This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / arch / powerpc / kernel / head_64.S
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
new file mode 100644 (file)
index 0000000..b7d1404
--- /dev/null
@@ -0,0 +1,2002 @@
+/*
+ *  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.
+ *
+ *  Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
+ *    Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
+ *
+ *  This file contains the low-level support and setup for the
+ *  PowerPC-64 platform, including trap and interrupt dispatch.
+ *
+ *  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 <linux/threads.h>
+#include <asm/reg.h>
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/bug.h>
+#include <asm/cputable.h>
+#include <asm/setup.h>
+#include <asm/hvcall.h>
+#include <asm/iseries/lpar_map.h>
+#include <asm/thread_info.h>
+
+#ifdef CONFIG_PPC_ISERIES
+#define DO_SOFT_DISABLE
+#endif
+
+/*
+ * We layout physical memory as follows:
+ * 0x0000 - 0x00ff : Secondary processor spin code
+ * 0x0100 - 0x2fff : pSeries Interrupt prologs
+ * 0x3000 - 0x5fff : interrupt support, iSeries and common interrupt prologs
+ * 0x6000 - 0x6fff : Initial (CPU0) segment table
+ * 0x7000 - 0x7fff : FWNMI data area
+ * 0x8000 -        : Early init and support code
+ */
+
+/*
+ *   SPRG Usage
+ *
+ *   Register  Definition
+ *
+ *   SPRG0     reserved for hypervisor
+ *   SPRG1     temp - used to save gpr
+ *   SPRG2     temp - used to save gpr
+ *   SPRG3     virt addr of paca
+ */
+
+/*
+ * Entering into this code we make the following assumptions:
+ *  For pSeries:
+ *   1. The MMU is off & open firmware is running in real mode.
+ *   2. The kernel is entered at __start
+ *
+ *  For iSeries:
+ *   1. The MMU is on (as it always is for iSeries)
+ *   2. The kernel is entered at system_reset_iSeries
+ */
+
+       .text
+       .globl  _stext
+_stext:
+#ifdef CONFIG_PPC_MULTIPLATFORM
+_GLOBAL(__start)
+       /* NOP this out unconditionally */
+BEGIN_FTR_SECTION
+       b       .__start_initialization_multiplatform
+END_FTR_SECTION(0, 1)
+#endif /* CONFIG_PPC_MULTIPLATFORM */
+
+       /* Catch branch to 0 in real mode */
+       trap
+
+#ifdef CONFIG_PPC_ISERIES
+       /*
+        * At offset 0x20, there is a pointer to iSeries LPAR data.
+        * This is required by the hypervisor
+        */
+       . = 0x20
+       .llong hvReleaseData-KERNELBASE
+
+       /*
+        * At offset 0x28 and 0x30 are offsets to the mschunks_map
+        * array (used by the iSeries LPAR debugger to do translation
+        * between physical addresses and absolute addresses) and
+        * to the pidhash table (also used by the debugger)
+        */
+       .llong mschunks_map-KERNELBASE
+       .llong 0        /* pidhash-KERNELBASE SFRXXX */
+
+       /* Offset 0x38 - Pointer to start of embedded System.map */
+       .globl  embedded_sysmap_start
+embedded_sysmap_start:
+       .llong  0
+       /* Offset 0x40 - Pointer to end of embedded System.map */
+       .globl  embedded_sysmap_end
+embedded_sysmap_end:
+       .llong  0
+
+#endif /* CONFIG_PPC_ISERIES */
+
+       /* Secondary processors spin on this value until it goes to 1. */
+       .globl  __secondary_hold_spinloop
+__secondary_hold_spinloop:
+       .llong  0x0
+
+       /* Secondary processors write this value with their cpu # */
+       /* after they enter the spin loop immediately below.      */
+       .globl  __secondary_hold_acknowledge
+__secondary_hold_acknowledge:
+       .llong  0x0
+
+       . = 0x60
+/*
+ * The following code is used on pSeries to hold secondary processors
+ * in a spin loop after they have been freed from OpenFirmware, but
+ * before the bulk of the kernel has been relocated.  This code
+ * is relocated to physical address 0x60 before prom_init is run.
+ * All of it must fit below the first exception vector at 0x100.
+ */
+_GLOBAL(__secondary_hold)
+       mfmsr   r24
+       ori     r24,r24,MSR_RI
+       mtmsrd  r24                     /* RI on */
+
+       /* Grab our physical cpu number */
+       mr      r24,r3
+
+       /* Tell the master cpu we're here */
+       /* Relocation is off & we are located at an address less */
+       /* than 0x100, so only need to grab low order offset.    */
+       std     r24,__secondary_hold_acknowledge@l(0)
+       sync
+
+       /* All secondary cpus wait here until told to start. */
+100:   ld      r4,__secondary_hold_spinloop@l(0)
+       cmpdi   0,r4,1
+       bne     100b
+
+#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
+       LOAD_REG_IMMEDIATE(r4, .pSeries_secondary_smp_init)
+       mtctr   r4
+       mr      r3,r24
+       bctr
+#else
+       BUG_OPCODE
+#endif
+
+/* This value is used to mark exception frames on the stack. */
+       .section ".toc","aw"
+exception_marker:
+       .tc     ID_72656773_68657265[TC],0x7265677368657265
+       .text
+
+/*
+ * The following macros define the code that appears as
+ * the prologue to each of the exception handlers.  They
+ * are split into two parts to allow a single kernel binary
+ * to be used for pSeries and iSeries.
+ * LOL.  One day... - paulus
+ */
+
+/*
+ * We make as much of the exception code common between native
+ * exception handlers (including pSeries LPAR) and iSeries LPAR
+ * implementations as possible.
+ */
+
+/*
+ * This is the start of the interrupt handlers for pSeries
+ * This code runs with relocation off.
+ */
+#define EX_R9          0
+#define EX_R10         8
+#define EX_R11         16
+#define EX_R12         24
+#define EX_R13         32
+#define EX_SRR0                40
+#define EX_DAR         48
+#define EX_DSISR       56
+#define EX_CCR         60
+#define EX_R3          64
+#define EX_LR          72
+
+/*
+ * We're short on space and time in the exception prolog, so we can't
+ * use the normal SET_REG_IMMEDIATE macro. Normally we just need the
+ * low halfword of the address, but for Kdump we need the whole low
+ * word.
+ */
+#ifdef CONFIG_CRASH_DUMP
+#define LOAD_HANDLER(reg, label)                                       \
+       oris    reg,reg,(label)@h;      /* virt addr of handler ... */  \
+       ori     reg,reg,(label)@l;      /* .. and the rest */
+#else
+#define LOAD_HANDLER(reg, label)                                       \
+       ori     reg,reg,(label)@l;      /* virt addr of handler ... */
+#endif
+
+#define EXCEPTION_PROLOG_PSERIES(area, label)                          \
+       mfspr   r13,SPRN_SPRG3;         /* get paca address into r13 */ \
+       std     r9,area+EX_R9(r13);     /* save r9 - r12 */             \
+       std     r10,area+EX_R10(r13);                                   \
+       std     r11,area+EX_R11(r13);                                   \
+       std     r12,area+EX_R12(r13);                                   \
+       mfspr   r9,SPRN_SPRG1;                                          \
+       std     r9,area+EX_R13(r13);                                    \
+       mfcr    r9;                                                     \
+       clrrdi  r12,r13,32;             /* get high part of &label */   \
+       mfmsr   r10;                                                    \
+       mfspr   r11,SPRN_SRR0;          /* save SRR0 */                 \
+       LOAD_HANDLER(r12,label)                                         \
+       ori     r10,r10,MSR_IR|MSR_DR|MSR_RI;                           \
+       mtspr   SPRN_SRR0,r12;                                          \
+       mfspr   r12,SPRN_SRR1;          /* and SRR1 */                  \
+       mtspr   SPRN_SRR1,r10;                                          \
+       rfid;                                                           \
+       b       .       /* prevent speculative execution */
+
+/*
+ * This is the start of the interrupt handlers for iSeries
+ * This code runs with relocation on.
+ */
+#define EXCEPTION_PROLOG_ISERIES_1(area)                               \
+       mfspr   r13,SPRN_SPRG3;         /* get paca address into r13 */ \
+       std     r9,area+EX_R9(r13);     /* save r9 - r12 */             \
+       std     r10,area+EX_R10(r13);                                   \
+       std     r11,area+EX_R11(r13);                                   \
+       std     r12,area+EX_R12(r13);                                   \
+       mfspr   r9,SPRN_SPRG1;                                          \
+       std     r9,area+EX_R13(r13);                                    \
+       mfcr    r9
+
+#define EXCEPTION_PROLOG_ISERIES_2                                     \
+       mfmsr   r10;                                                    \
+       ld      r12,PACALPPACAPTR(r13);                                 \
+       ld      r11,LPPACASRR0(r12);                                    \
+       ld      r12,LPPACASRR1(r12);                                    \
+       ori     r10,r10,MSR_RI;                                         \
+       mtmsrd  r10,1
+
+/*
+ * The common exception prolog is used for all except a few exceptions
+ * such as a segment miss on a kernel address.  We have to be prepared
+ * to take another exception from the point where we first touch the
+ * kernel stack onwards.
+ *
+ * On entry r13 points to the paca, r9-r13 are saved in the paca,
+ * r9 contains the saved CR, r11 and r12 contain the saved SRR0 and
+ * SRR1, and relocation is on.
+ */
+#define EXCEPTION_PROLOG_COMMON(n, area)                                  \
+       andi.   r10,r12,MSR_PR;         /* See if coming from user      */ \
+       mr      r10,r1;                 /* Save r1                      */ \
+       subi    r1,r1,INT_FRAME_SIZE;   /* alloc frame on kernel stack  */ \
+       beq-    1f;                                                        \
+       ld      r1,PACAKSAVE(r13);      /* kernel stack to use          */ \
+1:     cmpdi   cr1,r1,0;               /* check if r1 is in userspace  */ \
+       bge-    cr1,bad_stack;          /* abort if it is               */ \
+       std     r9,_CCR(r1);            /* save CR in stackframe        */ \
+       std     r11,_NIP(r1);           /* save SRR0 in stackframe      */ \
+       std     r12,_MSR(r1);           /* save SRR1 in stackframe      */ \
+       std     r10,0(r1);              /* make stack chain pointer     */ \
+       std     r0,GPR0(r1);            /* save r0 in stackframe        */ \
+       std     r10,GPR1(r1);           /* save r1 in stackframe        */ \
+       ACCOUNT_CPU_USER_ENTRY(r9, r10);                                   \
+       std     r2,GPR2(r1);            /* save r2 in stackframe        */ \
+       SAVE_4GPRS(3, r1);              /* save r3 - r6 in stackframe   */ \
+       SAVE_2GPRS(7, r1);              /* save r7, r8 in stackframe    */ \
+       ld      r9,area+EX_R9(r13);     /* move r9, r10 to stackframe   */ \
+       ld      r10,area+EX_R10(r13);                                      \
+       std     r9,GPR9(r1);                                               \
+       std     r10,GPR10(r1);                                             \
+       ld      r9,area+EX_R11(r13);    /* move r11 - r13 to stackframe */ \
+       ld      r10,area+EX_R12(r13);                                      \
+       ld      r11,area+EX_R13(r13);                                      \
+       std     r9,GPR11(r1);                                              \
+       std     r10,GPR12(r1);                                             \
+       std     r11,GPR13(r1);                                             \
+       ld      r2,PACATOC(r13);        /* get kernel TOC into r2       */ \
+       mflr    r9;                     /* save LR in stackframe        */ \
+       std     r9,_LINK(r1);                                              \
+       mfctr   r10;                    /* save CTR in stackframe       */ \
+       std     r10,_CTR(r1);                                              \
+       mfspr   r11,SPRN_XER;           /* save XER in stackframe       */ \
+       std     r11,_XER(r1);                                              \
+       li      r9,(n)+1;                                                  \
+       std     r9,_TRAP(r1);           /* set trap number              */ \
+       li      r10,0;                                                     \
+       ld      r11,exception_marker@toc(r2);                              \
+       std     r10,RESULT(r1);         /* clear regs->result           */ \
+       std     r11,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame      */
+
+/*
+ * Exception vectors.
+ */
+#define STD_EXCEPTION_PSERIES(n, label)                        \
+       . = n;                                          \
+       .globl label##_pSeries;                         \
+label##_pSeries:                                       \
+       HMT_MEDIUM;                                     \
+       mtspr   SPRN_SPRG1,r13;         /* save r13 */  \
+       EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
+
+#define STD_EXCEPTION_ISERIES(n, label, area)          \
+       .globl label##_iSeries;                         \
+label##_iSeries:                                       \
+       HMT_MEDIUM;                                     \
+       mtspr   SPRN_SPRG1,r13;         /* save r13 */  \
+       EXCEPTION_PROLOG_ISERIES_1(area);               \
+       EXCEPTION_PROLOG_ISERIES_2;                     \
+       b       label##_common
+
+#define MASKABLE_EXCEPTION_ISERIES(n, label)                           \
+       .globl label##_iSeries;                                         \
+label##_iSeries:                                                       \
+       HMT_MEDIUM;                                                     \
+       mtspr   SPRN_SPRG1,r13;         /* save r13 */                  \
+       EXCEPTION_PROLOG_ISERIES_1(PACA_EXGEN);                         \
+       lbz     r10,PACAPROCENABLED(r13);                               \
+       cmpwi   0,r10,0;                                                \
+       beq-    label##_iSeries_masked;                                 \
+       EXCEPTION_PROLOG_ISERIES_2;                                     \
+       b       label##_common;                                         \
+
+#ifdef DO_SOFT_DISABLE
+#define DISABLE_INTS                           \
+       lbz     r10,PACAPROCENABLED(r13);       \
+       li      r11,0;                          \
+       std     r10,SOFTE(r1);                  \
+       mfmsr   r10;                            \
+       stb     r11,PACAPROCENABLED(r13);       \
+       ori     r10,r10,MSR_EE;                 \
+       mtmsrd  r10,1
+
+#define ENABLE_INTS                            \
+       lbz     r10,PACAPROCENABLED(r13);       \
+       mfmsr   r11;                            \
+       std     r10,SOFTE(r1);                  \
+       ori     r11,r11,MSR_EE;                 \
+       mtmsrd  r11,1
+
+#else  /* hard enable/disable interrupts */
+#define DISABLE_INTS
+
+#define ENABLE_INTS                            \
+       ld      r12,_MSR(r1);                   \
+       mfmsr   r11;                            \
+       rlwimi  r11,r12,0,MSR_EE;               \
+       mtmsrd  r11,1
+
+#endif
+
+#define STD_EXCEPTION_COMMON(trap, label, hdlr)                \
+       .align  7;                                      \
+       .globl label##_common;                          \
+label##_common:                                                \
+       EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);      \
+       DISABLE_INTS;                                   \
+       bl      .save_nvgprs;                           \
+       addi    r3,r1,STACK_FRAME_OVERHEAD;             \
+       bl      hdlr;                                   \
+       b       .ret_from_except
+
+/*
+ * Like STD_EXCEPTION_COMMON, but for exceptions that can occur
+ * in the idle task and therefore need the special idle handling.
+ */
+#define STD_EXCEPTION_COMMON_IDLE(trap, label, hdlr)   \
+       .align  7;                                      \
+       .globl label##_common;                          \
+label##_common:                                                \
+       EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);      \
+       FINISH_NAP;                                     \
+       DISABLE_INTS;                                   \
+       bl      .save_nvgprs;                           \
+       addi    r3,r1,STACK_FRAME_OVERHEAD;             \
+       bl      hdlr;                                   \
+       b       .ret_from_except
+
+#define STD_EXCEPTION_COMMON_LITE(trap, label, hdlr)   \
+       .align  7;                                      \
+       .globl label##_common;                          \
+label##_common:                                                \
+       EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);      \
+       FINISH_NAP;                                     \
+       DISABLE_INTS;                                   \
+       bl      .ppc64_runlatch_on;                     \
+       addi    r3,r1,STACK_FRAME_OVERHEAD;             \
+       bl      hdlr;                                   \
+       b       .ret_from_except_lite
+
+/*
+ * When the idle code in power4_idle puts the CPU into NAP mode,
+ * it has to do so in a loop, and relies on the external interrupt
+ * and decrementer interrupt entry code to get it out of the loop.
+ * It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
+ * to signal that it is in the loop and needs help to get out.
+ */
+#ifdef CONFIG_PPC_970_NAP
+#define FINISH_NAP                             \
+BEGIN_FTR_SECTION                              \
+       clrrdi  r11,r1,THREAD_SHIFT;            \
+       ld      r9,TI_LOCAL_FLAGS(r11);         \
+       andi.   r10,r9,_TLF_NAPPING;            \
+       bnel    power4_fixup_nap;               \
+END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
+#else
+#define FINISH_NAP
+#endif
+
+/*
+ * Start of pSeries system interrupt routines
+ */
+       . = 0x100
+       .globl __start_interrupts
+__start_interrupts:
+
+       STD_EXCEPTION_PSERIES(0x100, system_reset)
+
+       . = 0x200
+_machine_check_pSeries:
+       HMT_MEDIUM
+       mtspr   SPRN_SPRG1,r13          /* save r13 */
+       EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)
+
+       . = 0x300
+       .globl data_access_pSeries
+data_access_pSeries:
+       HMT_MEDIUM
+       mtspr   SPRN_SPRG1,r13
+BEGIN_FTR_SECTION
+       mtspr   SPRN_SPRG2,r12
+       mfspr   r13,SPRN_DAR
+       mfspr   r12,SPRN_DSISR
+       srdi    r13,r13,60
+       rlwimi  r13,r12,16,0x20
+       mfcr    r12
+       cmpwi   r13,0x2c
+       beq     .do_stab_bolted_pSeries
+       mtcrf   0x80,r12
+       mfspr   r12,SPRN_SPRG2
+END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
+       EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, data_access_common)
+
+       . = 0x380
+       .globl data_access_slb_pSeries
+data_access_slb_pSeries:
+       HMT_MEDIUM
+       mtspr   SPRN_SPRG1,r13
+       mfspr   r13,SPRN_SPRG3          /* get paca address into r13 */
+       std     r3,PACA_EXSLB+EX_R3(r13)
+       mfspr   r3,SPRN_DAR
+       std     r9,PACA_EXSLB+EX_R9(r13)        /* save r9 - r12 */
+       mfcr    r9
+#ifdef __DISABLED__
+       /* Keep that around for when we re-implement dynamic VSIDs */
+       cmpdi   r3,0
+       bge     slb_miss_user_pseries
+#endif /* __DISABLED__ */
+       std     r10,PACA_EXSLB+EX_R10(r13)
+       std     r11,PACA_EXSLB+EX_R11(r13)
+       std     r12,PACA_EXSLB+EX_R12(r13)
+       mfspr   r10,SPRN_SPRG1
+       std     r10,PACA_EXSLB+EX_R13(r13)
+       mfspr   r12,SPRN_SRR1           /* and SRR1 */
+       b       .slb_miss_realmode      /* Rel. branch works in real mode */
+
+       STD_EXCEPTION_PSERIES(0x400, instruction_access)
+
+       . = 0x480
+       .globl instruction_access_slb_pSeries
+instruction_access_slb_pSeries:
+       HMT_MEDIUM
+       mtspr   SPRN_SPRG1,r13
+       mfspr   r13,SPRN_SPRG3          /* get paca address into r13 */
+       std     r3,PACA_EXSLB+EX_R3(r13)
+       mfspr   r3,SPRN_SRR0            /* SRR0 is faulting address */
+       std     r9,PACA_EXSLB+EX_R9(r13)        /* save r9 - r12 */
+       mfcr    r9
+#ifdef __DISABLED__
+       /* Keep that around for when we re-implement dynamic VSIDs */
+       cmpdi   r3,0
+       bge     slb_miss_user_pseries
+#endif /* __DISABLED__ */
+       std     r10,PACA_EXSLB+EX_R10(r13)
+       std     r11,PACA_EXSLB+EX_R11(r13)
+       std     r12,PACA_EXSLB+EX_R12(r13)
+       mfspr   r10,SPRN_SPRG1
+       std     r10,PACA_EXSLB+EX_R13(r13)
+       mfspr   r12,SPRN_SRR1           /* and SRR1 */
+       b       .slb_miss_realmode      /* Rel. branch works in real mode */
+
+       STD_EXCEPTION_PSERIES(0x500, hardware_interrupt)
+       STD_EXCEPTION_PSERIES(0x600, alignment)
+       STD_EXCEPTION_PSERIES(0x700, program_check)
+       STD_EXCEPTION_PSERIES(0x800, fp_unavailable)
+       STD_EXCEPTION_PSERIES(0x900, decrementer)
+       STD_EXCEPTION_PSERIES(0xa00, trap_0a)
+       STD_EXCEPTION_PSERIES(0xb00, trap_0b)
+
+       . = 0xc00
+       .globl  system_call_pSeries
+system_call_pSeries:
+       HMT_MEDIUM
+       mr      r9,r13
+       mfmsr   r10
+       mfspr   r13,SPRN_SPRG3
+       mfspr   r11,SPRN_SRR0
+       clrrdi  r12,r13,32
+       oris    r12,r12,system_call_common@h
+       ori     r12,r12,system_call_common@l
+       mtspr   SPRN_SRR0,r12
+       ori     r10,r10,MSR_IR|MSR_DR|MSR_RI
+       mfspr   r12,SPRN_SRR1
+       mtspr   SPRN_SRR1,r10
+       rfid
+       b       .       /* prevent speculative execution */
+
+       STD_EXCEPTION_PSERIES(0xd00, single_step)
+       STD_EXCEPTION_PSERIES(0xe00, trap_0e)
+
+       /* We need to deal with the Altivec unavailable exception
+        * here which is at 0xf20, thus in the middle of the
+        * prolog code of the PerformanceMonitor one. A little
+        * trickery is thus necessary
+        */
+       . = 0xf00
+       b       performance_monitor_pSeries
+
+       STD_EXCEPTION_PSERIES(0xf20, altivec_unavailable)
+
+       STD_EXCEPTION_PSERIES(0x1300, instruction_breakpoint)
+       STD_EXCEPTION_PSERIES(0x1700, altivec_assist)
+
+       . = 0x3000
+
+/*** pSeries interrupt support ***/
+
+       /* moved from 0xf00 */
+       STD_EXCEPTION_PSERIES(., performance_monitor)
+
+       .align  7
+_GLOBAL(do_stab_bolted_pSeries)
+       mtcrf   0x80,r12
+       mfspr   r12,SPRN_SPRG2
+       EXCEPTION_PROLOG_PSERIES(PACA_EXSLB, .do_stab_bolted)
+
+/*
+ * We have some room here  we use that to put
+ * the peries slb miss user trampoline code so it's reasonably
+ * away from slb_miss_user_common to avoid problems with rfid
+ *
+ * This is used for when the SLB miss handler has to go virtual,
+ * which doesn't happen for now anymore but will once we re-implement
+ * dynamic VSIDs for shared page tables
+ */
+#ifdef __DISABLED__
+slb_miss_user_pseries:
+       std     r10,PACA_EXGEN+EX_R10(r13)
+       std     r11,PACA_EXGEN+EX_R11(r13)
+       std     r12,PACA_EXGEN+EX_R12(r13)
+       mfspr   r10,SPRG1
+       ld      r11,PACA_EXSLB+EX_R9(r13)
+       ld      r12,PACA_EXSLB+EX_R3(r13)
+       std     r10,PACA_EXGEN+EX_R13(r13)
+       std     r11,PACA_EXGEN+EX_R9(r13)
+       std     r12,PACA_EXGEN+EX_R3(r13)
+       clrrdi  r12,r13,32
+       mfmsr   r10
+       mfspr   r11,SRR0                        /* save SRR0 */
+       ori     r12,r12,slb_miss_user_common@l  /* virt addr of handler */
+       ori     r10,r10,MSR_IR|MSR_DR|MSR_RI
+       mtspr   SRR0,r12
+       mfspr   r12,SRR1                        /* and SRR1 */
+       mtspr   SRR1,r10
+       rfid
+       b       .                               /* prevent spec. execution */
+#endif /* __DISABLED__ */
+
+/*
+ * Vectors for the FWNMI option.  Share common code.
+ */
+       .globl system_reset_fwnmi
+      .align 7
+system_reset_fwnmi:
+       HMT_MEDIUM
+       mtspr   SPRN_SPRG1,r13          /* save r13 */
+       EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common)
+
+       .globl machine_check_fwnmi
+      .align 7
+machine_check_fwnmi:
+       HMT_MEDIUM
+       mtspr   SPRN_SPRG1,r13          /* save r13 */
+       EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)
+
+#ifdef CONFIG_PPC_ISERIES
+/***  ISeries-LPAR interrupt handlers ***/
+
+       STD_EXCEPTION_ISERIES(0x200, machine_check, PACA_EXMC)
+
+       .globl data_access_iSeries
+data_access_iSeries:
+       mtspr   SPRN_SPRG1,r13
+BEGIN_FTR_SECTION
+       mtspr   SPRN_SPRG2,r12
+       mfspr   r13,SPRN_DAR
+       mfspr   r12,SPRN_DSISR
+       srdi    r13,r13,60
+       rlwimi  r13,r12,16,0x20
+       mfcr    r12
+       cmpwi   r13,0x2c
+       beq     .do_stab_bolted_iSeries
+       mtcrf   0x80,r12
+       mfspr   r12,SPRN_SPRG2
+END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
+       EXCEPTION_PROLOG_ISERIES_1(PACA_EXGEN)
+       EXCEPTION_PROLOG_ISERIES_2
+       b       data_access_common
+
+.do_stab_bolted_iSeries:
+       mtcrf   0x80,r12
+       mfspr   r12,SPRN_SPRG2
+       EXCEPTION_PROLOG_ISERIES_1(PACA_EXSLB)
+       EXCEPTION_PROLOG_ISERIES_2
+       b       .do_stab_bolted
+
+       .globl  data_access_slb_iSeries
+data_access_slb_iSeries:
+       mtspr   SPRN_SPRG1,r13          /* save r13 */
+       mfspr   r13,SPRN_SPRG3          /* get paca address into r13 */
+       std     r3,PACA_EXSLB+EX_R3(r13)
+       mfspr   r3,SPRN_DAR
+       std     r9,PACA_EXSLB+EX_R9(r13)
+       mfcr    r9
+#ifdef __DISABLED__
+       cmpdi   r3,0
+       bge     slb_miss_user_iseries
+#endif
+       std     r10,PACA_EXSLB+EX_R10(r13)
+       std     r11,PACA_EXSLB+EX_R11(r13)
+       std     r12,PACA_EXSLB+EX_R12(r13)
+       mfspr   r10,SPRN_SPRG1
+       std     r10,PACA_EXSLB+EX_R13(r13)
+       ld      r12,PACALPPACAPTR(r13)
+       ld      r12,LPPACASRR1(r12)
+       b       .slb_miss_realmode
+
+       STD_EXCEPTION_ISERIES(0x400, instruction_access, PACA_EXGEN)
+
+       .globl  instruction_access_slb_iSeries
+instruction_access_slb_iSeries:
+       mtspr   SPRN_SPRG1,r13          /* save r13 */
+       mfspr   r13,SPRN_SPRG3          /* get paca address into r13 */
+       std     r3,PACA_EXSLB+EX_R3(r13)
+       ld      r3,PACALPPACAPTR(r13)
+       ld      r3,LPPACASRR0(r3)       /* get SRR0 value */
+       std     r9,PACA_EXSLB+EX_R9(r13)
+       mfcr    r9
+#ifdef __DISABLED__
+       cmpdi   r3,0
+       bge     .slb_miss_user_iseries
+#endif
+       std     r10,PACA_EXSLB+EX_R10(r13)
+       std     r11,PACA_EXSLB+EX_R11(r13)
+       std     r12,PACA_EXSLB+EX_R12(r13)
+       mfspr   r10,SPRN_SPRG1
+       std     r10,PACA_EXSLB+EX_R13(r13)
+       ld      r12,PACALPPACAPTR(r13)
+       ld      r12,LPPACASRR1(r12)
+       b       .slb_miss_realmode
+
+#ifdef __DISABLED__
+slb_miss_user_iseries:
+       std     r10,PACA_EXGEN+EX_R10(r13)
+       std     r11,PACA_EXGEN+EX_R11(r13)
+       std     r12,PACA_EXGEN+EX_R12(r13)
+       mfspr   r10,SPRG1
+       ld      r11,PACA_EXSLB+EX_R9(r13)
+       ld      r12,PACA_EXSLB+EX_R3(r13)
+       std     r10,PACA_EXGEN+EX_R13(r13)
+       std     r11,PACA_EXGEN+EX_R9(r13)
+       std     r12,PACA_EXGEN+EX_R3(r13)
+       EXCEPTION_PROLOG_ISERIES_2
+       b       slb_miss_user_common
+#endif
+
+       MASKABLE_EXCEPTION_ISERIES(0x500, hardware_interrupt)
+       STD_EXCEPTION_ISERIES(0x600, alignment, PACA_EXGEN)
+       STD_EXCEPTION_ISERIES(0x700, program_check, PACA_EXGEN)
+       STD_EXCEPTION_ISERIES(0x800, fp_unavailable, PACA_EXGEN)
+       MASKABLE_EXCEPTION_ISERIES(0x900, decrementer)
+       STD_EXCEPTION_ISERIES(0xa00, trap_0a, PACA_EXGEN)
+       STD_EXCEPTION_ISERIES(0xb00, trap_0b, PACA_EXGEN)
+
+       .globl  system_call_iSeries
+system_call_iSeries:
+       mr      r9,r13
+       mfspr   r13,SPRN_SPRG3
+       EXCEPTION_PROLOG_ISERIES_2
+       b       system_call_common
+
+       STD_EXCEPTION_ISERIES( 0xd00, single_step, PACA_EXGEN)
+       STD_EXCEPTION_ISERIES( 0xe00, trap_0e, PACA_EXGEN)
+       STD_EXCEPTION_ISERIES( 0xf00, performance_monitor, PACA_EXGEN)
+
+       .globl system_reset_iSeries
+system_reset_iSeries:
+       mfspr   r13,SPRN_SPRG3          /* Get paca address */
+       mfmsr   r24
+       ori     r24,r24,MSR_RI
+       mtmsrd  r24                     /* RI on */
+       lhz     r24,PACAPACAINDEX(r13)  /* Get processor # */
+       cmpwi   0,r24,0                 /* Are we processor 0? */
+       beq     .__start_initialization_iSeries /* Start up the first processor */
+       mfspr   r4,SPRN_CTRLF
+       li      r5,CTRL_RUNLATCH        /* Turn off the run light */
+       andc    r4,r4,r5
+       mtspr   SPRN_CTRLT,r4
+
+1:
+       HMT_LOW
+#ifdef CONFIG_SMP
+       lbz     r23,PACAPROCSTART(r13)  /* Test if this processor
+                                        * should start */
+       sync
+       LOAD_REG_IMMEDIATE(r3,current_set)
+       sldi    r28,r24,3               /* get current_set[cpu#] */
+       ldx     r3,r3,r28
+       addi    r1,r3,THREAD_SIZE
+       subi    r1,r1,STACK_FRAME_OVERHEAD
+
+       cmpwi   0,r23,0
+       beq     iSeries_secondary_smp_loop      /* Loop until told to go */
+       bne     .__secondary_start              /* Loop until told to go */
+iSeries_secondary_smp_loop:
+       /* Let the Hypervisor know we are alive */
+       /* 8002 is a call to HvCallCfg::getLps, a harmless Hypervisor function */
+       lis     r3,0x8002
+       rldicr  r3,r3,32,15             /* r0 = (r3 << 32) & 0xffff000000000000 */
+#else /* CONFIG_SMP */
+       /* Yield the processor.  This is required for non-SMP kernels
+               which are running on multi-threaded machines. */
+       lis     r3,0x8000
+       rldicr  r3,r3,32,15             /* r3 = (r3 << 32) & 0xffff000000000000 */
+       addi    r3,r3,18                /* r3 = 0x8000000000000012 which is "yield" */
+       li      r4,0                    /* "yield timed" */
+       li      r5,-1                   /* "yield forever" */
+#endif /* CONFIG_SMP */
+       li      r0,-1                   /* r0=-1 indicates a Hypervisor call */
+       sc                              /* Invoke the hypervisor via a system call */
+       mfspr   r13,SPRN_SPRG3          /* Put r13 back ???? */
+       b       1b                      /* If SMP not configured, secondaries
+                                        * loop forever */
+
+       .globl decrementer_iSeries_masked
+decrementer_iSeries_masked:
+       /* We may not have a valid TOC pointer in here. */
+       li      r11,1
+       ld      r12,PACALPPACAPTR(r13)
+       stb     r11,LPPACADECRINT(r12)
+       LOAD_REG_IMMEDIATE(r12, tb_ticks_per_jiffy)
+       lwz     r12,0(r12)
+       mtspr   SPRN_DEC,r12
+       /* fall through */
+
+       .globl hardware_interrupt_iSeries_masked
+hardware_interrupt_iSeries_masked:
+       mtcrf   0x80,r9         /* Restore regs */
+       ld      r12,PACALPPACAPTR(r13)
+       ld      r11,LPPACASRR0(r12)
+       ld      r12,LPPACASRR1(r12)
+       mtspr   SPRN_SRR0,r11
+       mtspr   SPRN_SRR1,r12
+       ld      r9,PACA_EXGEN+EX_R9(r13)
+       ld      r10,PACA_EXGEN+EX_R10(r13)
+       ld      r11,PACA_EXGEN+EX_R11(r13)
+       ld      r12,PACA_EXGEN+EX_R12(r13)
+       ld      r13,PACA_EXGEN+EX_R13(r13)
+       rfid
+       b       .       /* prevent speculative execution */
+#endif /* CONFIG_PPC_ISERIES */
+
+/*** Common interrupt handlers ***/
+
+       STD_EXCEPTION_COMMON(0x100, system_reset, .system_reset_exception)
+
+       /*
+        * Machine check is different because we use a different
+        * save area: PACA_EXMC instead of PACA_EXGEN.
+        */
+       .align  7
+       .globl machine_check_common
+machine_check_common:
+       EXCEPTION_PROLOG_COMMON(0x200, PACA_EXMC)
+       FINISH_NAP
+       DISABLE_INTS
+       bl      .save_nvgprs
+       addi    r3,r1,STACK_FRAME_OVERHEAD
+       bl      .machine_check_exception
+       b       .ret_from_except
+
+       STD_EXCEPTION_COMMON_LITE(0x900, decrementer, .timer_interrupt)
+       STD_EXCEPTION_COMMON(0xa00, trap_0a, .unknown_exception)
+       STD_EXCEPTION_COMMON(0xb00, trap_0b, .unknown_exception)
+       STD_EXCEPTION_COMMON(0xd00, single_step, .single_step_exception)
+       STD_EXCEPTION_COMMON(0xe00, trap_0e, .unknown_exception)
+       STD_EXCEPTION_COMMON_IDLE(0xf00, performance_monitor, .performance_monitor_exception)
+       STD_EXCEPTION_COMMON(0x1300, instruction_breakpoint, .instruction_breakpoint_exception)
+#ifdef CONFIG_ALTIVEC
+       STD_EXCEPTION_COMMON(0x1700, altivec_assist, .altivec_assist_exception)
+#else
+       STD_EXCEPTION_COMMON(0x1700, altivec_assist, .unknown_exception)
+#endif
+
+/*
+ * Here we have detected that the kernel stack pointer is bad.
+ * R9 contains the saved CR, r13 points to the paca,
+ * r10 contains the (bad) kernel stack pointer,
+ * r11 and r12 contain the saved SRR0 and SRR1.
+ * We switch to using an emergency stack, save the registers there,
+ * and call kernel_bad_stack(), which panics.
+ */
+bad_stack:
+       ld      r1,PACAEMERGSP(r13)
+       subi    r1,r1,64+INT_FRAME_SIZE
+       std     r9,_CCR(r1)
+       std     r10,GPR1(r1)
+       std     r11,_NIP(r1)
+       std     r12,_MSR(r1)
+       mfspr   r11,SPRN_DAR
+       mfspr   r12,SPRN_DSISR
+       std     r11,_DAR(r1)
+       std     r12,_DSISR(r1)
+       mflr    r10
+       mfctr   r11
+       mfxer   r12
+       std     r10,_LINK(r1)
+       std     r11,_CTR(r1)
+       std     r12,_XER(r1)
+       SAVE_GPR(0,r1)
+       SAVE_GPR(2,r1)
+       SAVE_4GPRS(3,r1)
+       SAVE_2GPRS(7,r1)
+       SAVE_10GPRS(12,r1)
+       SAVE_10GPRS(22,r1)
+       addi    r11,r1,INT_FRAME_SIZE
+       std     r11,0(r1)
+       li      r12,0
+       std     r12,0(r11)
+       ld      r2,PACATOC(r13)
+1:     addi    r3,r1,STACK_FRAME_OVERHEAD
+       bl      .kernel_bad_stack
+       b       1b
+
+/*
+ * Return from an exception with minimal checks.
+ * The caller is assumed to have done EXCEPTION_PROLOG_COMMON.
+ * If interrupts have been enabled, or anything has been
+ * done that might have changed the scheduling status of
+ * any task or sent any task a signal, you should use
+ * ret_from_except or ret_from_except_lite instead of this.
+ */
+       .globl  fast_exception_return
+fast_exception_return:
+       ld      r12,_MSR(r1)
+       ld      r11,_NIP(r1)
+       andi.   r3,r12,MSR_RI           /* check if RI is set */
+       beq-    unrecov_fer
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+       andi.   r3,r12,MSR_PR
+       beq     2f
+       ACCOUNT_CPU_USER_EXIT(r3, r4)
+2:
+#endif
+
+       ld      r3,_CCR(r1)
+       ld      r4,_LINK(r1)
+       ld      r5,_CTR(r1)
+       ld      r6,_XER(r1)
+       mtcr    r3
+       mtlr    r4
+       mtctr   r5
+       mtxer   r6
+       REST_GPR(0, r1)
+       REST_8GPRS(2, r1)
+
+       mfmsr   r10
+       clrrdi  r10,r10,2               /* clear RI (LE is 0 already) */
+       mtmsrd  r10,1
+
+       mtspr   SPRN_SRR1,r12
+       mtspr   SPRN_SRR0,r11
+       REST_4GPRS(10, r1)
+       ld      r1,GPR1(r1)
+       rfid
+       b       .       /* prevent speculative execution */
+
+unrecov_fer:
+       bl      .save_nvgprs
+1:     addi    r3,r1,STACK_FRAME_OVERHEAD
+       bl      .unrecoverable_exception
+       b       1b
+
+/*
+ * Here r13 points to the paca, r9 contains the saved CR,
+ * SRR0 and SRR1 are saved in r11 and r12,
+ * r9 - r13 are saved in paca->exgen.
+ */
+       .align  7
+       .globl data_access_common
+data_access_common:
+       mfspr   r10,SPRN_DAR
+       std     r10,PACA_EXGEN+EX_DAR(r13)
+       mfspr   r10,SPRN_DSISR
+       stw     r10,PACA_EXGEN+EX_DSISR(r13)
+       EXCEPTION_PROLOG_COMMON(0x300, PACA_EXGEN)
+       ld      r3,PACA_EXGEN+EX_DAR(r13)
+       lwz     r4,PACA_EXGEN+EX_DSISR(r13)
+       li      r5,0x300
+       b       .do_hash_page           /* Try to handle as hpte fault */
+
+       .align  7
+       .globl instruction_access_common
+instruction_access_common:
+       EXCEPTION_PROLOG_COMMON(0x400, PACA_EXGEN)
+       ld      r3,_NIP(r1)
+       andis.  r4,r12,0x5820
+       li      r5,0x400
+       b       .do_hash_page           /* Try to handle as hpte fault */
+
+/*
+ * Here is the common SLB miss user that is used when going to virtual
+ * mode for SLB misses, that is currently not used
+ */
+#ifdef __DISABLED__
+       .align  7
+       .globl  slb_miss_user_common
+slb_miss_user_common:
+       mflr    r10
+       std     r3,PACA_EXGEN+EX_DAR(r13)
+       stw     r9,PACA_EXGEN+EX_CCR(r13)
+       std     r10,PACA_EXGEN+EX_LR(r13)
+       std     r11,PACA_EXGEN+EX_SRR0(r13)
+       bl      .slb_allocate_user
+
+       ld      r10,PACA_EXGEN+EX_LR(r13)
+       ld      r3,PACA_EXGEN+EX_R3(r13)
+       lwz     r9,PACA_EXGEN+EX_CCR(r13)
+       ld      r11,PACA_EXGEN+EX_SRR0(r13)
+       mtlr    r10
+       beq-    slb_miss_fault
+
+       andi.   r10,r12,MSR_RI          /* check for unrecoverable exception */
+       beq-    unrecov_user_slb
+       mfmsr   r10
+
+.machine push
+.machine "power4"
+       mtcrf   0x80,r9
+.machine pop
+
+       clrrdi  r10,r10,2               /* clear RI before setting SRR0/1 */
+       mtmsrd  r10,1
+
+       mtspr   SRR0,r11
+       mtspr   SRR1,r12
+
+       ld      r9,PACA_EXGEN+EX_R9(r13)
+       ld      r10,PACA_EXGEN+EX_R10(r13)
+       ld      r11,PACA_EXGEN+EX_R11(r13)
+       ld      r12,PACA_EXGEN+EX_R12(r13)
+       ld      r13,PACA_EXGEN+EX_R13(r13)
+       rfid
+       b       .
+
+slb_miss_fault:
+       EXCEPTION_PROLOG_COMMON(0x380, PACA_EXGEN)
+       ld      r4,PACA_EXGEN+EX_DAR(r13)
+       li      r5,0
+       std     r4,_DAR(r1)
+       std     r5,_DSISR(r1)
+       b       .handle_page_fault
+
+unrecov_user_slb:
+       EXCEPTION_PROLOG_COMMON(0x4200, PACA_EXGEN)
+       DISABLE_INTS
+       bl      .save_nvgprs
+1:     addi    r3,r1,STACK_FRAME_OVERHEAD
+       bl      .unrecoverable_exception
+       b       1b
+
+#endif /* __DISABLED__ */
+
+
+/*
+ * r13 points to the PACA, r9 contains the saved CR,
+ * r12 contain the saved SRR1, SRR0 is still ready for return
+ * r3 has the faulting address
+ * r9 - r13 are saved in paca->exslb.
+ * r3 is saved in paca->slb_r3
+ * We assume we aren't going to take any exceptions during this procedure.
+ */
+_GLOBAL(slb_miss_realmode)
+       mflr    r10
+
+       stw     r9,PACA_EXSLB+EX_CCR(r13)       /* save CR in exc. frame */
+       std     r10,PACA_EXSLB+EX_LR(r13)       /* save LR */
+
+       bl      .slb_allocate_realmode
+
+       /* All done -- return from exception. */
+
+       ld      r10,PACA_EXSLB+EX_LR(r13)
+       ld      r3,PACA_EXSLB+EX_R3(r13)
+       lwz     r9,PACA_EXSLB+EX_CCR(r13)       /* get saved CR */
+#ifdef CONFIG_PPC_ISERIES
+       ld      r11,PACALPPACAPTR(r13)
+       ld      r11,LPPACASRR0(r11)             /* get SRR0 value */
+#endif /* CONFIG_PPC_ISERIES */
+
+       mtlr    r10
+
+       andi.   r10,r12,MSR_RI  /* check for unrecoverable exception */
+       beq-    unrecov_slb
+
+.machine       push
+.machine       "power4"
+       mtcrf   0x80,r9
+       mtcrf   0x01,r9         /* slb_allocate uses cr0 and cr7 */
+.machine       pop
+
+#ifdef CONFIG_PPC_ISERIES
+       mtspr   SPRN_SRR0,r11
+       mtspr   SPRN_SRR1,r12
+#endif /* CONFIG_PPC_ISERIES */
+       ld      r9,PACA_EXSLB+EX_R9(r13)
+       ld      r10,PACA_EXSLB+EX_R10(r13)
+       ld      r11,PACA_EXSLB+EX_R11(r13)
+       ld      r12,PACA_EXSLB+EX_R12(r13)
+       ld      r13,PACA_EXSLB+EX_R13(r13)
+       rfid
+       b       .       /* prevent speculative execution */
+
+unrecov_slb:
+       EXCEPTION_PROLOG_COMMON(0x4100, PACA_EXSLB)
+       DISABLE_INTS
+       bl      .save_nvgprs
+1:     addi    r3,r1,STACK_FRAME_OVERHEAD
+       bl      .unrecoverable_exception
+       b       1b
+
+       .align  7
+       .globl hardware_interrupt_common
+       .globl hardware_interrupt_entry
+hardware_interrupt_common:
+       EXCEPTION_PROLOG_COMMON(0x500, PACA_EXGEN)
+       FINISH_NAP
+hardware_interrupt_entry:
+       DISABLE_INTS
+       bl      .ppc64_runlatch_on
+       addi    r3,r1,STACK_FRAME_OVERHEAD
+       bl      .do_IRQ
+       b       .ret_from_except_lite
+
+#ifdef CONFIG_PPC_970_NAP
+power4_fixup_nap:
+       andc    r9,r9,r10
+       std     r9,TI_LOCAL_FLAGS(r11)
+       ld      r10,_LINK(r1)           /* make idle task do the */
+       std     r10,_NIP(r1)            /* equivalent of a blr */
+       blr
+#endif
+
+       .align  7
+       .globl alignment_common
+alignment_common:
+       mfspr   r10,SPRN_DAR
+       std     r10,PACA_EXGEN+EX_DAR(r13)
+       mfspr   r10,SPRN_DSISR
+       stw     r10,PACA_EXGEN+EX_DSISR(r13)
+       EXCEPTION_PROLOG_COMMON(0x600, PACA_EXGEN)
+       ld      r3,PACA_EXGEN+EX_DAR(r13)
+       lwz     r4,PACA_EXGEN+EX_DSISR(r13)
+       std     r3,_DAR(r1)
+       std     r4,_DSISR(r1)
+       bl      .save_nvgprs
+       addi    r3,r1,STACK_FRAME_OVERHEAD
+       ENABLE_INTS
+       bl      .alignment_exception
+       b       .ret_from_except
+
+       .align  7
+       .globl program_check_common
+program_check_common:
+       EXCEPTION_PROLOG_COMMON(0x700, PACA_EXGEN)
+       bl      .save_nvgprs
+       addi    r3,r1,STACK_FRAME_OVERHEAD
+       ENABLE_INTS
+       bl      .program_check_exception
+       b       .ret_from_except
+
+       .align  7
+       .globl fp_unavailable_common
+fp_unavailable_common:
+       EXCEPTION_PROLOG_COMMON(0x800, PACA_EXGEN)
+       bne     .load_up_fpu            /* if from user, just load it up */
+       bl      .save_nvgprs
+       addi    r3,r1,STACK_FRAME_OVERHEAD
+       ENABLE_INTS
+       bl      .kernel_fp_unavailable_exception
+       BUG_OPCODE
+
+       .align  7
+       .globl altivec_unavailable_common
+altivec_unavailable_common:
+       EXCEPTION_PROLOG_COMMON(0xf20, PACA_EXGEN)
+#ifdef CONFIG_ALTIVEC
+BEGIN_FTR_SECTION
+       bne     .load_up_altivec        /* if from user, just load it up */
+END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
+#endif
+       bl      .save_nvgprs
+       addi    r3,r1,STACK_FRAME_OVERHEAD
+       ENABLE_INTS
+       bl      .altivec_unavailable_exception
+       b       .ret_from_except
+
+#ifdef CONFIG_ALTIVEC
+/*
+ * load_up_altivec(unused, unused, tsk)
+ * Disable VMX for the task which had it previously,
+ * and save its vector registers in its thread_struct.
+ * Enables the VMX for use in the kernel on return.
+ * On SMP we know the VMX is free, since we give it up every
+ * switch (ie, no lazy save of the vector registers).
+ * On entry: r13 == 'current' && last_task_used_altivec != 'current'
+ */
+_STATIC(load_up_altivec)
+       mfmsr   r5                      /* grab the current MSR */
+       oris    r5,r5,MSR_VEC@h
+       mtmsrd  r5                      /* enable use of VMX now */
+       isync
+
+/*
+ * For SMP, we don't do lazy VMX switching because it just gets too
+ * horrendously complex, especially when a task switches from one CPU
+ * to another.  Instead we call giveup_altvec in switch_to.
+ * VRSAVE isn't dealt with here, that is done in the normal context
+ * switch code. Note that we could rely on vrsave value to eventually
+ * avoid saving all of the VREGs here...
+ */
+#ifndef CONFIG_SMP
+       ld      r3,last_task_used_altivec@got(r2)
+       ld      r4,0(r3)
+       cmpdi   0,r4,0
+       beq     1f
+       /* Save VMX state to last_task_used_altivec's THREAD struct */
+       addi    r4,r4,THREAD
+       SAVE_32VRS(0,r5,r4)
+       mfvscr  vr0
+       li      r10,THREAD_VSCR
+       stvx    vr0,r10,r4
+       /* Disable VMX for last_task_used_altivec */
+       ld      r5,PT_REGS(r4)
+       ld      r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+       lis     r6,MSR_VEC@h
+       andc    r4,r4,r6
+       std     r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+1:
+#endif /* CONFIG_SMP */
+       /* Hack: if we get an altivec unavailable trap with VRSAVE
+        * set to all zeros, we assume this is a broken application
+        * that fails to set it properly, and thus we switch it to
+        * all 1's
+        */
+       mfspr   r4,SPRN_VRSAVE
+       cmpdi   0,r4,0
+       bne+    1f
+       li      r4,-1
+       mtspr   SPRN_VRSAVE,r4
+1:
+       /* enable use of VMX after return */
+       ld      r4,PACACURRENT(r13)
+       addi    r5,r4,THREAD            /* Get THREAD */
+       oris    r12,r12,MSR_VEC@h
+       std     r12,_MSR(r1)
+       li      r4,1
+       li      r10,THREAD_VSCR
+       stw     r4,THREAD_USED_VR(r5)
+       lvx     vr0,r10,r5
+       mtvscr  vr0
+       REST_32VRS(0,r4,r5)
+#ifndef CONFIG_SMP
+       /* Update last_task_used_math to 'current' */
+       subi    r4,r5,THREAD            /* Back to 'current' */
+       std     r4,0(r3)
+#endif /* CONFIG_SMP */
+       /* restore registers and return */
+       b       fast_exception_return
+#endif /* CONFIG_ALTIVEC */
+
+/*
+ * Hash table stuff
+ */
+       .align  7
+_GLOBAL(do_hash_page)
+       std     r3,_DAR(r1)
+       std     r4,_DSISR(r1)
+
+       andis.  r0,r4,0xa450            /* weird error? */
+       bne-    .handle_page_fault      /* if not, try to insert a HPTE */
+BEGIN_FTR_SECTION
+       andis.  r0,r4,0x0020            /* Is it a segment table fault? */
+       bne-    .do_ste_alloc           /* If so handle it */
+END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
+
+       /*
+        * We need to set the _PAGE_USER bit if MSR_PR is set or if we are
+        * accessing a userspace segment (even from the kernel). We assume
+        * kernel addresses always have the high bit set.
+        */
+       rlwinm  r4,r4,32-25+9,31-9,31-9 /* DSISR_STORE -> _PAGE_RW */
+       rotldi  r0,r3,15                /* Move high bit into MSR_PR posn */
+       orc     r0,r12,r0               /* MSR_PR | ~high_bit */
+       rlwimi  r4,r0,32-13,30,30       /* becomes _PAGE_USER access bit */
+       ori     r4,r4,1                 /* add _PAGE_PRESENT */
+       rlwimi  r4,r5,22+2,31-2,31-2    /* Set _PAGE_EXEC if trap is 0x400 */
+
+       /*
+        * On iSeries, we soft-disable interrupts here, then
+        * hard-enable interrupts so that the hash_page code can spin on
+        * the hash_table_lock without problems on a shared processor.
+        */
+       DISABLE_INTS
+
+       /*
+        * r3 contains the faulting address
+        * r4 contains the required access permissions
+        * r5 contains the trap number
+        *
+        * at return r3 = 0 for success
+        */
+       bl      .hash_page              /* build HPTE if possible */
+       cmpdi   r3,0                    /* see if hash_page succeeded */
+
+#ifdef DO_SOFT_DISABLE
+       /*
+        * If we had interrupts soft-enabled at the point where the
+        * DSI/ISI occurred, and an interrupt came in during hash_page,
+        * handle it now.
+        * We jump to ret_from_except_lite rather than fast_exception_return
+        * because ret_from_except_lite will check for and handle pending
+        * interrupts if necessary.
+        */
+       beq     .ret_from_except_lite
+       /* For a hash failure, we don't bother re-enabling interrupts */
+       ble-    12f
+
+       /*
+        * hash_page couldn't handle it, set soft interrupt enable back
+        * to what it was before the trap.  Note that .local_irq_restore
+        * handles any interrupts pending at this point.
+        */
+       ld      r3,SOFTE(r1)
+       bl      .local_irq_restore
+       b       11f
+#else
+       beq     fast_exception_return   /* Return from exception on success */
+       ble-    12f                     /* Failure return from hash_page */
+
+       /* fall through */
+#endif
+
+/* Here we have a page fault that hash_page can't handle. */
+_GLOBAL(handle_page_fault)
+       ENABLE_INTS
+11:    ld      r4,_DAR(r1)
+       ld      r5,_DSISR(r1)
+       addi    r3,r1,STACK_FRAME_OVERHEAD
+       bl      .do_page_fault
+       cmpdi   r3,0
+       beq+    .ret_from_except_lite
+       bl      .save_nvgprs
+       mr      r5,r3
+       addi    r3,r1,STACK_FRAME_OVERHEAD
+       lwz     r4,_DAR(r1)
+       bl      .bad_page_fault
+       b       .ret_from_except
+
+/* We have a page fault that hash_page could handle but HV refused
+ * the PTE insertion
+ */
+12:    bl      .save_nvgprs
+       addi    r3,r1,STACK_FRAME_OVERHEAD
+       lwz     r4,_DAR(r1)
+       bl      .low_hash_fault
+       b       .ret_from_except
+
+       /* here we have a segment miss */
+_GLOBAL(do_ste_alloc)
+       bl      .ste_allocate           /* try to insert stab entry */
+       cmpdi   r3,0
+       beq+    fast_exception_return
+       b       .handle_page_fault
+
+/*
+ * r13 points to the PACA, r9 contains the saved CR,
+ * r11 and r12 contain the saved SRR0 and SRR1.
+ * r9 - r13 are saved in paca->exslb.
+ * We assume we aren't going to take any exceptions during this procedure.
+ * We assume (DAR >> 60) == 0xc.
+ */
+       .align  7
+_GLOBAL(do_stab_bolted)
+       stw     r9,PACA_EXSLB+EX_CCR(r13)       /* save CR in exc. frame */
+       std     r11,PACA_EXSLB+EX_SRR0(r13)     /* save SRR0 in exc. frame */
+
+       /* Hash to the primary group */
+       ld      r10,PACASTABVIRT(r13)
+       mfspr   r11,SPRN_DAR
+       srdi    r11,r11,28
+       rldimi  r10,r11,7,52    /* r10 = first ste of the group */
+
+       /* Calculate VSID */
+       /* This is a kernel address, so protovsid = ESID */
+       ASM_VSID_SCRAMBLE(r11, r9)
+       rldic   r9,r11,12,16    /* r9 = vsid << 12 */
+
+       /* Search the primary group for a free entry */
+1:     ld      r11,0(r10)      /* Test valid bit of the current ste    */
+       andi.   r11,r11,0x80
+       beq     2f
+       addi    r10,r10,16
+       andi.   r11,r10,0x70
+       bne     1b
+
+       /* Stick for only searching the primary group for now.          */
+       /* At least for now, we use a very simple random castout scheme */
+       /* Use the TB as a random number ;  OR in 1 to avoid entry 0    */
+       mftb    r11
+       rldic   r11,r11,4,57    /* r11 = (r11 << 4) & 0x70 */
+       ori     r11,r11,0x10
+
+       /* r10 currently points to an ste one past the group of interest */
+       /* make it point to the randomly selected entry                 */
+       subi    r10,r10,128
+       or      r10,r10,r11     /* r10 is the entry to invalidate       */
+
+       isync                   /* mark the entry invalid               */
+       ld      r11,0(r10)
+       rldicl  r11,r11,56,1    /* clear the valid bit */
+       rotldi  r11,r11,8
+       std     r11,0(r10)
+       sync
+
+       clrrdi  r11,r11,28      /* Get the esid part of the ste         */
+       slbie   r11
+
+2:     std     r9,8(r10)       /* Store the vsid part of the ste       */
+       eieio
+
+       mfspr   r11,SPRN_DAR            /* Get the new esid                     */
+       clrrdi  r11,r11,28      /* Permits a full 32b of ESID           */
+       ori     r11,r11,0x90    /* Turn on valid and kp                 */
+       std     r11,0(r10)      /* Put new entry back into the stab     */
+
+       sync
+
+       /* All done -- return from exception. */
+       lwz     r9,PACA_EXSLB+EX_CCR(r13)       /* get saved CR */
+       ld      r11,PACA_EXSLB+EX_SRR0(r13)     /* get saved SRR0 */
+
+       andi.   r10,r12,MSR_RI
+       beq-    unrecov_slb
+
+       mtcrf   0x80,r9                 /* restore CR */
+
+       mfmsr   r10
+       clrrdi  r10,r10,2
+       mtmsrd  r10,1
+
+       mtspr   SPRN_SRR0,r11
+       mtspr   SPRN_SRR1,r12
+       ld      r9,PACA_EXSLB+EX_R9(r13)
+       ld      r10,PACA_EXSLB+EX_R10(r13)
+       ld      r11,PACA_EXSLB+EX_R11(r13)
+       ld      r12,PACA_EXSLB+EX_R12(r13)
+       ld      r13,PACA_EXSLB+EX_R13(r13)
+       rfid
+       b       .       /* prevent speculative execution */
+
+/*
+ * Space for CPU0's segment table.
+ *
+ * On iSeries, the hypervisor must fill in at least one entry before
+ * we get control (with relocate on).  The address is give to the hv
+ * as a page number (see xLparMap in lpardata.c), so this must be at a
+ * fixed address (the linker can't compute (u64)&initial_stab >>
+ * PAGE_SHIFT).
+ */
+       . = STAB0_OFFSET        /* 0x6000 */
+       .globl initial_stab
+initial_stab:
+       .space  4096
+
+/*
+ * Data area reserved for FWNMI option.
+ * This address (0x7000) is fixed by the RPA.
+ */
+       .= 0x7000
+       .globl fwnmi_data_area
+fwnmi_data_area:
+
+       /* iSeries does not use the FWNMI stuff, so it is safe to put
+        * this here, even if we later allow kernels that will boot on
+        * both pSeries and iSeries */
+#ifdef CONFIG_PPC_ISERIES
+        . = LPARMAP_PHYS
+#include "lparmap.s"
+/*
+ * This ".text" is here for old compilers that generate a trailing
+ * .note section when compiling .c files to .s
+ */
+       .text
+#endif /* CONFIG_PPC_ISERIES */
+
+        . = 0x8000
+
+/*
+ * On pSeries, secondary processors spin in the following code.
+ * At entry, r3 = this processor's number (physical cpu id)
+ */
+_GLOBAL(pSeries_secondary_smp_init)
+       mr      r24,r3
+       
+       /* turn on 64-bit mode */
+       bl      .enable_64b_mode
+       isync
+
+       /* Copy some CPU settings from CPU 0 */
+       bl      .__restore_cpu_setup
+
+       /* Set up a paca value for this processor. Since we have the
+        * physical cpu id in r24, we need to search the pacas to find
+        * which logical id maps to our physical one.
+        */
+       LOAD_REG_IMMEDIATE(r13, paca)   /* Get base vaddr of paca array  */
+       li      r5,0                    /* logical cpu id                */
+1:     lhz     r6,PACAHWCPUID(r13)     /* Load HW procid from paca      */
+       cmpw    r6,r24                  /* Compare to our id             */
+       beq     2f
+       addi    r13,r13,PACA_SIZE       /* Loop to next PACA on miss     */
+       addi    r5,r5,1
+       cmpwi   r5,NR_CPUS
+       blt     1b
+
+       mr      r3,r24                  /* not found, copy phys to r3    */
+       b       .kexec_wait             /* next kernel might do better   */
+
+2:     mtspr   SPRN_SPRG3,r13          /* Save vaddr of paca in SPRG3   */
+       /* From now on, r24 is expected to be logical cpuid */
+       mr      r24,r5
+3:     HMT_LOW
+       lbz     r23,PACAPROCSTART(r13)  /* Test if this processor should */
+                                       /* start.                        */
+       sync
+
+       /* Create a temp kernel stack for use before relocation is on.  */
+       ld      r1,PACAEMERGSP(r13)
+       subi    r1,r1,STACK_FRAME_OVERHEAD
+
+       cmpwi   0,r23,0
+#ifdef CONFIG_SMP
+       bne     .__secondary_start
+#endif
+       b       3b                      /* Loop until told to go         */
+
+#ifdef CONFIG_PPC_ISERIES
+_STATIC(__start_initialization_iSeries)
+       /* Clear out the BSS */
+       LOAD_REG_IMMEDIATE(r11,__bss_stop)
+       LOAD_REG_IMMEDIATE(r8,__bss_start)
+       sub     r11,r11,r8              /* bss size                     */
+       addi    r11,r11,7               /* round up to an even double word */
+       rldicl. r11,r11,61,3            /* shift right by 3             */
+       beq     4f
+       addi    r8,r8,-8
+       li      r0,0
+       mtctr   r11                     /* zero this many doublewords   */
+3:     stdu    r0,8(r8)
+       bdnz    3b
+4:
+       LOAD_REG_IMMEDIATE(r1,init_thread_union)
+       addi    r1,r1,THREAD_SIZE
+       li      r0,0
+       stdu    r0,-STACK_FRAME_OVERHEAD(r1)
+
+       LOAD_REG_IMMEDIATE(r3,cpu_specs)
+       LOAD_REG_IMMEDIATE(r4,cur_cpu_spec)
+       li      r5,0
+       bl      .identify_cpu
+
+       LOAD_REG_IMMEDIATE(r2,__toc_start)
+       addi    r2,r2,0x4000
+       addi    r2,r2,0x4000
+
+       bl      .iSeries_early_setup
+       bl      .early_setup
+
+       /* relocation is on at this point */
+
+       b       .start_here_common
+#endif /* CONFIG_PPC_ISERIES */
+
+#ifdef CONFIG_PPC_MULTIPLATFORM
+
+_STATIC(__mmu_off)
+       mfmsr   r3
+       andi.   r0,r3,MSR_IR|MSR_DR
+       beqlr
+       andc    r3,r3,r0
+       mtspr   SPRN_SRR0,r4
+       mtspr   SPRN_SRR1,r3
+       sync
+       rfid
+       b       .       /* prevent speculative execution */
+
+
+/*
+ * Here is our main kernel entry point. We support currently 2 kind of entries
+ * depending on the value of r5.
+ *
+ *   r5 != NULL -> OF entry, we go to prom_init, "legacy" parameter content
+ *                 in r3...r7
+ *   
+ *   r5 == NULL -> kexec style entry. r3 is a physical pointer to the
+ *                 DT block, r4 is a physical pointer to the kernel itself
+ *
+ */
+_GLOBAL(__start_initialization_multiplatform)
+#ifdef CONFIG_PPC_MULTIPLATFORM
+       /*
+        * Are we booted from a PROM Of-type client-interface ?
+        */
+       cmpldi  cr0,r5,0
+       bne     .__boot_from_prom               /* yes -> prom */
+#endif
+
+       /* Save parameters */
+       mr      r31,r3
+       mr      r30,r4
+
+       /* Make sure we are running in 64 bits mode */
+       bl      .enable_64b_mode
+
+       /* Setup some critical 970 SPRs before switching MMU off */
+       bl      .__970_cpu_preinit
+
+       /* cpu # */
+       li      r24,0
+
+       /* Switch off MMU if not already */
+       LOAD_REG_IMMEDIATE(r4, .__after_prom_start - KERNELBASE)
+       add     r4,r4,r30
+       bl      .__mmu_off
+       b       .__after_prom_start
+
+#ifdef CONFIG_PPC_MULTIPLATFORM
+_STATIC(__boot_from_prom)
+       /* Save parameters */
+       mr      r31,r3
+       mr      r30,r4
+       mr      r29,r5
+       mr      r28,r6
+       mr      r27,r7
+
+       /*
+        * Align the stack to 16-byte boundary
+        * Depending on the size and layout of the ELF sections in the initial
+        * boot binary, the stack pointer will be unalignet on PowerMac
+        */
+       rldicr  r1,r1,0,59
+
+       /* Make sure we are running in 64 bits mode */
+       bl      .enable_64b_mode
+
+       /* put a relocation offset into r3 */
+       bl      .reloc_offset
+
+       LOAD_REG_IMMEDIATE(r2,__toc_start)
+       addi    r2,r2,0x4000
+       addi    r2,r2,0x4000
+
+       /* Relocate the TOC from a virt addr to a real addr */
+       add     r2,r2,r3
+
+       /* Restore parameters */
+       mr      r3,r31
+       mr      r4,r30
+       mr      r5,r29
+       mr      r6,r28
+       mr      r7,r27
+
+       /* Do all of the interaction with OF client interface */
+       bl      .prom_init
+       /* We never return */
+       trap
+#endif
+
+/*
+ * At this point, r3 contains the physical address we are running at,
+ * returned by prom_init()
+ */
+_STATIC(__after_prom_start)
+
+/*
+ * We need to run with __start at physical address PHYSICAL_START.
+ * This will leave some code in the first 256B of
+ * real memory, which are reserved for software use.
+ * The remainder of the first page is loaded with the fixed
+ * interrupt vectors.  The next two pages are filled with
+ * unknown exception placeholders.
+ *
+ * Note: This process overwrites the OF exception vectors.
+ *     r26 == relocation offset
+ *     r27 == KERNELBASE
+ */
+       bl      .reloc_offset
+       mr      r26,r3
+       LOAD_REG_IMMEDIATE(r27, KERNELBASE)
+
+       LOAD_REG_IMMEDIATE(r3, PHYSICAL_START)  /* target addr */
+
+       // XXX FIXME: Use phys returned by OF (r30)
+       add     r4,r27,r26              /* source addr                   */
+                                       /* current address of _start     */
+                                       /*   i.e. where we are running   */
+                                       /*      the source addr          */
+
+       LOAD_REG_IMMEDIATE(r5,copy_to_here) /* # bytes of memory to copy */
+       sub     r5,r5,r27
+
+       li      r6,0x100                /* Start offset, the first 0x100 */
+                                       /* bytes were copied earlier.    */
+
+       bl      .copy_and_flush         /* copy the first n bytes        */
+                                       /* this includes the code being  */
+                                       /* executed here.                */
+
+       LOAD_REG_IMMEDIATE(r0, 4f)      /* Jump to the copy of this code */
+       mtctr   r0                      /* that we just made/relocated   */
+       bctr
+
+4:     LOAD_REG_IMMEDIATE(r5,klimit)
+       add     r5,r5,r26
+       ld      r5,0(r5)                /* get the value of klimit */
+       sub     r5,r5,r27
+       bl      .copy_and_flush         /* copy the rest */
+       b       .start_here_multiplatform
+
+#endif /* CONFIG_PPC_MULTIPLATFORM */
+
+/*
+ * 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.
+ *
+ * Note: this routine *only* clobbers r0, r6 and lr
+ */
+_GLOBAL(copy_and_flush)
+       addi    r5,r5,-8
+       addi    r6,r6,-8
+4:     li      r0,16                   /* Use the least common         */
+                                       /* denominator cache line       */
+                                       /* size.  This results in       */
+                                       /* extra cache line flushes     */
+                                       /* but operation is correct.    */
+                                       /* Can't get cache line size    */
+                                       /* from NACA as it is being     */
+                                       /* moved too.                   */
+
+       mtctr   r0                      /* put # words/line in ctr      */
+3:     addi    r6,r6,8                 /* copy a cache line            */
+       ldx     r0,r6,r4
+       stdx    r0,r6,r3
+       bdnz    3b
+       dcbst   r6,r3                   /* write it to memory           */
+       sync
+       icbi    r6,r3                   /* flush the icache line        */
+       cmpld   0,r6,r5
+       blt     4b
+       sync
+       addi    r5,r5,8
+       addi    r6,r6,8
+       blr
+
+.align 8
+copy_to_here:
+
+#ifdef CONFIG_SMP
+#ifdef CONFIG_PPC_PMAC
+/*
+ * On PowerMac, secondary processors starts from the reset vector, which
+ * is temporarily turned into a call to one of the functions below.
+ */
+       .section ".text";
+       .align 2 ;
+
+       .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:
+       
+_GLOBAL(pmac_secondary_start)
+       /* turn on 64-bit mode */
+       bl      .enable_64b_mode
+       isync
+
+       /* Copy some CPU settings from CPU 0 */
+       bl      .__restore_cpu_setup
+
+       /* pSeries do that early though I don't think we really need it */
+       mfmsr   r3
+       ori     r3,r3,MSR_RI
+       mtmsrd  r3                      /* RI on */
+
+       /* Set up a paca value for this processor. */
+       LOAD_REG_IMMEDIATE(r4, paca)    /* Get base vaddr of paca array */
+       mulli   r13,r24,PACA_SIZE        /* Calculate vaddr of right paca */
+       add     r13,r13,r4              /* for this processor.          */
+       mtspr   SPRN_SPRG3,r13           /* Save vaddr of paca in SPRG3 */
+
+       /* Create a temp kernel stack for use before relocation is on.  */
+       ld      r1,PACAEMERGSP(r13)
+       subi    r1,r1,STACK_FRAME_OVERHEAD
+
+       b       .__secondary_start
+
+#endif /* CONFIG_PPC_PMAC */
+
+/*
+ * This function is called after the master CPU has released the
+ * secondary processors.  The execution environment is relocation off.
+ * The paca for this processor has the following fields initialized at
+ * this point:
+ *   1. Processor number
+ *   2. Segment table pointer (virtual address)
+ * On entry the following are set:
+ *   r1        = stack pointer.  vaddr for iSeries, raddr (temp stack) for pSeries
+ *   r24   = cpu# (in Linux terms)
+ *   r13   = paca virtual address
+ *   SPRG3 = paca virtual address
+ */
+_GLOBAL(__secondary_start)
+       /* Set thread priority to MEDIUM */
+       HMT_MEDIUM
+
+       /* Load TOC */
+       ld      r2,PACATOC(r13)
+
+       /* Do early setup for that CPU (stab, slb, hash table pointer) */
+       bl      .early_setup_secondary
+
+       /* Initialize the kernel stack.  Just a repeat for iSeries.      */
+       LOAD_REG_ADDR(r3, current_set)
+       sldi    r28,r24,3               /* get current_set[cpu#]         */
+       ldx     r1,r3,r28
+       addi    r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
+       std     r1,PACAKSAVE(r13)
+
+       /* Clear backchain so we get nice backtraces */
+       li      r7,0
+       mtlr    r7
+
+       /* enable MMU and jump to start_secondary */
+       LOAD_REG_ADDR(r3, .start_secondary_prolog)
+       LOAD_REG_IMMEDIATE(r4, MSR_KERNEL)
+#ifdef DO_SOFT_DISABLE
+       ori     r4,r4,MSR_EE
+#endif
+       mtspr   SPRN_SRR0,r3
+       mtspr   SPRN_SRR1,r4
+       rfid
+       b       .       /* prevent speculative execution */
+
+/* 
+ * Running with relocation on at this point.  All we want to do is
+ * zero the stack back-chain pointer before going into C code.
+ */
+_GLOBAL(start_secondary_prolog)
+       li      r3,0
+       std     r3,0(r1)                /* Zero the stack frame pointer */
+       bl      .start_secondary
+       b       .
+#endif
+
+/*
+ * This subroutine clobbers r11 and r12
+ */
+_GLOBAL(enable_64b_mode)
+       mfmsr   r11                     /* grab the current MSR */
+       li      r12,1
+       rldicr  r12,r12,MSR_SF_LG,(63-MSR_SF_LG)
+       or      r11,r11,r12
+       li      r12,1
+       rldicr  r12,r12,MSR_ISF_LG,(63-MSR_ISF_LG)
+       or      r11,r11,r12
+       mtmsrd  r11
+       isync
+       blr
+
+#ifdef CONFIG_PPC_MULTIPLATFORM
+/*
+ * This is where the main kernel code starts.
+ */
+_STATIC(start_here_multiplatform)
+       /* get a new offset, now that the kernel has moved. */
+       bl      .reloc_offset
+       mr      r26,r3
+
+       /* Clear out the BSS. It may have been done in prom_init,
+        * already but that's irrelevant since prom_init will soon
+        * be detached from the kernel completely. Besides, we need
+        * to clear it now for kexec-style entry.
+        */
+       LOAD_REG_IMMEDIATE(r11,__bss_stop)
+       LOAD_REG_IMMEDIATE(r8,__bss_start)
+       sub     r11,r11,r8              /* bss size                     */
+       addi    r11,r11,7               /* round up to an even double word */
+       rldicl. r11,r11,61,3            /* shift right by 3             */
+       beq     4f
+       addi    r8,r8,-8
+       li      r0,0
+       mtctr   r11                     /* zero this many doublewords   */
+3:     stdu    r0,8(r8)
+       bdnz    3b
+4:
+
+       mfmsr   r6
+       ori     r6,r6,MSR_RI
+       mtmsrd  r6                      /* RI on */
+
+       /* The following gets the stack and TOC set up with the regs */
+       /* pointing to the real addr of the kernel stack.  This is   */
+       /* all done to support the C function call below which sets  */
+       /* up the htab.  This is done because we have relocated the  */
+       /* kernel but are still running in real mode. */
+
+       LOAD_REG_IMMEDIATE(r3,init_thread_union)
+       add     r3,r3,r26
+
+       /* set up a stack pointer (physical address) */
+       addi    r1,r3,THREAD_SIZE
+       li      r0,0
+       stdu    r0,-STACK_FRAME_OVERHEAD(r1)
+
+       /* set up the TOC (physical address) */
+       LOAD_REG_IMMEDIATE(r2,__toc_start)
+       addi    r2,r2,0x4000
+       addi    r2,r2,0x4000
+       add     r2,r2,r26
+
+       LOAD_REG_IMMEDIATE(r3, cpu_specs)
+       add     r3,r3,r26
+       LOAD_REG_IMMEDIATE(r4,cur_cpu_spec)
+       add     r4,r4,r26
+       mr      r5,r26
+       bl      .identify_cpu
+
+       /* Save some low level config HIDs of CPU0 to be copied to
+        * other CPUs later on, or used for suspend/resume
+        */
+       bl      .__save_cpu_setup
+       sync
+
+       /* Do very early kernel initializations, including initial hash table,
+        * stab and slb setup before we turn on relocation.     */
+
+       /* Restore parameters passed from prom_init/kexec */
+       mr      r3,r31
+       bl      .early_setup
+
+       LOAD_REG_IMMEDIATE(r3, .start_here_common)
+       LOAD_REG_IMMEDIATE(r4, MSR_KERNEL)
+       mtspr   SPRN_SRR0,r3
+       mtspr   SPRN_SRR1,r4
+       rfid
+       b       .       /* prevent speculative execution */
+#endif /* CONFIG_PPC_MULTIPLATFORM */
+       
+       /* This is where all platforms converge execution */
+_STATIC(start_here_common)
+       /* relocation is on at this point */
+
+       /* The following code sets up the SP and TOC now that we are */
+       /* running with translation enabled. */
+
+       LOAD_REG_IMMEDIATE(r3,init_thread_union)
+
+       /* set up the stack */
+       addi    r1,r3,THREAD_SIZE
+       li      r0,0
+       stdu    r0,-STACK_FRAME_OVERHEAD(r1)
+
+       /* Apply the CPUs-specific fixups (nop out sections not relevant
+        * to this CPU
+        */
+       li      r3,0
+       bl      .do_cpu_ftr_fixups
+
+       LOAD_REG_IMMEDIATE(r26, boot_cpuid)
+       lwz     r26,0(r26)
+
+       LOAD_REG_IMMEDIATE(r24, paca)   /* Get base vaddr of paca array  */
+       mulli   r13,r26,PACA_SIZE       /* Calculate vaddr of right paca */
+       add     r13,r13,r24             /* for this processor.           */
+       mtspr   SPRN_SPRG3,r13
+
+       /* ptr to current */
+       LOAD_REG_IMMEDIATE(r4, init_task)
+       std     r4,PACACURRENT(r13)
+
+       /* Load the TOC */
+       ld      r2,PACATOC(r13)
+       std     r1,PACAKSAVE(r13)
+
+       bl      .setup_system
+
+       /* Load up the kernel context */
+5:
+#ifdef DO_SOFT_DISABLE
+       li      r5,0
+       stb     r5,PACAPROCENABLED(r13) /* Soft Disabled */
+       mfmsr   r5
+       ori     r5,r5,MSR_EE            /* Hard Enabled */
+       mtmsrd  r5
+#endif
+
+       bl .start_kernel
+
+       /* Not reached */
+       BUG_OPCODE
+
+/* Put the paca pointer into r13 and SPRG3 */
+_GLOBAL(setup_boot_paca)
+       LOAD_REG_IMMEDIATE(r3, boot_cpuid)
+       lwz     r3,0(r3)
+       LOAD_REG_IMMEDIATE(r4, paca)    /* Get base vaddr of paca array  */
+       mulli   r3,r3,PACA_SIZE         /* Calculate vaddr of right paca */
+       add     r13,r3,r4               /* for this processor.           */
+       mtspr   SPRN_SPRG3,r13
+
+       blr
+
+/*
+ * We put a few things here that have to be page-aligned.
+ * This stuff goes at the beginning of the bss, which is page-aligned.
+ */
+       .section ".bss"
+
+       .align  PAGE_SHIFT
+
+       .globl  empty_zero_page
+empty_zero_page:
+       .space  PAGE_SIZE
+
+       .globl  swapper_pg_dir
+swapper_pg_dir:
+       .space  PAGE_SIZE
+
+/*
+ * 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  COMMAND_LINE_SIZE