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linux/arch/powerpc/kernel/head_44x.S
Dave Kleikamp 029b8f662b powerpc/47x: Make sure mcsr is cleared before enabling machine check interrupts 
Clear the machine check syndrom register before enabling machine check
interrupts.  The initial state of the tlb can lead to parity errors being
flagged early after a cold boot.

Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
2010-08-23 07:36:58 -04:00

1162 lines
29 KiB
ArmAsm
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/*
* Kernel execution entry point code.
*
* Copyright (c) 1995-1996 Gary Thomas <gdt@linuxppc.org>
* Initial PowerPC version.
* Copyright (c) 1996 Cort Dougan <cort@cs.nmt.edu>
* Rewritten for PReP
* Copyright (c) 1996 Paul Mackerras <paulus@cs.anu.edu.au>
* Low-level exception handers, MMU support, and rewrite.
* Copyright (c) 1997 Dan Malek <dmalek@jlc.net>
* PowerPC 8xx modifications.
* Copyright (c) 1998-1999 TiVo, Inc.
* PowerPC 403GCX modifications.
* Copyright (c) 1999 Grant Erickson <grant@lcse.umn.edu>
* PowerPC 403GCX/405GP modifications.
* Copyright 2000 MontaVista Software Inc.
* PPC405 modifications
* PowerPC 403GCX/405GP modifications.
* Author: MontaVista Software, Inc.
* frank_rowand@mvista.com or source@mvista.com
* debbie_chu@mvista.com
* Copyright 2002-2005 MontaVista Software, Inc.
* PowerPC 44x support, Matt Porter <mporter@kernel.crashing.org>
*
* 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/init.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/pgtable.h>
#include <asm/cputable.h>
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/synch.h>
#include "head_booke.h"
/* As with the other PowerPC ports, it is expected that when code
* execution begins here, the following registers contain valid, yet
* optional, information:
*
* r3 - Board info structure pointer (DRAM, frequency, MAC address, etc.)
* r4 - Starting address of the init RAM disk
* r5 - Ending address of the init RAM disk
* r6 - Start of kernel command line string (e.g. "mem=128")
* r7 - End of kernel command line string
*
*/
__HEAD
_ENTRY(_stext);
_ENTRY(_start);
/*
* Reserve a word at a fixed location to store the address
* of abatron_pteptrs
*/
nop
/*
* Save parameters we are passed
*/
mr r31,r3
mr r30,r4
mr r29,r5
mr r28,r6
mr r27,r7
li r24,0 /* CPU number */
bl init_cpu_state
/*
* This is where the main kernel code starts.
*/
/* ptr to current */
lis r2,init_task@h
ori r2,r2,init_task@l
/* ptr to current thread */
addi r4,r2,THREAD /* init task's THREAD */
mtspr SPRN_SPRG_THREAD,r4
/* stack */
lis r1,init_thread_union@h
ori r1,r1,init_thread_union@l
li r0,0
stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)
bl early_init
/*
* Decide what sort of machine this is and initialize the MMU.
*/
mr r3,r31
mr r4,r30
mr r5,r29
mr r6,r28
mr r7,r27
bl machine_init
bl MMU_init
/* Setup PTE pointers for the Abatron bdiGDB */
lis r6, swapper_pg_dir@h
ori r6, r6, swapper_pg_dir@l
lis r5, abatron_pteptrs@h
ori r5, r5, abatron_pteptrs@l
lis r4, KERNELBASE@h
ori r4, r4, KERNELBASE@l
stw r5, 0(r4) /* Save abatron_pteptrs at a fixed location */
stw r6, 0(r5)
/* Clear the Machine Check Syndrome Register */
li r0,0
mtspr SPRN_MCSR,r0
/* Let's move on */
lis r4,start_kernel@h
ori r4,r4,start_kernel@l
lis r3,MSR_KERNEL@h
ori r3,r3,MSR_KERNEL@l
mtspr SPRN_SRR0,r4
mtspr SPRN_SRR1,r3
rfi /* change context and jump to start_kernel */
/*
* Interrupt vector entry code
*
* The Book E MMUs are always on so we don't need to handle
* interrupts in real mode as with previous PPC processors. In
* this case we handle interrupts in the kernel virtual address
* space.
*
* Interrupt vectors are dynamically placed relative to the
* interrupt prefix as determined by the address of interrupt_base.
* The interrupt vectors offsets are programmed using the labels
* for each interrupt vector entry.
*
* Interrupt vectors must be aligned on a 16 byte boundary.
* We align on a 32 byte cache line boundary for good measure.
*/
interrupt_base:
/* Critical Input Interrupt */
CRITICAL_EXCEPTION(0x0100, CriticalInput, unknown_exception)
/* Machine Check Interrupt */
CRITICAL_EXCEPTION(0x0200, MachineCheck, machine_check_exception)
MCHECK_EXCEPTION(0x0210, MachineCheckA, machine_check_exception)
/* Data Storage Interrupt */
DATA_STORAGE_EXCEPTION
/* Instruction Storage Interrupt */
INSTRUCTION_STORAGE_EXCEPTION
/* External Input Interrupt */
EXCEPTION(0x0500, ExternalInput, do_IRQ, EXC_XFER_LITE)
/* Alignment Interrupt */
ALIGNMENT_EXCEPTION
/* Program Interrupt */
PROGRAM_EXCEPTION
/* Floating Point Unavailable Interrupt */
#ifdef CONFIG_PPC_FPU
FP_UNAVAILABLE_EXCEPTION
#else
EXCEPTION(0x2010, FloatingPointUnavailable, unknown_exception, EXC_XFER_EE)
#endif
/* System Call Interrupt */
START_EXCEPTION(SystemCall)
NORMAL_EXCEPTION_PROLOG
EXC_XFER_EE_LITE(0x0c00, DoSyscall)
/* Auxillary Processor Unavailable Interrupt */
EXCEPTION(0x2020, AuxillaryProcessorUnavailable, unknown_exception, EXC_XFER_EE)
/* Decrementer Interrupt */
DECREMENTER_EXCEPTION
/* Fixed Internal Timer Interrupt */
/* TODO: Add FIT support */
EXCEPTION(0x1010, FixedIntervalTimer, unknown_exception, EXC_XFER_EE)
/* Watchdog Timer Interrupt */
/* TODO: Add watchdog support */
#ifdef CONFIG_BOOKE_WDT
CRITICAL_EXCEPTION(0x1020, WatchdogTimer, WatchdogException)
#else
CRITICAL_EXCEPTION(0x1020, WatchdogTimer, unknown_exception)
#endif
/* Data TLB Error Interrupt */
START_EXCEPTION(DataTLBError44x)
mtspr SPRN_SPRG_WSCRATCH0, r10 /* Save some working registers */
mtspr SPRN_SPRG_WSCRATCH1, r11
mtspr SPRN_SPRG_WSCRATCH2, r12
mtspr SPRN_SPRG_WSCRATCH3, r13
mfcr r11
mtspr SPRN_SPRG_WSCRATCH4, r11
mfspr r10, SPRN_DEAR /* Get faulting address */
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
*/
lis r11, PAGE_OFFSET@h
cmplw r10, r11
blt+ 3f
lis r11, swapper_pg_dir@h
ori r11, r11, swapper_pg_dir@l
mfspr r12,SPRN_MMUCR
rlwinm r12,r12,0,0,23 /* Clear TID */
b 4f
/* Get the PGD for the current thread */
3:
mfspr r11,SPRN_SPRG_THREAD
lwz r11,PGDIR(r11)
/* Load PID into MMUCR TID */
mfspr r12,SPRN_MMUCR
mfspr r13,SPRN_PID /* Get PID */
rlwimi r12,r13,0,24,31 /* Set TID */
4:
mtspr SPRN_MMUCR,r12
/* Mask of required permission bits. Note that while we
* do copy ESR:ST to _PAGE_RW position as trying to write
* to an RO page is pretty common, we don't do it with
* _PAGE_DIRTY. We could do it, but it's a fairly rare
* event so I'd rather take the overhead when it happens
* rather than adding an instruction here. We should measure
* whether the whole thing is worth it in the first place
* as we could avoid loading SPRN_ESR completely in the first
* place...
*
* TODO: Is it worth doing that mfspr & rlwimi in the first
* place or can we save a couple of instructions here ?
*/
mfspr r12,SPRN_ESR
li r13,_PAGE_PRESENT|_PAGE_ACCESSED
rlwimi r13,r12,10,30,30
/* Load the PTE */
/* Compute pgdir/pmd offset */
rlwinm r12, r10, PPC44x_PGD_OFF_SHIFT, PPC44x_PGD_OFF_MASK_BIT, 29
lwzx r11, r12, r11 /* Get pgd/pmd entry */
rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */
beq 2f /* Bail if no table */
/* Compute pte address */
rlwimi r12, r10, PPC44x_PTE_ADD_SHIFT, PPC44x_PTE_ADD_MASK_BIT, 28
lwz r11, 0(r12) /* Get high word of pte entry */
lwz r12, 4(r12) /* Get low word of pte entry */
lis r10,tlb_44x_index@ha
andc. r13,r13,r12 /* Check permission */
/* Load the next available TLB index */
lwz r13,tlb_44x_index@l(r10)
bne 2f /* Bail if permission mismach */
/* Increment, rollover, and store TLB index */
addi r13,r13,1
/* Compare with watermark (instruction gets patched) */
.globl tlb_44x_patch_hwater_D
tlb_44x_patch_hwater_D:
cmpwi 0,r13,1 /* reserve entries */
ble 5f
li r13,0
5:
/* Store the next available TLB index */
stw r13,tlb_44x_index@l(r10)
/* Re-load the faulting address */
mfspr r10,SPRN_DEAR
/* Jump to common tlb load */
b finish_tlb_load_44x
2:
/* The bailout. Restore registers to pre-exception conditions
* and call the heavyweights to help us out.
*/
mfspr r11, SPRN_SPRG_RSCRATCH4
mtcr r11
mfspr r13, SPRN_SPRG_RSCRATCH3
mfspr r12, SPRN_SPRG_RSCRATCH2
mfspr r11, SPRN_SPRG_RSCRATCH1
mfspr r10, SPRN_SPRG_RSCRATCH0
b DataStorage
/* Instruction TLB Error Interrupt */
/*
* Nearly the same as above, except we get our
* information from different registers and bailout
* to a different point.
*/
START_EXCEPTION(InstructionTLBError44x)
mtspr SPRN_SPRG_WSCRATCH0, r10 /* Save some working registers */
mtspr SPRN_SPRG_WSCRATCH1, r11
mtspr SPRN_SPRG_WSCRATCH2, r12
mtspr SPRN_SPRG_WSCRATCH3, r13
mfcr r11
mtspr SPRN_SPRG_WSCRATCH4, r11
mfspr r10, SPRN_SRR0 /* Get faulting address */
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
*/
lis r11, PAGE_OFFSET@h
cmplw r10, r11
blt+ 3f
lis r11, swapper_pg_dir@h
ori r11, r11, swapper_pg_dir@l
mfspr r12,SPRN_MMUCR
rlwinm r12,r12,0,0,23 /* Clear TID */
b 4f
/* Get the PGD for the current thread */
3:
mfspr r11,SPRN_SPRG_THREAD
lwz r11,PGDIR(r11)
/* Load PID into MMUCR TID */
mfspr r12,SPRN_MMUCR
mfspr r13,SPRN_PID /* Get PID */
rlwimi r12,r13,0,24,31 /* Set TID */
4:
mtspr SPRN_MMUCR,r12
/* Make up the required permissions */
li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
/* Compute pgdir/pmd offset */
rlwinm r12, r10, PPC44x_PGD_OFF_SHIFT, PPC44x_PGD_OFF_MASK_BIT, 29
lwzx r11, r12, r11 /* Get pgd/pmd entry */
rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */
beq 2f /* Bail if no table */
/* Compute pte address */
rlwimi r12, r10, PPC44x_PTE_ADD_SHIFT, PPC44x_PTE_ADD_MASK_BIT, 28
lwz r11, 0(r12) /* Get high word of pte entry */
lwz r12, 4(r12) /* Get low word of pte entry */
lis r10,tlb_44x_index@ha
andc. r13,r13,r12 /* Check permission */
/* Load the next available TLB index */
lwz r13,tlb_44x_index@l(r10)
bne 2f /* Bail if permission mismach */
/* Increment, rollover, and store TLB index */
addi r13,r13,1
/* Compare with watermark (instruction gets patched) */
.globl tlb_44x_patch_hwater_I
tlb_44x_patch_hwater_I:
cmpwi 0,r13,1 /* reserve entries */
ble 5f
li r13,0
5:
/* Store the next available TLB index */
stw r13,tlb_44x_index@l(r10)
/* Re-load the faulting address */
mfspr r10,SPRN_SRR0
/* Jump to common TLB load point */
b finish_tlb_load_44x
2:
/* The bailout. Restore registers to pre-exception conditions
* and call the heavyweights to help us out.
*/
mfspr r11, SPRN_SPRG_RSCRATCH4
mtcr r11
mfspr r13, SPRN_SPRG_RSCRATCH3
mfspr r12, SPRN_SPRG_RSCRATCH2
mfspr r11, SPRN_SPRG_RSCRATCH1
mfspr r10, SPRN_SPRG_RSCRATCH0
b InstructionStorage
/*
* Both the instruction and data TLB miss get to this
* point to load the TLB.
* r10 - EA of fault
* r11 - PTE high word value
* r12 - PTE low word value
* r13 - TLB index
* MMUCR - loaded with proper value when we get here
* Upon exit, we reload everything and RFI.
*/
finish_tlb_load_44x:
/* Combine RPN & ERPN an write WS 0 */
rlwimi r11,r12,0,0,31-PAGE_SHIFT
tlbwe r11,r13,PPC44x_TLB_XLAT
/*
* Create WS1. This is the faulting address (EPN),
* page size, and valid flag.
*/
li r11,PPC44x_TLB_VALID | PPC44x_TLBE_SIZE
/* Insert valid and page size */
rlwimi r10,r11,0,PPC44x_PTE_ADD_MASK_BIT,31
tlbwe r10,r13,PPC44x_TLB_PAGEID /* Write PAGEID */
/* And WS 2 */
li r10,0xf85 /* Mask to apply from PTE */
rlwimi r10,r12,29,30,30 /* DIRTY -> SW position */
and r11,r12,r10 /* Mask PTE bits to keep */
andi. r10,r12,_PAGE_USER /* User page ? */
beq 1f /* nope, leave U bits empty */
rlwimi r11,r11,3,26,28 /* yes, copy S bits to U */
1: tlbwe r11,r13,PPC44x_TLB_ATTRIB /* Write ATTRIB */
/* Done...restore registers and get out of here.
*/
mfspr r11, SPRN_SPRG_RSCRATCH4
mtcr r11
mfspr r13, SPRN_SPRG_RSCRATCH3
mfspr r12, SPRN_SPRG_RSCRATCH2
mfspr r11, SPRN_SPRG_RSCRATCH1
mfspr r10, SPRN_SPRG_RSCRATCH0
rfi /* Force context change */
/* TLB error interrupts for 476
*/
#ifdef CONFIG_PPC_47x
START_EXCEPTION(DataTLBError47x)
mtspr SPRN_SPRG_WSCRATCH0,r10 /* Save some working registers */
mtspr SPRN_SPRG_WSCRATCH1,r11
mtspr SPRN_SPRG_WSCRATCH2,r12
mtspr SPRN_SPRG_WSCRATCH3,r13
mfcr r11
mtspr SPRN_SPRG_WSCRATCH4,r11
mfspr r10,SPRN_DEAR /* Get faulting address */
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
*/
lis r11,PAGE_OFFSET@h
cmplw cr0,r10,r11
blt+ 3f
lis r11,swapper_pg_dir@h
ori r11,r11, swapper_pg_dir@l
li r12,0 /* MMUCR = 0 */
b 4f
/* Get the PGD for the current thread and setup MMUCR */
3: mfspr r11,SPRN_SPRG3
lwz r11,PGDIR(r11)
mfspr r12,SPRN_PID /* Get PID */
4: mtspr SPRN_MMUCR,r12 /* Set MMUCR */
/* Mask of required permission bits. Note that while we
* do copy ESR:ST to _PAGE_RW position as trying to write
* to an RO page is pretty common, we don't do it with
* _PAGE_DIRTY. We could do it, but it's a fairly rare
* event so I'd rather take the overhead when it happens
* rather than adding an instruction here. We should measure
* whether the whole thing is worth it in the first place
* as we could avoid loading SPRN_ESR completely in the first
* place...
*
* TODO: Is it worth doing that mfspr & rlwimi in the first
* place or can we save a couple of instructions here ?
*/
mfspr r12,SPRN_ESR
li r13,_PAGE_PRESENT|_PAGE_ACCESSED
rlwimi r13,r12,10,30,30
/* Load the PTE */
/* Compute pgdir/pmd offset */
rlwinm r12,r10,PPC44x_PGD_OFF_SHIFT,PPC44x_PGD_OFF_MASK_BIT,29
lwzx r11,r12,r11 /* Get pgd/pmd entry */
/* Word 0 is EPN,V,TS,DSIZ */
li r12,PPC47x_TLB0_VALID | PPC47x_TLBE_SIZE
rlwimi r10,r12,0,32-PAGE_SHIFT,31 /* Insert valid and page size*/
li r12,0
tlbwe r10,r12,0
/* XXX can we do better ? Need to make sure tlbwe has established
* latch V bit in MMUCR0 before the PTE is loaded further down */
#ifdef CONFIG_SMP
isync
#endif
rlwinm. r12,r11,0,0,20 /* Extract pt base address */
/* Compute pte address */
rlwimi r12,r10,PPC44x_PTE_ADD_SHIFT,PPC44x_PTE_ADD_MASK_BIT,28
beq 2f /* Bail if no table */
lwz r11,0(r12) /* Get high word of pte entry */
/* XXX can we do better ? maybe insert a known 0 bit from r11 into the
* bottom of r12 to create a data dependency... We can also use r10
* as destination nowadays
*/
#ifdef CONFIG_SMP
lwsync
#endif
lwz r12,4(r12) /* Get low word of pte entry */
andc. r13,r13,r12 /* Check permission */
/* Jump to common tlb load */
beq finish_tlb_load_47x
2: /* The bailout. Restore registers to pre-exception conditions
* and call the heavyweights to help us out.
*/
mfspr r11,SPRN_SPRG_RSCRATCH4
mtcr r11
mfspr r13,SPRN_SPRG_RSCRATCH3
mfspr r12,SPRN_SPRG_RSCRATCH2
mfspr r11,SPRN_SPRG_RSCRATCH1
mfspr r10,SPRN_SPRG_RSCRATCH0
b DataStorage
/* Instruction TLB Error Interrupt */
/*
* Nearly the same as above, except we get our
* information from different registers and bailout
* to a different point.
*/
START_EXCEPTION(InstructionTLBError47x)
mtspr SPRN_SPRG_WSCRATCH0,r10 /* Save some working registers */
mtspr SPRN_SPRG_WSCRATCH1,r11
mtspr SPRN_SPRG_WSCRATCH2,r12
mtspr SPRN_SPRG_WSCRATCH3,r13
mfcr r11
mtspr SPRN_SPRG_WSCRATCH4,r11
mfspr r10,SPRN_SRR0 /* Get faulting address */
/* If we are faulting a kernel address, we have to use the
* kernel page tables.
*/
lis r11,PAGE_OFFSET@h
cmplw cr0,r10,r11
blt+ 3f
lis r11,swapper_pg_dir@h
ori r11,r11, swapper_pg_dir@l
li r12,0 /* MMUCR = 0 */
b 4f
/* Get the PGD for the current thread and setup MMUCR */
3: mfspr r11,SPRN_SPRG_THREAD
lwz r11,PGDIR(r11)
mfspr r12,SPRN_PID /* Get PID */
4: mtspr SPRN_MMUCR,r12 /* Set MMUCR */
/* Make up the required permissions */
li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
/* Load PTE */
/* Compute pgdir/pmd offset */
rlwinm r12,r10,PPC44x_PGD_OFF_SHIFT,PPC44x_PGD_OFF_MASK_BIT,29
lwzx r11,r12,r11 /* Get pgd/pmd entry */
/* Word 0 is EPN,V,TS,DSIZ */
li r12,PPC47x_TLB0_VALID | PPC47x_TLBE_SIZE
rlwimi r10,r12,0,32-PAGE_SHIFT,31 /* Insert valid and page size*/
li r12,0
tlbwe r10,r12,0
/* XXX can we do better ? Need to make sure tlbwe has established
* latch V bit in MMUCR0 before the PTE is loaded further down */
#ifdef CONFIG_SMP
isync
#endif
rlwinm. r12,r11,0,0,20 /* Extract pt base address */
/* Compute pte address */
rlwimi r12,r10,PPC44x_PTE_ADD_SHIFT,PPC44x_PTE_ADD_MASK_BIT,28
beq 2f /* Bail if no table */
lwz r11,0(r12) /* Get high word of pte entry */
/* XXX can we do better ? maybe insert a known 0 bit from r11 into the
* bottom of r12 to create a data dependency... We can also use r10
* as destination nowadays
*/
#ifdef CONFIG_SMP
lwsync
#endif
lwz r12,4(r12) /* Get low word of pte entry */
andc. r13,r13,r12 /* Check permission */
/* Jump to common TLB load point */
beq finish_tlb_load_47x
2: /* The bailout. Restore registers to pre-exception conditions
* and call the heavyweights to help us out.
*/
mfspr r11, SPRN_SPRG_RSCRATCH4
mtcr r11
mfspr r13, SPRN_SPRG_RSCRATCH3
mfspr r12, SPRN_SPRG_RSCRATCH2
mfspr r11, SPRN_SPRG_RSCRATCH1
mfspr r10, SPRN_SPRG_RSCRATCH0
b InstructionStorage
/*
* Both the instruction and data TLB miss get to this
* point to load the TLB.
* r10 - free to use
* r11 - PTE high word value
* r12 - PTE low word value
* r13 - free to use
* MMUCR - loaded with proper value when we get here
* Upon exit, we reload everything and RFI.
*/
finish_tlb_load_47x:
/* Combine RPN & ERPN an write WS 1 */
rlwimi r11,r12,0,0,31-PAGE_SHIFT
tlbwe r11,r13,1
/* And make up word 2 */
li r10,0xf85 /* Mask to apply from PTE */
rlwimi r10,r12,29,30,30 /* DIRTY -> SW position */
and r11,r12,r10 /* Mask PTE bits to keep */
andi. r10,r12,_PAGE_USER /* User page ? */
beq 1f /* nope, leave U bits empty */
rlwimi r11,r11,3,26,28 /* yes, copy S bits to U */
1: tlbwe r11,r13,2
/* Done...restore registers and get out of here.
*/
mfspr r11, SPRN_SPRG_RSCRATCH4
mtcr r11
mfspr r13, SPRN_SPRG_RSCRATCH3
mfspr r12, SPRN_SPRG_RSCRATCH2
mfspr r11, SPRN_SPRG_RSCRATCH1
mfspr r10, SPRN_SPRG_RSCRATCH0
rfi
#endif /* CONFIG_PPC_47x */
/* Debug Interrupt */
/*
* This statement needs to exist at the end of the IVPR
* definition just in case you end up taking a debug
* exception within another exception.
*/
DEBUG_CRIT_EXCEPTION
/*
* Global functions
*/
/*
* Adjust the machine check IVOR on 440A cores
*/
_GLOBAL(__fixup_440A_mcheck)
li r3,MachineCheckA@l
mtspr SPRN_IVOR1,r3
sync
blr
/*
* extern void giveup_altivec(struct task_struct *prev)
*
* The 44x core does not have an AltiVec unit.
*/
_GLOBAL(giveup_altivec)
blr
/*
* extern void giveup_fpu(struct task_struct *prev)
*
* The 44x core does not have an FPU.
*/
#ifndef CONFIG_PPC_FPU
_GLOBAL(giveup_fpu)
blr
#endif
_GLOBAL(set_context)
#ifdef CONFIG_BDI_SWITCH
/* Context switch the PTE pointer for the Abatron BDI2000.
* The PGDIR is the second parameter.
*/
lis r5, abatron_pteptrs@h
ori r5, r5, abatron_pteptrs@l
stw r4, 0x4(r5)
#endif
mtspr SPRN_PID,r3
isync /* Force context change */
blr
/*
* Init CPU state. This is called at boot time or for secondary CPUs
* to setup initial TLB entries, setup IVORs, etc...
*
*/
_GLOBAL(init_cpu_state)
mflr r22
#ifdef CONFIG_PPC_47x
/* We use the PVR to differenciate 44x cores from 476 */
mfspr r3,SPRN_PVR
srwi r3,r3,16
cmplwi cr0,r3,PVR_476@h
beq head_start_47x
cmplwi cr0,r3,PVR_476_ISS@h
beq head_start_47x
#endif /* CONFIG_PPC_47x */
/*
* In case the firmware didn't do it, we apply some workarounds
* that are good for all 440 core variants here
*/
mfspr r3,SPRN_CCR0
rlwinm r3,r3,0,0,27 /* disable icache prefetch */
isync
mtspr SPRN_CCR0,r3
isync
sync
/*
* Set up the initial MMU state for 44x
*
* We are still executing code at the virtual address
* mappings set by the firmware for the base of RAM.
*
* We first invalidate all TLB entries but the one
* we are running from. We then load the KERNELBASE
* mappings so we can begin to use kernel addresses
* natively and so the interrupt vector locations are
* permanently pinned (necessary since Book E
* implementations always have translation enabled).
*
* TODO: Use the known TLB entry we are running from to
* determine which physical region we are located
* in. This can be used to determine where in RAM
* (on a shared CPU system) or PCI memory space
* (on a DRAMless system) we are located.
* For now, we assume a perfect world which means
* we are located at the base of DRAM (physical 0).
*/
/*
* Search TLB for entry that we are currently using.
* Invalidate all entries but the one we are using.
*/
/* Load our current PID->MMUCR TID and MSR IS->MMUCR STS */
mfspr r3,SPRN_PID /* Get PID */
mfmsr r4 /* Get MSR */
andi. r4,r4,MSR_IS@l /* TS=1? */
beq wmmucr /* If not, leave STS=0 */
oris r3,r3,PPC44x_MMUCR_STS@h /* Set STS=1 */
wmmucr: mtspr SPRN_MMUCR,r3 /* Put MMUCR */
sync
bl invstr /* Find our address */
invstr: mflr r5 /* Make it accessible */
tlbsx r23,0,r5 /* Find entry we are in */
li r4,0 /* Start at TLB entry 0 */
li r3,0 /* Set PAGEID inval value */
1: cmpw r23,r4 /* Is this our entry? */
beq skpinv /* If so, skip the inval */
tlbwe r3,r4,PPC44x_TLB_PAGEID /* If not, inval the entry */
skpinv: addi r4,r4,1 /* Increment */
cmpwi r4,64 /* Are we done? */
bne 1b /* If not, repeat */
isync /* If so, context change */
/*
* Configure and load pinned entry into TLB slot 63.
*/
lis r3,PAGE_OFFSET@h
ori r3,r3,PAGE_OFFSET@l
/* Kernel is at the base of RAM */
li r4, 0 /* Load the kernel physical address */
/* Load the kernel PID = 0 */
li r0,0
mtspr SPRN_PID,r0
sync
/* Initialize MMUCR */
li r5,0
mtspr SPRN_MMUCR,r5
sync
/* pageid fields */
clrrwi r3,r3,10 /* Mask off the effective page number */
ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_256M
/* xlat fields */
clrrwi r4,r4,10 /* Mask off the real page number */
/* ERPN is 0 for first 4GB page */
/* attrib fields */
/* Added guarded bit to protect against speculative loads/stores */
li r5,0
ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_SX | PPC44x_TLB_G)
li r0,63 /* TLB slot 63 */
tlbwe r3,r0,PPC44x_TLB_PAGEID /* Load the pageid fields */
tlbwe r4,r0,PPC44x_TLB_XLAT /* Load the translation fields */
tlbwe r5,r0,PPC44x_TLB_ATTRIB /* Load the attrib/access fields */
/* Force context change */
mfmsr r0
mtspr SPRN_SRR1, r0
lis r0,3f@h
ori r0,r0,3f@l
mtspr SPRN_SRR0,r0
sync
rfi
/* If necessary, invalidate original entry we used */
3: cmpwi r23,63
beq 4f
li r6,0
tlbwe r6,r23,PPC44x_TLB_PAGEID
isync
4:
#ifdef CONFIG_PPC_EARLY_DEBUG_44x
/* Add UART mapping for early debug. */
/* pageid fields */
lis r3,PPC44x_EARLY_DEBUG_VIRTADDR@h
ori r3,r3,PPC44x_TLB_VALID|PPC44x_TLB_TS|PPC44x_TLB_64K
/* xlat fields */
lis r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW@h
ori r4,r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSHIGH
/* attrib fields */
li r5,(PPC44x_TLB_SW|PPC44x_TLB_SR|PPC44x_TLB_I|PPC44x_TLB_G)
li r0,62 /* TLB slot 0 */
tlbwe r3,r0,PPC44x_TLB_PAGEID
tlbwe r4,r0,PPC44x_TLB_XLAT
tlbwe r5,r0,PPC44x_TLB_ATTRIB
/* Force context change */
isync
#endif /* CONFIG_PPC_EARLY_DEBUG_44x */
/* Establish the interrupt vector offsets */
SET_IVOR(0, CriticalInput);
SET_IVOR(1, MachineCheck);
SET_IVOR(2, DataStorage);
SET_IVOR(3, InstructionStorage);
SET_IVOR(4, ExternalInput);
SET_IVOR(5, Alignment);
SET_IVOR(6, Program);
SET_IVOR(7, FloatingPointUnavailable);
SET_IVOR(8, SystemCall);
SET_IVOR(9, AuxillaryProcessorUnavailable);
SET_IVOR(10, Decrementer);
SET_IVOR(11, FixedIntervalTimer);
SET_IVOR(12, WatchdogTimer);
SET_IVOR(13, DataTLBError44x);
SET_IVOR(14, InstructionTLBError44x);
SET_IVOR(15, DebugCrit);
b head_start_common
#ifdef CONFIG_PPC_47x
#ifdef CONFIG_SMP
/* Entry point for secondary 47x processors */
_GLOBAL(start_secondary_47x)
mr r24,r3 /* CPU number */
bl init_cpu_state
/* Now we need to bolt the rest of kernel memory which
* is done in C code. We must be careful because our task
* struct or our stack can (and will probably) be out
* of reach of the initial 256M TLB entry, so we use a
* small temporary stack in .bss for that. This works
* because only one CPU at a time can be in this code
*/
lis r1,temp_boot_stack@h
ori r1,r1,temp_boot_stack@l
addi r1,r1,1024-STACK_FRAME_OVERHEAD
li r0,0
stw r0,0(r1)
bl mmu_init_secondary
/* Now we can get our task struct and real stack pointer */
/* Get current_thread_info and current */
lis r1,secondary_ti@ha
lwz r1,secondary_ti@l(r1)
lwz r2,TI_TASK(r1)
/* Current stack pointer */
addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
li r0,0
stw r0,0(r1)
/* Kernel stack for exception entry in SPRG3 */
addi r4,r2,THREAD /* init task's THREAD */
mtspr SPRN_SPRG3,r4
b start_secondary
#endif /* CONFIG_SMP */
/*
* Set up the initial MMU state for 44x
*
* We are still executing code at the virtual address
* mappings set by the firmware for the base of RAM.
*/
head_start_47x:
/* Load our current PID->MMUCR TID and MSR IS->MMUCR STS */
mfspr r3,SPRN_PID /* Get PID */
mfmsr r4 /* Get MSR */
andi. r4,r4,MSR_IS@l /* TS=1? */
beq 1f /* If not, leave STS=0 */
oris r3,r3,PPC47x_MMUCR_STS@h /* Set STS=1 */
1: mtspr SPRN_MMUCR,r3 /* Put MMUCR */
sync
/* Find the entry we are running from */
bl 1f
1: mflr r23
tlbsx r23,0,r23
tlbre r24,r23,0
tlbre r25,r23,1
tlbre r26,r23,2
/*
* Cleanup time
*/
/* Initialize MMUCR */
li r5,0
mtspr SPRN_MMUCR,r5
sync
clear_all_utlb_entries:
#; Set initial values.
addis r3,0,0x8000
addi r4,0,0
addi r5,0,0
b clear_utlb_entry
#; Align the loop to speed things up.
.align 6
clear_utlb_entry:
tlbwe r4,r3,0
tlbwe r5,r3,1
tlbwe r5,r3,2
addis r3,r3,0x2000
cmpwi r3,0
bne clear_utlb_entry
addis r3,0,0x8000
addis r4,r4,0x100
cmpwi r4,0
bne clear_utlb_entry
#; Restore original entry.
oris r23,r23,0x8000 /* specify the way */
tlbwe r24,r23,0
tlbwe r25,r23,1
tlbwe r26,r23,2
/*
* Configure and load pinned entry into TLB for the kernel core
*/
lis r3,PAGE_OFFSET@h
ori r3,r3,PAGE_OFFSET@l
/* Kernel is at the base of RAM */
li r4, 0 /* Load the kernel physical address */
/* Load the kernel PID = 0 */
li r0,0
mtspr SPRN_PID,r0
sync
/* Word 0 */
clrrwi r3,r3,12 /* Mask off the effective page number */
ori r3,r3,PPC47x_TLB0_VALID | PPC47x_TLB0_256M
/* Word 1 */
clrrwi r4,r4,12 /* Mask off the real page number */
/* ERPN is 0 for first 4GB page */
/* Word 2 */
li r5,0
ori r5,r5,PPC47x_TLB2_S_RWX
#ifdef CONFIG_SMP
ori r5,r5,PPC47x_TLB2_M
#endif
/* We write to way 0 and bolted 0 */
lis r0,0x8800
tlbwe r3,r0,0
tlbwe r4,r0,1
tlbwe r5,r0,2
/*
* Configure SSPCR, ISPCR and USPCR for now to search everything, we can fix
* them up later
*/
LOAD_REG_IMMEDIATE(r3, 0x9abcdef0)
mtspr SPRN_SSPCR,r3
mtspr SPRN_USPCR,r3
LOAD_REG_IMMEDIATE(r3, 0x12345670)
mtspr SPRN_ISPCR,r3
/* Force context change */
mfmsr r0
mtspr SPRN_SRR1, r0
lis r0,3f@h
ori r0,r0,3f@l
mtspr SPRN_SRR0,r0
sync
rfi
/* Invalidate original entry we used */
3:
rlwinm r24,r24,0,21,19 /* clear the "valid" bit */
tlbwe r24,r23,0
addi r24,0,0
tlbwe r24,r23,1
tlbwe r24,r23,2
isync /* Clear out the shadow TLB entries */
#ifdef CONFIG_PPC_EARLY_DEBUG_44x
/* Add UART mapping for early debug. */
/* Word 0 */
lis r3,PPC44x_EARLY_DEBUG_VIRTADDR@h
ori r3,r3,PPC47x_TLB0_VALID | PPC47x_TLB0_TS | PPC47x_TLB0_1M
/* Word 1 */
lis r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSLOW@h
ori r4,r4,CONFIG_PPC_EARLY_DEBUG_44x_PHYSHIGH
/* Word 2 */
li r5,(PPC47x_TLB2_S_RW | PPC47x_TLB2_IMG)
/* Bolted in way 0, bolt slot 5, we -hope- we don't hit the same
* congruence class as the kernel, we need to make sure of it at
* some point
*/
lis r0,0x8d00
tlbwe r3,r0,0
tlbwe r4,r0,1
tlbwe r5,r0,2
/* Force context change */
isync
#endif /* CONFIG_PPC_EARLY_DEBUG_44x */
/* Establish the interrupt vector offsets */
SET_IVOR(0, CriticalInput);
SET_IVOR(1, MachineCheckA);
SET_IVOR(2, DataStorage);
SET_IVOR(3, InstructionStorage);
SET_IVOR(4, ExternalInput);
SET_IVOR(5, Alignment);
SET_IVOR(6, Program);
SET_IVOR(7, FloatingPointUnavailable);
SET_IVOR(8, SystemCall);
SET_IVOR(9, AuxillaryProcessorUnavailable);
SET_IVOR(10, Decrementer);
SET_IVOR(11, FixedIntervalTimer);
SET_IVOR(12, WatchdogTimer);
SET_IVOR(13, DataTLBError47x);
SET_IVOR(14, InstructionTLBError47x);
SET_IVOR(15, DebugCrit);
/* We configure icbi to invalidate 128 bytes at a time since the
* current 32-bit kernel code isn't too happy with icache != dcache
* block size
*/
mfspr r3,SPRN_CCR0
oris r3,r3,0x0020
mtspr SPRN_CCR0,r3
isync
#endif /* CONFIG_PPC_47x */
/*
* Here we are back to code that is common between 44x and 47x
*
* We proceed to further kernel initialization and return to the
* main kernel entry
*/
head_start_common:
/* Establish the interrupt vector base */
lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */
mtspr SPRN_IVPR,r4
addis r22,r22,KERNELBASE@h
mtlr r22
isync
blr
/*
* We put a few things here that have to be page-aligned. This stuff
* goes at the beginning of the data segment, which is page-aligned.
*/
.data
.align PAGE_SHIFT
.globl sdata
sdata:
.globl empty_zero_page
empty_zero_page:
.space PAGE_SIZE
/*
* To support >32-bit physical addresses, we use an 8KB pgdir.
*/
.globl swapper_pg_dir
swapper_pg_dir:
.space PGD_TABLE_SIZE
/*
* Room for two PTE pointers, usually the kernel and current user pointers
* to their respective root page table.
*/
abatron_pteptrs:
.space 8
#ifdef CONFIG_SMP
.align 12
temp_boot_stack:
.space 1024
#endif /* CONFIG_SMP */
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