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+/*
+ * PowerPC version
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
+ * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
+ * Adapted for Power Macintosh by Paul Mackerras.
+ * Low-level exception handlers and MMU support
+ * rewritten by Paul Mackerras.
+ * Copyright (C) 1996 Paul Mackerras.
+ * MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net).
+ * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
+ *
+ * This file contains the low-level support and setup for the
+ * PowerPC platform, including trap and interrupt dispatch.
+ * (The PPC 8xx embedded CPUs use head_8xx.S instead.)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/config.h>
+#include <asm/processor.h>
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/pgtable.h>
+#include <asm/cputable.h>
+#include <asm/cache.h>
+#include <asm/thread_info.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+
+#ifdef CONFIG_APUS
+#include <asm/amigappc.h>
+#endif
+
+#ifdef CONFIG_PPC64BRIDGE
+#define LOAD_BAT(n, reg, RA, RB) \
+ ld RA,(n*32)+0(reg); \
+ ld RB,(n*32)+8(reg); \
+ mtspr SPRN_IBAT##n##U,RA; \
+ mtspr SPRN_IBAT##n##L,RB; \
+ ld RA,(n*32)+16(reg); \
+ ld RB,(n*32)+24(reg); \
+ mtspr SPRN_DBAT##n##U,RA; \
+ mtspr SPRN_DBAT##n##L,RB; \
+
+#else /* CONFIG_PPC64BRIDGE */
+
+/* 601 only have IBAT; cr0.eq is set on 601 when using this macro */
+#define LOAD_BAT(n, reg, RA, RB) \
+ /* see the comment for clear_bats() -- Cort */ \
+ li RA,0; \
+ mtspr SPRN_IBAT##n##U,RA; \
+ mtspr SPRN_DBAT##n##U,RA; \
+ lwz RA,(n*16)+0(reg); \
+ lwz RB,(n*16)+4(reg); \
+ mtspr SPRN_IBAT##n##U,RA; \
+ mtspr SPRN_IBAT##n##L,RB; \
+ beq 1f; \
+ lwz RA,(n*16)+8(reg); \
+ lwz RB,(n*16)+12(reg); \
+ mtspr SPRN_DBAT##n##U,RA; \
+ mtspr SPRN_DBAT##n##L,RB; \
+1:
+#endif /* CONFIG_PPC64BRIDGE */
+
+ .text
+ .stabs "arch/ppc/kernel/",N_SO,0,0,0f
+ .stabs "head.S",N_SO,0,0,0f
+0:
+ .globl _stext
+_stext:
+
+/*
+ * _start is defined this way because the XCOFF loader in the OpenFirmware
+ * on the powermac expects the entry point to be a procedure descriptor.
+ */
+ .text
+ .globl _start
+_start:
+ /*
+ * These are here for legacy reasons, the kernel used to
+ * need to look like a coff function entry for the pmac
+ * but we're always started by some kind of bootloader now.
+ * -- Cort
+ */
+ nop /* used by __secondary_hold on prep (mtx) and chrp smp */
+ nop /* used by __secondary_hold on prep (mtx) and chrp smp */
+ nop
+
+/* PMAC
+ * Enter here with the kernel text, data and bss loaded starting at
+ * 0, running with virtual == physical mapping.
+ * r5 points to the prom entry point (the client interface handler
+ * address). Address translation is turned on, with the prom
+ * managing the hash table. Interrupts are disabled. The stack
+ * pointer (r1) points to just below the end of the half-meg region
+ * from 0x380000 - 0x400000, which is mapped in already.
+ *
+ * If we are booted from MacOS via BootX, we enter with the kernel
+ * image loaded somewhere, and the following values in registers:
+ * r3: 'BooX' (0x426f6f58)
+ * r4: virtual address of boot_infos_t
+ * r5: 0
+ *
+ * APUS
+ * r3: 'APUS'
+ * r4: physical address of memory base
+ * Linux/m68k style BootInfo structure at &_end.
+ *
+ * PREP
+ * This is jumped to on prep systems right after the kernel is relocated
+ * to its proper place in memory by the boot loader. The expected layout
+ * of the regs is:
+ * r3: ptr to residual data
+ * r4: initrd_start or if no initrd then 0
+ * r5: initrd_end - unused if r4 is 0
+ * r6: Start of command line string
+ * r7: End of command line string
+ *
+ * This just gets a minimal mmu environment setup so we can call
+ * start_here() to do the real work.
+ * -- Cort
+ */
+
+ .globl __start
+__start:
+/*
+ * We have to do any OF calls before we map ourselves to KERNELBASE,
+ * because OF may have I/O devices mapped into that area
+ * (particularly on CHRP).
+ */
+ mr r31,r3 /* save parameters */
+ mr r30,r4
+ mr r29,r5
+ mr r28,r6
+ mr r27,r7
+ li r24,0 /* cpu # */
+
+/*
+ * early_init() does the early machine identification and does
+ * the necessary low-level setup and clears the BSS
+ * -- Cort <cort@fsmlabs.com>
+ */
+ bl early_init
+
+/*
+ * On POWER4, we first need to tweak some CPU configuration registers
+ * like real mode cache inhibit or exception base
+ */
+#ifdef CONFIG_POWER4
+ bl __970_cpu_preinit
+#endif /* CONFIG_POWER4 */
+
+#ifdef CONFIG_APUS
+/* On APUS the __va/__pa constants need to be set to the correct
+ * values before continuing.
+ */
+ mr r4,r30
+ bl fix_mem_constants
+#endif /* CONFIG_APUS */
+
+/* Switch MMU off, clear BATs and flush TLB. At this point, r3 contains
+ * the physical address we are running at, returned by early_init()
+ */
+ bl mmu_off
+__after_mmu_off:
+#ifndef CONFIG_POWER4
+ bl clear_bats
+ bl flush_tlbs
+
+ bl initial_bats
+#if !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT)
+ bl setup_disp_bat
+#endif
+#else /* CONFIG_POWER4 */
+ bl reloc_offset
+ bl initial_mm_power4
+#endif /* CONFIG_POWER4 */
+
+/*
+ * Call setup_cpu for CPU 0 and initialize 6xx Idle
+ */
+ bl reloc_offset
+ li r24,0 /* cpu# */
+ bl call_setup_cpu /* Call setup_cpu for this CPU */
+#ifdef CONFIG_6xx
+ bl reloc_offset
+ bl init_idle_6xx
+#endif /* CONFIG_6xx */
+#ifdef CONFIG_POWER4
+ bl reloc_offset
+ bl init_idle_power4
+#endif /* CONFIG_POWER4 */
+
+
+#ifndef CONFIG_APUS
+/*
+ * We need to run with _start at physical address 0.
+ * On CHRP, we are loaded at 0x10000 since OF on CHRP uses
+ * the exception vectors at 0 (and therefore this copy
+ * overwrites OF's exception vectors with our own).
+ * If the MMU is already turned on, we copy stuff to KERNELBASE,
+ * otherwise we copy it to 0.
+ */
+ bl reloc_offset
+ mr r26,r3
+ addis r4,r3,KERNELBASE@h /* current address of _start */
+ cmpwi 0,r4,0 /* are we already running at 0? */
+ bne relocate_kernel
+#endif /* CONFIG_APUS */
+/*
+ * we now have the 1st 16M of ram mapped with the bats.
+ * prep needs the mmu to be turned on here, but pmac already has it on.
+ * this shouldn't bother the pmac since it just gets turned on again
+ * as we jump to our code at KERNELBASE. -- Cort
+ * Actually no, pmac doesn't have it on any more. BootX enters with MMU
+ * off, and in other cases, we now turn it off before changing BATs above.
+ */
+turn_on_mmu:
+ mfmsr r0
+ ori r0,r0,MSR_DR|MSR_IR
+ mtspr SPRN_SRR1,r0
+ lis r0,start_here@h
+ ori r0,r0,start_here@l
+ mtspr SPRN_SRR0,r0
+ SYNC
+ RFI /* enables MMU */
+
+/*
+ * We need __secondary_hold as a place to hold the other cpus on
+ * an SMP machine, even when we are running a UP kernel.
+ */
+ . = 0xc0 /* for prep bootloader */
+ li r3,1 /* MTX only has 1 cpu */
+ .globl __secondary_hold
+__secondary_hold:
+ /* tell the master we're here */
+ stw r3,4(0)
+#ifdef CONFIG_SMP
+100: lwz r4,0(0)
+ /* wait until we're told to start */
+ cmpw 0,r4,r3
+ bne 100b
+ /* our cpu # was at addr 0 - go */
+ mr r24,r3 /* cpu # */
+ b __secondary_start
+#else
+ b .
+#endif /* CONFIG_SMP */
+
+/*
+ * Exception entry code. This code runs with address translation
+ * turned off, i.e. using physical addresses.
+ * We assume sprg3 has the physical address of the current
+ * task's thread_struct.
+ */
+#define EXCEPTION_PROLOG \
+ mtspr SPRN_SPRG0,r10; \
+ mtspr SPRN_SPRG1,r11; \
+ mfcr r10; \
+ EXCEPTION_PROLOG_1; \
+ EXCEPTION_PROLOG_2
+
+#define EXCEPTION_PROLOG_1 \
+ mfspr r11,SPRN_SRR1; /* check whether user or kernel */ \
+ andi. r11,r11,MSR_PR; \
+ tophys(r11,r1); /* use tophys(r1) if kernel */ \
+ beq 1f; \
+ mfspr r11,SPRN_SPRG3; \
+ lwz r11,THREAD_INFO-THREAD(r11); \
+ addi r11,r11,THREAD_SIZE; \
+ tophys(r11,r11); \
+1: subi r11,r11,INT_FRAME_SIZE /* alloc exc. frame */
+
+
+#define EXCEPTION_PROLOG_2 \
+ CLR_TOP32(r11); \
+ stw r10,_CCR(r11); /* save registers */ \
+ stw r12,GPR12(r11); \
+ stw r9,GPR9(r11); \
+ mfspr r10,SPRN_SPRG0; \
+ stw r10,GPR10(r11); \
+ mfspr r12,SPRN_SPRG1; \
+ stw r12,GPR11(r11); \
+ mflr r10; \
+ stw r10,_LINK(r11); \
+ mfspr r12,SPRN_SRR0; \
+ mfspr r9,SPRN_SRR1; \
+ stw r1,GPR1(r11); \
+ stw r1,0(r11); \
+ tovirt(r1,r11); /* set new kernel sp */ \
+ li r10,MSR_KERNEL & ~(MSR_IR|MSR_DR); /* can take exceptions */ \
+ MTMSRD(r10); /* (except for mach check in rtas) */ \
+ stw r0,GPR0(r11); \
+ SAVE_4GPRS(3, r11); \
+ SAVE_2GPRS(7, r11)
+
+/*
+ * Note: code which follows this uses cr0.eq (set if from kernel),
+ * r11, r12 (SRR0), and r9 (SRR1).
+ *
+ * Note2: once we have set r1 we are in a position to take exceptions
+ * again, and we could thus set MSR:RI at that point.
+ */
+
+/*
+ * Exception vectors.
+ */
+#define EXCEPTION(n, label, hdlr, xfer) \
+ . = n; \
+label: \
+ EXCEPTION_PROLOG; \
+ addi r3,r1,STACK_FRAME_OVERHEAD; \
+ xfer(n, hdlr)
+
+#define EXC_XFER_TEMPLATE(n, hdlr, trap, copyee, tfer, ret) \
+ li r10,trap; \
+ stw r10,TRAP(r11); \
+ li r10,MSR_KERNEL; \
+ copyee(r10, r9); \
+ bl tfer; \
+i##n: \
+ .long hdlr; \
+ .long ret
+
+#define COPY_EE(d, s) rlwimi d,s,0,16,16
+#define NOCOPY(d, s)
+
+#define EXC_XFER_STD(n, hdlr) \
+ EXC_XFER_TEMPLATE(n, hdlr, n, NOCOPY, transfer_to_handler_full, \
+ ret_from_except_full)
+
+#define EXC_XFER_LITE(n, hdlr) \
+ EXC_XFER_TEMPLATE(n, hdlr, n+1, NOCOPY, transfer_to_handler, \
+ ret_from_except)
+
+#define EXC_XFER_EE(n, hdlr) \
+ EXC_XFER_TEMPLATE(n, hdlr, n, COPY_EE, transfer_to_handler_full, \
+ ret_from_except_full)
+
+#define EXC_XFER_EE_LITE(n, hdlr) \
+ EXC_XFER_TEMPLATE(n, hdlr, n+1, COPY_EE, transfer_to_handler, \
+ ret_from_except)
+
+/* System reset */
+/* core99 pmac starts the seconary here by changing the vector, and
+ putting it back to what it was (UnknownException) when done. */
+#if defined(CONFIG_GEMINI) && defined(CONFIG_SMP)
+ . = 0x100
+ b __secondary_start_gemini
+#else
+ EXCEPTION(0x100, Reset, UnknownException, EXC_XFER_STD)
+#endif
+
+/* Machine check */
+/*
+ * On CHRP, this is complicated by the fact that we could get a
+ * machine check inside RTAS, and we have no guarantee that certain
+ * critical registers will have the values we expect. The set of
+ * registers that might have bad values includes all the GPRs
+ * and all the BATs. We indicate that we are in RTAS by putting
+ * a non-zero value, the address of the exception frame to use,
+ * in SPRG2. The machine check handler checks SPRG2 and uses its
+ * value if it is non-zero. If we ever needed to free up SPRG2,
+ * we could use a field in the thread_info or thread_struct instead.
+ * (Other exception handlers assume that r1 is a valid kernel stack
+ * pointer when we take an exception from supervisor mode.)
+ * -- paulus.
+ */
+ . = 0x200
+ mtspr SPRN_SPRG0,r10
+ mtspr SPRN_SPRG1,r11
+ mfcr r10
+#ifdef CONFIG_PPC_CHRP
+ mfspr r11,SPRN_SPRG2
+ cmpwi 0,r11,0
+ bne 7f
+#endif /* CONFIG_PPC_CHRP */
+ EXCEPTION_PROLOG_1
+7: EXCEPTION_PROLOG_2
+ addi r3,r1,STACK_FRAME_OVERHEAD
+#ifdef CONFIG_PPC_CHRP
+ mfspr r4,SPRN_SPRG2
+ cmpwi cr1,r4,0
+ bne cr1,1f
+#endif
+ EXC_XFER_STD(0x200, MachineCheckException)
+#ifdef CONFIG_PPC_CHRP
+1: b machine_check_in_rtas
+#endif
+
+/* Data access exception. */
+ . = 0x300
+#ifdef CONFIG_PPC64BRIDGE
+ b DataAccess
+DataAccessCont:
+#else
+DataAccess:
+ EXCEPTION_PROLOG
+#endif /* CONFIG_PPC64BRIDGE */
+ mfspr r10,SPRN_DSISR
+ andis. r0,r10,0xa470 /* weird error? */
+ bne 1f /* if not, try to put a PTE */
+ mfspr r4,SPRN_DAR /* into the hash table */
+ rlwinm r3,r10,32-15,21,21 /* DSISR_STORE -> _PAGE_RW */
+ bl hash_page
+1: stw r10,_DSISR(r11)
+ mr r5,r10
+ mfspr r4,SPRN_DAR
+ EXC_XFER_EE_LITE(0x300, handle_page_fault)
+
+#ifdef CONFIG_PPC64BRIDGE
+/* SLB fault on data access. */
+ . = 0x380
+ b DataSegment
+#endif /* CONFIG_PPC64BRIDGE */
+
+/* Instruction access exception. */
+ . = 0x400
+#ifdef CONFIG_PPC64BRIDGE
+ b InstructionAccess
+InstructionAccessCont:
+#else
+InstructionAccess:
+ EXCEPTION_PROLOG
+#endif /* CONFIG_PPC64BRIDGE */
+ andis. r0,r9,0x4000 /* no pte found? */
+ beq 1f /* if so, try to put a PTE */
+ li r3,0 /* into the hash table */
+ mr r4,r12 /* SRR0 is fault address */
+ bl hash_page
+1: mr r4,r12
+ mr r5,r9
+ EXC_XFER_EE_LITE(0x400, handle_page_fault)
+
+#ifdef CONFIG_PPC64BRIDGE
+/* SLB fault on instruction access. */
+ . = 0x480
+ b InstructionSegment
+#endif /* CONFIG_PPC64BRIDGE */
+
+/* External interrupt */
+ EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
+
+/* Alignment exception */
+ . = 0x600
+Alignment:
+ EXCEPTION_PROLOG
+ mfspr r4,SPRN_DAR
+ stw r4,_DAR(r11)
+ mfspr r5,SPRN_DSISR
+ stw r5,_DSISR(r11)
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ EXC_XFER_EE(0x600, AlignmentException)
+
+/* Program check exception */
+ EXCEPTION(0x700, ProgramCheck, ProgramCheckException, EXC_XFER_STD)
+
+/* Floating-point unavailable */
+ . = 0x800
+FPUnavailable:
+ EXCEPTION_PROLOG
+ bne load_up_fpu /* if from user, just load it up */
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ EXC_XFER_EE_LITE(0x800, KernelFP)
+
+/* Decrementer */
+ EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
+
+ EXCEPTION(0xa00, Trap_0a, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0xb00, Trap_0b, UnknownException, EXC_XFER_EE)
+
+/* System call */
+ . = 0xc00
+SystemCall:
+ EXCEPTION_PROLOG
+ EXC_XFER_EE_LITE(0xc00, DoSyscall)
+
+/* Single step - not used on 601 */
+ EXCEPTION(0xd00, SingleStep, SingleStepException, EXC_XFER_STD)
+ EXCEPTION(0xe00, Trap_0e, UnknownException, EXC_XFER_EE)
+
+/*
+ * The Altivec unavailable trap is at 0x0f20. Foo.
+ * We effectively remap it to 0x3000.
+ * We include an altivec unavailable exception vector even if
+ * not configured for Altivec, so that you can't panic a
+ * non-altivec kernel running on a machine with altivec just
+ * by executing an altivec instruction.
+ */
+ . = 0xf00
+ b Trap_0f
+
+ . = 0xf20
+ b AltiVecUnavailable
+
+Trap_0f:
+ EXCEPTION_PROLOG
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ EXC_XFER_EE(0xf00, UnknownException)
+
+/*
+ * Handle TLB miss for instruction on 603/603e.
+ * Note: we get an alternate set of r0 - r3 to use automatically.
+ */
+ . = 0x1000
+InstructionTLBMiss:
+/*
+ * r0: stored ctr
+ * r1: linux style pte ( later becomes ppc hardware pte )
+ * r2: ptr to linux-style pte
+ * r3: scratch
+ */
+ mfctr r0
+ /* Get PTE (linux-style) and check access */
+ mfspr r3,SPRN_IMISS
+ lis r1,KERNELBASE@h /* check if kernel address */
+ cmplw 0,r3,r1
+ mfspr r2,SPRN_SPRG3
+ li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
+ lwz r2,PGDIR(r2)
+ blt+ 112f
+ lis r2,swapper_pg_dir@ha /* if kernel address, use */
+ addi r2,r2,swapper_pg_dir@l /* kernel page table */
+ mfspr r1,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
+ rlwinm r1,r1,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
+112: tophys(r2,r2)
+ rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
+ lwz r2,0(r2) /* get pmd entry */
+ rlwinm. r2,r2,0,0,19 /* extract address of pte page */
+ beq- InstructionAddressInvalid /* return if no mapping */
+ rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
+ lwz r3,0(r2) /* get linux-style pte */
+ andc. r1,r1,r3 /* check access & ~permission */
+ bne- InstructionAddressInvalid /* return if access not permitted */
+ ori r3,r3,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
+ /*
+ * NOTE! We are assuming this is not an SMP system, otherwise
+ * we would need to update the pte atomically with lwarx/stwcx.
+ */
+ stw r3,0(r2) /* update PTE (accessed bit) */
+ /* Convert linux-style PTE to low word of PPC-style PTE */
+ rlwinm r1,r3,32-10,31,31 /* _PAGE_RW -> PP lsb */
+ rlwinm r2,r3,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
+ and r1,r1,r2 /* writable if _RW and _DIRTY */
+ rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
+ rlwimi r3,r3,32-1,31,31 /* _PAGE_USER -> PP lsb */
+ ori r1,r1,0xe14 /* clear out reserved bits and M */
+ andc r1,r3,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
+ mtspr SPRN_RPA,r1
+ mfspr r3,SPRN_IMISS
+ tlbli r3
+ mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
+ mtcrf 0x80,r3
+ rfi
+InstructionAddressInvalid:
+ mfspr r3,SPRN_SRR1
+ rlwinm r1,r3,9,6,6 /* Get load/store bit */
+
+ addis r1,r1,0x2000
+ mtspr SPRN_DSISR,r1 /* (shouldn't be needed) */
+ mtctr r0 /* Restore CTR */
+ andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
+ or r2,r2,r1
+ mtspr SPRN_SRR1,r2
+ mfspr r1,SPRN_IMISS /* Get failing address */
+ rlwinm. r2,r2,0,31,31 /* Check for little endian access */
+ rlwimi r2,r2,1,30,30 /* change 1 -> 3 */
+ xor r1,r1,r2
+ mtspr SPRN_DAR,r1 /* Set fault address */
+ mfmsr r0 /* Restore "normal" registers */
+ xoris r0,r0,MSR_TGPR>>16
+ mtcrf 0x80,r3 /* Restore CR0 */
+ mtmsr r0
+ b InstructionAccess
+
+/*
+ * Handle TLB miss for DATA Load operation on 603/603e
+ */
+ . = 0x1100
+DataLoadTLBMiss:
+/*
+ * r0: stored ctr
+ * r1: linux style pte ( later becomes ppc hardware pte )
+ * r2: ptr to linux-style pte
+ * r3: scratch
+ */
+ mfctr r0
+ /* Get PTE (linux-style) and check access */
+ mfspr r3,SPRN_DMISS
+ lis r1,KERNELBASE@h /* check if kernel address */
+ cmplw 0,r3,r1
+ mfspr r2,SPRN_SPRG3
+ li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
+ lwz r2,PGDIR(r2)
+ blt+ 112f
+ lis r2,swapper_pg_dir@ha /* if kernel address, use */
+ addi r2,r2,swapper_pg_dir@l /* kernel page table */
+ mfspr r1,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
+ rlwinm r1,r1,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
+112: tophys(r2,r2)
+ rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
+ lwz r2,0(r2) /* get pmd entry */
+ rlwinm. r2,r2,0,0,19 /* extract address of pte page */
+ beq- DataAddressInvalid /* return if no mapping */
+ rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
+ lwz r3,0(r2) /* get linux-style pte */
+ andc. r1,r1,r3 /* check access & ~permission */
+ bne- DataAddressInvalid /* return if access not permitted */
+ ori r3,r3,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
+ /*
+ * NOTE! We are assuming this is not an SMP system, otherwise
+ * we would need to update the pte atomically with lwarx/stwcx.
+ */
+ stw r3,0(r2) /* update PTE (accessed bit) */
+ /* Convert linux-style PTE to low word of PPC-style PTE */
+ rlwinm r1,r3,32-10,31,31 /* _PAGE_RW -> PP lsb */
+ rlwinm r2,r3,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
+ and r1,r1,r2 /* writable if _RW and _DIRTY */
+ rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
+ rlwimi r3,r3,32-1,31,31 /* _PAGE_USER -> PP lsb */
+ ori r1,r1,0xe14 /* clear out reserved bits and M */
+ andc r1,r3,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
+ mtspr SPRN_RPA,r1
+ mfspr r3,SPRN_DMISS
+ tlbld r3
+ mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
+ mtcrf 0x80,r3
+ rfi
+DataAddressInvalid:
+ mfspr r3,SPRN_SRR1
+ rlwinm r1,r3,9,6,6 /* Get load/store bit */
+ addis r1,r1,0x2000
+ mtspr SPRN_DSISR,r1
+ mtctr r0 /* Restore CTR */
+ andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
+ mtspr SPRN_SRR1,r2
+ mfspr r1,SPRN_DMISS /* Get failing address */
+ rlwinm. r2,r2,0,31,31 /* Check for little endian access */
+ beq 20f /* Jump if big endian */
+ xori r1,r1,3
+20: mtspr SPRN_DAR,r1 /* Set fault address */
+ mfmsr r0 /* Restore "normal" registers */
+ xoris r0,r0,MSR_TGPR>>16
+ mtcrf 0x80,r3 /* Restore CR0 */
+ mtmsr r0
+ b DataAccess
+
+/*
+ * Handle TLB miss for DATA Store on 603/603e
+ */
+ . = 0x1200
+DataStoreTLBMiss:
+/*
+ * r0: stored ctr
+ * r1: linux style pte ( later becomes ppc hardware pte )
+ * r2: ptr to linux-style pte
+ * r3: scratch
+ */
+ mfctr r0
+ /* Get PTE (linux-style) and check access */
+ mfspr r3,SPRN_DMISS
+ lis r1,KERNELBASE@h /* check if kernel address */
+ cmplw 0,r3,r1
+ mfspr r2,SPRN_SPRG3
+ li r1,_PAGE_RW|_PAGE_USER|_PAGE_PRESENT /* access flags */
+ lwz r2,PGDIR(r2)
+ blt+ 112f
+ lis r2,swapper_pg_dir@ha /* if kernel address, use */
+ addi r2,r2,swapper_pg_dir@l /* kernel page table */
+ mfspr r1,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
+ rlwinm r1,r1,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
+112: tophys(r2,r2)
+ rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
+ lwz r2,0(r2) /* get pmd entry */
+ rlwinm. r2,r2,0,0,19 /* extract address of pte page */
+ beq- DataAddressInvalid /* return if no mapping */
+ rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
+ lwz r3,0(r2) /* get linux-style pte */
+ andc. r1,r1,r3 /* check access & ~permission */
+ bne- DataAddressInvalid /* return if access not permitted */
+ ori r3,r3,_PAGE_ACCESSED|_PAGE_DIRTY
+ /*
+ * NOTE! We are assuming this is not an SMP system, otherwise
+ * we would need to update the pte atomically with lwarx/stwcx.
+ */
+ stw r3,0(r2) /* update PTE (accessed/dirty bits) */
+ /* Convert linux-style PTE to low word of PPC-style PTE */
+ rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
+ li r1,0xe15 /* clear out reserved bits and M */
+ andc r1,r3,r1 /* PP = user? 2: 0 */
+ mtspr SPRN_RPA,r1
+ mfspr r3,SPRN_DMISS
+ tlbld r3
+ mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
+ mtcrf 0x80,r3
+ rfi
+
+#ifndef CONFIG_ALTIVEC
+#define AltivecAssistException UnknownException
+#endif
+
+ EXCEPTION(0x1300, Trap_13, InstructionBreakpoint, EXC_XFER_EE)
+ EXCEPTION(0x1400, SMI, SMIException, EXC_XFER_EE)
+ EXCEPTION(0x1500, Trap_15, UnknownException, EXC_XFER_EE)
+#ifdef CONFIG_POWER4
+ EXCEPTION(0x1600, Trap_16, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1700, Trap_17, AltivecAssistException, EXC_XFER_EE)
+ EXCEPTION(0x1800, Trap_18, TAUException, EXC_XFER_STD)
+#else /* !CONFIG_POWER4 */
+ EXCEPTION(0x1600, Trap_16, AltivecAssistException, EXC_XFER_EE)
+ EXCEPTION(0x1700, Trap_17, TAUException, EXC_XFER_STD)
+ EXCEPTION(0x1800, Trap_18, UnknownException, EXC_XFER_EE)
+#endif /* CONFIG_POWER4 */
+ EXCEPTION(0x1900, Trap_19, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1a00, Trap_1a, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1b00, Trap_1b, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1c00, Trap_1c, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1d00, Trap_1d, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1e00, Trap_1e, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1f00, Trap_1f, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2000, RunMode, RunModeException, EXC_XFER_EE)
+ EXCEPTION(0x2100, Trap_21, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2200, Trap_22, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2300, Trap_23, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2400, Trap_24, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2500, Trap_25, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2600, Trap_26, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2700, Trap_27, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2800, Trap_28, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2900, Trap_29, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2a00, Trap_2a, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2b00, Trap_2b, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2c00, Trap_2c, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2d00, Trap_2d, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2e00, Trap_2e, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2f00, MOLTrampoline, UnknownException, EXC_XFER_EE_LITE)
+
+ .globl mol_trampoline
+ .set mol_trampoline, i0x2f00
+
+ . = 0x3000
+
+AltiVecUnavailable:
+ EXCEPTION_PROLOG
+#ifdef CONFIG_ALTIVEC
+ bne load_up_altivec /* if from user, just load it up */
+#endif /* CONFIG_ALTIVEC */
+ EXC_XFER_EE_LITE(0xf20, AltivecUnavailException)
+
+#ifdef CONFIG_PPC64BRIDGE
+DataAccess:
+ EXCEPTION_PROLOG
+ b DataAccessCont
+
+InstructionAccess:
+ EXCEPTION_PROLOG
+ b InstructionAccessCont
+
+DataSegment:
+ EXCEPTION_PROLOG
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ mfspr r4,SPRN_DAR
+ stw r4,_DAR(r11)
+ EXC_XFER_STD(0x380, UnknownException)
+
+InstructionSegment:
+ EXCEPTION_PROLOG
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ EXC_XFER_STD(0x480, UnknownException)
+#endif /* CONFIG_PPC64BRIDGE */
+
+#ifdef CONFIG_ALTIVEC
+/* Note that the AltiVec support is closely modeled after the FP
+ * support. Changes to one are likely to be applicable to the
+ * other! */
+load_up_altivec:
+/*
+ * Disable AltiVec for the task which had AltiVec previously,
+ * and save its AltiVec registers in its thread_struct.
+ * Enables AltiVec for use in the kernel on return.
+ * On SMP we know the AltiVec units are free, since we give it up every
+ * switch. -- Kumar
+ */
+ mfmsr r5
+ oris r5,r5,MSR_VEC@h
+ MTMSRD(r5) /* enable use of AltiVec now */
+ isync
+/*
+ * For SMP, we don't do lazy AltiVec switching because it just gets too
+ * horrendously complex, especially when a task switches from one CPU
+ * to another. Instead we call giveup_altivec in switch_to.
+ */
+#ifndef CONFIG_SMP
+ tophys(r6,0)
+ addis r3,r6,last_task_used_altivec@ha
+ lwz r4,last_task_used_altivec@l(r3)
+ cmpwi 0,r4,0
+ beq 1f
+ add r4,r4,r6
+ addi r4,r4,THREAD /* want THREAD of last_task_used_altivec */
+ SAVE_32VRS(0,r10,r4)
+ mfvscr vr0
+ li r10,THREAD_VSCR
+ stvx vr0,r10,r4
+ lwz r5,PT_REGS(r4)
+ add r5,r5,r6
+ lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+ lis r10,MSR_VEC@h
+ andc r4,r4,r10 /* disable altivec for previous task */
+ stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+1:
+#endif /* CONFIG_SMP */
+ /* enable use of AltiVec after return */
+ oris r9,r9,MSR_VEC@h
+ mfspr r5,SPRN_SPRG3 /* current task's THREAD (phys) */
+ li r4,1
+ li r10,THREAD_VSCR
+ stw r4,THREAD_USED_VR(r5)
+ lvx vr0,r10,r5
+ mtvscr vr0
+ REST_32VRS(0,r10,r5)
+#ifndef CONFIG_SMP
+ subi r4,r5,THREAD
+ sub r4,r4,r6
+ stw r4,last_task_used_altivec@l(r3)
+#endif /* CONFIG_SMP */
+ /* restore registers and return */
+ /* we haven't used ctr or xer or lr */
+ b fast_exception_return
+
+/*
+ * AltiVec unavailable trap from kernel - print a message, but let
+ * the task use AltiVec in the kernel until it returns to user mode.
+ */
+KernelAltiVec:
+ lwz r3,_MSR(r1)
+ oris r3,r3,MSR_VEC@h
+ stw r3,_MSR(r1) /* enable use of AltiVec after return */
+ lis r3,87f@h
+ ori r3,r3,87f@l
+ mr r4,r2 /* current */
+ lwz r5,_NIP(r1)
+ bl printk
+ b ret_from_except
+87: .string "AltiVec used in kernel (task=%p, pc=%x) \n"
+ .align 4,0
+
+/*
+ * giveup_altivec(tsk)
+ * Disable AltiVec for the task given as the argument,
+ * and save the AltiVec registers in its thread_struct.
+ * Enables AltiVec for use in the kernel on return.
+ */
+
+ .globl giveup_altivec
+giveup_altivec:
+ mfmsr r5
+ oris r5,r5,MSR_VEC@h
+ SYNC
+ MTMSRD(r5) /* enable use of AltiVec now */
+ isync
+ cmpwi 0,r3,0
+ beqlr- /* if no previous owner, done */
+ addi r3,r3,THREAD /* want THREAD of task */
+ lwz r5,PT_REGS(r3)
+ cmpwi 0,r5,0
+ SAVE_32VRS(0, r4, r3)
+ mfvscr vr0
+ li r4,THREAD_VSCR
+ stvx vr0,r4,r3
+ beq 1f
+ lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+ lis r3,MSR_VEC@h
+ andc r4,r4,r3 /* disable AltiVec for previous task */
+ stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+1:
+#ifndef CONFIG_SMP
+ li r5,0
+ lis r4,last_task_used_altivec@ha
+ stw r5,last_task_used_altivec@l(r4)
+#endif /* CONFIG_SMP */
+ blr
+#endif /* CONFIG_ALTIVEC */
+
+/*
+ * This code is jumped to from the startup code to copy
+ * the kernel image to physical address 0.
+ */
+relocate_kernel:
+ addis r9,r26,klimit@ha /* fetch klimit */
+ lwz r25,klimit@l(r9)
+ addis r25,r25,-KERNELBASE@h
+ li r3,0 /* Destination base address */
+ li r6,0 /* Destination offset */
+ li r5,0x4000 /* # bytes of memory to copy */
+ bl copy_and_flush /* copy the first 0x4000 bytes */
+ addi r0,r3,4f@l /* jump to the address of 4f */
+ mtctr r0 /* in copy and do the rest. */
+ bctr /* jump to the copy */
+4: mr r5,r25
+ bl copy_and_flush /* copy the rest */
+ b turn_on_mmu
+
+/*
+ * Copy routine used to copy the kernel to start at physical address 0
+ * and flush and invalidate the caches as needed.
+ * r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset
+ * on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5.
+ */
+copy_and_flush:
+ addi r5,r5,-4
+ addi r6,r6,-4
+4: li r0,L1_CACHE_LINE_SIZE/4
+ mtctr r0
+3: addi r6,r6,4 /* copy a cache line */
+ lwzx r0,r6,r4
+ stwx r0,r6,r3
+ bdnz 3b
+ dcbst r6,r3 /* write it to memory */
+ sync
+ icbi r6,r3 /* flush the icache line */
+ cmplw 0,r6,r5
+ blt 4b
+ sync /* additional sync needed on g4 */
+ isync
+ addi r5,r5,4
+ addi r6,r6,4
+ blr
+
+#ifdef CONFIG_APUS
+/*
+ * On APUS the physical base address of the kernel is not known at compile
+ * time, which means the __pa/__va constants used are incorrect. In the
+ * __init section is recorded the virtual addresses of instructions using
+ * these constants, so all that has to be done is fix these before
+ * continuing the kernel boot.
+ *
+ * r4 = The physical address of the kernel base.
+ */
+fix_mem_constants:
+ mr r10,r4
+ addis r10,r10,-KERNELBASE@h /* virt_to_phys constant */
+ neg r11,r10 /* phys_to_virt constant */
+
+ lis r12,__vtop_table_begin@h
+ ori r12,r12,__vtop_table_begin@l
+ add r12,r12,r10 /* table begin phys address */
+ lis r13,__vtop_table_end@h
+ ori r13,r13,__vtop_table_end@l
+ add r13,r13,r10 /* table end phys address */
+ subi r12,r12,4
+ subi r13,r13,4
+1: lwzu r14,4(r12) /* virt address of instruction */
+ add r14,r14,r10 /* phys address of instruction */
+ lwz r15,0(r14) /* instruction, now insert top */
+ rlwimi r15,r10,16,16,31 /* half of vp const in low half */
+ stw r15,0(r14) /* of instruction and restore. */
+ dcbst r0,r14 /* write it to memory */
+ sync
+ icbi r0,r14 /* flush the icache line */
+ cmpw r12,r13
+ bne 1b
+ sync /* additional sync needed on g4 */
+ isync
+
+/*
+ * Map the memory where the exception handlers will
+ * be copied to when hash constants have been patched.
+ */
+#ifdef CONFIG_APUS_FAST_EXCEPT
+ lis r8,0xfff0
+#else
+ lis r8,0
+#endif
+ ori r8,r8,0x2 /* 128KB, supervisor */
+ mtspr SPRN_DBAT3U,r8
+ mtspr SPRN_DBAT3L,r8
+
+ lis r12,__ptov_table_begin@h
+ ori r12,r12,__ptov_table_begin@l
+ add r12,r12,r10 /* table begin phys address */
+ lis r13,__ptov_table_end@h
+ ori r13,r13,__ptov_table_end@l
+ add r13,r13,r10 /* table end phys address */
+ subi r12,r12,4
+ subi r13,r13,4
+1: lwzu r14,4(r12) /* virt address of instruction */
+ add r14,r14,r10 /* phys address of instruction */
+ lwz r15,0(r14) /* instruction, now insert top */
+ rlwimi r15,r11,16,16,31 /* half of pv const in low half*/
+ stw r15,0(r14) /* of instruction and restore. */
+ dcbst r0,r14 /* write it to memory */
+ sync
+ icbi r0,r14 /* flush the icache line */
+ cmpw r12,r13
+ bne 1b
+
+ sync /* additional sync needed on g4 */
+ isync /* No speculative loading until now */
+ blr
+
+/***********************************************************************
+ * Please note that on APUS the exception handlers are located at the
+ * physical address 0xfff0000. For this reason, the exception handlers
+ * cannot use relative branches to access the code below.
+ ***********************************************************************/
+#endif /* CONFIG_APUS */
+
+#ifdef CONFIG_SMP
+#ifdef CONFIG_GEMINI
+ .globl __secondary_start_gemini
+__secondary_start_gemini:
+ mfspr r4,SPRN_HID0
+ ori r4,r4,HID0_ICFI
+ li r3,0
+ ori r3,r3,HID0_ICE
+ andc r4,r4,r3
+ mtspr SPRN_HID0,r4
+ sync
+ b __secondary_start
+#endif /* CONFIG_GEMINI */
+
+ .globl __secondary_start_pmac_0
+__secondary_start_pmac_0:
+ /* NB the entries for cpus 0, 1, 2 must each occupy 8 bytes. */
+ li r24,0
+ b 1f
+ li r24,1
+ b 1f
+ li r24,2
+ b 1f
+ li r24,3
+1:
+ /* on powersurge, we come in here with IR=0 and DR=1, and DBAT 0
+ set to map the 0xf0000000 - 0xffffffff region */
+ mfmsr r0
+ rlwinm r0,r0,0,28,26 /* clear DR (0x10) */
+ SYNC
+ mtmsr r0
+ isync
+
+ .globl __secondary_start
+__secondary_start:
+#ifdef CONFIG_PPC64BRIDGE
+ mfmsr r0
+ clrldi r0,r0,1 /* make sure it's in 32-bit mode */
+ SYNC
+ MTMSRD(r0)
+ isync
+#endif
+ /* Copy some CPU settings from CPU 0 */
+ bl __restore_cpu_setup
+
+ lis r3,-KERNELBASE@h
+ mr r4,r24
+ bl identify_cpu
+ bl call_setup_cpu /* Call setup_cpu for this CPU */
+#ifdef CONFIG_6xx
+ lis r3,-KERNELBASE@h
+ bl init_idle_6xx
+#endif /* CONFIG_6xx */
+#ifdef CONFIG_POWER4
+ lis r3,-KERNELBASE@h
+ bl init_idle_power4
+#endif /* CONFIG_POWER4 */
+
+ /* get current_thread_info and current */
+ lis r1,secondary_ti@ha
+ tophys(r1,r1)
+ lwz r1,secondary_ti@l(r1)
+ tophys(r2,r1)
+ lwz r2,TI_TASK(r2)
+
+ /* stack */
+ addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
+ li r0,0
+ tophys(r3,r1)
+ stw r0,0(r3)
+
+ /* load up the MMU */
+ bl load_up_mmu
+
+ /* ptr to phys current thread */
+ tophys(r4,r2)
+ addi r4,r4,THREAD /* phys address of our thread_struct */
+ CLR_TOP32(r4)
+ mtspr SPRN_SPRG3,r4
+ li r3,0
+ mtspr SPRN_SPRG2,r3 /* 0 => not in RTAS */
+
+ /* enable MMU and jump to start_secondary */
+ li r4,MSR_KERNEL
+ FIX_SRR1(r4,r5)
+ lis r3,start_secondary@h
+ ori r3,r3,start_secondary@l
+ mtspr SPRN_SRR0,r3
+ mtspr SPRN_SRR1,r4
+ SYNC
+ RFI
+#endif /* CONFIG_SMP */
+
+/*
+ * Those generic dummy functions are kept for CPUs not
+ * included in CONFIG_6xx
+ */
+_GLOBAL(__setup_cpu_power3)
+ blr
+_GLOBAL(__setup_cpu_generic)
+ blr
+
+#if !defined(CONFIG_6xx) && !defined(CONFIG_POWER4)
+_GLOBAL(__save_cpu_setup)
+ blr
+_GLOBAL(__restore_cpu_setup)
+ blr
+#endif /* !defined(CONFIG_6xx) && !defined(CONFIG_POWER4) */
+
+
+/*
+ * Load stuff into the MMU. Intended to be called with
+ * IR=0 and DR=0.
+ */
+load_up_mmu:
+ sync /* Force all PTE updates to finish */
+ isync
+ tlbia /* Clear all TLB entries */
+ sync /* wait for tlbia/tlbie to finish */
+ TLBSYNC /* ... on all CPUs */
+ /* Load the SDR1 register (hash table base & size) */
+ lis r6,_SDR1@ha
+ tophys(r6,r6)
+ lwz r6,_SDR1@l(r6)
+ mtspr SPRN_SDR1,r6
+#ifdef CONFIG_PPC64BRIDGE
+ /* clear the ASR so we only use the pseudo-segment registers. */
+ li r6,0
+ mtasr r6
+#endif /* CONFIG_PPC64BRIDGE */
+ li r0,16 /* load up segment register values */
+ mtctr r0 /* for context 0 */
+ lis r3,0x2000 /* Ku = 1, VSID = 0 */
+ li r4,0
+3: mtsrin r3,r4
+ addi r3,r3,0x111 /* increment VSID */
+ addis r4,r4,0x1000 /* address of next segment */
+ bdnz 3b
+#ifndef CONFIG_POWER4
+/* Load the BAT registers with the values set up by MMU_init.
+ MMU_init takes care of whether we're on a 601 or not. */
+ mfpvr r3
+ srwi r3,r3,16
+ cmpwi r3,1
+ lis r3,BATS@ha
+ addi r3,r3,BATS@l
+ tophys(r3,r3)
+ LOAD_BAT(0,r3,r4,r5)
+ LOAD_BAT(1,r3,r4,r5)
+ LOAD_BAT(2,r3,r4,r5)
+ LOAD_BAT(3,r3,r4,r5)
+#endif /* CONFIG_POWER4 */
+ blr
+
+/*
+ * This is where the main kernel code starts.
+ */
+start_here:
+ /* ptr to current */
+ lis r2,init_task@h
+ ori r2,r2,init_task@l
+ /* Set up for using our exception vectors */
+ /* ptr to phys current thread */
+ tophys(r4,r2)
+ addi r4,r4,THREAD /* init task's THREAD */
+ CLR_TOP32(r4)
+ mtspr SPRN_SPRG3,r4
+ li r3,0
+ mtspr SPRN_SPRG2,r3 /* 0 => not in RTAS */
+
+ /* stack */
+ lis r1,init_thread_union@ha
+ addi r1,r1,init_thread_union@l
+ li r0,0
+ stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
+/*
+ * Do early bootinfo parsing, platform-specific initialization,
+ * and set up the MMU.
+ */
+ mr r3,r31
+ mr r4,r30
+ mr r5,r29
+ mr r6,r28
+ mr r7,r27
+ bl machine_init
+ bl MMU_init
+
+#ifdef CONFIG_APUS
+ /* Copy exception code to exception vector base on APUS. */
+ lis r4,KERNELBASE@h
+#ifdef CONFIG_APUS_FAST_EXCEPT
+ lis r3,0xfff0 /* Copy to 0xfff00000 */
+#else
+ lis r3,0 /* Copy to 0x00000000 */
+#endif
+ li r5,0x4000 /* # bytes of memory to copy */
+ li r6,0
+ bl copy_and_flush /* copy the first 0x4000 bytes */
+#endif /* CONFIG_APUS */
+
+/*
+ * Go back to running unmapped so we can load up new values
+ * for SDR1 (hash table pointer) and the segment registers
+ * and change to using our exception vectors.
+ */
+ lis r4,2f@h
+ ori r4,r4,2f@l
+ tophys(r4,r4)
+ li r3,MSR_KERNEL & ~(MSR_IR|MSR_DR)
+ FIX_SRR1(r3,r5)
+ mtspr SPRN_SRR0,r4
+ mtspr SPRN_SRR1,r3
+ SYNC
+ RFI
+/* Load up the kernel context */
+2: bl load_up_mmu
+
+#ifdef CONFIG_BDI_SWITCH
+ /* Add helper information for the Abatron bdiGDB debugger.
+ * We do this here because we know the mmu is disabled, and
+ * will be enabled for real in just a few instructions.
+ */
+ lis r5, abatron_pteptrs@h
+ ori r5, r5, abatron_pteptrs@l
+ stw r5, 0xf0(r0) /* This much match your Abatron config */
+ lis r6, swapper_pg_dir@h
+ ori r6, r6, swapper_pg_dir@l
+ tophys(r5, r5)
+ stw r6, 0(r5)
+#endif /* CONFIG_BDI_SWITCH */
+
+/* Now turn on the MMU for real! */
+ li r4,MSR_KERNEL
+ FIX_SRR1(r4,r5)
+ lis r3,start_kernel@h
+ ori r3,r3,start_kernel@l
+ mtspr SPRN_SRR0,r3
+ mtspr SPRN_SRR1,r4
+ SYNC
+ RFI
+
+/*
+ * Set up the segment registers for a new context.
+ */
+_GLOBAL(set_context)
+ mulli r3,r3,897 /* multiply context by skew factor */
+ rlwinm r3,r3,4,8,27 /* VSID = (context & 0xfffff) << 4 */
+ addis r3,r3,0x6000 /* Set Ks, Ku bits */
+ li r0,NUM_USER_SEGMENTS
+ mtctr r0
+
+#ifdef CONFIG_BDI_SWITCH
+ /* Context switch the PTE pointer for the Abatron BDI2000.
+ * The PGDIR is passed as second argument.
+ */
+ lis r5, KERNELBASE@h
+ lwz r5, 0xf0(r5)
+ stw r4, 0x4(r5)
+#endif
+ li r4,0
+ isync
+3:
+#ifdef CONFIG_PPC64BRIDGE
+ slbie r4
+#endif /* CONFIG_PPC64BRIDGE */
+ mtsrin r3,r4
+ addi r3,r3,0x111 /* next VSID */
+ rlwinm r3,r3,0,8,3 /* clear out any overflow from VSID field */
+ addis r4,r4,0x1000 /* address of next segment */
+ bdnz 3b
+ sync
+ isync
+ blr
+
+/*
+ * An undocumented "feature" of 604e requires that the v bit
+ * be cleared before changing BAT values.
+ *
+ * Also, newer IBM firmware does not clear bat3 and 4 so
+ * this makes sure it's done.
+ * -- Cort
+ */
+clear_bats:
+ li r10,0
+ mfspr r9,SPRN_PVR
+ rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
+ cmpwi r9, 1
+ beq 1f
+
+ mtspr SPRN_DBAT0U,r10
+ mtspr SPRN_DBAT0L,r10
+ mtspr SPRN_DBAT1U,r10
+ mtspr SPRN_DBAT1L,r10
+ mtspr SPRN_DBAT2U,r10
+ mtspr SPRN_DBAT2L,r10
+ mtspr SPRN_DBAT3U,r10
+ mtspr SPRN_DBAT3L,r10
+1:
+ mtspr SPRN_IBAT0U,r10
+ mtspr SPRN_IBAT0L,r10
+ mtspr SPRN_IBAT1U,r10
+ mtspr SPRN_IBAT1L,r10
+ mtspr SPRN_IBAT2U,r10
+ mtspr SPRN_IBAT2L,r10
+ mtspr SPRN_IBAT3U,r10
+ mtspr SPRN_IBAT3L,r10
+BEGIN_FTR_SECTION
+ /* Here's a tweak: at this point, CPU setup have
+ * not been called yet, so HIGH_BAT_EN may not be
+ * set in HID0 for the 745x processors. However, it
+ * seems that doesn't affect our ability to actually
+ * write to these SPRs.
+ */
+ mtspr SPRN_DBAT4U,r10
+ mtspr SPRN_DBAT4L,r10
+ mtspr SPRN_DBAT5U,r10
+ mtspr SPRN_DBAT5L,r10
+ mtspr SPRN_DBAT6U,r10
+ mtspr SPRN_DBAT6L,r10
+ mtspr SPRN_DBAT7U,r10
+ mtspr SPRN_DBAT7L,r10
+ mtspr SPRN_IBAT4U,r10
+ mtspr SPRN_IBAT4L,r10
+ mtspr SPRN_IBAT5U,r10
+ mtspr SPRN_IBAT5L,r10
+ mtspr SPRN_IBAT6U,r10
+ mtspr SPRN_IBAT6L,r10
+ mtspr SPRN_IBAT7U,r10
+ mtspr SPRN_IBAT7L,r10
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_HIGH_BATS)
+ blr
+
+flush_tlbs:
+ lis r10, 0x40
+1: addic. r10, r10, -0x1000
+ tlbie r10
+ blt 1b
+ sync
+ blr
+
+mmu_off:
+ addi r4, r3, __after_mmu_off - _start
+ mfmsr r3
+ andi. r0,r3,MSR_DR|MSR_IR /* MMU enabled? */
+ beqlr
+ andc r3,r3,r0
+ mtspr SPRN_SRR0,r4
+ mtspr SPRN_SRR1,r3
+ sync
+ RFI
+
+#ifndef CONFIG_POWER4
+/*
+ * Use the first pair of BAT registers to map the 1st 16MB
+ * of RAM to KERNELBASE. From this point on we can't safely
+ * call OF any more.
+ */
+initial_bats:
+ lis r11,KERNELBASE@h
+#ifndef CONFIG_PPC64BRIDGE
+ mfspr r9,SPRN_PVR
+ rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
+ cmpwi 0,r9,1
+ bne 4f
+ ori r11,r11,4 /* set up BAT registers for 601 */
+ li r8,0x7f /* valid, block length = 8MB */
+ oris r9,r11,0x800000@h /* set up BAT reg for 2nd 8M */
+ oris r10,r8,0x800000@h /* set up BAT reg for 2nd 8M */
+ mtspr SPRN_IBAT0U,r11 /* N.B. 601 has valid bit in */
+ mtspr SPRN_IBAT0L,r8 /* lower BAT register */
+ mtspr SPRN_IBAT1U,r9
+ mtspr SPRN_IBAT1L,r10
+ isync
+ blr
+#endif /* CONFIG_PPC64BRIDGE */
+
+4: tophys(r8,r11)
+#ifdef CONFIG_SMP
+ ori r8,r8,0x12 /* R/W access, M=1 */
+#else
+ ori r8,r8,2 /* R/W access */
+#endif /* CONFIG_SMP */
+#ifdef CONFIG_APUS
+ ori r11,r11,BL_8M<<2|0x2 /* set up 8MB BAT registers for 604 */
+#else
+ ori r11,r11,BL_256M<<2|0x2 /* set up BAT registers for 604 */
+#endif /* CONFIG_APUS */
+
+#ifdef CONFIG_PPC64BRIDGE
+ /* clear out the high 32 bits in the BAT */
+ clrldi r11,r11,32
+ clrldi r8,r8,32
+#endif /* CONFIG_PPC64BRIDGE */
+ mtspr SPRN_DBAT0L,r8 /* N.B. 6xx (not 601) have valid */
+ mtspr SPRN_DBAT0U,r11 /* bit in upper BAT register */
+ mtspr SPRN_IBAT0L,r8
+ mtspr SPRN_IBAT0U,r11
+ isync
+ blr
+
+#if !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT)
+setup_disp_bat:
+ /*
+ * setup the display bat prepared for us in prom.c
+ */
+ mflr r8
+ bl reloc_offset
+ mtlr r8
+ addis r8,r3,disp_BAT@ha
+ addi r8,r8,disp_BAT@l
+ lwz r11,0(r8)
+ lwz r8,4(r8)
+ mfspr r9,SPRN_PVR
+ rlwinm r9,r9,16,16,31 /* r9 = 1 for 601, 4 for 604 */
+ cmpwi 0,r9,1
+ beq 1f
+ mtspr SPRN_DBAT3L,r8
+ mtspr SPRN_DBAT3U,r11
+ blr
+1: mtspr SPRN_IBAT3L,r8
+ mtspr SPRN_IBAT3U,r11
+ blr
+
+#endif /* !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT) */
+
+#else /* CONFIG_POWER4 */
+/*
+ * Load up the SDR1 and segment register values now
+ * since we don't have the BATs.
+ * Also make sure we are running in 32-bit mode.
+ */
+
+initial_mm_power4:
+ addis r14,r3,_SDR1@ha /* get the value from _SDR1 */
+ lwz r14,_SDR1@l(r14) /* assume hash table below 4GB */
+ mtspr SPRN_SDR1,r14
+ slbia
+ lis r4,0x2000 /* set pseudo-segment reg 12 */
+ ori r5,r4,0x0ccc
+ mtsr 12,r5
+#if 0
+ ori r5,r4,0x0888 /* set pseudo-segment reg 8 */
+ mtsr 8,r5 /* (for access to serial port) */
+#endif
+#ifdef CONFIG_BOOTX_TEXT
+ ori r5,r4,0x0999 /* set pseudo-segment reg 9 */
+ mtsr 9,r5 /* (for access to screen) */
+#endif
+ mfmsr r0
+ clrldi r0,r0,1
+ sync
+ mtmsr r0
+ isync
+ blr
+
+#endif /* CONFIG_POWER4 */
+
+#ifdef CONFIG_8260
+/* Jump into the system reset for the rom.
+ * We first disable the MMU, and then jump to the ROM reset address.
+ *
+ * r3 is the board info structure, r4 is the location for starting.
+ * I use this for building a small kernel that can load other kernels,
+ * rather than trying to write or rely on a rom monitor that can tftp load.
+ */
+ .globl m8260_gorom
+m8260_gorom:
+ mfmsr r0
+ rlwinm r0,r0,0,17,15 /* clear MSR_EE in r0 */
+ sync
+ mtmsr r0
+ sync
+ mfspr r11, SPRN_HID0
+ lis r10, 0
+ ori r10,r10,HID0_ICE|HID0_DCE
+ andc r11, r11, r10
+ mtspr SPRN_HID0, r11
+ isync
+ li r5, MSR_ME|MSR_RI
+ lis r6,2f@h
+ addis r6,r6,-KERNELBASE@h
+ ori r6,r6,2f@l
+ mtspr SPRN_SRR0,r6
+ mtspr SPRN_SRR1,r5
+ isync
+ sync
+ rfi
+2:
+ mtlr r4
+ blr
+#endif
+
+
+/*
+ * We put a few things here that have to be page-aligned.
+ * This stuff goes at the beginning of the data segment,
+ * which is page-aligned.
+ */
+ .data
+ .globl sdata
+sdata:
+ .globl empty_zero_page
+empty_zero_page:
+ .space 4096
+
+ .globl swapper_pg_dir
+swapper_pg_dir:
+ .space 4096
+
+/*
+ * This space gets a copy of optional info passed to us by the bootstrap
+ * Used to pass parameters into the kernel like root=/dev/sda1, etc.
+ */
+ .globl cmd_line
+cmd_line:
+ .space 512
+
+ .globl intercept_table
+intercept_table:
+ .long 0, 0, i0x200, i0x300, i0x400, 0, i0x600, i0x700
+ .long i0x800, 0, 0, 0, 0, i0xd00, 0, 0
+ .long 0, 0, 0, i0x1300, 0, 0, 0, 0
+ .long 0, 0, 0, 0, 0, 0, 0, 0
+ .long 0, 0, 0, 0, 0, 0, 0, 0
+ .long 0, 0, 0, 0, 0, 0, 0, 0
+
+/* Room for two PTE pointers, usually the kernel and current user pointers
+ * to their respective root page table.
+ */
+abatron_pteptrs:
+ .space 8