![Olof Johansson](/assets/img/avatar_default.png)
Commit5c0484e25e
('powerpc: Endian safe trampoline') resulted in losing proper alignment of the spinlock variables used when booting secondary CPUs, causing some quite odd issues with failing to boot on PA Semi-based systems. This showed itself on ppc64_defconfig, but not on pasemi_defconfig, so it had gone unnoticed when I initially tested the LE patch set. Fix is to add explicit alignment instead of relying on good luck. :) [ It appears that there is a different issue with PA Semi systems however this fix is definitely correct so applying anyway -- BenH ] Fixes:5c0484e25e
('powerpc: Endian safe trampoline') Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=67811 Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
827 lines
21 KiB
ArmAsm
827 lines
21 KiB
ArmAsm
/*
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* PowerPC version
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
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* Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
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* Adapted for Power Macintosh by Paul Mackerras.
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* Low-level exception handlers and MMU support
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* rewritten by Paul Mackerras.
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* Copyright (C) 1996 Paul Mackerras.
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*
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* Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
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* Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
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*
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* This file contains the entry point for the 64-bit kernel along
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* with some early initialization code common to all 64-bit powerpc
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* variants.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/threads.h>
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#include <asm/reg.h>
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#include <asm/page.h>
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#include <asm/mmu.h>
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#include <asm/ppc_asm.h>
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#include <asm/asm-offsets.h>
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#include <asm/bug.h>
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#include <asm/cputable.h>
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#include <asm/setup.h>
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#include <asm/hvcall.h>
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#include <asm/thread_info.h>
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#include <asm/firmware.h>
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#include <asm/page_64.h>
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#include <asm/irqflags.h>
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#include <asm/kvm_book3s_asm.h>
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#include <asm/ptrace.h>
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#include <asm/hw_irq.h>
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/* The physical memory is laid out such that the secondary processor
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* spin code sits at 0x0000...0x00ff. On server, the vectors follow
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* using the layout described in exceptions-64s.S
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*/
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/*
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* Entering into this code we make the following assumptions:
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*
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* For pSeries or server processors:
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* 1. The MMU is off & open firmware is running in real mode.
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* 2. The kernel is entered at __start
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* -or- For OPAL entry:
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* 1. The MMU is off, processor in HV mode, primary CPU enters at 0
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* with device-tree in gpr3. We also get OPAL base in r8 and
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* entry in r9 for debugging purposes
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* 2. Secondary processors enter at 0x60 with PIR in gpr3
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*
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* For Book3E processors:
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* 1. The MMU is on running in AS0 in a state defined in ePAPR
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* 2. The kernel is entered at __start
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*/
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.text
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.globl _stext
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_stext:
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_GLOBAL(__start)
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/* NOP this out unconditionally */
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BEGIN_FTR_SECTION
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FIXUP_ENDIAN
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b .__start_initialization_multiplatform
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END_FTR_SECTION(0, 1)
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/* Catch branch to 0 in real mode */
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trap
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/* Secondary processors spin on this value until it becomes nonzero.
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* When it does it contains the real address of the descriptor
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* of the function that the cpu should jump to to continue
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* initialization.
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*/
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.balign 8
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.globl __secondary_hold_spinloop
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__secondary_hold_spinloop:
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.llong 0x0
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/* Secondary processors write this value with their cpu # */
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/* after they enter the spin loop immediately below. */
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.globl __secondary_hold_acknowledge
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__secondary_hold_acknowledge:
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.llong 0x0
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#ifdef CONFIG_RELOCATABLE
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/* This flag is set to 1 by a loader if the kernel should run
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* at the loaded address instead of the linked address. This
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* is used by kexec-tools to keep the the kdump kernel in the
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* crash_kernel region. The loader is responsible for
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* observing the alignment requirement.
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*/
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/* Do not move this variable as kexec-tools knows about it. */
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. = 0x5c
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.globl __run_at_load
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__run_at_load:
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.long 0x72756e30 /* "run0" -- relocate to 0 by default */
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#endif
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. = 0x60
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/*
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* The following code is used to hold secondary processors
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* in a spin loop after they have entered the kernel, but
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* before the bulk of the kernel has been relocated. This code
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* is relocated to physical address 0x60 before prom_init is run.
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* All of it must fit below the first exception vector at 0x100.
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* Use .globl here not _GLOBAL because we want __secondary_hold
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* to be the actual text address, not a descriptor.
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*/
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.globl __secondary_hold
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__secondary_hold:
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FIXUP_ENDIAN
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#ifndef CONFIG_PPC_BOOK3E
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mfmsr r24
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ori r24,r24,MSR_RI
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mtmsrd r24 /* RI on */
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#endif
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/* Grab our physical cpu number */
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mr r24,r3
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/* stash r4 for book3e */
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mr r25,r4
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/* Tell the master cpu we're here */
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/* Relocation is off & we are located at an address less */
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/* than 0x100, so only need to grab low order offset. */
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std r24,__secondary_hold_acknowledge-_stext(0)
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sync
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li r26,0
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#ifdef CONFIG_PPC_BOOK3E
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tovirt(r26,r26)
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#endif
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/* All secondary cpus wait here until told to start. */
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100: ld r4,__secondary_hold_spinloop-_stext(r26)
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cmpdi 0,r4,0
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beq 100b
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#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
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#ifdef CONFIG_PPC_BOOK3E
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tovirt(r4,r4)
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#endif
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ld r4,0(r4) /* deref function descriptor */
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mtctr r4
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mr r3,r24
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/*
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* it may be the case that other platforms have r4 right to
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* begin with, this gives us some safety in case it is not
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*/
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#ifdef CONFIG_PPC_BOOK3E
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mr r4,r25
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#else
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li r4,0
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#endif
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/* Make sure that patched code is visible */
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isync
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bctr
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#else
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BUG_OPCODE
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#endif
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/* This value is used to mark exception frames on the stack. */
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.section ".toc","aw"
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exception_marker:
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.tc ID_72656773_68657265[TC],0x7265677368657265
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.text
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/*
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* On server, we include the exception vectors code here as it
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* relies on absolute addressing which is only possible within
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* this compilation unit
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*/
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#ifdef CONFIG_PPC_BOOK3S
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#include "exceptions-64s.S"
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#endif
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_GLOBAL(generic_secondary_thread_init)
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mr r24,r3
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/* turn on 64-bit mode */
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bl .enable_64b_mode
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/* get a valid TOC pointer, wherever we're mapped at */
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bl .relative_toc
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tovirt(r2,r2)
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#ifdef CONFIG_PPC_BOOK3E
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/* Book3E initialization */
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mr r3,r24
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bl .book3e_secondary_thread_init
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#endif
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b generic_secondary_common_init
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/*
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* On pSeries and most other platforms, secondary processors spin
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* in the following code.
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* At entry, r3 = this processor's number (physical cpu id)
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*
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* On Book3E, r4 = 1 to indicate that the initial TLB entry for
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* this core already exists (setup via some other mechanism such
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* as SCOM before entry).
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*/
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_GLOBAL(generic_secondary_smp_init)
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FIXUP_ENDIAN
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mr r24,r3
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mr r25,r4
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/* turn on 64-bit mode */
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bl .enable_64b_mode
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/* get a valid TOC pointer, wherever we're mapped at */
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bl .relative_toc
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tovirt(r2,r2)
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#ifdef CONFIG_PPC_BOOK3E
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/* Book3E initialization */
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mr r3,r24
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mr r4,r25
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bl .book3e_secondary_core_init
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#endif
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generic_secondary_common_init:
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/* Set up a paca value for this processor. Since we have the
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* physical cpu id in r24, we need to search the pacas to find
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* which logical id maps to our physical one.
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*/
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LOAD_REG_ADDR(r13, paca) /* Load paca pointer */
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ld r13,0(r13) /* Get base vaddr of paca array */
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#ifndef CONFIG_SMP
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addi r13,r13,PACA_SIZE /* know r13 if used accidentally */
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b .kexec_wait /* wait for next kernel if !SMP */
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#else
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LOAD_REG_ADDR(r7, nr_cpu_ids) /* Load nr_cpu_ids address */
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lwz r7,0(r7) /* also the max paca allocated */
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li r5,0 /* logical cpu id */
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1: lhz r6,PACAHWCPUID(r13) /* Load HW procid from paca */
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cmpw r6,r24 /* Compare to our id */
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beq 2f
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addi r13,r13,PACA_SIZE /* Loop to next PACA on miss */
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addi r5,r5,1
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cmpw r5,r7 /* Check if more pacas exist */
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blt 1b
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mr r3,r24 /* not found, copy phys to r3 */
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b .kexec_wait /* next kernel might do better */
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2: SET_PACA(r13)
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#ifdef CONFIG_PPC_BOOK3E
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addi r12,r13,PACA_EXTLB /* and TLB exc frame in another */
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mtspr SPRN_SPRG_TLB_EXFRAME,r12
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#endif
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/* From now on, r24 is expected to be logical cpuid */
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mr r24,r5
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/* See if we need to call a cpu state restore handler */
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LOAD_REG_ADDR(r23, cur_cpu_spec)
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ld r23,0(r23)
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ld r23,CPU_SPEC_RESTORE(r23)
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cmpdi 0,r23,0
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beq 3f
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ld r23,0(r23)
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mtctr r23
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bctrl
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3: LOAD_REG_ADDR(r3, spinning_secondaries) /* Decrement spinning_secondaries */
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lwarx r4,0,r3
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subi r4,r4,1
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stwcx. r4,0,r3
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bne 3b
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isync
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4: HMT_LOW
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lbz r23,PACAPROCSTART(r13) /* Test if this processor should */
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/* start. */
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cmpwi 0,r23,0
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beq 4b /* Loop until told to go */
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sync /* order paca.run and cur_cpu_spec */
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isync /* In case code patching happened */
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/* Create a temp kernel stack for use before relocation is on. */
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ld r1,PACAEMERGSP(r13)
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subi r1,r1,STACK_FRAME_OVERHEAD
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b __secondary_start
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#endif /* SMP */
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/*
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* Turn the MMU off.
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* Assumes we're mapped EA == RA if the MMU is on.
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*/
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#ifdef CONFIG_PPC_BOOK3S
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_STATIC(__mmu_off)
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mfmsr r3
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andi. r0,r3,MSR_IR|MSR_DR
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beqlr
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mflr r4
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andc r3,r3,r0
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mtspr SPRN_SRR0,r4
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mtspr SPRN_SRR1,r3
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sync
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rfid
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b . /* prevent speculative execution */
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#endif
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/*
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* Here is our main kernel entry point. We support currently 2 kind of entries
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* depending on the value of r5.
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*
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* r5 != NULL -> OF entry, we go to prom_init, "legacy" parameter content
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* in r3...r7
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*
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* r5 == NULL -> kexec style entry. r3 is a physical pointer to the
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* DT block, r4 is a physical pointer to the kernel itself
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*
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*/
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_GLOBAL(__start_initialization_multiplatform)
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/* Make sure we are running in 64 bits mode */
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bl .enable_64b_mode
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/* Get TOC pointer (current runtime address) */
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bl .relative_toc
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/* find out where we are now */
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bcl 20,31,$+4
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0: mflr r26 /* r26 = runtime addr here */
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addis r26,r26,(_stext - 0b)@ha
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addi r26,r26,(_stext - 0b)@l /* current runtime base addr */
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/*
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* Are we booted from a PROM Of-type client-interface ?
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*/
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cmpldi cr0,r5,0
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beq 1f
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b .__boot_from_prom /* yes -> prom */
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1:
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/* Save parameters */
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mr r31,r3
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mr r30,r4
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#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL
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/* Save OPAL entry */
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mr r28,r8
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mr r29,r9
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#endif
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#ifdef CONFIG_PPC_BOOK3E
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bl .start_initialization_book3e
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b .__after_prom_start
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#else
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/* Setup some critical 970 SPRs before switching MMU off */
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mfspr r0,SPRN_PVR
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srwi r0,r0,16
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cmpwi r0,0x39 /* 970 */
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beq 1f
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cmpwi r0,0x3c /* 970FX */
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beq 1f
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cmpwi r0,0x44 /* 970MP */
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beq 1f
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cmpwi r0,0x45 /* 970GX */
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bne 2f
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1: bl .__cpu_preinit_ppc970
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2:
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/* Switch off MMU if not already off */
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bl .__mmu_off
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b .__after_prom_start
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#endif /* CONFIG_PPC_BOOK3E */
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_INIT_STATIC(__boot_from_prom)
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#ifdef CONFIG_PPC_OF_BOOT_TRAMPOLINE
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/* Save parameters */
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mr r31,r3
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mr r30,r4
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mr r29,r5
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mr r28,r6
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mr r27,r7
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/*
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* Align the stack to 16-byte boundary
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* Depending on the size and layout of the ELF sections in the initial
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* boot binary, the stack pointer may be unaligned on PowerMac
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*/
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rldicr r1,r1,0,59
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#ifdef CONFIG_RELOCATABLE
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/* Relocate code for where we are now */
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mr r3,r26
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bl .relocate
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#endif
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/* Restore parameters */
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mr r3,r31
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mr r4,r30
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mr r5,r29
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mr r6,r28
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mr r7,r27
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/* Do all of the interaction with OF client interface */
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mr r8,r26
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bl .prom_init
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#endif /* #CONFIG_PPC_OF_BOOT_TRAMPOLINE */
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/* We never return. We also hit that trap if trying to boot
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* from OF while CONFIG_PPC_OF_BOOT_TRAMPOLINE isn't selected */
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trap
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_STATIC(__after_prom_start)
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#ifdef CONFIG_RELOCATABLE
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/* process relocations for the final address of the kernel */
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lis r25,PAGE_OFFSET@highest /* compute virtual base of kernel */
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sldi r25,r25,32
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lwz r7,__run_at_load-_stext(r26)
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cmplwi cr0,r7,1 /* flagged to stay where we are ? */
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bne 1f
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add r25,r25,r26
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1: mr r3,r25
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bl .relocate
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#endif
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/*
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* We need to run with _stext at physical address PHYSICAL_START.
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* This will leave some code in the first 256B of
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* real memory, which are reserved for software use.
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*
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* Note: This process overwrites the OF exception vectors.
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*/
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li r3,0 /* target addr */
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#ifdef CONFIG_PPC_BOOK3E
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tovirt(r3,r3) /* on booke, we already run at PAGE_OFFSET */
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#endif
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mr. r4,r26 /* In some cases the loader may */
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beq 9f /* have already put us at zero */
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li r6,0x100 /* Start offset, the first 0x100 */
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/* bytes were copied earlier. */
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#ifdef CONFIG_PPC_BOOK3E
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tovirt(r6,r6) /* on booke, we already run at PAGE_OFFSET */
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#endif
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#ifdef CONFIG_RELOCATABLE
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/*
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* Check if the kernel has to be running as relocatable kernel based on the
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* variable __run_at_load, if it is set the kernel is treated as relocatable
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* kernel, otherwise it will be moved to PHYSICAL_START
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*/
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lwz r7,__run_at_load-_stext(r26)
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cmplwi cr0,r7,1
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bne 3f
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/* just copy interrupts */
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LOAD_REG_IMMEDIATE(r5, __end_interrupts - _stext)
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b 5f
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3:
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#endif
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lis r5,(copy_to_here - _stext)@ha
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addi r5,r5,(copy_to_here - _stext)@l /* # bytes of memory to copy */
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bl .copy_and_flush /* copy the first n bytes */
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/* this includes the code being */
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/* executed here. */
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addis r8,r3,(4f - _stext)@ha /* Jump to the copy of this code */
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addi r8,r8,(4f - _stext)@l /* that we just made */
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mtctr r8
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bctr
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.balign 8
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p_end: .llong _end - _stext
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4: /* Now copy the rest of the kernel up to _end */
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addis r5,r26,(p_end - _stext)@ha
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ld r5,(p_end - _stext)@l(r5) /* get _end */
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5: bl .copy_and_flush /* copy the rest */
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9: b .start_here_multiplatform
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/*
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* Copy routine used to copy the kernel to start at physical address 0
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* and flush and invalidate the caches as needed.
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* r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset
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* on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5.
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|
*
|
|
* Note: this routine *only* clobbers r0, r6 and lr
|
|
*/
|
|
_GLOBAL(copy_and_flush)
|
|
addi r5,r5,-8
|
|
addi r6,r6,-8
|
|
4: li r0,8 /* Use the smallest 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
|
|
isync
|
|
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
|
|
|
|
li r0,0
|
|
mfspr r3,SPRN_HID4
|
|
rldimi r3,r0,40,23 /* clear bit 23 (rm_ci) */
|
|
sync
|
|
mtspr SPRN_HID4,r3
|
|
isync
|
|
sync
|
|
slbia
|
|
|
|
/* get TOC pointer (real address) */
|
|
bl .relative_toc
|
|
tovirt(r2,r2)
|
|
|
|
/* Copy some CPU settings from CPU 0 */
|
|
bl .__restore_cpu_ppc970
|
|
|
|
/* 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_ADDR(r4,paca) /* Load paca pointer */
|
|
ld r4,0(r4) /* Get base vaddr of paca array */
|
|
mulli r13,r24,PACA_SIZE /* Calculate vaddr of right paca */
|
|
add r13,r13,r4 /* for this processor. */
|
|
SET_PACA(r13) /* Save vaddr of paca in an SPRG*/
|
|
|
|
/* Mark interrupts soft and hard disabled (they might be enabled
|
|
* in the PACA when doing hotplug)
|
|
*/
|
|
li r0,0
|
|
stb r0,PACASOFTIRQEN(r13)
|
|
li r0,PACA_IRQ_HARD_DIS
|
|
stb r0,PACAIRQHAPPENED(r13)
|
|
|
|
/* 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 (real addr of temp stack)
|
|
* r24 = cpu# (in Linux terms)
|
|
* r13 = paca virtual address
|
|
* SPRG_PACA = paca virtual address
|
|
*/
|
|
.section ".text";
|
|
.align 2 ;
|
|
|
|
.globl __secondary_start
|
|
__secondary_start:
|
|
/* Set thread priority to MEDIUM */
|
|
HMT_MEDIUM
|
|
|
|
/* Initialize the kernel stack */
|
|
LOAD_REG_ADDR(r3, current_set)
|
|
sldi r28,r24,3 /* get current_set[cpu#] */
|
|
ldx r14,r3,r28
|
|
addi r14,r14,THREAD_SIZE-STACK_FRAME_OVERHEAD
|
|
std r14,PACAKSAVE(r13)
|
|
|
|
/* Do early setup for that CPU (stab, slb, hash table pointer) */
|
|
bl .early_setup_secondary
|
|
|
|
/*
|
|
* setup the new stack pointer, but *don't* use this until
|
|
* translation is on.
|
|
*/
|
|
mr r1, r14
|
|
|
|
/* Clear backchain so we get nice backtraces */
|
|
li r7,0
|
|
mtlr r7
|
|
|
|
/* Mark interrupts soft and hard disabled (they might be enabled
|
|
* in the PACA when doing hotplug)
|
|
*/
|
|
stb r7,PACASOFTIRQEN(r13)
|
|
li r0,PACA_IRQ_HARD_DIS
|
|
stb r0,PACAIRQHAPPENED(r13)
|
|
|
|
/* enable MMU and jump to start_secondary */
|
|
LOAD_REG_ADDR(r3, .start_secondary_prolog)
|
|
LOAD_REG_IMMEDIATE(r4, MSR_KERNEL)
|
|
|
|
mtspr SPRN_SRR0,r3
|
|
mtspr SPRN_SRR1,r4
|
|
RFI
|
|
b . /* prevent speculative execution */
|
|
|
|
/*
|
|
* Running with relocation on at this point. All we want to do is
|
|
* zero the stack back-chain pointer and get the TOC virtual address
|
|
* before going into C code.
|
|
*/
|
|
_GLOBAL(start_secondary_prolog)
|
|
ld r2,PACATOC(r13)
|
|
li r3,0
|
|
std r3,0(r1) /* Zero the stack frame pointer */
|
|
bl .start_secondary
|
|
b .
|
|
/*
|
|
* Reset stack pointer and call start_secondary
|
|
* to continue with online operation when woken up
|
|
* from cede in cpu offline.
|
|
*/
|
|
_GLOBAL(start_secondary_resume)
|
|
ld r1,PACAKSAVE(r13) /* Reload kernel stack pointer */
|
|
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 */
|
|
#ifdef CONFIG_PPC_BOOK3E
|
|
oris r11,r11,0x8000 /* CM bit set, we'll set ICM later */
|
|
mtmsr r11
|
|
#else /* CONFIG_PPC_BOOK3E */
|
|
li r12,(MSR_64BIT | MSR_ISF)@highest
|
|
sldi r12,r12,48
|
|
or r11,r11,r12
|
|
mtmsrd r11
|
|
isync
|
|
#endif
|
|
blr
|
|
|
|
/*
|
|
* This puts the TOC pointer into r2, offset by 0x8000 (as expected
|
|
* by the toolchain). It computes the correct value for wherever we
|
|
* are running at the moment, using position-independent code.
|
|
*
|
|
* Note: The compiler constructs pointers using offsets from the
|
|
* TOC in -mcmodel=medium mode. After we relocate to 0 but before
|
|
* the MMU is on we need our TOC to be a virtual address otherwise
|
|
* these pointers will be real addresses which may get stored and
|
|
* accessed later with the MMU on. We use tovirt() at the call
|
|
* sites to handle this.
|
|
*/
|
|
_GLOBAL(relative_toc)
|
|
mflr r0
|
|
bcl 20,31,$+4
|
|
0: mflr r11
|
|
ld r2,(p_toc - 0b)(r11)
|
|
add r2,r2,r11
|
|
mtlr r0
|
|
blr
|
|
|
|
.balign 8
|
|
p_toc: .llong __toc_start + 0x8000 - 0b
|
|
|
|
/*
|
|
* This is where the main kernel code starts.
|
|
*/
|
|
_INIT_STATIC(start_here_multiplatform)
|
|
/* set up the TOC */
|
|
bl .relative_toc
|
|
tovirt(r2,r2)
|
|
|
|
/* 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_ADDR(r11,__bss_stop)
|
|
LOAD_REG_ADDR(r8,__bss_start)
|
|
sub r11,r11,r8 /* bss size */
|
|
addi r11,r11,7 /* round up to an even double word */
|
|
srdi. r11,r11,3 /* 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:
|
|
|
|
#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL
|
|
/* Setup OPAL entry */
|
|
LOAD_REG_ADDR(r11, opal)
|
|
std r28,0(r11);
|
|
std r29,8(r11);
|
|
#endif
|
|
|
|
#ifndef CONFIG_PPC_BOOK3E
|
|
mfmsr r6
|
|
ori r6,r6,MSR_RI
|
|
mtmsrd r6 /* RI on */
|
|
#endif
|
|
|
|
#ifdef CONFIG_RELOCATABLE
|
|
/* Save the physical address we're running at in kernstart_addr */
|
|
LOAD_REG_ADDR(r4, kernstart_addr)
|
|
clrldi r0,r25,2
|
|
std r0,0(r4)
|
|
#endif
|
|
|
|
/* The following gets the stack 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_ADDR(r3,init_thread_union)
|
|
|
|
/* set up a stack pointer */
|
|
addi r1,r3,THREAD_SIZE
|
|
li r0,0
|
|
stdu r0,-STACK_FRAME_OVERHEAD(r1)
|
|
|
|
/* 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 /* also sets r13 and SPRG_PACA */
|
|
|
|
LOAD_REG_ADDR(r3, .start_here_common)
|
|
ld r4,PACAKMSR(r13)
|
|
mtspr SPRN_SRR0,r3
|
|
mtspr SPRN_SRR1,r4
|
|
RFI
|
|
b . /* prevent speculative execution */
|
|
|
|
/* This is where all platforms converge execution */
|
|
_INIT_GLOBAL(start_here_common)
|
|
/* relocation is on at this point */
|
|
std r1,PACAKSAVE(r13)
|
|
|
|
/* Load the TOC (virtual address) */
|
|
ld r2,PACATOC(r13)
|
|
|
|
/* Do more system initializations in virtual mode */
|
|
bl .setup_system
|
|
|
|
/* Mark interrupts soft and hard disabled (they might be enabled
|
|
* in the PACA when doing hotplug)
|
|
*/
|
|
li r0,0
|
|
stb r0,PACASOFTIRQEN(r13)
|
|
li r0,PACA_IRQ_HARD_DIS
|
|
stb r0,PACAIRQHAPPENED(r13)
|
|
|
|
/* Generic kernel entry */
|
|
bl .start_kernel
|
|
|
|
/* Not reached */
|
|
BUG_OPCODE
|
|
|
|
/*
|
|
* 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 PGD_TABLE_SIZE
|