diff options
Diffstat (limited to 'arch/ppc/kernel/head_44x.S')
| -rw-r--r-- | arch/ppc/kernel/head_44x.S | 753 |
1 files changed, 753 insertions, 0 deletions
diff --git a/arch/ppc/kernel/head_44x.S b/arch/ppc/kernel/head_44x.S new file mode 100644 index 00000000000..9ed8165a3d6 --- /dev/null +++ b/arch/ppc/kernel/head_44x.S @@ -0,0 +1,753 @@ +/* + * 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. + */ + andis. r11, r10, 0x8000 + beq 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 */ + EXCEPTION(0x2010, FloatingPointUnavailable, UnknownException, EXC_XFER_EE) + + /* 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. + */ + andis. r11, r10, 0x8000 + beq 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. + */ + andis. r11, r10, 0x8000 + beq 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. + */ +_GLOBAL(giveup_fpu) + blr + +/* + * 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 + + |