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linux-stable/arch/powerpc/kernel/head_64.S
Paul Mackerras fa28237cfc [POWERPC] Provide a way to protect 4k subpages when using 64k pages 
Using 64k pages on 64-bit PowerPC systems makes life difficult for
emulators that are trying to emulate an ISA, such as x86, which use a
smaller page size, since the emulator can no longer use the MMU and
the normal system calls for controlling page protections.  Of course,
the emulator can emulate the MMU by checking and possibly remapping
the address for each memory access in software, but that is pretty
slow.

This provides a facility for such programs to control the access
permissions on individual 4k sub-pages of 64k pages.  The idea is
that the emulator supplies an array of protection masks to apply to a
specified range of virtual addresses.  These masks are applied at the
level where hardware PTEs are inserted into the hardware page table
based on the Linux PTEs, so the Linux PTEs are not affected.  Note
that this new mechanism does not allow any access that would otherwise
be prohibited; it can only prohibit accesses that would otherwise be
allowed.  This new facility is only available on 64-bit PowerPC and
only when the kernel is configured for 64k pages.

The masks are supplied using a new subpage_prot system call, which
takes a starting virtual address and length, and a pointer to an array
of protection masks in memory.  The array has a 32-bit word per 64k
page to be protected; each 32-bit word consists of 16 2-bit fields,
for which 0 allows any access (that is otherwise allowed), 1 prevents
write accesses, and 2 or 3 prevent any access.

Implicit in this is that the regions of the address space that are
protected are switched to use 4k hardware pages rather than 64k
hardware pages (on machines with hardware 64k page support).  In fact
the whole process is switched to use 4k hardware pages when the
subpage_prot system call is used, but this could be improved in future
to switch only the affected segments.

The subpage protection bits are stored in a 3 level tree akin to the
page table tree.  The top level of this tree is stored in a structure
that is appended to the top level of the page table tree, i.e., the
pgd array.  Since it will often only be 32-bit addresses (below 4GB)
that are protected, the pointers to the first four bottom level pages
are also stored in this structure (each bottom level page contains the
protection bits for 1GB of address space), so the protection bits for
addresses below 4GB can be accessed with one fewer loads than those
for higher addresses.

Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-01-24 10:06:01 +11:00

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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>
#define DO_SOFT_DISABLE
/*
* 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
mr r9,r13
mfmsr r10
mfspr r13,SPRN_SPRG3
mfspr r11,SPRN_SRR0
clrrdi r12,r13,32
oris r12,r12,system_call_common@h
ori r12,r12,system_call_common@l
mtspr SPRN_SRR0,r12
ori r10,r10,MSR_IR|MSR_DR|MSR_RI
mfspr r12,SPRN_SRR1
mtspr SPRN_SRR1,r10
rfid
b . /* prevent speculative execution */
STD_EXCEPTION_PSERIES(0xd00, single_step)
STD_EXCEPTION_PSERIES(0xe00, trap_0e)
/* We need to deal with the Altivec unavailable exception
* here which is at 0xf20, thus in the middle of the
* prolog code of the PerformanceMonitor one. A little
* trickery is thus necessary
*/
. = 0xf00
b performance_monitor_pSeries
STD_EXCEPTION_PSERIES(0xf20, altivec_unavailable)
#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)
ld r12,_MSR(r1)
stb r3,PACASOFTIRQEN(r13) /* restore paca->soft_enabled */
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- unrecov_slb
.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 */
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
_GLOBAL(do_hash_page)
std r3,_DAR(r1)
std r4,_DSISR(r1)
andis. r0,r4,0xa450 /* weird error? */
bne- handle_page_fault /* if not, try to insert a HPTE */
BEGIN_FTR_SECTION
andis. r0,r4,0x0020 /* Is it a segment table fault? */
bne- do_ste_alloc /* If so handle it */
END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
/*
* We need to set the _PAGE_USER bit if MSR_PR is set or if we are
* accessing a userspace segment (even from the kernel). We assume
* kernel addresses always have the high bit set.
*/
rlwinm r4,r4,32-25+9,31-9,31-9 /* DSISR_STORE -> _PAGE_RW */
rotldi r0,r3,15 /* Move high bit into MSR_PR posn */
orc r0,r12,r0 /* MSR_PR | ~high_bit */
rlwimi r4,r0,32-13,30,30 /* becomes _PAGE_USER access bit */
ori r4,r4,1 /* add _PAGE_PRESENT */
rlwimi r4,r5,22+2,31-2,31-2 /* Set _PAGE_EXEC if trap is 0x400 */
/*
* On iSeries, we soft-disable interrupts here, then
* hard-enable interrupts so that the hash_page code can spin on
* the hash_table_lock without problems on a shared processor.
*/
DISABLE_INTS
/*
* r3 contains the faulting address
* r4 contains the required access permissions
* r5 contains the trap number
*
* at return r3 = 0 for success
*/
bl .hash_page /* build HPTE if possible */
cmpdi r3,0 /* see if hash_page succeeded */
#ifdef DO_SOFT_DISABLE
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)
#endif
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 .local_irq_restore
* handles any interrupts pending at this point.
*/
ld r3,SOFTE(r1)
bl .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
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
#endif
BEGIN_FW_FTR_SECTION
stb r7,PACASOFTIRQEN(r13)
stb r7,PACAHARDIRQEN(r13)
END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES)
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
/* 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)
/* ptr to current */
LOAD_REG_IMMEDIATE(r4, init_task)
std r4,PACACURRENT(r13)
/* Load the TOC */
ld r2,PACATOC(r13)
std r1,PACAKSAVE(r13)
bl .setup_system
/* Load up the kernel context */
5:
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 */
mtmsrd r5
END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
#endif
BEGIN_FW_FTR_SECTION
stb r5,PACAHARDIRQEN(r13)
END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES)
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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