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).
13 * This file contains the low-level support and setup for the
14 * PowerPC platform, including trap and interrupt dispatch.
15 * (The PPC 8xx embedded CPUs use head_8xx.S instead.)
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version
20 * 2 of the License, or (at your option) any later version.
24 #include <linux/init.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>
34 #include <asm/ptrace.h>
37 /* 601 only have IBAT; cr0.eq is set on 601 when using this macro */
38 #define LOAD_BAT(n, reg, RA, RB) \
39 /* see the comment for clear_bats() -- Cort */ \
41 mtspr SPRN_IBAT##n##U,RA; \
42 mtspr SPRN_DBAT##n##U,RA; \
43 lwz RA,(n*16)+0(reg); \
44 lwz RB,(n*16)+4(reg); \
45 mtspr SPRN_IBAT##n##U,RA; \
46 mtspr SPRN_IBAT##n##L,RB; \
48 lwz RA,(n*16)+8(reg); \
49 lwz RB,(n*16)+12(reg); \
50 mtspr SPRN_DBAT##n##U,RA; \
51 mtspr SPRN_DBAT##n##L,RB; \
55 .stabs "arch/powerpc/kernel/",N_SO,0,0,0f
56 .stabs "head_32.S",N_SO,0,0,0f
61 * _start is defined this way because the XCOFF loader in the OpenFirmware
62 * on the powermac expects the entry point to be a procedure descriptor.
66 * These are here for legacy reasons, the kernel used to
67 * need to look like a coff function entry for the pmac
68 * but we're always started by some kind of bootloader now.
71 nop /* used by __secondary_hold on prep (mtx) and chrp smp */
72 nop /* used by __secondary_hold on prep (mtx) and chrp smp */
76 * Enter here with the kernel text, data and bss loaded starting at
77 * 0, running with virtual == physical mapping.
78 * r5 points to the prom entry point (the client interface handler
79 * address). Address translation is turned on, with the prom
80 * managing the hash table. Interrupts are disabled. The stack
81 * pointer (r1) points to just below the end of the half-meg region
82 * from 0x380000 - 0x400000, which is mapped in already.
84 * If we are booted from MacOS via BootX, we enter with the kernel
85 * image loaded somewhere, and the following values in registers:
86 * r3: 'BooX' (0x426f6f58)
87 * r4: virtual address of boot_infos_t
91 * This is jumped to on prep systems right after the kernel is relocated
92 * to its proper place in memory by the boot loader. The expected layout
94 * r3: ptr to residual data
95 * r4: initrd_start or if no initrd then 0
96 * r5: initrd_end - unused if r4 is 0
97 * r6: Start of command line string
98 * r7: End of command line string
100 * This just gets a minimal mmu environment setup so we can call
101 * start_here() to do the real work.
108 * We have to do any OF calls before we map ourselves to KERNELBASE,
109 * because OF may have I/O devices mapped into that area
110 * (particularly on CHRP).
115 #ifdef CONFIG_PPC_OF_BOOT_TRAMPOLINE
116 /* find out where we are now */
118 0: mflr r8 /* r8 = runtime addr here */
119 addis r8,r8,(_stext - 0b)@ha
120 addi r8,r8,(_stext - 0b)@l /* current runtime base addr */
122 #endif /* CONFIG_PPC_OF_BOOT_TRAMPOLINE */
124 /* We never return. We also hit that trap if trying to boot
125 * from OF while CONFIG_PPC_OF_BOOT_TRAMPOLINE isn't selected */
129 * Check for BootX signature when supporting PowerMac and branch to
130 * appropriate trampoline if it's present
132 #ifdef CONFIG_PPC_PMAC
139 #endif /* CONFIG_PPC_PMAC */
141 1: mr r31,r3 /* save parameters */
146 * early_init() does the early machine identification and does
147 * the necessary low-level setup and clears the BSS
148 * -- Cort <cort@fsmlabs.com>
152 /* Switch MMU off, clear BATs and flush TLB. At this point, r3 contains
153 * the physical address we are running at, returned by early_init()
161 #if defined(CONFIG_BOOTX_TEXT)
164 #ifdef CONFIG_PPC_EARLY_DEBUG_CPM
169 * Call setup_cpu for CPU 0 and initialize 6xx Idle
173 bl call_setup_cpu /* Call setup_cpu for this CPU */
177 #endif /* CONFIG_6xx */
181 * We need to run with _start at physical address 0.
182 * On CHRP, we are loaded at 0x10000 since OF on CHRP uses
183 * the exception vectors at 0 (and therefore this copy
184 * overwrites OF's exception vectors with our own).
185 * The MMU is off at this point.
189 addis r4,r3,KERNELBASE@h /* current address of _start */
190 lis r5,PHYSICAL_START@h
191 cmplw 0,r4,r5 /* already running at PHYSICAL_START? */
194 * we now have the 1st 16M of ram mapped with the bats.
195 * prep needs the mmu to be turned on here, but pmac already has it on.
196 * this shouldn't bother the pmac since it just gets turned on again
197 * as we jump to our code at KERNELBASE. -- Cort
198 * Actually no, pmac doesn't have it on any more. BootX enters with MMU
199 * off, and in other cases, we now turn it off before changing BATs above.
203 ori r0,r0,MSR_DR|MSR_IR
206 ori r0,r0,start_here@l
209 RFI /* enables MMU */
212 * We need __secondary_hold as a place to hold the other cpus on
213 * an SMP machine, even when we are running a UP kernel.
215 . = 0xc0 /* for prep bootloader */
216 li r3,1 /* MTX only has 1 cpu */
217 .globl __secondary_hold
219 /* tell the master we're here */
220 stw r3,__secondary_hold_acknowledge@l(0)
223 /* wait until we're told to start */
226 /* our cpu # was at addr 0 - go */
227 mr r24,r3 /* cpu # */
231 #endif /* CONFIG_SMP */
233 .globl __secondary_hold_spinloop
234 __secondary_hold_spinloop:
236 .globl __secondary_hold_acknowledge
237 __secondary_hold_acknowledge:
241 * Exception entry code. This code runs with address translation
242 * turned off, i.e. using physical addresses.
243 * We assume sprg3 has the physical address of the current
244 * task's thread_struct.
246 #define EXCEPTION_PROLOG \
247 mtspr SPRN_SPRG0,r10; \
248 mtspr SPRN_SPRG1,r11; \
250 EXCEPTION_PROLOG_1; \
253 #define EXCEPTION_PROLOG_1 \
254 mfspr r11,SPRN_SRR1; /* check whether user or kernel */ \
255 andi. r11,r11,MSR_PR; \
256 tophys(r11,r1); /* use tophys(r1) if kernel */ \
258 mfspr r11,SPRN_SPRG3; \
259 lwz r11,THREAD_INFO-THREAD(r11); \
260 addi r11,r11,THREAD_SIZE; \
262 1: subi r11,r11,INT_FRAME_SIZE /* alloc exc. frame */
265 #define EXCEPTION_PROLOG_2 \
267 stw r10,_CCR(r11); /* save registers */ \
268 stw r12,GPR12(r11); \
270 mfspr r10,SPRN_SPRG0; \
271 stw r10,GPR10(r11); \
272 mfspr r12,SPRN_SPRG1; \
273 stw r12,GPR11(r11); \
275 stw r10,_LINK(r11); \
276 mfspr r12,SPRN_SRR0; \
277 mfspr r9,SPRN_SRR1; \
280 tovirt(r1,r11); /* set new kernel sp */ \
281 li r10,MSR_KERNEL & ~(MSR_IR|MSR_DR); /* can take exceptions */ \
282 MTMSRD(r10); /* (except for mach check in rtas) */ \
284 lis r10,STACK_FRAME_REGS_MARKER@ha; /* exception frame marker */ \
285 addi r10,r10,STACK_FRAME_REGS_MARKER@l; \
287 SAVE_4GPRS(3, r11); \
291 * Note: code which follows this uses cr0.eq (set if from kernel),
292 * r11, r12 (SRR0), and r9 (SRR1).
294 * Note2: once we have set r1 we are in a position to take exceptions
295 * again, and we could thus set MSR:RI at that point.
301 #define EXCEPTION(n, label, hdlr, xfer) \
305 addi r3,r1,STACK_FRAME_OVERHEAD; \
308 #define EXC_XFER_TEMPLATE(n, hdlr, trap, copyee, tfer, ret) \
310 stw r10,_TRAP(r11); \
318 #define COPY_EE(d, s) rlwimi d,s,0,16,16
321 #define EXC_XFER_STD(n, hdlr) \
322 EXC_XFER_TEMPLATE(n, hdlr, n, NOCOPY, transfer_to_handler_full, \
323 ret_from_except_full)
325 #define EXC_XFER_LITE(n, hdlr) \
326 EXC_XFER_TEMPLATE(n, hdlr, n+1, NOCOPY, transfer_to_handler, \
329 #define EXC_XFER_EE(n, hdlr) \
330 EXC_XFER_TEMPLATE(n, hdlr, n, COPY_EE, transfer_to_handler_full, \
331 ret_from_except_full)
333 #define EXC_XFER_EE_LITE(n, hdlr) \
334 EXC_XFER_TEMPLATE(n, hdlr, n+1, COPY_EE, transfer_to_handler, \
338 /* core99 pmac starts the seconary here by changing the vector, and
339 putting it back to what it was (unknown_exception) when done. */
340 EXCEPTION(0x100, Reset, unknown_exception, EXC_XFER_STD)
344 * On CHRP, this is complicated by the fact that we could get a
345 * machine check inside RTAS, and we have no guarantee that certain
346 * critical registers will have the values we expect. The set of
347 * registers that might have bad values includes all the GPRs
348 * and all the BATs. We indicate that we are in RTAS by putting
349 * a non-zero value, the address of the exception frame to use,
350 * in SPRG2. The machine check handler checks SPRG2 and uses its
351 * value if it is non-zero. If we ever needed to free up SPRG2,
352 * we could use a field in the thread_info or thread_struct instead.
353 * (Other exception handlers assume that r1 is a valid kernel stack
354 * pointer when we take an exception from supervisor mode.)
361 #ifdef CONFIG_PPC_CHRP
365 #endif /* CONFIG_PPC_CHRP */
367 7: EXCEPTION_PROLOG_2
368 addi r3,r1,STACK_FRAME_OVERHEAD
369 #ifdef CONFIG_PPC_CHRP
374 EXC_XFER_STD(0x200, machine_check_exception)
375 #ifdef CONFIG_PPC_CHRP
376 1: b machine_check_in_rtas
379 /* Data access exception. */
385 andis. r0,r10,0xa470 /* weird error? */
386 bne 1f /* if not, try to put a PTE */
387 mfspr r4,SPRN_DAR /* into the hash table */
388 rlwinm r3,r10,32-15,21,21 /* DSISR_STORE -> _PAGE_RW */
390 1: lwz r5,_DSISR(r11) /* get DSISR value */
392 EXC_XFER_EE_LITE(0x300, handle_page_fault)
395 /* Instruction access exception. */
399 andis. r0,r9,0x4000 /* no pte found? */
400 beq 1f /* if so, try to put a PTE */
401 li r3,0 /* into the hash table */
402 mr r4,r12 /* SRR0 is fault address */
406 EXC_XFER_EE_LITE(0x400, handle_page_fault)
408 /* External interrupt */
409 EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
411 /* Alignment exception */
419 addi r3,r1,STACK_FRAME_OVERHEAD
420 EXC_XFER_EE(0x600, alignment_exception)
422 /* Program check exception */
423 EXCEPTION(0x700, ProgramCheck, program_check_exception, EXC_XFER_STD)
425 /* Floating-point unavailable */
430 * Certain Freescale cores don't have a FPU and treat fp instructions
431 * as a FP Unavailable exception. Redirect to illegal/emulation handling.
434 END_FTR_SECTION_IFSET(CPU_FTR_FPU_UNAVAILABLE)
437 bl load_up_fpu /* if from user, just load it up */
438 b fast_exception_return
439 1: addi r3,r1,STACK_FRAME_OVERHEAD
440 EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
443 EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
445 EXCEPTION(0xa00, Trap_0a, unknown_exception, EXC_XFER_EE)
446 EXCEPTION(0xb00, Trap_0b, unknown_exception, EXC_XFER_EE)
452 EXC_XFER_EE_LITE(0xc00, DoSyscall)
454 /* Single step - not used on 601 */
455 EXCEPTION(0xd00, SingleStep, single_step_exception, EXC_XFER_STD)
456 EXCEPTION(0xe00, Trap_0e, unknown_exception, EXC_XFER_EE)
459 * The Altivec unavailable trap is at 0x0f20. Foo.
460 * We effectively remap it to 0x3000.
461 * We include an altivec unavailable exception vector even if
462 * not configured for Altivec, so that you can't panic a
463 * non-altivec kernel running on a machine with altivec just
464 * by executing an altivec instruction.
473 * Handle TLB miss for instruction on 603/603e.
474 * Note: we get an alternate set of r0 - r3 to use automatically.
480 * r1: linux style pte ( later becomes ppc hardware pte )
481 * r2: ptr to linux-style pte
484 /* Get PTE (linux-style) and check access */
486 lis r1,PAGE_OFFSET@h /* check if kernel address */
489 li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
492 mfspr r2,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
493 rlwimi r1,r2,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
494 lis r2,swapper_pg_dir@ha /* if kernel address, use */
495 addi r2,r2,swapper_pg_dir@l /* kernel page table */
497 rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
498 lwz r2,0(r2) /* get pmd entry */
499 rlwinm. r2,r2,0,0,19 /* extract address of pte page */
500 beq- InstructionAddressInvalid /* return if no mapping */
501 rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
502 lwz r0,0(r2) /* get linux-style pte */
503 andc. r1,r1,r0 /* check access & ~permission */
504 bne- InstructionAddressInvalid /* return if access not permitted */
505 ori r0,r0,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
507 * NOTE! We are assuming this is not an SMP system, otherwise
508 * we would need to update the pte atomically with lwarx/stwcx.
510 stw r0,0(r2) /* update PTE (accessed bit) */
511 /* Convert linux-style PTE to low word of PPC-style PTE */
512 rlwinm r1,r0,32-10,31,31 /* _PAGE_RW -> PP lsb */
513 rlwinm r2,r0,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
514 and r1,r1,r2 /* writable if _RW and _DIRTY */
515 rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */
516 rlwimi r0,r0,32-1,31,31 /* _PAGE_USER -> PP lsb */
517 ori r1,r1,0xe04 /* clear out reserved bits */
518 andc r1,r0,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
520 rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */
521 END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
524 mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
527 InstructionAddressInvalid:
529 rlwinm r1,r3,9,6,6 /* Get load/store bit */
532 mtspr SPRN_DSISR,r1 /* (shouldn't be needed) */
533 andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
536 mfspr r1,SPRN_IMISS /* Get failing address */
537 rlwinm. r2,r2,0,31,31 /* Check for little endian access */
538 rlwimi r2,r2,1,30,30 /* change 1 -> 3 */
540 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 Load operation on 603/603e
554 * r1: linux style pte ( later becomes ppc hardware pte )
555 * r2: ptr to linux-style pte
558 /* Get PTE (linux-style) and check access */
560 lis r1,PAGE_OFFSET@h /* check if kernel address */
563 li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
566 mfspr r2,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
567 rlwimi r1,r2,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
568 lis r2,swapper_pg_dir@ha /* if kernel address, use */
569 addi r2,r2,swapper_pg_dir@l /* kernel page table */
571 rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
572 lwz r2,0(r2) /* get pmd entry */
573 rlwinm. r2,r2,0,0,19 /* extract address of pte page */
574 beq- DataAddressInvalid /* return if no mapping */
575 rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
576 lwz r0,0(r2) /* get linux-style pte */
577 andc. r1,r1,r0 /* check access & ~permission */
578 bne- DataAddressInvalid /* return if access not permitted */
579 ori r0,r0,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
581 * NOTE! We are assuming this is not an SMP system, otherwise
582 * we would need to update the pte atomically with lwarx/stwcx.
584 stw r0,0(r2) /* update PTE (accessed bit) */
585 /* Convert linux-style PTE to low word of PPC-style PTE */
586 rlwinm r1,r0,32-10,31,31 /* _PAGE_RW -> PP lsb */
587 rlwinm r2,r0,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
588 and r1,r1,r2 /* writable if _RW and _DIRTY */
589 rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */
590 rlwimi r0,r0,32-1,31,31 /* _PAGE_USER -> PP lsb */
591 ori r1,r1,0xe04 /* clear out reserved bits */
592 andc r1,r0,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
594 rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */
595 END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
597 mfspr r2,SPRN_SRR1 /* Need to restore CR0 */
599 BEGIN_MMU_FTR_SECTION
602 rlwinm r2,r3,20,27,31 /* Get Address bits 15:19 */
608 rlwimi r2,r0,31-14,14,14
610 END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
615 rlwinm r1,r3,9,6,6 /* Get load/store bit */
618 andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
620 mfspr r1,SPRN_DMISS /* Get failing address */
621 rlwinm. r2,r2,0,31,31 /* Check for little endian access */
622 beq 20f /* Jump if big endian */
624 20: mtspr SPRN_DAR,r1 /* Set fault address */
625 mfmsr r0 /* Restore "normal" registers */
626 xoris r0,r0,MSR_TGPR>>16
627 mtcrf 0x80,r3 /* Restore CR0 */
632 * Handle TLB miss for DATA Store on 603/603e
638 * r1: linux style pte ( later becomes ppc hardware pte )
639 * r2: ptr to linux-style pte
642 /* Get PTE (linux-style) and check access */
644 lis r1,PAGE_OFFSET@h /* check if kernel address */
647 li r1,_PAGE_RW|_PAGE_USER|_PAGE_PRESENT /* access flags */
650 mfspr r2,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
651 rlwimi r1,r2,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
652 lis r2,swapper_pg_dir@ha /* if kernel address, use */
653 addi r2,r2,swapper_pg_dir@l /* kernel page table */
655 rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
656 lwz r2,0(r2) /* get pmd entry */
657 rlwinm. r2,r2,0,0,19 /* extract address of pte page */
658 beq- DataAddressInvalid /* return if no mapping */
659 rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
660 lwz r0,0(r2) /* get linux-style pte */
661 andc. r1,r1,r0 /* check access & ~permission */
662 bne- DataAddressInvalid /* return if access not permitted */
663 ori r0,r0,_PAGE_ACCESSED|_PAGE_DIRTY
665 * NOTE! We are assuming this is not an SMP system, otherwise
666 * we would need to update the pte atomically with lwarx/stwcx.
668 stw r0,0(r2) /* update PTE (accessed/dirty bits) */
669 /* Convert linux-style PTE to low word of PPC-style PTE */
670 rlwimi r0,r0,32-1,30,30 /* _PAGE_USER -> PP msb */
671 li r1,0xe05 /* clear out reserved bits & PP lsb */
672 andc r1,r0,r1 /* PP = user? 2: 0 */
674 rlwinm r1,r1,0,~_PAGE_COHERENT /* clear M (coherence not required) */
675 END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
677 mfspr r2,SPRN_SRR1 /* Need to restore CR0 */
679 BEGIN_MMU_FTR_SECTION
682 rlwinm r2,r3,20,27,31 /* Get Address bits 15:19 */
688 rlwimi r2,r0,31-14,14,14
690 END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
694 #ifndef CONFIG_ALTIVEC
695 #define altivec_assist_exception unknown_exception
698 EXCEPTION(0x1300, Trap_13, instruction_breakpoint_exception, EXC_XFER_EE)
699 EXCEPTION(0x1400, SMI, SMIException, EXC_XFER_EE)
700 EXCEPTION(0x1500, Trap_15, unknown_exception, EXC_XFER_EE)
701 EXCEPTION(0x1600, Trap_16, altivec_assist_exception, EXC_XFER_EE)
702 EXCEPTION(0x1700, Trap_17, TAUException, EXC_XFER_STD)
703 EXCEPTION(0x1800, Trap_18, unknown_exception, EXC_XFER_EE)
704 EXCEPTION(0x1900, Trap_19, unknown_exception, EXC_XFER_EE)
705 EXCEPTION(0x1a00, Trap_1a, unknown_exception, EXC_XFER_EE)
706 EXCEPTION(0x1b00, Trap_1b, unknown_exception, EXC_XFER_EE)
707 EXCEPTION(0x1c00, Trap_1c, unknown_exception, EXC_XFER_EE)
708 EXCEPTION(0x1d00, Trap_1d, unknown_exception, EXC_XFER_EE)
709 EXCEPTION(0x1e00, Trap_1e, unknown_exception, EXC_XFER_EE)
710 EXCEPTION(0x1f00, Trap_1f, unknown_exception, EXC_XFER_EE)
711 EXCEPTION(0x2000, RunMode, RunModeException, EXC_XFER_EE)
712 EXCEPTION(0x2100, Trap_21, unknown_exception, EXC_XFER_EE)
713 EXCEPTION(0x2200, Trap_22, unknown_exception, EXC_XFER_EE)
714 EXCEPTION(0x2300, Trap_23, unknown_exception, EXC_XFER_EE)
715 EXCEPTION(0x2400, Trap_24, unknown_exception, EXC_XFER_EE)
716 EXCEPTION(0x2500, Trap_25, unknown_exception, EXC_XFER_EE)
717 EXCEPTION(0x2600, Trap_26, unknown_exception, EXC_XFER_EE)
718 EXCEPTION(0x2700, Trap_27, unknown_exception, EXC_XFER_EE)
719 EXCEPTION(0x2800, Trap_28, unknown_exception, EXC_XFER_EE)
720 EXCEPTION(0x2900, Trap_29, unknown_exception, EXC_XFER_EE)
721 EXCEPTION(0x2a00, Trap_2a, unknown_exception, EXC_XFER_EE)
722 EXCEPTION(0x2b00, Trap_2b, unknown_exception, EXC_XFER_EE)
723 EXCEPTION(0x2c00, Trap_2c, unknown_exception, EXC_XFER_EE)
724 EXCEPTION(0x2d00, Trap_2d, unknown_exception, EXC_XFER_EE)
725 EXCEPTION(0x2e00, Trap_2e, unknown_exception, EXC_XFER_EE)
726 EXCEPTION(0x2f00, MOLTrampoline, unknown_exception, EXC_XFER_EE_LITE)
728 .globl mol_trampoline
729 .set mol_trampoline, i0x2f00
735 #ifdef CONFIG_ALTIVEC
737 bl load_up_altivec /* if from user, just load it up */
738 b fast_exception_return
739 #endif /* CONFIG_ALTIVEC */
740 1: addi r3,r1,STACK_FRAME_OVERHEAD
741 EXC_XFER_EE_LITE(0xf20, altivec_unavailable_exception)
745 addi r3,r1,STACK_FRAME_OVERHEAD
746 EXC_XFER_STD(0xf00, performance_monitor_exception)
750 * This code is jumped to from the startup code to copy
751 * the kernel image to physical address PHYSICAL_START.
754 addis r9,r26,klimit@ha /* fetch klimit */
756 addis r25,r25,-KERNELBASE@h
757 lis r3,PHYSICAL_START@h /* Destination base address */
758 li r6,0 /* Destination offset */
759 li r5,0x4000 /* # bytes of memory to copy */
760 bl copy_and_flush /* copy the first 0x4000 bytes */
761 addi r0,r3,4f@l /* jump to the address of 4f */
762 mtctr r0 /* in copy and do the rest. */
763 bctr /* jump to the copy */
765 bl copy_and_flush /* copy the rest */
769 * Copy routine used to copy the kernel to start at physical address 0
770 * and flush and invalidate the caches as needed.
771 * r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset
772 * on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5.
774 _ENTRY(copy_and_flush)
777 4: li r0,L1_CACHE_BYTES/4
779 3: addi r6,r6,4 /* copy a cache line */
783 dcbst r6,r3 /* write it to memory */
785 icbi r6,r3 /* flush the icache line */
788 sync /* additional sync needed on g4 */
796 .globl __secondary_start_gemini
797 __secondary_start_gemini:
806 #endif /* CONFIG_GEMINI */
808 .globl __secondary_start_mpc86xx
809 __secondary_start_mpc86xx:
811 stw r3, __secondary_hold_acknowledge@l(0)
812 mr r24, r3 /* cpu # */
815 .globl __secondary_start_pmac_0
816 __secondary_start_pmac_0:
817 /* NB the entries for cpus 0, 1, 2 must each occupy 8 bytes. */
826 /* on powersurge, we come in here with IR=0 and DR=1, and DBAT 0
827 set to map the 0xf0000000 - 0xffffffff region */
829 rlwinm r0,r0,0,28,26 /* clear DR (0x10) */
834 .globl __secondary_start
836 /* Copy some CPU settings from CPU 0 */
837 bl __restore_cpu_setup
841 bl call_setup_cpu /* Call setup_cpu for this CPU */
845 #endif /* CONFIG_6xx */
847 /* get current_thread_info and current */
848 lis r1,secondary_ti@ha
850 lwz r1,secondary_ti@l(r1)
855 addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
860 /* load up the MMU */
863 /* ptr to phys current thread */
865 addi r4,r4,THREAD /* phys address of our thread_struct */
869 mtspr SPRN_SPRG2,r3 /* 0 => not in RTAS */
871 /* enable MMU and jump to start_secondary */
874 lis r3,start_secondary@h
875 ori r3,r3,start_secondary@l
880 #endif /* CONFIG_SMP */
883 * Those generic dummy functions are kept for CPUs not
884 * included in CONFIG_6xx
886 #if !defined(CONFIG_6xx)
887 _ENTRY(__save_cpu_setup)
889 _ENTRY(__restore_cpu_setup)
891 #endif /* !defined(CONFIG_6xx) */
895 * Load stuff into the MMU. Intended to be called with
899 sync /* Force all PTE updates to finish */
901 tlbia /* Clear all TLB entries */
902 sync /* wait for tlbia/tlbie to finish */
903 TLBSYNC /* ... on all CPUs */
904 /* Load the SDR1 register (hash table base & size) */
909 li r0,16 /* load up segment register values */
910 mtctr r0 /* for context 0 */
911 lis r3,0x2000 /* Ku = 1, VSID = 0 */
914 addi r3,r3,0x111 /* increment VSID */
915 addis r4,r4,0x1000 /* address of next segment */
918 /* Load the BAT registers with the values set up by MMU_init.
919 MMU_init takes care of whether we're on a 601 or not. */
930 BEGIN_MMU_FTR_SECTION
935 END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
939 * This is where the main kernel code starts.
944 ori r2,r2,init_task@l
945 /* Set up for using our exception vectors */
946 /* ptr to phys current thread */
948 addi r4,r4,THREAD /* init task's THREAD */
952 mtspr SPRN_SPRG2,r3 /* 0 => not in RTAS */
955 lis r1,init_thread_union@ha
956 addi r1,r1,init_thread_union@l
958 stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
960 * Do early platform-specific initialization,
961 * and set up the MMU.
970 * Go back to running unmapped so we can load up new values
971 * for SDR1 (hash table pointer) and the segment registers
972 * and change to using our exception vectors.
977 li r3,MSR_KERNEL & ~(MSR_IR|MSR_DR)
983 /* Load up the kernel context */
986 #ifdef CONFIG_BDI_SWITCH
987 /* Add helper information for the Abatron bdiGDB debugger.
988 * We do this here because we know the mmu is disabled, and
989 * will be enabled for real in just a few instructions.
991 lis r5, abatron_pteptrs@h
992 ori r5, r5, abatron_pteptrs@l
993 stw r5, 0xf0(r0) /* This much match your Abatron config */
994 lis r6, swapper_pg_dir@h
995 ori r6, r6, swapper_pg_dir@l
998 #endif /* CONFIG_BDI_SWITCH */
1000 /* Now turn on the MMU for real! */
1003 lis r3,start_kernel@h
1004 ori r3,r3,start_kernel@l
1011 * void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
1013 * Set up the segment registers for a new context.
1015 _ENTRY(switch_mmu_context)
1016 lwz r3,MMCONTEXTID(r4)
1019 mulli r3,r3,897 /* multiply context by skew factor */
1020 rlwinm r3,r3,4,8,27 /* VSID = (context & 0xfffff) << 4 */
1021 addis r3,r3,0x6000 /* Set Ks, Ku bits */
1022 li r0,NUM_USER_SEGMENTS
1025 #ifdef CONFIG_BDI_SWITCH
1026 /* Context switch the PTE pointer for the Abatron BDI2000.
1027 * The PGDIR is passed as second argument.
1030 lis r5, KERNELBASE@h
1038 addi r3,r3,0x111 /* next VSID */
1039 rlwinm r3,r3,0,8,3 /* clear out any overflow from VSID field */
1040 addis r4,r4,0x1000 /* address of next segment */
1046 EMIT_BUG_ENTRY 4b,__FILE__,__LINE__,0
1050 * An undocumented "feature" of 604e requires that the v bit
1051 * be cleared before changing BAT values.
1053 * Also, newer IBM firmware does not clear bat3 and 4 so
1054 * this makes sure it's done.
1060 rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
1064 mtspr SPRN_DBAT0U,r10
1065 mtspr SPRN_DBAT0L,r10
1066 mtspr SPRN_DBAT1U,r10
1067 mtspr SPRN_DBAT1L,r10
1068 mtspr SPRN_DBAT2U,r10
1069 mtspr SPRN_DBAT2L,r10
1070 mtspr SPRN_DBAT3U,r10
1071 mtspr SPRN_DBAT3L,r10
1073 mtspr SPRN_IBAT0U,r10
1074 mtspr SPRN_IBAT0L,r10
1075 mtspr SPRN_IBAT1U,r10
1076 mtspr SPRN_IBAT1L,r10
1077 mtspr SPRN_IBAT2U,r10
1078 mtspr SPRN_IBAT2L,r10
1079 mtspr SPRN_IBAT3U,r10
1080 mtspr SPRN_IBAT3L,r10
1081 BEGIN_MMU_FTR_SECTION
1082 /* Here's a tweak: at this point, CPU setup have
1083 * not been called yet, so HIGH_BAT_EN may not be
1084 * set in HID0 for the 745x processors. However, it
1085 * seems that doesn't affect our ability to actually
1086 * write to these SPRs.
1088 mtspr SPRN_DBAT4U,r10
1089 mtspr SPRN_DBAT4L,r10
1090 mtspr SPRN_DBAT5U,r10
1091 mtspr SPRN_DBAT5L,r10
1092 mtspr SPRN_DBAT6U,r10
1093 mtspr SPRN_DBAT6L,r10
1094 mtspr SPRN_DBAT7U,r10
1095 mtspr SPRN_DBAT7L,r10
1096 mtspr SPRN_IBAT4U,r10
1097 mtspr SPRN_IBAT4L,r10
1098 mtspr SPRN_IBAT5U,r10
1099 mtspr SPRN_IBAT5L,r10
1100 mtspr SPRN_IBAT6U,r10
1101 mtspr SPRN_IBAT6L,r10
1102 mtspr SPRN_IBAT7U,r10
1103 mtspr SPRN_IBAT7L,r10
1104 END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
1109 1: addic. r10, r10, -0x1000
1116 addi r4, r3, __after_mmu_off - _start
1118 andi. r0,r3,MSR_DR|MSR_IR /* MMU enabled? */
1127 * On 601, we use 3 BATs to map up to 24M of RAM at _PAGE_OFFSET
1128 * (we keep one for debugging) and on others, we use one 256M BAT.
1131 lis r11,PAGE_OFFSET@h
1133 rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
1136 ori r11,r11,4 /* set up BAT registers for 601 */
1137 li r8,0x7f /* valid, block length = 8MB */
1138 mtspr SPRN_IBAT0U,r11 /* N.B. 601 has valid bit in */
1139 mtspr SPRN_IBAT0L,r8 /* lower BAT register */
1140 addis r11,r11,0x800000@h
1141 addis r8,r8,0x800000@h
1142 mtspr SPRN_IBAT1U,r11
1143 mtspr SPRN_IBAT1L,r8
1144 addis r11,r11,0x800000@h
1145 addis r8,r8,0x800000@h
1146 mtspr SPRN_IBAT2U,r11
1147 mtspr SPRN_IBAT2L,r8
1153 ori r8,r8,0x12 /* R/W access, M=1 */
1155 ori r8,r8,2 /* R/W access */
1156 #endif /* CONFIG_SMP */
1157 ori r11,r11,BL_256M<<2|0x2 /* set up BAT registers for 604 */
1159 mtspr SPRN_DBAT0L,r8 /* N.B. 6xx (not 601) have valid */
1160 mtspr SPRN_DBAT0U,r11 /* bit in upper BAT register */
1161 mtspr SPRN_IBAT0L,r8
1162 mtspr SPRN_IBAT0U,r11
1167 #ifdef CONFIG_BOOTX_TEXT
1170 * setup the display bat prepared for us in prom.c
1175 addis r8,r3,disp_BAT@ha
1176 addi r8,r8,disp_BAT@l
1182 rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
1185 mtspr SPRN_DBAT3L,r8
1186 mtspr SPRN_DBAT3U,r11
1188 1: mtspr SPRN_IBAT3L,r8
1189 mtspr SPRN_IBAT3U,r11
1191 #endif /* CONFIG_BOOTX_TEXT */
1193 #ifdef CONFIG_PPC_EARLY_DEBUG_CPM
1197 mtspr SPRN_DBAT1L, r8
1200 ori r11, r11, (BL_1M << 2) | 2
1201 mtspr SPRN_DBAT1U, r11
1207 /* Jump into the system reset for the rom.
1208 * We first disable the MMU, and then jump to the ROM reset address.
1210 * r3 is the board info structure, r4 is the location for starting.
1211 * I use this for building a small kernel that can load other kernels,
1212 * rather than trying to write or rely on a rom monitor that can tftp load.
1217 rlwinm r0,r0,0,17,15 /* clear MSR_EE in r0 */
1221 mfspr r11, SPRN_HID0
1223 ori r10,r10,HID0_ICE|HID0_DCE
1225 mtspr SPRN_HID0, r11
1227 li r5, MSR_ME|MSR_RI
1229 addis r6,r6,-KERNELBASE@h
1243 * We put a few things here that have to be page-aligned.
1244 * This stuff goes at the beginning of the data segment,
1245 * which is page-aligned.
1250 .globl empty_zero_page
1254 .globl swapper_pg_dir
1256 .space PGD_TABLE_SIZE
1258 .globl intercept_table
1260 .long 0, 0, i0x200, i0x300, i0x400, 0, i0x600, i0x700
1261 .long i0x800, 0, 0, 0, 0, i0xd00, 0, 0
1262 .long 0, 0, 0, i0x1300, 0, 0, 0, 0
1263 .long 0, 0, 0, 0, 0, 0, 0, 0
1264 .long 0, 0, 0, 0, 0, 0, 0, 0
1265 .long 0, 0, 0, 0, 0, 0, 0, 0
1267 /* Room for two PTE pointers, usually the kernel and current user pointers
1268 * to their respective root page table.