0f
60 * _start is defined this way because the XCOFF loader in the OpenFirmware
61 * on the powermac expects the entry point to be a procedure descriptor.
67 * These are here for legacy reasons, the kernel used to
68 * need to look like a coff function entry for the pmac
69 * but we're always started by some kind of bootloader now.
72 nop /* used by __secondary_hold on prep (mtx) and chrp smp */
73 nop /* used by __secondary_hold on prep (mtx) and chrp smp */
77 * Enter here with the kernel text, data and bss loaded starting at
78 * 0, running with virtual == physical mapping.
79 * r5 points to the prom entry point (the client interface handler
80 * address). Address translation is turned on, with the prom
81 * managing the hash table. Interrupts are disabled. The stack
82 * pointer (r1) points to just below the end of the half-meg region
83 * from 0x380000 - 0x400000, which is mapped in already.
85 * If we are booted from MacOS via BootX, we enter with the kernel
86 * image loaded somewhere, and the following values in registers:
87 * r3: 'BooX' (0x426f6f58)
88 * r4: virtual address of boot_infos_t
93 * r4: physical address of memory base
94 * Linux/m68k style BootInfo structure at &_end.
97 * This is jumped to on prep systems right after the kernel is relocated
98 * to its proper place in memory by the boot loader. The expected layout
100 * r3: ptr to residual data
101 * r4: initrd_start or if no initrd then 0
102 * r5: initrd_end - unused if r4 is 0
103 * r6: Start of command line string
104 * r7: End of command line string
106 * This just gets a minimal mmu environment setup so we can call
107 * start_here() to do the real work.
113 mr r31,r3 /* save parameters */
121 * early_init() does the early machine identification and does
122 * the necessary low-level setup and clears the BSS
123 * -- Cort <cort@fsmlabs.com>
127 /* Switch MMU off, clear BATs and flush TLB. At this point, r3 contains
128 * the physical address we are running at, returned by early_init()
136 #ifdef CONFIG_BOOTX_TEXT
141 * Call setup_cpu for CPU 0 and initialize 6xx Idle
145 bl call_setup_cpu /* Call setup_cpu for this CPU */
149 #endif /* CONFIG_6xx */
153 * We need to run with _start at physical address 0.
154 * If the MMU is already turned on, we copy stuff to KERNELBASE,
155 * otherwise we copy it to 0.
159 addis r4,r3,KERNELBASE@h /* current address of _start */
160 cmpwi 0,r4,0 /* are we already running at 0? */
164 * we now have the 1st 16M of ram mapped with the bats.
165 * prep needs the mmu to be turned on here, but pmac already has it on.
166 * this shouldn't bother the pmac since it just gets turned on again
167 * as we jump to our code at KERNELBASE. -- Cort
168 * Actually no, pmac doesn't have it on any more. BootX enters with MMU
169 * off, and in other cases, we now turn it off before changing BATs above.
173 ori r0,r0,MSR_DR|MSR_IR
176 ori r0,r0,start_here@l
179 RFI /* enables MMU */
182 * We need __secondary_hold as a place to hold the other cpus on
183 * an SMP machine, even when we are running a UP kernel.
185 . = 0xc0 /* for prep bootloader */
186 li r3,1 /* MTX only has 1 cpu */
187 .globl __secondary_hold
189 /* tell the master we're here */
193 /* wait until we're told to start */
196 /* our cpu # was at addr 0 - go */
197 mr r24,r3 /* cpu # */
201 #endif /* CONFIG_SMP */
204 * Exception entry code. This code runs with address translation
205 * turned off, i.e. using physical addresses.
206 * We assume sprg3 has the physical address of the current
207 * task's thread_struct.
209 #define EXCEPTION_PROLOG \
210 mtspr SPRN_SPRG0,r10; \
211 mtspr SPRN_SPRG1,r11; \
213 EXCEPTION_PROLOG_1; \
216 #define EXCEPTION_PROLOG_1 \
217 mfspr r11,SPRN_SRR1; /* check whether user or kernel */ \
218 andi. r11,r11,MSR_PR; \
219 tophys(r11,r1); /* use tophys(r1) if kernel */ \
221 mfspr r11,SPRN_SPRG3; \
222 lwz r11,THREAD_INFO-THREAD(r11); \
223 addi r11,r11,THREAD_SIZE; \
225 1: subi r11,r11,INT_FRAME_SIZE /* alloc exc. frame */
228 #define EXCEPTION_PROLOG_2 \
230 stw r10,_CCR(r11); /* save registers */ \
231 stw r12,GPR12(r11); \
233 mfspr r10,SPRN_SPRG0; \
234 stw r10,GPR10(r11); \
235 mfspr r12,SPRN_SPRG1; \
236 stw r12,GPR11(r11); \
238 stw r10,_LINK(r11); \
239 mfspr r12,SPRN_SRR0; \
240 mfspr r9,SPRN_SRR1; \
243 tovirt(r1,r11); /* set new kernel sp */ \
244 li r10,MSR_KERNEL & ~(MSR_IR|MSR_DR); /* can take exceptions */ \
245 MTMSRD(r10); /* (except for mach check in rtas) */ \
247 SAVE_4GPRS(3, r11); \
251 * Note: code which follows this uses cr0.eq (set if from kernel),
252 * r11, r12 (SRR0), and r9 (SRR1).
254 * Note2: once we have set r1 we are in a position to take exceptions
255 * again, and we could thus set MSR:RI at that point.
261 #define EXCEPTION(n, label, hdlr, xfer) \
265 addi r3,r1,STACK_FRAME_OVERHEAD; \
268 #define EXC_XFER_TEMPLATE(n, hdlr, trap, copyee, tfer, ret) \
278 #define COPY_EE(d, s) rlwimi d,s,0,16,16
281 #define EXC_XFER_STD(n, hdlr) \
282 EXC_XFER_TEMPLATE(n, hdlr, n, NOCOPY, transfer_to_handler_full, \
283 ret_from_except_full)
285 #define EXC_XFER_LITE(n, hdlr) \
286 EXC_XFER_TEMPLATE(n, hdlr, n+1, NOCOPY, transfer_to_handler, \
289 #define EXC_XFER_EE(n, hdlr) \
290 EXC_XFER_TEMPLATE(n, hdlr, n, COPY_EE, transfer_to_handler_full, \
291 ret_from_except_full)
293 #define EXC_XFER_EE_LITE(n, hdlr) \
294 EXC_XFER_TEMPLATE(n, hdlr, n+1, COPY_EE, transfer_to_handler, \
298 /* core99 pmac starts the seconary here by changing the vector, and
299 putting it back to what it was (unknown_exception) when done. */
300 EXCEPTION(0x100, Reset, unknown_exception, EXC_XFER_STD)
308 7: EXCEPTION_PROLOG_2
309 addi r3,r1,STACK_FRAME_OVERHEAD
310 EXC_XFER_STD(0x200, machine_check_exception)
312 /* Data access exception. */
317 andis. r0,r10,0xa470 /* weird error? */
318 bne 1f /* if not, try to put a PTE */
319 mfspr r4,SPRN_DAR /* into the hash table */
320 rlwinm r3,r10,32-15,21,21 /* DSISR_STORE -> _PAGE_RW */
322 1: stw r10,_DSISR(r11)
325 EXC_XFER_EE_LITE(0x300, handle_page_fault)
327 /* Instruction access exception. */
331 andis. r0,r9,0x4000 /* no pte found? */
332 beq 1f /* if so, try to put a PTE */
333 li r3,0 /* into the hash table */
334 mr r4,r12 /* SRR0 is fault address */
338 EXC_XFER_EE_LITE(0x400, handle_page_fault)
340 /* External interrupt */
341 EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
343 /* Alignment exception */
351 addi r3,r1,STACK_FRAME_OVERHEAD
352 EXC_XFER_EE(0x600, alignment_exception)
354 /* Program check exception */
355 EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
357 /* Floating-point unavailable */
361 bne load_up_fpu /* if from user, just load it up */
362 addi r3,r1,STACK_FRAME_OVERHEAD
363 EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
366 EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
368 EXCEPTION(0xa00, Trap_0a, unknown_exception, EXC_XFER_EE)
369 EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_EE)
375 EXC_XFER_EE_LITE(0xc00, DoSyscall)
377 /* Single step - not used on 601 */
378 EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD)
379 EXCEPTION(0xe00, Trap_0e, unknown_exception, EXC_XFER_EE)
382 * The Altivec unavailable trap is at 0x0f20. Foo.
383 * We effectively remap it to 0x3000.
384 * We include an altivec unavailable exception vector even if
385 * not configured for Altivec, so that you can't panic a
386 * non-altivec kernel running on a machine with altivec just
387 * by executing an altivec instruction.
397 addi r3,r1,STACK_FRAME_OVERHEAD
398 EXC_XFER_EE(0xf00, unknown_exception)
401 * Handle TLB miss for instruction on 603/603e.
402 * Note: we get an alternate set of r0 - r3 to use automatically.
408 * r1: linux style pte ( later becomes ppc hardware pte )
409 * r2: ptr to linux-style pte
413 /* Get PTE (linux-style) and check access */
415 lis r1,KERNELBASE@h /* check if kernel address */
418 li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
421 lis r2,swapper_pg_dir@ha /* if kernel address, use */
422 addi r2,r2,swapper_pg_dir@l /* kernel page table */
423 mfspr r1,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
424 rlwinm r1,r1,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
426 rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
427 lwz r2,0(r2) /* get pmd entry */
428 rlwinm. r2,r2,0,0,19 /* extract address of pte page */
429 beq- InstructionAddressInvalid /* return if no mapping */
430 rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
431 lwz r3,0(r2) /* get linux-style pte */
432 andc. r1,r1,r3 /* check access & ~permission */
433 bne- InstructionAddressInvalid /* return if access not permitted */
434 ori r3,r3,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
436 * NOTE! We are assuming this is not an SMP system, otherwise
437 * we would need to update the pte atomically with lwarx/stwcx.
439 stw r3,0(r2) /* update PTE (accessed bit) */
440 /* Convert linux-style PTE to low word of PPC-style PTE */
441 rlwinm r1,r3,32-10,31,31 /* _PAGE_RW -> PP lsb */
442 rlwinm r2,r3,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
443 and r1,r1,r2 /* writable if _RW and _DIRTY */
444 rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
445 rlwimi r3,r3,32-1,31,31 /* _PAGE_USER -> PP lsb */
446 ori r1,r1,0xe14 /* clear out reserved bits and M */
447 andc r1,r3,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
451 mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
454 InstructionAddressInvalid:
456 rlwinm r1,r3,9,6,6 /* Get load/store bit */
459 mtspr SPRN_DSISR,r1 /* (shouldn't be needed) */
460 mtctr r0 /* Restore CTR */
461 andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
464 mfspr r1,SPRN_IMISS /* Get failing address */
465 rlwinm. r2,r2,0,31,31 /* Check for little endian access */
466 rlwimi r2,r2,1,30,30 /* change 1 -> 3 */
468 mtspr SPRN_DAR,r1 /* Set fault address */
469 mfmsr r0 /* Restore "normal" registers */
470 xoris r0,r0,MSR_TGPR>>16
471 mtcrf 0x80,r3 /* Restore CR0 */
476 * Handle TLB miss for DATA Load operation on 603/603e
482 * r1: linux style pte ( later becomes ppc hardware pte )
483 * r2: ptr to linux-style pte
487 /* Get PTE (linux-style) and check access */
489 lis r1,KERNELBASE@h /* check if kernel address */
492 li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
495 lis r2,swapper_pg_dir@ha /* if kernel address, use */
496 addi r2,r2,swapper_pg_dir@l /* kernel page table */
497 mfspr r1,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
498 rlwinm r1,r1,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
500 rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
501 lwz r2,0(r2) /* get pmd entry */
502 rlwinm. r2,r2,0,0,19 /* extract address of pte page */
503 beq- DataAddressInvalid /* return if no mapping */
504 rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
505 lwz r3,0(r2) /* get linux-style pte */
506 andc. r1,r1,r3 /* check access & ~permission */
507 bne- DataAddressInvalid /* return if access not permitted */
508 ori r3,r3,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
510 * NOTE! We are assuming this is not an SMP system, otherwise
511 * we would need to update the pte atomically with lwarx/stwcx.
513 stw r3,0(r2) /* update PTE (accessed bit) */
514 /* Convert linux-style PTE to low word of PPC-style PTE */
515 rlwinm r1,r3,32-10,31,31 /* _PAGE_RW -> PP lsb */
516 rlwinm r2,r3,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
517 and r1,r1,r2 /* writable if _RW and _DIRTY */
518 rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
519 rlwimi r3,r3,32-1,31,31 /* _PAGE_USER -> PP lsb */
520 ori r1,r1,0xe14 /* clear out reserved bits and M */
521 andc r1,r3,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
525 mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
530 rlwinm r1,r3,9,6,6 /* Get load/store bit */
533 mtctr r0 /* Restore CTR */
534 andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
536 mfspr r1,SPRN_DMISS /* Get failing address */
537 rlwinm. r2,r2,0,31,31 /* Check for little endian access */
538 beq 20f /* Jump if big endian */
540 20: mtspr SPRN_DAR,r1 /* Set fault address */
541 mfmsr r0 /* Restore "normal" registers */
542 xoris r0,r0,MSR_TGPR>>16
543 mtcrf 0x80,r3 /* Restore CR0 */
548 * Handle TLB miss for DATA Store on 603/603e
554 * r1: linux style pte ( later becomes ppc hardware pte )
555 * r2: ptr to linux-style pte
559 /* Get PTE (linux-style) and check access */
561 lis r1,KERNELBASE@h /* check if kernel address */
564 li r1,_PAGE_RW|_PAGE_USER|_PAGE_PRESENT /* access flags */
567 lis r2,swapper_pg_dir@ha /* if kernel address, use */
568 addi r2,r2,swapper_pg_dir@l /* kernel page table */
569 mfspr r1,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
570 rlwinm r1,r1,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
572 rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
573 lwz r2,0(r2) /* get pmd entry */
574 rlwinm. r2,r2,0,0,19 /* extract address of pte page */
575 beq- DataAddressInvalid /* return if no mapping */
576 rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
577 lwz r3,0(r2) /* get linux-style pte */
578 andc. r1,r1,r3 /* check access & ~permission */
579 bne- DataAddressInvalid /* return if access not permitted */
580 ori r3,r3,_PAGE_ACCESSED|_PAGE_DIRTY
582 * NOTE! We are assuming this is not an SMP system, otherwise
583 * we would need to update the pte atomically with lwarx/stwcx.
585 stw r3,0(r2) /* update PTE (accessed/dirty bits) */
586 /* Convert linux-style PTE to low word of PPC-style PTE */
587 rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
588 li r1,0xe15 /* clear out reserved bits and M */
589 andc r1,r3,r1 /* PP = user? 2: 0 */
593 mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
597 #ifndef CONFIG_ALTIVEC
598 #define altivec_assist_exception unknown_exception
601 EXCEPTION(0x1300, Trap_13, instruction_breakpoint_exception, EXC_XFER_EE)
602 EXCEPTION(0x1400, SMI, SMIException, EXC_XFER_EE)
603 EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
604 EXCEPTION(0x1600, Trap_16, altivec_assist_exception, EXC_XFER_EE)
605 EXCEPTION(0x1700, Trap_17, TAUException, EXC_XFER_STD)
606 EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_EE)
607 EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_EE)
608 EXCEPTION(0x1a00, Trap_1a, unknown_exception, EXC_XFER_EE)
609 EXCEPTION(0x1b00, Trap_1b, unknown_exception, EXC_XFER_EE)
610 EXCEPTION(0x1c00, Trap_1c, unknown_exception, EXC_XFER_EE)
611 EXCEPTION(0x1d00, Trap_1d, unknown_exception, EXC_XFER_EE)
612 EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_EE)
613 EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_EE)
614 EXCEPTION(0x2000, RunMode, RunModeException, EXC_XFER_EE)
615 EXCEPTION(0x2100, Trap_21, unknown_exception, EXC_XFER_EE)
616 EXCEPTION(0x2200, Trap_22, unknown_exception, EXC_XFER_EE)
617 EXCEPTION(0x2300, Trap_23, unknown_exception, EXC_XFER_EE)
618 EXCEPTION(0x2400, Trap_24, unknown_exception, EXC_XFER_EE)
619 EXCEPTION(0x2500, Trap_25, unknown_exception, EXC_XFER_EE)
620 EXCEPTION(0x2600, Trap_26, unknown_exception, EXC_XFER_EE)
621 EXCEPTION(0x2700, Trap_27, unknown_exception, EXC_XFER_EE)
622 EXCEPTION(0x2800, Trap_28, unknown_exception, EXC_XFER_EE)
623 EXCEPTION(0x2900, Trap_29, unknown_exception, EXC_XFER_EE)
624 EXCEPTION(0x2a00, Trap_2a, unknown_exception, EXC_XFER_EE)
625 EXCEPTION(0x2b00, Trap_2b, unknown_exception, EXC_XFER_EE)
626 EXCEPTION(0x2c00, Trap_2c, unknown_exception, EXC_XFER_EE)
627 EXCEPTION(0x2d00, Trap_2d, unknown_exception, EXC_XFER_EE)
628 EXCEPTION(0x2e00, Trap_2e, unknown_exception, EXC_XFER_EE)
629 EXCEPTION(0x2f00, MOLTrampoline, unknown_exception, EXC_XFER_EE_LITE)
631 .globl mol_trampoline
632 .set mol_trampoline, i0x2f00
638 #ifdef CONFIG_ALTIVEC
639 bne load_up_altivec /* if from user, just load it up */
640 #endif /* CONFIG_ALTIVEC */
641 addi r3,r1,STACK_FRAME_OVERHEAD
642 EXC_XFER_EE_LITE(0xf20, altivec_unavailable_exception)
644 #ifdef CONFIG_ALTIVEC
645 /* Note that the AltiVec support is closely modeled after the FP
646 * support. Changes to one are likely to be applicable to the
650 * Disable AltiVec for the task which had AltiVec previously,
651 * and save its AltiVec registers in its thread_struct.
652 * Enables AltiVec for use in the kernel on return.
653 * On SMP we know the AltiVec units are free, since we give it up every
658 MTMSRD(r5) /* enable use of AltiVec now */
661 * For SMP, we don't do lazy AltiVec switching because it just gets too
662 * horrendously complex, especially when a task switches from one CPU
663 * to another. Instead we call giveup_altivec in switch_to.
667 addis r3,r6,last_task_used_altivec@ha
668 lwz r4,last_task_used_altivec@l(r3)
672 addi r4,r4,THREAD /* want THREAD of last_task_used_altivec */
679 lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
681 andc r4,r4,r10 /* disable altivec for previous task */
682 stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
684 #endif /* CONFIG_SMP */
685 /* enable use of AltiVec after return */
687 mfspr r5,SPRN_SPRG3 /* current task's THREAD (phys) */
690 stw r4,THREAD_USED_VR(r5)
697 stw r4,last_task_used_altivec@l(r3)
698 #endif /* CONFIG_SMP */
699 /* restore registers and return */
700 /* we haven't used ctr or xer or lr */
701 b fast_exception_return
704 * AltiVec unavailable trap from kernel - print a message, but let
705 * the task use AltiVec in the kernel until it returns to user mode.
710 stw r3,_MSR(r1) /* enable use of AltiVec after return */
713 mr r4,r2 /* current */
717 87: .string "AltiVec used in kernel (task=%p, pc=%x) \n"
721 * giveup_altivec(tsk)
722 * Disable AltiVec for the task given as the argument,
723 * and save the AltiVec registers in its thread_struct.
724 * Enables AltiVec for use in the kernel on return.
727 .globl giveup_altivec
732 MTMSRD(r5) /* enable use of AltiVec now */
735 beqlr- /* if no previous owner, done */
736 addi r3,r3,THREAD /* want THREAD of task */
739 SAVE_32VRS(0, r4, r3)
744 lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
746 andc r4,r4,r3 /* disable AltiVec for previous task */
747 stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
751 lis r4,last_task_used_altivec@ha
752 stw r5,last_task_used_altivec@l(r4)
753 #endif /* CONFIG_SMP */
755 #endif /* CONFIG_ALTIVEC */
758 * This code is jumped to from the startup code to copy
759 * the kernel image to physical address 0.
762 addis r9,r26,klimit@ha /* fetch klimit */
764 addis r25,r25,-KERNELBASE@h
765 li r3,0 /* Destination base address */
766 li r6,0 /* Destination offset */
767 li r5,0x4000 /* # bytes of memory to copy */
768 bl copy_and_flush /* copy the first 0x4000 bytes */
769 addi r0,r3,4f@l /* jump to the address of 4f */
770 mtctr r0 /* in copy and do the rest. */
771 bctr /* jump to the copy */
773 bl copy_and_flush /* copy the rest */
777 * Copy routine used to copy the kernel to start at physical address 0
778 * and flush and invalidate the caches as needed.
779 * r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset
780 * on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5.
785 4: li r0,L1_CACHE_BYTES/4
787 3: addi r6,r6,4 /* copy a cache line */
791 dcbst r6,r3 /* write it to memory */
793 icbi r6,r3 /* flush the icache line */
796 sync /* additional sync needed on g4 */
803 .globl __secondary_start_pmac_0
804 __secondary_start_pmac_0:
805 /* NB the entries for cpus 0, 1, 2 must each occupy 8 bytes. */
814 /* on powersurge, we come in here with IR=0 and DR=1, and DBAT 0
815 set to map the 0xf0000000 - 0xffffffff region */
817 rlwinm r0,r0,0,28,26 /* clear DR (0x10) */
822 .globl __secondary_start
824 /* Copy some CPU settings from CPU 0 */
825 bl __restore_cpu_setup
829 bl call_setup_cpu /* Call setup_cpu for this CPU */
833 #endif /* CONFIG_6xx */
835 /* get current_thread_info and current */
836 lis r1,secondary_ti@ha
838 lwz r1,secondary_ti@l(r1)
843 addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
848 /* load up the MMU */
851 /* ptr to phys current thread */
853 addi r4,r4,THREAD /* phys address of our thread_struct */
857 mtspr SPRN_SPRG2,r3 /* 0 => not in RTAS */
859 /* enable MMU and jump to start_secondary */
862 lis r3,start_secondary@h
863 ori r3,r3,start_secondary@l
868 #endif /* CONFIG_SMP */
871 * Those generic dummy functions are kept for CPUs not
872 * included in CONFIG_6xx
874 #if !defined(CONFIG_6xx)
875 _GLOBAL(__save_cpu_setup)
877 _GLOBAL(__restore_cpu_setup)
879 #endif /* !defined(CONFIG_6xx) */
883 * Load stuff into the MMU. Intended to be called with
887 sync /* Force all PTE updates to finish */
889 tlbia /* Clear all TLB entries */
890 sync /* wait for tlbia/tlbie to finish */
891 TLBSYNC /* ... on all CPUs */
892 /* Load the SDR1 register (hash table base & size) */
897 li r0,16 /* load up segment register values */
898 mtctr r0 /* for context 0 */
899 lis r3,0x2000 /* Ku = 1, VSID = 0 */
902 addi r3,r3,0x111 /* increment VSID */
903 addis r4,r4,0x1000 /* address of next segment */
906 /* Load the BAT registers with the values set up by MMU_init.
907 MMU_init takes care of whether we're on a 601 or not. */
922 * This is where the main kernel code starts.
927 ori r2,r2,init_task@l
928 /* Set up for using our exception vectors */
929 /* ptr to phys current thread */
931 addi r4,r4,THREAD /* init task's THREAD */
935 mtspr SPRN_SPRG2,r3 /* 0 => not in RTAS */
938 lis r1,init_thread_union@ha
939 addi r1,r1,init_thread_union@l
941 stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
943 * Do early bootinfo parsing, platform-specific initialization,
944 * and set up the MMU.
955 * Go back to running unmapped so we can load up new values
956 * for SDR1 (hash table pointer) and the segment registers
957 * and change to using our exception vectors.
962 li r3,MSR_KERNEL & ~(MSR_IR|MSR_DR)
968 /* Load up the kernel context */
971 #ifdef CONFIG_BDI_SWITCH
972 /* Add helper information for the Abatron bdiGDB debugger.
973 * We do this here because we know the mmu is disabled, and
974 * will be enabled for real in just a few instructions.
976 lis r5, abatron_pteptrs@h
977 ori r5, r5, abatron_pteptrs@l
978 stw r5, 0xf0(r0) /* This much match your Abatron config */
979 lis r6, swapper_pg_dir@h
980 ori r6, r6, swapper_pg_dir@l
983 #endif /* CONFIG_BDI_SWITCH */
985 /* Now turn on the MMU for real! */
988 lis r3,start_kernel@h
989 ori r3,r3,start_kernel@l
996 * Set up the segment registers for a new context.
999 mulli r3,r3,897 /* multiply context by skew factor */
1000 rlwinm r3,r3,4,8,27 /* VSID = (context & 0xfffff) << 4 */
1001 addis r3,r3,0x6000 /* Set Ks, Ku bits */
1002 li r0,NUM_USER_SEGMENTS
1005 #ifdef CONFIG_BDI_SWITCH
1006 /* Context switch the PTE pointer for the Abatron BDI2000.
1007 * The PGDIR is passed as second argument.
1009 lis r5, KERNELBASE@h
1017 addi r3,r3,0x111 /* next VSID */
1018 rlwinm r3,r3,0,8,3 /* clear out any overflow from VSID field */
1019 addis r4,r4,0x1000 /* address of next segment */
1026 * An undocumented "feature" of 604e requires that the v bit
1027 * be cleared before changing BAT values.
1029 * Also, newer IBM firmware does not clear bat3 and 4 so
1030 * this makes sure it's done.
1036 rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
1040 mtspr SPRN_DBAT0U,r10
1041 mtspr SPRN_DBAT0L,r10
1042 mtspr SPRN_DBAT1U,r10
1043 mtspr SPRN_DBAT1L,r10
1044 mtspr SPRN_DBAT2U,r10
1045 mtspr SPRN_DBAT2L,r10
1046 mtspr SPRN_DBAT3U,r10
1047 mtspr SPRN_DBAT3L,r10
1049 mtspr SPRN_IBAT0U,r10
1050 mtspr SPRN_IBAT0L,r10
1051 mtspr SPRN_IBAT1U,r10
1052 mtspr SPRN_IBAT1L,r10
1053 mtspr SPRN_IBAT2U,r10
1054 mtspr SPRN_IBAT2L,r10
1055 mtspr SPRN_IBAT3U,r10
1056 mtspr SPRN_IBAT3L,r10
1058 /* Here's a tweak: at this point, CPU setup have
1059 * not been called yet, so HIGH_BAT_EN may not be
1060 * set in HID0 for the 745x processors. However, it
1061 * seems that doesn't affect our ability to actually
1062 * write to these SPRs.
1064 mtspr SPRN_DBAT4U,r10
1065 mtspr SPRN_DBAT4L,r10
1066 mtspr SPRN_DBAT5U,r10
1067 mtspr SPRN_DBAT5L,r10
1068 mtspr SPRN_DBAT6U,r10
1069 mtspr SPRN_DBAT6L,r10
1070 mtspr SPRN_DBAT7U,r10
1071 mtspr SPRN_DBAT7L,r10
1072 mtspr SPRN_IBAT4U,r10
1073 mtspr SPRN_IBAT4L,r10
1074 mtspr SPRN_IBAT5U,r10
1075 mtspr SPRN_IBAT5L,r10
1076 mtspr SPRN_IBAT6U,r10
1077 mtspr SPRN_IBAT6L,r10
1078 mtspr SPRN_IBAT7U,r10
1079 mtspr SPRN_IBAT7L,r10
1080 END_FTR_SECTION_IFSET(CPU_FTR_HAS_HIGH_BATS)
1085 1: addic. r10, r10, -0x1000
1092 addi r4, r3, __after_mmu_off - _start
1094 andi. r0,r3,MSR_DR|MSR_IR /* MMU enabled? */
1103 * Use the first pair of BAT registers to map the 1st 16MB
1104 * of RAM to KERNELBASE. From this point on we can't safely
1108 lis r11,KERNELBASE@h
1110 rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
1113 ori r11,r11,4 /* set up BAT registers for 601 */
1114 li r8,0x7f /* valid, block length = 8MB */
1115 oris r9,r11,0x800000@h /* set up BAT reg for 2nd 8M */
1116 oris r10,r8,0x800000@h /* set up BAT reg for 2nd 8M */
1117 mtspr SPRN_IBAT0U,r11 /* N.B. 601 has valid bit in */
1118 mtspr SPRN_IBAT0L,r8 /* lower BAT register */
1119 mtspr SPRN_IBAT1U,r9
1120 mtspr SPRN_IBAT1L,r10
1126 ori r8,r8,0x12 /* R/W access, M=1 */
1128 ori r8,r8,2 /* R/W access */
1129 #endif /* CONFIG_SMP */
1130 ori r11,r11,BL_256M<<2|0x2 /* set up BAT registers for 604 */
1132 mtspr SPRN_DBAT0L,r8 /* N.B. 6xx (not 601) have valid */
1133 mtspr SPRN_DBAT0U,r11 /* bit in upper BAT register */
1134 mtspr SPRN_IBAT0L,r8
1135 mtspr SPRN_IBAT0U,r11
1139 #ifdef CONFIG_BOOTX_TEXT
1142 * setup the display bat prepared for us in prom.c
1147 addis r8,r3,disp_BAT@ha
1148 addi r8,r8,disp_BAT@l
1152 rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
1155 mtspr SPRN_DBAT3L,r8
1156 mtspr SPRN_DBAT3U,r11
1158 1: mtspr SPRN_IBAT3L,r8
1159 mtspr SPRN_IBAT3U,r11
1162 #endif /* defined(CONFIG_BOOTX_TEXT) */
1165 /* Jump into the system reset for the rom.
1166 * We first disable the MMU, and then jump to the ROM reset address.
1168 * r3 is the board info structure, r4 is the location for starting.
1169 * I use this for building a small kernel that can load other kernels,
1170 * rather than trying to write or rely on a rom monitor that can tftp load.
1175 rlwinm r0,r0,0,17,15 /* clear MSR_EE in r0 */
1179 mfspr r11, SPRN_HID0
1181 ori r10,r10,HID0_ICE|HID0_DCE
1183 mtspr SPRN_HID0, r11
1185 li r5, MSR_ME|MSR_RI
1187 addis r6,r6,-KERNELBASE@h
1201 * We put a few things here that have to be page-aligned.
1202 * This stuff goes at the beginning of the data segment,
1203 * which is page-aligned.
1208 .globl empty_zero_page
1212 .globl swapper_pg_dir
1217 * This space gets a copy of optional info passed to us by the bootstrap
1218 * Used to pass parameters into the kernel like root=/dev/sda1, etc.
1224 .globl intercept_table
1226 .long 0, 0, i0x200, i0x300, i0x400, 0, i0x600, i0x700
1227 .long i0x800, 0, 0, 0, 0, i0xd00, 0, 0
1228 .long 0, 0, 0, i0x1300, 0, 0, 0, 0
1229 .long 0, 0, 0, 0, 0, 0, 0, 0
1230 .long 0, 0, 0, 0, 0, 0, 0, 0
1231 .long 0, 0, 0, 0, 0, 0, 0, 0
1233 /* Room for two PTE pointers, usually the kernel and current user pointers
1234 * to their respective root page table.