forked from Minki/linux
b2665f92ae
This patch fixed CONFIG_TASK_SIZE handling on 44x. Currently head_44x.S hardcodes 0x80000000, which breaks if user chooses to change TASK_SIZE (e.g. for 3G user-space). Tested on Ocotea in 3G/1G configuration. Signed-off-by: Eugene Surovegin <ebs@ebshome.net> Signed-off-by: Matt Porter <mporter@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
763 lines
20 KiB
ArmAsm
763 lines
20 KiB
ArmAsm
/*
|
|
* arch/ppc/kernel/head_44x.S
|
|
*
|
|
* 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/config.h>
|
|
#include <asm/processor.h>
|
|
#include <asm/page.h>
|
|
#include <asm/mmu.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/ibm4xx.h>
|
|
#include <asm/ibm44x.h>
|
|
#include <asm/cputable.h>
|
|
#include <asm/thread_info.h>
|
|
#include <asm/ppc_asm.h>
|
|
#include <asm/offsets.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
|
|
*
|
|
*/
|
|
.text
|
|
_GLOBAL(_stext)
|
|
_GLOBAL(_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 */
|
|
|
|
/*
|
|
* Set up the initial MMU state
|
|
*
|
|
* 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,KERNELBASE@h /* Load the kernel virtual address */
|
|
ori r3,r3,KERNELBASE@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_SERIAL_TEXT_DEBUG
|
|
/*
|
|
* Add temporary UART mapping for early debug. This
|
|
* mapping must be identical to that used by the early
|
|
* bootloader code since the same asm/serial.h parameters
|
|
* are used for polled operation.
|
|
*/
|
|
/* pageid fields */
|
|
lis r3,UART0_IO_BASE@h
|
|
ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_256M
|
|
|
|
/* xlat fields */
|
|
lis r4,UART0_PHYS_IO_BASE@h /* RPN depends on SoC */
|
|
ori r4,r4,0x0001 /* ERPN is 1 for second 4GB page */
|
|
|
|
/* attrib fields */
|
|
li r5,0
|
|
ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_I | PPC44x_TLB_G)
|
|
|
|
li r0,1 /* TLB slot 1 */
|
|
|
|
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 */
|
|
isync
|
|
#endif /* CONFIG_SERIAL_TEXT_DEBUG */
|
|
|
|
/* 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, DataTLBError);
|
|
SET_IVOR(14, InstructionTLBError);
|
|
SET_IVOR(15, Debug);
|
|
|
|
/* Establish the interrupt vector base */
|
|
lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */
|
|
mtspr SPRN_IVPR,r4
|
|
|
|
/*
|
|
* 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_SPRG3,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)
|
|
|
|
/* 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, UnknownException)
|
|
|
|
/* Machine Check Interrupt */
|
|
#ifdef CONFIG_440A
|
|
MCHECK_EXCEPTION(0x0200, MachineCheck, MachineCheckException)
|
|
#else
|
|
CRITICAL_EXCEPTION(0x0200, MachineCheck, MachineCheckException)
|
|
#endif
|
|
|
|
/* Data Storage Interrupt */
|
|
START_EXCEPTION(DataStorage)
|
|
mtspr SPRN_SPRG0, r10 /* Save some working registers */
|
|
mtspr SPRN_SPRG1, r11
|
|
mtspr SPRN_SPRG4W, r12
|
|
mtspr SPRN_SPRG5W, r13
|
|
mfcr r11
|
|
mtspr SPRN_SPRG7W, r11
|
|
|
|
/*
|
|
* Check if it was a store fault, if not then bail
|
|
* because a user tried to access a kernel or
|
|
* read-protected page. Otherwise, get the
|
|
* offending address and handle it.
|
|
*/
|
|
mfspr r10, SPRN_ESR
|
|
andis. r10, r10, ESR_ST@h
|
|
beq 2f
|
|
|
|
mfspr r10, SPRN_DEAR /* Get faulting address */
|
|
|
|
/* If we are faulting a kernel address, we have to use the
|
|
* kernel page tables.
|
|
*/
|
|
lis r11, TASK_SIZE@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_SPRG3
|
|
lwz r11,PGDIR(r11)
|
|
|
|
/* Load PID into MMUCR TID */
|
|
mfspr r12,SPRN_MMUCR /* Get MMUCR */
|
|
mfspr r13,SPRN_PID /* Get PID */
|
|
rlwimi r12,r13,0,24,31 /* Set TID */
|
|
|
|
4:
|
|
mtspr SPRN_MMUCR,r12
|
|
|
|
rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */
|
|
lwzx r11, r12, r11 /* Get pgd/pmd entry */
|
|
rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */
|
|
beq 2f /* Bail if no table */
|
|
|
|
rlwimi r12, r10, 23, 20, 28 /* Compute pte address */
|
|
lwz r11, 4(r12) /* Get pte entry */
|
|
|
|
andi. r13, r11, _PAGE_RW /* Is it writeable? */
|
|
beq 2f /* Bail if not */
|
|
|
|
/* Update 'changed'.
|
|
*/
|
|
ori r11, r11, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE
|
|
stw r11, 4(r12) /* Update Linux page table */
|
|
|
|
li r13, PPC44x_TLB_SR@l /* Set SR */
|
|
rlwimi r13, r11, 29, 29, 29 /* SX = _PAGE_HWEXEC */
|
|
rlwimi r13, r11, 0, 30, 30 /* SW = _PAGE_RW */
|
|
rlwimi r13, r11, 29, 28, 28 /* UR = _PAGE_USER */
|
|
rlwimi r12, r11, 31, 26, 26 /* (_PAGE_USER>>1)->r12 */
|
|
rlwimi r12, r11, 29, 30, 30 /* (_PAGE_USER>>3)->r12 */
|
|
and r12, r12, r11 /* HWEXEC/RW & USER */
|
|
rlwimi r13, r12, 0, 26, 26 /* UX = HWEXEC & USER */
|
|
rlwimi r13, r12, 3, 27, 27 /* UW = RW & USER */
|
|
|
|
rlwimi r11,r13,0,26,31 /* Insert static perms */
|
|
|
|
rlwinm r11,r11,0,20,15 /* Clear U0-U3 */
|
|
|
|
/* find the TLB index that caused the fault. It has to be here. */
|
|
tlbsx r10, 0, r10
|
|
|
|
tlbwe r11, r10, PPC44x_TLB_ATTRIB /* Write ATTRIB */
|
|
|
|
/* Done...restore registers and get out of here.
|
|
*/
|
|
mfspr r11, SPRN_SPRG7R
|
|
mtcr r11
|
|
mfspr r13, SPRN_SPRG5R
|
|
mfspr r12, SPRN_SPRG4R
|
|
|
|
mfspr r11, SPRN_SPRG1
|
|
mfspr r10, SPRN_SPRG0
|
|
rfi /* Force context change */
|
|
|
|
2:
|
|
/*
|
|
* The bailout. Restore registers to pre-exception conditions
|
|
* and call the heavyweights to help us out.
|
|
*/
|
|
mfspr r11, SPRN_SPRG7R
|
|
mtcr r11
|
|
mfspr r13, SPRN_SPRG5R
|
|
mfspr r12, SPRN_SPRG4R
|
|
|
|
mfspr r11, SPRN_SPRG1
|
|
mfspr r10, SPRN_SPRG0
|
|
b data_access
|
|
|
|
/* 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, UnknownException, 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, UnknownException, EXC_XFER_EE)
|
|
|
|
/* Decrementer Interrupt */
|
|
DECREMENTER_EXCEPTION
|
|
|
|
/* Fixed Internal Timer Interrupt */
|
|
/* TODO: Add FIT support */
|
|
EXCEPTION(0x1010, FixedIntervalTimer, UnknownException, EXC_XFER_EE)
|
|
|
|
/* Watchdog Timer Interrupt */
|
|
/* TODO: Add watchdog support */
|
|
CRITICAL_EXCEPTION(0x1020, WatchdogTimer, UnknownException)
|
|
|
|
/* Data TLB Error Interrupt */
|
|
START_EXCEPTION(DataTLBError)
|
|
mtspr SPRN_SPRG0, r10 /* Save some working registers */
|
|
mtspr SPRN_SPRG1, r11
|
|
mtspr SPRN_SPRG4W, r12
|
|
mtspr SPRN_SPRG5W, r13
|
|
mfcr r11
|
|
mtspr SPRN_SPRG7W, 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, TASK_SIZE@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_SPRG3
|
|
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
|
|
|
|
rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */
|
|
lwzx r11, r12, r11 /* Get pgd/pmd entry */
|
|
rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */
|
|
beq 2f /* Bail if no table */
|
|
|
|
rlwimi r12, r10, 23, 20, 28 /* Compute pte address */
|
|
lwz r11, 4(r12) /* Get pte entry */
|
|
andi. r13, r11, _PAGE_PRESENT /* Is the page present? */
|
|
beq 2f /* Bail if not present */
|
|
|
|
ori r11, r11, _PAGE_ACCESSED
|
|
stw r11, 4(r12)
|
|
|
|
/* Jump to common tlb load */
|
|
b finish_tlb_load
|
|
|
|
2:
|
|
/* The bailout. Restore registers to pre-exception conditions
|
|
* and call the heavyweights to help us out.
|
|
*/
|
|
mfspr r11, SPRN_SPRG7R
|
|
mtcr r11
|
|
mfspr r13, SPRN_SPRG5R
|
|
mfspr r12, SPRN_SPRG4R
|
|
mfspr r11, SPRN_SPRG1
|
|
mfspr r10, SPRN_SPRG0
|
|
b data_access
|
|
|
|
/* 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(InstructionTLBError)
|
|
mtspr SPRN_SPRG0, r10 /* Save some working registers */
|
|
mtspr SPRN_SPRG1, r11
|
|
mtspr SPRN_SPRG4W, r12
|
|
mtspr SPRN_SPRG5W, r13
|
|
mfcr r11
|
|
mtspr SPRN_SPRG7W, 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, TASK_SIZE@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_SPRG3
|
|
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
|
|
|
|
rlwinm r12, r10, 13, 19, 29 /* Compute pgdir/pmd offset */
|
|
lwzx r11, r12, r11 /* Get pgd/pmd entry */
|
|
rlwinm. r12, r11, 0, 0, 20 /* Extract pt base address */
|
|
beq 2f /* Bail if no table */
|
|
|
|
rlwimi r12, r10, 23, 20, 28 /* Compute pte address */
|
|
lwz r11, 4(r12) /* Get pte entry */
|
|
andi. r13, r11, _PAGE_PRESENT /* Is the page present? */
|
|
beq 2f /* Bail if not present */
|
|
|
|
ori r11, r11, _PAGE_ACCESSED
|
|
stw r11, 4(r12)
|
|
|
|
/* Jump to common TLB load point */
|
|
b finish_tlb_load
|
|
|
|
2:
|
|
/* The bailout. Restore registers to pre-exception conditions
|
|
* and call the heavyweights to help us out.
|
|
*/
|
|
mfspr r11, SPRN_SPRG7R
|
|
mtcr r11
|
|
mfspr r13, SPRN_SPRG5R
|
|
mfspr r12, SPRN_SPRG4R
|
|
mfspr r11, SPRN_SPRG1
|
|
mfspr r10, SPRN_SPRG0
|
|
b InstructionStorage
|
|
|
|
/* Debug Interrupt */
|
|
DEBUG_EXCEPTION
|
|
|
|
/*
|
|
* Local functions
|
|
*/
|
|
/*
|
|
* Data TLB exceptions will bail out to this point
|
|
* if they can't resolve the lightweight TLB fault.
|
|
*/
|
|
data_access:
|
|
NORMAL_EXCEPTION_PROLOG
|
|
mfspr r5,SPRN_ESR /* Grab the ESR, save it, pass arg3 */
|
|
stw r5,_ESR(r11)
|
|
mfspr r4,SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */
|
|
EXC_XFER_EE_LITE(0x0300, handle_page_fault)
|
|
|
|
/*
|
|
|
|
* Both the instruction and data TLB miss get to this
|
|
* point to load the TLB.
|
|
* r10 - EA of fault
|
|
* r11 - available to use
|
|
* r12 - Pointer to the 64-bit PTE
|
|
* r13 - available to use
|
|
* MMUCR - loaded with proper value when we get here
|
|
* Upon exit, we reload everything and RFI.
|
|
*/
|
|
finish_tlb_load:
|
|
/*
|
|
* We set execute, because we don't have the granularity to
|
|
* properly set this at the page level (Linux problem).
|
|
* If shared is set, we cause a zero PID->TID load.
|
|
* Many of these bits are software only. Bits we don't set
|
|
* here we (properly should) assume have the appropriate value.
|
|
*/
|
|
|
|
/* Load the next available TLB index */
|
|
lis r13, tlb_44x_index@ha
|
|
lwz r13, tlb_44x_index@l(r13)
|
|
/* Load the TLB high watermark */
|
|
lis r11, tlb_44x_hwater@ha
|
|
lwz r11, tlb_44x_hwater@l(r11)
|
|
|
|
/* Increment, rollover, and store TLB index */
|
|
addi r13, r13, 1
|
|
cmpw 0, r13, r11 /* reserve entries */
|
|
ble 7f
|
|
li r13, 0
|
|
7:
|
|
/* Store the next available TLB index */
|
|
lis r11, tlb_44x_index@ha
|
|
stw r13, tlb_44x_index@l(r11)
|
|
|
|
lwz r11, 0(r12) /* Get MS word of PTE */
|
|
lwz r12, 4(r12) /* Get LS word of PTE */
|
|
rlwimi r11, r12, 0, 0 , 19 /* Insert RPN */
|
|
tlbwe r11, r13, PPC44x_TLB_XLAT /* Write XLAT */
|
|
|
|
/*
|
|
* Create PAGEID. This is the faulting address,
|
|
* page size, and valid flag.
|
|
*/
|
|
li r11, PPC44x_TLB_VALID | PPC44x_TLB_4K
|
|
rlwimi r10, r11, 0, 20, 31 /* Insert valid and page size */
|
|
tlbwe r10, r13, PPC44x_TLB_PAGEID /* Write PAGEID */
|
|
|
|
li r10, PPC44x_TLB_SR@l /* Set SR */
|
|
rlwimi r10, r12, 0, 30, 30 /* Set SW = _PAGE_RW */
|
|
rlwimi r10, r12, 29, 29, 29 /* SX = _PAGE_HWEXEC */
|
|
rlwimi r10, r12, 29, 28, 28 /* UR = _PAGE_USER */
|
|
rlwimi r11, r12, 31, 26, 26 /* (_PAGE_USER>>1)->r12 */
|
|
and r11, r12, r11 /* HWEXEC & USER */
|
|
rlwimi r10, r11, 0, 26, 26 /* UX = HWEXEC & USER */
|
|
|
|
rlwimi r12, r10, 0, 26, 31 /* Insert static perms */
|
|
rlwinm r12, r12, 0, 20, 15 /* Clear U0-U3 */
|
|
tlbwe r12, r13, PPC44x_TLB_ATTRIB /* Write ATTRIB */
|
|
|
|
/* Done...restore registers and get out of here.
|
|
*/
|
|
mfspr r11, SPRN_SPRG7R
|
|
mtcr r11
|
|
mfspr r13, SPRN_SPRG5R
|
|
mfspr r12, SPRN_SPRG4R
|
|
mfspr r11, SPRN_SPRG1
|
|
mfspr r10, SPRN_SPRG0
|
|
rfi /* Force context change */
|
|
|
|
/*
|
|
* Global functions
|
|
*/
|
|
|
|
/*
|
|
* 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
|
|
|
|
/*
|
|
* extern void abort(void)
|
|
*
|
|
* At present, this routine just applies a system reset.
|
|
*/
|
|
_GLOBAL(abort)
|
|
mfspr r13,SPRN_DBCR0
|
|
oris r13,r13,DBCR0_RST_SYSTEM@h
|
|
mtspr SPRN_DBCR0,r13
|
|
|
|
_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
|
|
|
|
/*
|
|
* 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
|
|
_GLOBAL(sdata)
|
|
_GLOBAL(empty_zero_page)
|
|
.space 4096
|
|
|
|
/*
|
|
* To support >32-bit physical addresses, we use an 8KB pgdir.
|
|
*/
|
|
_GLOBAL(swapper_pg_dir)
|
|
.space 8192
|
|
|
|
/* Reserved 4k for the critical exception stack & 4k for the machine
|
|
* check stack per CPU for kernel mode exceptions */
|
|
.section .bss
|
|
.align 12
|
|
exception_stack_bottom:
|
|
.space BOOKE_EXCEPTION_STACK_SIZE
|
|
_GLOBAL(exception_stack_top)
|
|
|
|
/*
|
|
* This space gets a copy of optional info passed to us by the bootstrap
|
|
* which is used to pass parameters into the kernel like root=/dev/sda1, etc.
|
|
*/
|
|
_GLOBAL(cmd_line)
|
|
.space 512
|
|
|
|
/*
|
|
* Room for two PTE pointers, usually the kernel and current user pointers
|
|
* to their respective root page table.
|
|
*/
|
|
abatron_pteptrs:
|
|
.space 8
|
|
|
|
|