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linux/arch/powerpc/kernel/head_64.S
Paul Mackerras 745a14cc26 [POWERPC] Add fast little-endian switch system call 
This adds a system call on 64-bit platforms for switching between
little-endian and big-endian modes that is much faster than doing a
prctl call.  This system call is handled as a special case right at
the start of the system call entry code, and because it is a special
case, it uses a system call number which is out of the range of
normal system calls, namely 0x1ebe.

Measurements with lmbench on a 4.2GHz POWER6 showed no measurable
change in the speed of normal system calls with this patch.

Switching endianness with this new system call takes around 60ns on a
4.2GHz POWER6, compared with around 300ns to switch endian mode with a
prctl.  This can provide a significant performance advantage for
emulators for little-endian architectures that want to switch between
big-endian and little-endian mode frequently, e.g. because they are
generating instructions sequences on the fly and they want to run
those sequences in little-endian mode.

The other thing about this system call is that it doesn't clobber as
many registers as a normal system call.  It only clobbers r12.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-29 15:57:34 +10:00

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/*
* PowerPC version
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
* Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
* Adapted for Power Macintosh by Paul Mackerras.
* Low-level exception handlers and MMU support
* rewritten by Paul Mackerras.
* Copyright (C) 1996 Paul Mackerras.
*
* Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
* Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
*
* This file contains the low-level support and setup for the
* PowerPC-64 platform, including trap and interrupt dispatch.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/threads.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/bug.h>
#include <asm/cputable.h>
#include <asm/setup.h>
#include <asm/hvcall.h>
#include <asm/iseries/lpar_map.h>
#include <asm/thread_info.h>
#include <asm/firmware.h>
#include <asm/page_64.h>
#include <asm/exception.h>
#include <asm/irqflags.h>
/*
* We layout physical memory as follows:
* 0x0000 - 0x00ff : Secondary processor spin code
* 0x0100 - 0x2fff : pSeries Interrupt prologs
* 0x3000 - 0x5fff : interrupt support, iSeries and common interrupt prologs
* 0x6000 - 0x6fff : Initial (CPU0) segment table
* 0x7000 - 0x7fff : FWNMI data area
* 0x8000 - : Early init and support code
*/
/*
* SPRG Usage
*
* Register Definition
*
* SPRG0 reserved for hypervisor
* SPRG1 temp - used to save gpr
* SPRG2 temp - used to save gpr
* SPRG3 virt addr of paca
*/
/*
* Entering into this code we make the following assumptions:
* For pSeries:
* 1. The MMU is off & open firmware is running in real mode.
* 2. The kernel is entered at __start
*
* For iSeries:
* 1. The MMU is on (as it always is for iSeries)
* 2. The kernel is entered at system_reset_iSeries
*/
.text
.globl _stext
_stext:
_GLOBAL(__start)
/* NOP this out unconditionally */
BEGIN_FTR_SECTION
b .__start_initialization_multiplatform
END_FTR_SECTION(0, 1)
/* Catch branch to 0 in real mode */
trap
/* Secondary processors spin on this value until it goes to 1. */
.globl __secondary_hold_spinloop
__secondary_hold_spinloop:
.llong 0x0
/* Secondary processors write this value with their cpu # */
/* after they enter the spin loop immediately below. */
.globl __secondary_hold_acknowledge
__secondary_hold_acknowledge:
.llong 0x0
#ifdef CONFIG_PPC_ISERIES
/*
* At offset 0x20, there is a pointer to iSeries LPAR data.
* This is required by the hypervisor
*/
. = 0x20
.llong hvReleaseData-KERNELBASE
#endif /* CONFIG_PPC_ISERIES */
. = 0x60
/*
* The following code is used to hold secondary processors
* in a spin loop after they have entered the kernel, but
* before the bulk of the kernel has been relocated. This code
* is relocated to physical address 0x60 before prom_init is run.
* All of it must fit below the first exception vector at 0x100.
*/
_GLOBAL(__secondary_hold)
mfmsr r24
ori r24,r24,MSR_RI
mtmsrd r24 /* RI on */
/* Grab our physical cpu number */
mr r24,r3
/* Tell the master cpu we're here */
/* Relocation is off & we are located at an address less */
/* than 0x100, so only need to grab low order offset. */
std r24,__secondary_hold_acknowledge@l(0)
sync
/* All secondary cpus wait here until told to start. */
100: ld r4,__secondary_hold_spinloop@l(0)
cmpdi 0,r4,1
bne 100b
#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC)
LOAD_REG_IMMEDIATE(r4, .generic_secondary_smp_init)
mtctr r4
mr r3,r24
bctr
#else
BUG_OPCODE
#endif
/* This value is used to mark exception frames on the stack. */
.section ".toc","aw"
exception_marker:
.tc ID_72656773_68657265[TC],0x7265677368657265
.text
/*
* This is the start of the interrupt handlers for pSeries
* This code runs with relocation off.
*/
. = 0x100
.globl __start_interrupts
__start_interrupts:
STD_EXCEPTION_PSERIES(0x100, system_reset)
. = 0x200
_machine_check_pSeries:
HMT_MEDIUM
mtspr SPRN_SPRG1,r13 /* save r13 */
EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)
. = 0x300
.globl data_access_pSeries
data_access_pSeries:
HMT_MEDIUM
mtspr SPRN_SPRG1,r13
BEGIN_FTR_SECTION
mtspr SPRN_SPRG2,r12
mfspr r13,SPRN_DAR
mfspr r12,SPRN_DSISR
srdi r13,r13,60
rlwimi r13,r12,16,0x20
mfcr r12
cmpwi r13,0x2c
beq do_stab_bolted_pSeries
mtcrf 0x80,r12
mfspr r12,SPRN_SPRG2
END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, data_access_common)
. = 0x380
.globl data_access_slb_pSeries
data_access_slb_pSeries:
HMT_MEDIUM
mtspr SPRN_SPRG1,r13
mfspr r13,SPRN_SPRG3 /* get paca address into r13 */
std r3,PACA_EXSLB+EX_R3(r13)
mfspr r3,SPRN_DAR
std r9,PACA_EXSLB+EX_R9(r13) /* save r9 - r12 */
mfcr r9
#ifdef __DISABLED__
/* Keep that around for when we re-implement dynamic VSIDs */
cmpdi r3,0
bge slb_miss_user_pseries
#endif /* __DISABLED__ */
std r10,PACA_EXSLB+EX_R10(r13)
std r11,PACA_EXSLB+EX_R11(r13)
std r12,PACA_EXSLB+EX_R12(r13)
mfspr r10,SPRN_SPRG1
std r10,PACA_EXSLB+EX_R13(r13)
mfspr r12,SPRN_SRR1 /* and SRR1 */
b .slb_miss_realmode /* Rel. branch works in real mode */
STD_EXCEPTION_PSERIES(0x400, instruction_access)
. = 0x480
.globl instruction_access_slb_pSeries
instruction_access_slb_pSeries:
HMT_MEDIUM
mtspr SPRN_SPRG1,r13
mfspr r13,SPRN_SPRG3 /* get paca address into r13 */
std r3,PACA_EXSLB+EX_R3(r13)
mfspr r3,SPRN_SRR0 /* SRR0 is faulting address */
std r9,PACA_EXSLB+EX_R9(r13) /* save r9 - r12 */
mfcr r9
#ifdef __DISABLED__
/* Keep that around for when we re-implement dynamic VSIDs */
cmpdi r3,0
bge slb_miss_user_pseries
#endif /* __DISABLED__ */
std r10,PACA_EXSLB+EX_R10(r13)
std r11,PACA_EXSLB+EX_R11(r13)
std r12,PACA_EXSLB+EX_R12(r13)
mfspr r10,SPRN_SPRG1
std r10,PACA_EXSLB+EX_R13(r13)
mfspr r12,SPRN_SRR1 /* and SRR1 */
b .slb_miss_realmode /* Rel. branch works in real mode */
MASKABLE_EXCEPTION_PSERIES(0x500, hardware_interrupt)
STD_EXCEPTION_PSERIES(0x600, alignment)
STD_EXCEPTION_PSERIES(0x700, program_check)
STD_EXCEPTION_PSERIES(0x800, fp_unavailable)
MASKABLE_EXCEPTION_PSERIES(0x900, decrementer)
STD_EXCEPTION_PSERIES(0xa00, trap_0a)
STD_EXCEPTION_PSERIES(0xb00, trap_0b)
. = 0xc00
.globl system_call_pSeries
system_call_pSeries:
HMT_MEDIUM
BEGIN_FTR_SECTION
cmpdi r0,0x1ebe
beq- 1f
END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE)
mr r9,r13
mfmsr r10
mfspr r13,SPRN_SPRG3
mfspr r11,SPRN_SRR0
clrrdi r12,r13,32
oris r12,r12,system_call_common@h
ori r12,r12,system_call_common@l
mtspr SPRN_SRR0,r12
ori r10,r10,MSR_IR|MSR_DR|MSR_RI
mfspr r12,SPRN_SRR1
mtspr SPRN_SRR1,r10
rfid
b . /* prevent speculative execution */
/* Fast LE/BE switch system call */
1: mfspr r12,SPRN_SRR1
xori r12,r12,MSR_LE
mtspr SPRN_SRR1,r12
rfid /* return to userspace */
b .
STD_EXCEPTION_PSERIES(0xd00, single_step)
STD_EXCEPTION_PSERIES(0xe00, trap_0e)
/* We need to deal with the Altivec unavailable exception
* here which is at 0xf20, thus in the middle of the
* prolog code of the PerformanceMonitor one. A little
* trickery is thus necessary
*/
. = 0xf00
b performance_monitor_pSeries
STD_EXCEPTION_PSERIES(0xf20, altivec_unavailable)
#ifdef CONFIG_CBE_RAS
HSTD_EXCEPTION_PSERIES(0x1200, cbe_system_error)
#endif /* CONFIG_CBE_RAS */
STD_EXCEPTION_PSERIES(0x1300, instruction_breakpoint)
#ifdef CONFIG_CBE_RAS
HSTD_EXCEPTION_PSERIES(0x1600, cbe_maintenance)
#endif /* CONFIG_CBE_RAS */
STD_EXCEPTION_PSERIES(0x1700, altivec_assist)
#ifdef CONFIG_CBE_RAS
HSTD_EXCEPTION_PSERIES(0x1800, cbe_thermal)
#endif /* CONFIG_CBE_RAS */
. = 0x3000
/*** pSeries interrupt support ***/
/* moved from 0xf00 */
STD_EXCEPTION_PSERIES(., performance_monitor)
/*
* An interrupt came in while soft-disabled; clear EE in SRR1,
* clear paca->hard_enabled and return.
*/
masked_interrupt:
stb r10,PACAHARDIRQEN(r13)
mtcrf 0x80,r9
ld r9,PACA_EXGEN+EX_R9(r13)
mfspr r10,SPRN_SRR1
rldicl r10,r10,48,1 /* clear MSR_EE */
rotldi r10,r10,16
mtspr SPRN_SRR1,r10
ld r10,PACA_EXGEN+EX_R10(r13)
mfspr r13,SPRN_SPRG1
rfid
b .
.align 7
do_stab_bolted_pSeries:
mtcrf 0x80,r12
mfspr r12,SPRN_SPRG2
EXCEPTION_PROLOG_PSERIES(PACA_EXSLB, .do_stab_bolted)
/*
* We have some room here we use that to put
* the peries slb miss user trampoline code so it's reasonably
* away from slb_miss_user_common to avoid problems with rfid
*
* This is used for when the SLB miss handler has to go virtual,
* which doesn't happen for now anymore but will once we re-implement
* dynamic VSIDs for shared page tables
*/
#ifdef __DISABLED__
slb_miss_user_pseries:
std r10,PACA_EXGEN+EX_R10(r13)
std r11,PACA_EXGEN+EX_R11(r13)
std r12,PACA_EXGEN+EX_R12(r13)
mfspr r10,SPRG1
ld r11,PACA_EXSLB+EX_R9(r13)
ld r12,PACA_EXSLB+EX_R3(r13)
std r10,PACA_EXGEN+EX_R13(r13)
std r11,PACA_EXGEN+EX_R9(r13)
std r12,PACA_EXGEN+EX_R3(r13)
clrrdi r12,r13,32
mfmsr r10
mfspr r11,SRR0 /* save SRR0 */
ori r12,r12,slb_miss_user_common@l /* virt addr of handler */
ori r10,r10,MSR_IR|MSR_DR|MSR_RI
mtspr SRR0,r12
mfspr r12,SRR1 /* and SRR1 */
mtspr SRR1,r10
rfid
b . /* prevent spec. execution */
#endif /* __DISABLED__ */
#ifdef CONFIG_PPC_PSERIES
/*
* Vectors for the FWNMI option. Share common code.
*/
.globl system_reset_fwnmi
.align 7
system_reset_fwnmi:
HMT_MEDIUM
mtspr SPRN_SPRG1,r13 /* save r13 */
EXCEPTION_PROLOG_PSERIES_FORCE_64BIT(PACA_EXGEN, system_reset_common)
.globl machine_check_fwnmi
.align 7
machine_check_fwnmi:
HMT_MEDIUM
mtspr SPRN_SPRG1,r13 /* save r13 */
EXCEPTION_PROLOG_PSERIES_FORCE_64BIT(PACA_EXMC, machine_check_common)
#endif /* CONFIG_PPC_PSERIES */
/*** Common interrupt handlers ***/
STD_EXCEPTION_COMMON(0x100, system_reset, .system_reset_exception)
/*
* Machine check is different because we use a different
* save area: PACA_EXMC instead of PACA_EXGEN.
*/
.align 7
.globl machine_check_common
machine_check_common:
EXCEPTION_PROLOG_COMMON(0x200, PACA_EXMC)
FINISH_NAP
DISABLE_INTS
bl .save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl .machine_check_exception
b .ret_from_except
STD_EXCEPTION_COMMON_LITE(0x900, decrementer, .timer_interrupt)
STD_EXCEPTION_COMMON(0xa00, trap_0a, .unknown_exception)
STD_EXCEPTION_COMMON(0xb00, trap_0b, .unknown_exception)
STD_EXCEPTION_COMMON(0xd00, single_step, .single_step_exception)
STD_EXCEPTION_COMMON(0xe00, trap_0e, .unknown_exception)
STD_EXCEPTION_COMMON_IDLE(0xf00, performance_monitor, .performance_monitor_exception)
STD_EXCEPTION_COMMON(0x1300, instruction_breakpoint, .instruction_breakpoint_exception)
#ifdef CONFIG_ALTIVEC
STD_EXCEPTION_COMMON(0x1700, altivec_assist, .altivec_assist_exception)
#else
STD_EXCEPTION_COMMON(0x1700, altivec_assist, .unknown_exception)
#endif
#ifdef CONFIG_CBE_RAS
STD_EXCEPTION_COMMON(0x1200, cbe_system_error, .cbe_system_error_exception)
STD_EXCEPTION_COMMON(0x1600, cbe_maintenance, .cbe_maintenance_exception)
STD_EXCEPTION_COMMON(0x1800, cbe_thermal, .cbe_thermal_exception)
#endif /* CONFIG_CBE_RAS */
/*
* Here we have detected that the kernel stack pointer is bad.
* R9 contains the saved CR, r13 points to the paca,
* r10 contains the (bad) kernel stack pointer,
* r11 and r12 contain the saved SRR0 and SRR1.
* We switch to using an emergency stack, save the registers there,
* and call kernel_bad_stack(), which panics.
*/
bad_stack:
ld r1,PACAEMERGSP(r13)
subi r1,r1,64+INT_FRAME_SIZE
std r9,_CCR(r1)
std r10,GPR1(r1)
std r11,_NIP(r1)
std r12,_MSR(r1)
mfspr r11,SPRN_DAR
mfspr r12,SPRN_DSISR
std r11,_DAR(r1)
std r12,_DSISR(r1)
mflr r10
mfctr r11
mfxer r12
std r10,_LINK(r1)
std r11,_CTR(r1)
std r12,_XER(r1)
SAVE_GPR(0,r1)
SAVE_GPR(2,r1)
SAVE_4GPRS(3,r1)
SAVE_2GPRS(7,r1)
SAVE_10GPRS(12,r1)
SAVE_10GPRS(22,r1)
lhz r12,PACA_TRAP_SAVE(r13)
std r12,_TRAP(r1)
addi r11,r1,INT_FRAME_SIZE
std r11,0(r1)
li r12,0
std r12,0(r11)
ld r2,PACATOC(r13)
1: addi r3,r1,STACK_FRAME_OVERHEAD
bl .kernel_bad_stack
b 1b
/*
* Return from an exception with minimal checks.
* The caller is assumed to have done EXCEPTION_PROLOG_COMMON.
* If interrupts have been enabled, or anything has been
* done that might have changed the scheduling status of
* any task or sent any task a signal, you should use
* ret_from_except or ret_from_except_lite instead of this.
*/
fast_exc_return_irq: /* restores irq state too */
ld r3,SOFTE(r1)
TRACE_AND_RESTORE_IRQ(r3);
ld r12,_MSR(r1)
rldicl r4,r12,49,63 /* get MSR_EE to LSB */
stb r4,PACAHARDIRQEN(r13) /* restore paca->hard_enabled */
b 1f
.globl fast_exception_return
fast_exception_return:
ld r12,_MSR(r1)
1: ld r11,_NIP(r1)
andi. r3,r12,MSR_RI /* check if RI is set */
beq- unrecov_fer
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
andi. r3,r12,MSR_PR
beq 2f
ACCOUNT_CPU_USER_EXIT(r3, r4)
2:
#endif
ld r3,_CCR(r1)
ld r4,_LINK(r1)
ld r5,_CTR(r1)
ld r6,_XER(r1)
mtcr r3
mtlr r4
mtctr r5
mtxer r6
REST_GPR(0, r1)
REST_8GPRS(2, r1)
mfmsr r10
rldicl r10,r10,48,1 /* clear EE */
rldicr r10,r10,16,61 /* clear RI (LE is 0 already) */
mtmsrd r10,1
mtspr SPRN_SRR1,r12
mtspr SPRN_SRR0,r11
REST_4GPRS(10, r1)
ld r1,GPR1(r1)
rfid
b . /* prevent speculative execution */
unrecov_fer:
bl .save_nvgprs
1: addi r3,r1,STACK_FRAME_OVERHEAD
bl .unrecoverable_exception
b 1b
/*
* Here r13 points to the paca, r9 contains the saved CR,
* SRR0 and SRR1 are saved in r11 and r12,
* r9 - r13 are saved in paca->exgen.
*/
.align 7
.globl data_access_common
data_access_common:
mfspr r10,SPRN_DAR
std r10,PACA_EXGEN+EX_DAR(r13)
mfspr r10,SPRN_DSISR
stw r10,PACA_EXGEN+EX_DSISR(r13)
EXCEPTION_PROLOG_COMMON(0x300, PACA_EXGEN)
ld r3,PACA_EXGEN+EX_DAR(r13)
lwz r4,PACA_EXGEN+EX_DSISR(r13)
li r5,0x300
b .do_hash_page /* Try to handle as hpte fault */
.align 7
.globl instruction_access_common
instruction_access_common:
EXCEPTION_PROLOG_COMMON(0x400, PACA_EXGEN)
ld r3,_NIP(r1)
andis. r4,r12,0x5820
li r5,0x400
b .do_hash_page /* Try to handle as hpte fault */
/*
* Here is the common SLB miss user that is used when going to virtual
* mode for SLB misses, that is currently not used
*/
#ifdef __DISABLED__
.align 7
.globl slb_miss_user_common
slb_miss_user_common:
mflr r10
std r3,PACA_EXGEN+EX_DAR(r13)
stw r9,PACA_EXGEN+EX_CCR(r13)
std r10,PACA_EXGEN+EX_LR(r13)
std r11,PACA_EXGEN+EX_SRR0(r13)
bl .slb_allocate_user
ld r10,PACA_EXGEN+EX_LR(r13)
ld r3,PACA_EXGEN+EX_R3(r13)
lwz r9,PACA_EXGEN+EX_CCR(r13)
ld r11,PACA_EXGEN+EX_SRR0(r13)
mtlr r10
beq- slb_miss_fault
andi. r10,r12,MSR_RI /* check for unrecoverable exception */
beq- unrecov_user_slb
mfmsr r10
.machine push
.machine "power4"
mtcrf 0x80,r9
.machine pop
clrrdi r10,r10,2 /* clear RI before setting SRR0/1 */
mtmsrd r10,1
mtspr SRR0,r11
mtspr SRR1,r12
ld r9,PACA_EXGEN+EX_R9(r13)
ld r10,PACA_EXGEN+EX_R10(r13)
ld r11,PACA_EXGEN+EX_R11(r13)
ld r12,PACA_EXGEN+EX_R12(r13)
ld r13,PACA_EXGEN+EX_R13(r13)
rfid
b .
slb_miss_fault:
EXCEPTION_PROLOG_COMMON(0x380, PACA_EXGEN)
ld r4,PACA_EXGEN+EX_DAR(r13)
li r5,0
std r4,_DAR(r1)
std r5,_DSISR(r1)
b handle_page_fault
unrecov_user_slb:
EXCEPTION_PROLOG_COMMON(0x4200, PACA_EXGEN)
DISABLE_INTS
bl .save_nvgprs
1: addi r3,r1,STACK_FRAME_OVERHEAD
bl .unrecoverable_exception
b 1b
#endif /* __DISABLED__ */
/*
* r13 points to the PACA, r9 contains the saved CR,
* r12 contain the saved SRR1, SRR0 is still ready for return
* r3 has the faulting address
* r9 - r13 are saved in paca->exslb.
* r3 is saved in paca->slb_r3
* We assume we aren't going to take any exceptions during this procedure.
*/
_GLOBAL(slb_miss_realmode)
mflr r10
stw r9,PACA_EXSLB+EX_CCR(r13) /* save CR in exc. frame */
std r10,PACA_EXSLB+EX_LR(r13) /* save LR */
bl .slb_allocate_realmode
/* All done -- return from exception. */
ld r10,PACA_EXSLB+EX_LR(r13)
ld r3,PACA_EXSLB+EX_R3(r13)
lwz r9,PACA_EXSLB+EX_CCR(r13) /* get saved CR */
#ifdef CONFIG_PPC_ISERIES
BEGIN_FW_FTR_SECTION
ld r11,PACALPPACAPTR(r13)
ld r11,LPPACASRR0(r11) /* get SRR0 value */
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
#endif /* CONFIG_PPC_ISERIES */
mtlr r10
andi. r10,r12,MSR_RI /* check for unrecoverable exception */
beq- 2f
.machine push
.machine "power4"
mtcrf 0x80,r9
mtcrf 0x01,r9 /* slb_allocate uses cr0 and cr7 */
.machine pop
#ifdef CONFIG_PPC_ISERIES
BEGIN_FW_FTR_SECTION
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r12
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
#endif /* CONFIG_PPC_ISERIES */
ld r9,PACA_EXSLB+EX_R9(r13)
ld r10,PACA_EXSLB+EX_R10(r13)
ld r11,PACA_EXSLB+EX_R11(r13)
ld r12,PACA_EXSLB+EX_R12(r13)
ld r13,PACA_EXSLB+EX_R13(r13)
rfid
b . /* prevent speculative execution */
2:
#ifdef CONFIG_PPC_ISERIES
BEGIN_FW_FTR_SECTION
b unrecov_slb
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
#endif /* CONFIG_PPC_ISERIES */
mfspr r11,SPRN_SRR0
clrrdi r10,r13,32
LOAD_HANDLER(r10,unrecov_slb)
mtspr SPRN_SRR0,r10
mfmsr r10
ori r10,r10,MSR_IR|MSR_DR|MSR_RI
mtspr SPRN_SRR1,r10
rfid
b .
unrecov_slb:
EXCEPTION_PROLOG_COMMON(0x4100, PACA_EXSLB)
DISABLE_INTS
bl .save_nvgprs
1: addi r3,r1,STACK_FRAME_OVERHEAD
bl .unrecoverable_exception
b 1b
.align 7
.globl hardware_interrupt_common
.globl hardware_interrupt_entry
hardware_interrupt_common:
EXCEPTION_PROLOG_COMMON(0x500, PACA_EXGEN)
FINISH_NAP
hardware_interrupt_entry:
DISABLE_INTS
BEGIN_FTR_SECTION
bl .ppc64_runlatch_on
END_FTR_SECTION_IFSET(CPU_FTR_CTRL)
addi r3,r1,STACK_FRAME_OVERHEAD
bl .do_IRQ
b .ret_from_except_lite
#ifdef CONFIG_PPC_970_NAP
power4_fixup_nap:
andc r9,r9,r10
std r9,TI_LOCAL_FLAGS(r11)
ld r10,_LINK(r1) /* make idle task do the */
std r10,_NIP(r1) /* equivalent of a blr */
blr
#endif
.align 7
.globl alignment_common
alignment_common:
mfspr r10,SPRN_DAR
std r10,PACA_EXGEN+EX_DAR(r13)
mfspr r10,SPRN_DSISR
stw r10,PACA_EXGEN+EX_DSISR(r13)
EXCEPTION_PROLOG_COMMON(0x600, PACA_EXGEN)
ld r3,PACA_EXGEN+EX_DAR(r13)
lwz r4,PACA_EXGEN+EX_DSISR(r13)
std r3,_DAR(r1)
std r4,_DSISR(r1)
bl .save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
ENABLE_INTS
bl .alignment_exception
b .ret_from_except
.align 7
.globl program_check_common
program_check_common:
EXCEPTION_PROLOG_COMMON(0x700, PACA_EXGEN)
bl .save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
ENABLE_INTS
bl .program_check_exception
b .ret_from_except
.align 7
.globl fp_unavailable_common
fp_unavailable_common:
EXCEPTION_PROLOG_COMMON(0x800, PACA_EXGEN)
bne 1f /* if from user, just load it up */
bl .save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
ENABLE_INTS
bl .kernel_fp_unavailable_exception
BUG_OPCODE
1: b .load_up_fpu
.align 7
.globl altivec_unavailable_common
altivec_unavailable_common:
EXCEPTION_PROLOG_COMMON(0xf20, PACA_EXGEN)
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
bne .load_up_altivec /* if from user, just load it up */
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
bl .save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
ENABLE_INTS
bl .altivec_unavailable_exception
b .ret_from_except
#ifdef CONFIG_ALTIVEC
/*
* load_up_altivec(unused, unused, tsk)
* Disable VMX for the task which had it previously,
* and save its vector registers in its thread_struct.
* Enables the VMX for use in the kernel on return.
* On SMP we know the VMX is free, since we give it up every
* switch (ie, no lazy save of the vector registers).
* On entry: r13 == 'current' && last_task_used_altivec != 'current'
*/
_STATIC(load_up_altivec)
mfmsr r5 /* grab the current MSR */
oris r5,r5,MSR_VEC@h
mtmsrd r5 /* enable use of VMX now */
isync
/*
* For SMP, we don't do lazy VMX switching because it just gets too
* horrendously complex, especially when a task switches from one CPU
* to another. Instead we call giveup_altvec in switch_to.
* VRSAVE isn't dealt with here, that is done in the normal context
* switch code. Note that we could rely on vrsave value to eventually
* avoid saving all of the VREGs here...
*/
#ifndef CONFIG_SMP
ld r3,last_task_used_altivec@got(r2)
ld r4,0(r3)
cmpdi 0,r4,0
beq 1f
/* Save VMX state to last_task_used_altivec's THREAD struct */
addi r4,r4,THREAD
SAVE_32VRS(0,r5,r4)
mfvscr vr0
li r10,THREAD_VSCR
stvx vr0,r10,r4
/* Disable VMX for last_task_used_altivec */
ld r5,PT_REGS(r4)
ld r4,_MSR-STACK_FRAME_OVERHEAD(r5)
lis r6,MSR_VEC@h
andc r4,r4,r6
std r4,_MSR-STACK_FRAME_OVERHEAD(r5)
1:
#endif /* CONFIG_SMP */
/* Hack: if we get an altivec unavailable trap with VRSAVE
* set to all zeros, we assume this is a broken application
* that fails to set it properly, and thus we switch it to
* all 1's
*/
mfspr r4,SPRN_VRSAVE
cmpdi 0,r4,0
bne+ 1f
li r4,-1
mtspr SPRN_VRSAVE,r4
1:
/* enable use of VMX after return */
ld r4,PACACURRENT(r13)
addi r5,r4,THREAD /* Get THREAD */
oris r12,r12,MSR_VEC@h
std r12,_MSR(r1)
li r4,1
li r10,THREAD_VSCR
stw r4,THREAD_USED_VR(r5)
lvx vr0,r10,r5
mtvscr vr0
REST_32VRS(0,r4,r5)
#ifndef CONFIG_SMP
/* Update last_task_used_math to 'current' */
subi r4,r5,THREAD /* Back to 'current' */
std r4,0(r3)
#endif /* CONFIG_SMP */
/* restore registers and return */
b fast_exception_return
#endif /* CONFIG_ALTIVEC */
/*
* Hash table stuff
*/
.align 7
_STATIC(do_hash_page)
std r3,_DAR(r1)
std r4,_DSISR(r1)
andis. r0,r4,0xa450 /* weird error? */
bne- handle_page_fault /* if not, try to insert a HPTE */
BEGIN_FTR_SECTION
andis. r0,r4,0x0020 /* Is it a segment table fault? */
bne- do_ste_alloc /* If so handle it */
END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
/*
* On iSeries, we soft-disable interrupts here, then
* hard-enable interrupts so that the hash_page code can spin on
* the hash_table_lock without problems on a shared processor.
*/
DISABLE_INTS
/*
* Currently, trace_hardirqs_off() will be called by DISABLE_INTS
* and will clobber volatile registers when irq tracing is enabled
* so we need to reload them. It may be possible to be smarter here
* and move the irq tracing elsewhere but let's keep it simple for
* now
*/
#ifdef CONFIG_TRACE_IRQFLAGS
ld r3,_DAR(r1)
ld r4,_DSISR(r1)
ld r5,_TRAP(r1)
ld r12,_MSR(r1)
clrrdi r5,r5,4
#endif /* CONFIG_TRACE_IRQFLAGS */
/*
* We need to set the _PAGE_USER bit if MSR_PR is set or if we are
* accessing a userspace segment (even from the kernel). We assume
* kernel addresses always have the high bit set.
*/
rlwinm r4,r4,32-25+9,31-9,31-9 /* DSISR_STORE -> _PAGE_RW */
rotldi r0,r3,15 /* Move high bit into MSR_PR posn */
orc r0,r12,r0 /* MSR_PR | ~high_bit */
rlwimi r4,r0,32-13,30,30 /* becomes _PAGE_USER access bit */
ori r4,r4,1 /* add _PAGE_PRESENT */
rlwimi r4,r5,22+2,31-2,31-2 /* Set _PAGE_EXEC if trap is 0x400 */
/*
* r3 contains the faulting address
* r4 contains the required access permissions
* r5 contains the trap number
*
* at return r3 = 0 for success
*/
bl .hash_page /* build HPTE if possible */
cmpdi r3,0 /* see if hash_page succeeded */
BEGIN_FW_FTR_SECTION
/*
* If we had interrupts soft-enabled at the point where the
* DSI/ISI occurred, and an interrupt came in during hash_page,
* handle it now.
* We jump to ret_from_except_lite rather than fast_exception_return
* because ret_from_except_lite will check for and handle pending
* interrupts if necessary.
*/
beq 13f
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
BEGIN_FW_FTR_SECTION
/*
* Here we have interrupts hard-disabled, so it is sufficient
* to restore paca->{soft,hard}_enable and get out.
*/
beq fast_exc_return_irq /* Return from exception on success */
END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES)
/* For a hash failure, we don't bother re-enabling interrupts */
ble- 12f
/*
* hash_page couldn't handle it, set soft interrupt enable back
* to what it was before the trap. Note that .raw_local_irq_restore
* handles any interrupts pending at this point.
*/
ld r3,SOFTE(r1)
TRACE_AND_RESTORE_IRQ_PARTIAL(r3, 11f)
bl .raw_local_irq_restore
b 11f
/* Here we have a page fault that hash_page can't handle. */
handle_page_fault:
ENABLE_INTS
11: ld r4,_DAR(r1)
ld r5,_DSISR(r1)
addi r3,r1,STACK_FRAME_OVERHEAD
bl .do_page_fault
cmpdi r3,0
beq+ 13f
bl .save_nvgprs
mr r5,r3
addi r3,r1,STACK_FRAME_OVERHEAD
lwz r4,_DAR(r1)
bl .bad_page_fault
b .ret_from_except
13: b .ret_from_except_lite
/* We have a page fault that hash_page could handle but HV refused
* the PTE insertion
*/
12: bl .save_nvgprs
mr r5,r3
addi r3,r1,STACK_FRAME_OVERHEAD
ld r4,_DAR(r1)
bl .low_hash_fault
b .ret_from_except
/* here we have a segment miss */
do_ste_alloc:
bl .ste_allocate /* try to insert stab entry */
cmpdi r3,0
bne- handle_page_fault
b fast_exception_return
/*
* r13 points to the PACA, r9 contains the saved CR,
* r11 and r12 contain the saved SRR0 and SRR1.
* r9 - r13 are saved in paca->exslb.
* We assume we aren't going to take any exceptions during this procedure.
* We assume (DAR >> 60) == 0xc.
*/
.align 7
_GLOBAL(do_stab_bolted)
stw r9,PACA_EXSLB+EX_CCR(r13) /* save CR in exc. frame */
std r11,PACA_EXSLB+EX_SRR0(r13) /* save SRR0 in exc. frame */
/* Hash to the primary group */
ld r10,PACASTABVIRT(r13)
mfspr r11,SPRN_DAR
srdi r11,r11,28
rldimi r10,r11,7,52 /* r10 = first ste of the group */
/* Calculate VSID */
/* This is a kernel address, so protovsid = ESID */
ASM_VSID_SCRAMBLE(r11, r9, 256M)
rldic r9,r11,12,16 /* r9 = vsid << 12 */
/* Search the primary group for a free entry */
1: ld r11,0(r10) /* Test valid bit of the current ste */
andi. r11,r11,0x80
beq 2f
addi r10,r10,16
andi. r11,r10,0x70
bne 1b
/* Stick for only searching the primary group for now. */
/* At least for now, we use a very simple random castout scheme */
/* Use the TB as a random number ; OR in 1 to avoid entry 0 */
mftb r11
rldic r11,r11,4,57 /* r11 = (r11 << 4) & 0x70 */
ori r11,r11,0x10
/* r10 currently points to an ste one past the group of interest */
/* make it point to the randomly selected entry */
subi r10,r10,128
or r10,r10,r11 /* r10 is the entry to invalidate */
isync /* mark the entry invalid */
ld r11,0(r10)
rldicl r11,r11,56,1 /* clear the valid bit */
rotldi r11,r11,8
std r11,0(r10)
sync
clrrdi r11,r11,28 /* Get the esid part of the ste */
slbie r11
2: std r9,8(r10) /* Store the vsid part of the ste */
eieio
mfspr r11,SPRN_DAR /* Get the new esid */
clrrdi r11,r11,28 /* Permits a full 32b of ESID */
ori r11,r11,0x90 /* Turn on valid and kp */
std r11,0(r10) /* Put new entry back into the stab */
sync
/* All done -- return from exception. */
lwz r9,PACA_EXSLB+EX_CCR(r13) /* get saved CR */
ld r11,PACA_EXSLB+EX_SRR0(r13) /* get saved SRR0 */
andi. r10,r12,MSR_RI
beq- unrecov_slb
mtcrf 0x80,r9 /* restore CR */
mfmsr r10
clrrdi r10,r10,2
mtmsrd r10,1
mtspr SPRN_SRR0,r11
mtspr SPRN_SRR1,r12
ld r9,PACA_EXSLB+EX_R9(r13)
ld r10,PACA_EXSLB+EX_R10(r13)
ld r11,PACA_EXSLB+EX_R11(r13)
ld r12,PACA_EXSLB+EX_R12(r13)
ld r13,PACA_EXSLB+EX_R13(r13)
rfid
b . /* prevent speculative execution */
/*
* Space for CPU0's segment table.
*
* On iSeries, the hypervisor must fill in at least one entry before
* we get control (with relocate on). The address is given to the hv
* as a page number (see xLparMap below), so this must be at a
* fixed address (the linker can't compute (u64)&initial_stab >>
* PAGE_SHIFT).
*/
. = STAB0_OFFSET /* 0x6000 */
.globl initial_stab
initial_stab:
.space 4096
#ifdef CONFIG_PPC_PSERIES
/*
* Data area reserved for FWNMI option.
* This address (0x7000) is fixed by the RPA.
*/
.= 0x7000
.globl fwnmi_data_area
fwnmi_data_area:
#endif /* CONFIG_PPC_PSERIES */
/* iSeries does not use the FWNMI stuff, so it is safe to put
* this here, even if we later allow kernels that will boot on
* both pSeries and iSeries */
#ifdef CONFIG_PPC_ISERIES
. = LPARMAP_PHYS
.globl xLparMap
xLparMap:
.quad HvEsidsToMap /* xNumberEsids */
.quad HvRangesToMap /* xNumberRanges */
.quad STAB0_PAGE /* xSegmentTableOffs */
.zero 40 /* xRsvd */
/* xEsids (HvEsidsToMap entries of 2 quads) */
.quad PAGE_OFFSET_ESID /* xKernelEsid */
.quad PAGE_OFFSET_VSID /* xKernelVsid */
.quad VMALLOC_START_ESID /* xKernelEsid */
.quad VMALLOC_START_VSID /* xKernelVsid */
/* xRanges (HvRangesToMap entries of 3 quads) */
.quad HvPagesToMap /* xPages */
.quad 0 /* xOffset */
.quad PAGE_OFFSET_VSID << (SID_SHIFT - HW_PAGE_SHIFT) /* xVPN */
#endif /* CONFIG_PPC_ISERIES */
#ifdef CONFIG_PPC_PSERIES
. = 0x8000
#endif /* CONFIG_PPC_PSERIES */
/*
* On pSeries and most other platforms, secondary processors spin
* in the following code.
* At entry, r3 = this processor's number (physical cpu id)
*/
_GLOBAL(generic_secondary_smp_init)
mr r24,r3
/* turn on 64-bit mode */
bl .enable_64b_mode
/* Set up a paca value for this processor. Since we have the
* physical cpu id in r24, we need to search the pacas to find
* which logical id maps to our physical one.
*/
LOAD_REG_IMMEDIATE(r13, paca) /* Get base vaddr of paca array */
li r5,0 /* logical cpu id */
1: lhz r6,PACAHWCPUID(r13) /* Load HW procid from paca */
cmpw r6,r24 /* Compare to our id */
beq 2f
addi r13,r13,PACA_SIZE /* Loop to next PACA on miss */
addi r5,r5,1
cmpwi r5,NR_CPUS
blt 1b
mr r3,r24 /* not found, copy phys to r3 */
b .kexec_wait /* next kernel might do better */
2: mtspr SPRN_SPRG3,r13 /* Save vaddr of paca in SPRG3 */
/* From now on, r24 is expected to be logical cpuid */
mr r24,r5
3: HMT_LOW
lbz r23,PACAPROCSTART(r13) /* Test if this processor should */
/* start. */
sync
#ifndef CONFIG_SMP
b 3b /* Never go on non-SMP */
#else
cmpwi 0,r23,0
beq 3b /* Loop until told to go */
/* See if we need to call a cpu state restore handler */
LOAD_REG_IMMEDIATE(r23, cur_cpu_spec)
ld r23,0(r23)
ld r23,CPU_SPEC_RESTORE(r23)
cmpdi 0,r23,0
beq 4f
ld r23,0(r23)
mtctr r23
bctrl
4: /* 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
_STATIC(__mmu_off)
mfmsr r3
andi. r0,r3,MSR_IR|MSR_DR
beqlr
andc r3,r3,r0
mtspr SPRN_SRR0,r4
mtspr SPRN_SRR1,r3
sync
rfid
b . /* prevent speculative execution */
/*
* Here is our main kernel entry point. We support currently 2 kind of entries
* depending on the value of r5.
*
* r5 != NULL -> OF entry, we go to prom_init, "legacy" parameter content
* in r3...r7
*
* r5 == NULL -> kexec style entry. r3 is a physical pointer to the
* DT block, r4 is a physical pointer to the kernel itself
*
*/
_GLOBAL(__start_initialization_multiplatform)
/*
* Are we booted from a PROM Of-type client-interface ?
*/
cmpldi cr0,r5,0
beq 1f
b .__boot_from_prom /* yes -> prom */
1:
/* Save parameters */
mr r31,r3
mr r30,r4
/* Make sure we are running in 64 bits mode */
bl .enable_64b_mode
/* Setup some critical 970 SPRs before switching MMU off */
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 */
LOAD_REG_IMMEDIATE(r4, .__after_prom_start - KERNELBASE)
add r4,r4,r30
bl .__mmu_off
b .__after_prom_start
_INIT_STATIC(__boot_from_prom)
/* Save parameters */
mr r31,r3
mr r30,r4
mr r29,r5
mr r28,r6
mr r27,r7
/*
* Align the stack to 16-byte boundary
* Depending on the size and layout of the ELF sections in the initial
* boot binary, the stack pointer will be unalignet on PowerMac
*/
rldicr r1,r1,0,59
/* Make sure we are running in 64 bits mode */
bl .enable_64b_mode
/* put a relocation offset into r3 */
bl .reloc_offset
LOAD_REG_IMMEDIATE(r2,__toc_start)
addi r2,r2,0x4000
addi r2,r2,0x4000
/* Relocate the TOC from a virt addr to a real addr */
add r2,r2,r3
/* Restore parameters */
mr r3,r31
mr r4,r30
mr r5,r29
mr r6,r28
mr r7,r27
/* Do all of the interaction with OF client interface */
bl .prom_init
/* We never return */
trap
_STATIC(__after_prom_start)
/*
* We need to run with __start at physical address PHYSICAL_START.
* This will leave some code in the first 256B of
* real memory, which are reserved for software use.
* The remainder of the first page is loaded with the fixed
* interrupt vectors. The next two pages are filled with
* unknown exception placeholders.
*
* Note: This process overwrites the OF exception vectors.
* r26 == relocation offset
* r27 == KERNELBASE
*/
bl .reloc_offset
mr r26,r3
LOAD_REG_IMMEDIATE(r27, KERNELBASE)
LOAD_REG_IMMEDIATE(r3, PHYSICAL_START) /* target addr */
// XXX FIXME: Use phys returned by OF (r30)
add r4,r27,r26 /* source addr */
/* current address of _start */
/* i.e. where we are running */
/* the source addr */
cmpdi r4,0 /* In some cases the loader may */
bne 1f
b .start_here_multiplatform /* have already put us at zero */
/* so we can skip the copy. */
1: LOAD_REG_IMMEDIATE(r5,copy_to_here) /* # bytes of memory to copy */
sub r5,r5,r27
li r6,0x100 /* Start offset, the first 0x100 */
/* bytes were copied earlier. */
bl .copy_and_flush /* copy the first n bytes */
/* this includes the code being */
/* executed here. */
LOAD_REG_IMMEDIATE(r0, 4f) /* Jump to the copy of this code */
mtctr r0 /* that we just made/relocated */
bctr
4: LOAD_REG_IMMEDIATE(r5,klimit)
add r5,r5,r26
ld r5,0(r5) /* get the value of klimit */
sub r5,r5,r27
bl .copy_and_flush /* copy the rest */
b .start_here_multiplatform
/*
* 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
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
/* 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_IMMEDIATE(r4, paca) /* Get base vaddr of paca array */
mulli r13,r24,PACA_SIZE /* Calculate vaddr of right paca */
add r13,r13,r4 /* for this processor. */
mtspr SPRN_SPRG3,r13 /* Save vaddr of paca in SPRG3 */
/* Create a temp kernel stack for use before relocation is on. */
ld r1,PACAEMERGSP(r13)
subi r1,r1,STACK_FRAME_OVERHEAD
b __secondary_start
#endif /* CONFIG_PPC_PMAC */
/*
* This function is called after the master CPU has released the
* secondary processors. The execution environment is relocation off.
* The paca for this processor has the following fields initialized at
* this point:
* 1. Processor number
* 2. Segment table pointer (virtual address)
* On entry the following are set:
* r1 = stack pointer. vaddr for iSeries, raddr (temp stack) for pSeries
* r24 = cpu# (in Linux terms)
* r13 = paca virtual address
* SPRG3 = paca virtual address
*/
.globl __secondary_start
__secondary_start:
/* Set thread priority to MEDIUM */
HMT_MEDIUM
/* Load TOC */
ld r2,PACATOC(r13)
/* Do early setup for that CPU (stab, slb, hash table pointer) */
bl .early_setup_secondary
/* Initialize the kernel stack. Just a repeat for iSeries. */
LOAD_REG_ADDR(r3, current_set)
sldi r28,r24,3 /* get current_set[cpu#] */
ldx r1,r3,r28
addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
std r1,PACAKSAVE(r13)
/* Clear backchain so we get nice backtraces */
li r7,0
mtlr r7
/* enable MMU and jump to start_secondary */
LOAD_REG_ADDR(r3, .start_secondary_prolog)
LOAD_REG_IMMEDIATE(r4, MSR_KERNEL)
#ifdef CONFIG_PPC_ISERIES
BEGIN_FW_FTR_SECTION
ori r4,r4,MSR_EE
li r8,1
stb r8,PACAHARDIRQEN(r13)
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
#endif
BEGIN_FW_FTR_SECTION
stb r7,PACAHARDIRQEN(r13)
END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES)
stb r7,PACASOFTIRQEN(r13)
mtspr SPRN_SRR0,r3
mtspr SPRN_SRR1,r4
rfid
b . /* prevent speculative execution */
/*
* Running with relocation on at this point. All we want to do is
* zero the stack back-chain pointer before going into C code.
*/
_GLOBAL(start_secondary_prolog)
li r3,0
std r3,0(r1) /* Zero the stack frame pointer */
bl .start_secondary
b .
#endif
/*
* This subroutine clobbers r11 and r12
*/
_GLOBAL(enable_64b_mode)
mfmsr r11 /* grab the current MSR */
li r12,1
rldicr r12,r12,MSR_SF_LG,(63-MSR_SF_LG)
or r11,r11,r12
li r12,1
rldicr r12,r12,MSR_ISF_LG,(63-MSR_ISF_LG)
or r11,r11,r12
mtmsrd r11
isync
blr
/*
* This is where the main kernel code starts.
*/
_INIT_STATIC(start_here_multiplatform)
/* get a new offset, now that the kernel has moved. */
bl .reloc_offset
mr r26,r3
/* Clear out the BSS. It may have been done in prom_init,
* already but that's irrelevant since prom_init will soon
* be detached from the kernel completely. Besides, we need
* to clear it now for kexec-style entry.
*/
LOAD_REG_IMMEDIATE(r11,__bss_stop)
LOAD_REG_IMMEDIATE(r8,__bss_start)
sub r11,r11,r8 /* bss size */
addi r11,r11,7 /* round up to an even double word */
rldicl. r11,r11,61,3 /* shift right by 3 */
beq 4f
addi r8,r8,-8
li r0,0
mtctr r11 /* zero this many doublewords */
3: stdu r0,8(r8)
bdnz 3b
4:
mfmsr r6
ori r6,r6,MSR_RI
mtmsrd r6 /* RI on */
/* The following gets the stack and TOC set up with the regs */
/* pointing to the real addr of the kernel stack. This is */
/* all done to support the C function call below which sets */
/* up the htab. This is done because we have relocated the */
/* kernel but are still running in real mode. */
LOAD_REG_IMMEDIATE(r3,init_thread_union)
add r3,r3,r26
/* set up a stack pointer (physical address) */
addi r1,r3,THREAD_SIZE
li r0,0
stdu r0,-STACK_FRAME_OVERHEAD(r1)
/* set up the TOC (physical address) */
LOAD_REG_IMMEDIATE(r2,__toc_start)
addi r2,r2,0x4000
addi r2,r2,0x4000
add r2,r2,r26
/* Set initial ptr to current */
LOAD_REG_IMMEDIATE(r4, init_task)
std r4,PACACURRENT(r13)
/* Do very early kernel initializations, including initial hash table,
* stab and slb setup before we turn on relocation. */
/* Restore parameters passed from prom_init/kexec */
mr r3,r31
bl .early_setup
LOAD_REG_IMMEDIATE(r3, .start_here_common)
LOAD_REG_IMMEDIATE(r4, MSR_KERNEL)
mtspr SPRN_SRR0,r3
mtspr SPRN_SRR1,r4
rfid
b . /* prevent speculative execution */
/* This is where all platforms converge execution */
_INIT_GLOBAL(start_here_common)
/* relocation is on at this point */
/* The following code sets up the SP and TOC now that we are */
/* running with translation enabled. */
LOAD_REG_IMMEDIATE(r3,init_thread_union)
/* set up the stack */
addi r1,r3,THREAD_SIZE
li r0,0
stdu r0,-STACK_FRAME_OVERHEAD(r1)
/* Load the TOC */
ld r2,PACATOC(r13)
std r1,PACAKSAVE(r13)
bl .setup_system
/* Load up the kernel context */
5:
li r5,0
stb r5,PACASOFTIRQEN(r13) /* Soft Disabled */
#ifdef CONFIG_PPC_ISERIES
BEGIN_FW_FTR_SECTION
mfmsr r5
ori r5,r5,MSR_EE /* Hard Enabled on iSeries*/
mtmsrd r5
li r5,1
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
#endif
stb r5,PACAHARDIRQEN(r13) /* Hard Disabled on others */
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
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