1003 lines
25 KiB
ArmAsm
1003 lines
25 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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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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#include <linux/threads.h>
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#include <linux/init.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/head-64.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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#include <asm/cputhreads.h>
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#include <asm/ppc-opcode.h>
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#include <asm/export.h>
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#include <asm/feature-fixups.h>
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#ifdef CONFIG_PPC_BOOK3S
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#include <asm/exception-64s.h>
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#else
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#include <asm/exception-64e.h>
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#endif
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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 primary CPU enters at __start.
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* 3. If the RTAS supports "query-cpu-stopped-state", then secondary
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* CPUs will enter as directed by "start-cpu" RTAS call, which is
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* generic_secondary_smp_init, with PIR in r3.
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* 4. Else the secondary CPUs will enter at secondary_hold (0x60) as
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* directed by the "start-cpu" RTS call, with PIR in r3.
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* -or- For OPAL entry:
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* 1. The MMU is off, processor in HV mode.
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* 2. The primary CPU enters at 0 with device-tree in r3, OPAL base
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* in r8, and entry in r9 for debugging purposes.
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* 3. Secondary CPUs enter as directed by OPAL_START_CPU call, which
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* is at generic_secondary_smp_init, with PIR in r3.
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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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OPEN_FIXED_SECTION(first_256B, 0x0, 0x100)
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USE_FIXED_SECTION(first_256B)
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/*
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* Offsets are relative from the start of fixed section, and
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* first_256B starts at 0. Offsets are a bit easier to use here
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* than the fixed section entry macros.
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*/
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. = 0x0
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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 non-zero.
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* When non-zero, it contains the real address of the function the cpu
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* should jump to.
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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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.8byte 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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.8byte 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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#ifdef CONFIG_RELOCATABLE_TEST
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#define RUN_AT_LOAD_DEFAULT 1 /* Test relocation, do not copy to 0 */
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#else
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#define RUN_AT_LOAD_DEFAULT 0x72756e30 /* "run0" -- relocate to 0 by default */
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#endif
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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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DEFINE_FIXED_SYMBOL(__run_at_load)
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.long RUN_AT_LOAD_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,(ABS_ADDR(__secondary_hold_acknowledge))(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 r12,(ABS_ADDR(__secondary_hold_spinloop))(r26)
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cmpdi 0,r12,0
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beq 100b
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#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC_CORE)
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#ifdef CONFIG_PPC_BOOK3E
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tovirt(r12,r12)
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#endif
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mtctr r12
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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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0: trap
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EMIT_BUG_ENTRY 0b, __FILE__, __LINE__, 0
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#endif
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CLOSE_FIXED_SECTION(first_256B)
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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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/* This value is used to mark exception frames on the stack. */
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exception_marker:
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.tc ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER
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.previous
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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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#else
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OPEN_TEXT_SECTION(0x100)
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#endif
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USE_TEXT_SECTION()
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#include "interrupt_64.S"
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#ifdef CONFIG_PPC_BOOK3E
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/*
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* The booting_thread_hwid holds the thread id we want to boot in cpu
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* hotplug case. It is set by cpu hotplug code, and is invalid by default.
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* The thread id is the same as the initial value of SPRN_PIR[THREAD_ID]
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* bit field.
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*/
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.globl booting_thread_hwid
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booting_thread_hwid:
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.long INVALID_THREAD_HWID
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.align 3
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/*
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* start a thread in the same core
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* input parameters:
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* r3 = the thread physical id
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* r4 = the entry point where thread starts
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*/
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_GLOBAL(book3e_start_thread)
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LOAD_REG_IMMEDIATE(r5, MSR_KERNEL)
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cmpwi r3, 0
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beq 10f
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cmpwi r3, 1
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beq 11f
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/* If the thread id is invalid, just exit. */
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b 13f
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10:
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MTTMR(TMRN_IMSR0, 5)
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MTTMR(TMRN_INIA0, 4)
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b 12f
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11:
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MTTMR(TMRN_IMSR1, 5)
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MTTMR(TMRN_INIA1, 4)
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12:
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isync
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li r6, 1
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sld r6, r6, r3
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mtspr SPRN_TENS, r6
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13:
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blr
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/*
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* stop a thread in the same core
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* input parameter:
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* r3 = the thread physical id
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*/
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_GLOBAL(book3e_stop_thread)
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cmpwi r3, 0
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beq 10f
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cmpwi r3, 1
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beq 10f
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/* If the thread id is invalid, just exit. */
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b 13f
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10:
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li r4, 1
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sld r4, r4, r3
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mtspr SPRN_TENC, r4
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13:
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blr
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_GLOBAL(fsl_secondary_thread_init)
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mfspr r4,SPRN_BUCSR
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/* Enable branch prediction */
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lis r3,BUCSR_INIT@h
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ori r3,r3,BUCSR_INIT@l
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mtspr SPRN_BUCSR,r3
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isync
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/*
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* Fix PIR to match the linear numbering in the device tree.
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*
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* On e6500, the reset value of PIR uses the low three bits for
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* the thread within a core, and the upper bits for the core
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* number. There are two threads per core, so shift everything
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* but the low bit right by two bits so that the cpu numbering is
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* continuous.
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*
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* If the old value of BUCSR is non-zero, this thread has run
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* before. Thus, we assume we are coming from kexec or a similar
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* scenario, and PIR is already set to the correct value. This
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* is a bit of a hack, but there are limited opportunities for
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* getting information into the thread and the alternatives
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* seemed like they'd be overkill. We can't tell just by looking
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* at the old PIR value which state it's in, since the same value
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* could be valid for one thread out of reset and for a different
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* thread in Linux.
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*/
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mfspr r3, SPRN_PIR
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cmpwi r4,0
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bne 1f
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rlwimi r3, r3, 30, 2, 30
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mtspr SPRN_PIR, r3
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1:
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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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/* Book3E initialization */
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mr r3,r24
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bl book3e_secondary_thread_init
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b generic_secondary_common_init
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#endif /* CONFIG_PPC_BOOK3E */
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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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/*
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* After common core init has finished, check if the current thread is the
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* one we wanted to boot. If not, start the specified thread and stop the
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* current thread.
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*/
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LOAD_REG_ADDR(r4, booting_thread_hwid)
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lwz r3, 0(r4)
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li r5, INVALID_THREAD_HWID
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cmpw r3, r5
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beq 20f
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/*
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* The value of booting_thread_hwid has been stored in r3,
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* so make it invalid.
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*/
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stw r5, 0(r4)
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/*
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* Get the current thread id and check if it is the one we wanted.
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* If not, start the one specified in booting_thread_hwid and stop
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* the current thread.
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*/
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mfspr r8, SPRN_TIR
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cmpw r3, r8
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beq 20f
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/* start the specified thread */
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LOAD_REG_ADDR(r5, fsl_secondary_thread_init)
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ld r4, 0(r5)
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bl book3e_start_thread
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/* stop the current thread */
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mr r3, r8
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bl book3e_stop_thread
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10:
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b 10b
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20:
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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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#ifndef CONFIG_SMP
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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(r8, paca_ptrs) /* Load paca_ptrs pointe */
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ld r8,0(r8) /* Get base vaddr of array */
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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:
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sldi r9,r5,3 /* get paca_ptrs[] index from cpu id */
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ldx r13,r9,r8 /* r13 = paca_ptrs[cpu id] */
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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 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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/* 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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/* 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 r12,CPU_SPEC_RESTORE(r23)
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cmpdi 0,r12,0
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beq 3f
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#ifdef PPC64_ELF_ABI_v1
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ld r12,0(r12)
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#endif
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mtctr r12
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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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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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__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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__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
|
|
b __boot_from_prom /* yes -> prom */
|
|
1:
|
|
/* Save parameters */
|
|
mr r31,r3
|
|
mr r30,r4
|
|
#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL
|
|
/* Save OPAL entry */
|
|
mr r28,r8
|
|
mr r29,r9
|
|
#endif
|
|
|
|
#ifdef CONFIG_PPC_BOOK3E
|
|
bl start_initialization_book3e
|
|
b __after_prom_start
|
|
#else
|
|
/* Setup some critical 970 SPRs before switching MMU off */
|
|
mfspr r0,SPRN_PVR
|
|
srwi r0,r0,16
|
|
cmpwi r0,0x39 /* 970 */
|
|
beq 1f
|
|
cmpwi r0,0x3c /* 970FX */
|
|
beq 1f
|
|
cmpwi r0,0x44 /* 970MP */
|
|
beq 1f
|
|
cmpwi r0,0x45 /* 970GX */
|
|
bne 2f
|
|
1: bl __cpu_preinit_ppc970
|
|
2:
|
|
|
|
/* Switch off MMU if not already off */
|
|
bl __mmu_off
|
|
b __after_prom_start
|
|
#endif /* CONFIG_PPC_BOOK3E */
|
|
|
|
__REF
|
|
__boot_from_prom:
|
|
#ifdef CONFIG_PPC_OF_BOOT_TRAMPOLINE
|
|
/* 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 may be unaligned on PowerMac
|
|
*/
|
|
rldicr r1,r1,0,59
|
|
|
|
#ifdef CONFIG_RELOCATABLE
|
|
/* Relocate code for where we are now */
|
|
mr r3,r26
|
|
bl relocate
|
|
#endif
|
|
|
|
/* 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 */
|
|
mr r8,r26
|
|
bl prom_init
|
|
#endif /* #CONFIG_PPC_OF_BOOT_TRAMPOLINE */
|
|
|
|
/* We never return. We also hit that trap if trying to boot
|
|
* from OF while CONFIG_PPC_OF_BOOT_TRAMPOLINE isn't selected */
|
|
trap
|
|
.previous
|
|
|
|
__after_prom_start:
|
|
#ifdef CONFIG_RELOCATABLE
|
|
/* process relocations for the final address of the kernel */
|
|
lis r25,PAGE_OFFSET@highest /* compute virtual base of kernel */
|
|
sldi r25,r25,32
|
|
#if defined(CONFIG_PPC_BOOK3E)
|
|
tovirt(r26,r26) /* on booke, we already run at PAGE_OFFSET */
|
|
#endif
|
|
lwz r7,(FIXED_SYMBOL_ABS_ADDR(__run_at_load))(r26)
|
|
#if defined(CONFIG_PPC_BOOK3E)
|
|
tophys(r26,r26)
|
|
#endif
|
|
cmplwi cr0,r7,1 /* flagged to stay where we are ? */
|
|
bne 1f
|
|
add r25,r25,r26
|
|
1: mr r3,r25
|
|
bl relocate
|
|
#if defined(CONFIG_PPC_BOOK3E)
|
|
/* IVPR needs to be set after relocation. */
|
|
bl init_core_book3e
|
|
#endif
|
|
#endif
|
|
|
|
/*
|
|
* We need to run with _stext at physical address PHYSICAL_START.
|
|
* This will leave some code in the first 256B of
|
|
* real memory, which are reserved for software use.
|
|
*
|
|
* Note: This process overwrites the OF exception vectors.
|
|
*/
|
|
li r3,0 /* target addr */
|
|
#ifdef CONFIG_PPC_BOOK3E
|
|
tovirt(r3,r3) /* on booke, we already run at PAGE_OFFSET */
|
|
#endif
|
|
mr. r4,r26 /* In some cases the loader may */
|
|
#if defined(CONFIG_PPC_BOOK3E)
|
|
tovirt(r4,r4)
|
|
#endif
|
|
beq 9f /* have already put us at zero */
|
|
li r6,0x100 /* Start offset, the first 0x100 */
|
|
/* bytes were copied earlier. */
|
|
|
|
#ifdef CONFIG_RELOCATABLE
|
|
/*
|
|
* Check if the kernel has to be running as relocatable kernel based on the
|
|
* variable __run_at_load, if it is set the kernel is treated as relocatable
|
|
* kernel, otherwise it will be moved to PHYSICAL_START
|
|
*/
|
|
#if defined(CONFIG_PPC_BOOK3E)
|
|
tovirt(r26,r26) /* on booke, we already run at PAGE_OFFSET */
|
|
#endif
|
|
lwz r7,(FIXED_SYMBOL_ABS_ADDR(__run_at_load))(r26)
|
|
cmplwi cr0,r7,1
|
|
bne 3f
|
|
|
|
#ifdef CONFIG_PPC_BOOK3E
|
|
LOAD_REG_ADDR(r5, __end_interrupts)
|
|
LOAD_REG_ADDR(r11, _stext)
|
|
sub r5,r5,r11
|
|
#else
|
|
/* just copy interrupts */
|
|
LOAD_REG_IMMEDIATE_SYM(r5, r11, FIXED_SYMBOL_ABS_ADDR(__end_interrupts))
|
|
#endif
|
|
b 5f
|
|
3:
|
|
#endif
|
|
/* # bytes of memory to copy */
|
|
lis r5,(ABS_ADDR(copy_to_here))@ha
|
|
addi r5,r5,(ABS_ADDR(copy_to_here))@l
|
|
|
|
bl copy_and_flush /* copy the first n bytes */
|
|
/* this includes the code being */
|
|
/* executed here. */
|
|
/* Jump to the copy of this code that we just made */
|
|
addis r8,r3,(ABS_ADDR(4f))@ha
|
|
addi r12,r8,(ABS_ADDR(4f))@l
|
|
mtctr r12
|
|
bctr
|
|
|
|
.balign 8
|
|
p_end: .8byte _end - copy_to_here
|
|
|
|
4:
|
|
/*
|
|
* Now copy the rest of the kernel up to _end, add
|
|
* _end - copy_to_here to the copy limit and run again.
|
|
*/
|
|
addis r8,r26,(ABS_ADDR(p_end))@ha
|
|
ld r8,(ABS_ADDR(p_end))@l(r8)
|
|
add r5,r5,r8
|
|
5: bl copy_and_flush /* copy the rest */
|
|
|
|
9: b start_here_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 r0,8 /* 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_ptrs) /* Load paca pointer */
|
|
ld r4,0(r4) /* Get base vaddr of paca_ptrs array */
|
|
sldi r5,r24,3 /* get paca_ptrs[] index from cpu id */
|
|
ldx r13,r5,r4 /* r13 = paca_ptrs[cpu id] */
|
|
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,IRQS_DISABLED
|
|
stb r0,PACAIRQSOFTMASK(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
|
|
|
|
/*
|
|
* Do early setup for this CPU, in particular initialising the MMU so we
|
|
* can turn it on below. This is a call to C, which is OK, we're still
|
|
* running on the emergency stack.
|
|
*/
|
|
bl early_setup_secondary
|
|
|
|
/*
|
|
* The primary has initialized our kernel stack for us in the paca, grab
|
|
* it and put it in r1. We must *not* use it until we turn on the MMU
|
|
* below, because it may not be inside the RMO.
|
|
*/
|
|
ld r1, PACAKSAVE(r13)
|
|
|
|
/* 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)
|
|
*/
|
|
li r7,IRQS_DISABLED
|
|
stb r7,PACAIRQSOFTMASK(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_TO_KERNEL
|
|
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.
|
|
*/
|
|
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
|
|
*/
|
|
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 */
|
|
LOAD_REG_IMMEDIATE(r12, MSR_64BIT)
|
|
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: .8byte __toc_start + 0x8000 - 0b
|
|
|
|
/*
|
|
* This is where the main kernel code starts.
|
|
*/
|
|
__REF
|
|
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
|
|
|
|
/* set up a stack pointer */
|
|
LOAD_REG_ADDR(r3,init_thread_union)
|
|
LOAD_REG_IMMEDIATE(r1,THREAD_SIZE)
|
|
add r1,r3,r1
|
|
li r0,0
|
|
stdu r0,-STACK_FRAME_OVERHEAD(r1)
|
|
|
|
/*
|
|
* Do very early kernel initializations, including initial hash table
|
|
* and SLB setup before we turn on relocation.
|
|
*/
|
|
|
|
/* Restore parameters passed from prom_init/kexec */
|
|
mr r3,r31
|
|
LOAD_REG_ADDR(r12, DOTSYM(early_setup))
|
|
mtctr r12
|
|
bctrl /* 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_TO_KERNEL
|
|
b . /* prevent speculative execution */
|
|
|
|
/* This is where all platforms converge execution */
|
|
|
|
start_here_common:
|
|
/* relocation is on at this point */
|
|
std r1,PACAKSAVE(r13)
|
|
|
|
/* Load the TOC (virtual address) */
|
|
ld r2,PACATOC(r13)
|
|
|
|
/* Mark interrupts soft and hard disabled (they might be enabled
|
|
* in the PACA when doing hotplug)
|
|
*/
|
|
li r0,IRQS_DISABLED
|
|
stb r0,PACAIRQSOFTMASK(r13)
|
|
li r0,PACA_IRQ_HARD_DIS
|
|
stb r0,PACAIRQHAPPENED(r13)
|
|
|
|
/* Generic kernel entry */
|
|
bl start_kernel
|
|
|
|
/* Not reached */
|
|
0: trap
|
|
EMIT_BUG_ENTRY 0b, __FILE__, __LINE__, 0
|
|
.previous
|