| /* |
| * 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/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. |
| * We can map UART registers wherever we want as long as they don't |
| * interfere with other system mappings (e.g. with pinned entries). |
| * For an example of how we handle this - see ocotea.h. --ebs |
| */ |
| /* pageid fields */ |
| lis r3,UART0_IO_BASE@h |
| ori r3,r3,PPC44x_TLB_VALID | PPC44x_TLB_4K |
| |
| /* xlat fields */ |
| lis r4,UART0_PHYS_IO_BASE@h /* RPN depends on SoC */ |
| #ifdef UART0_PHYS_ERPN |
| ori r4,r4,UART0_PHYS_ERPN /* Add ERPN if above 4GB */ |
| #endif |
| |
| /* attrib fields */ |
| li r5,0 |
| ori r5,r5,(PPC44x_TLB_SW | PPC44x_TLB_SR | PPC44x_TLB_I | PPC44x_TLB_G) |
| |
| li r0,0 /* TLB slot 0 */ |
| |
| 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 |
| |
| #ifdef CONFIG_440EP |
| /* Clear DAPUIB flag in CCR0 (enable APU between CPU and FPU) */ |
| mfspr r2,SPRN_CCR0 |
| lis r3,0xffef |
| ori r3,r3,0xffff |
| and r2,r2,r3 |
| mtspr SPRN_CCR0,r2 |
| isync |
| #endif |
| |
| /* |
| * 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, unknown_exception) |
| |
| /* Machine Check Interrupt */ |
| #ifdef CONFIG_440A |
| MCHECK_EXCEPTION(0x0200, MachineCheck, machine_check_exception) |
| #else |
| CRITICAL_EXCEPTION(0x0200, MachineCheck, machine_check_exception) |
| #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, 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(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 |
| .align 12 |
| .globl sdata |
| sdata: |
| .globl empty_zero_page |
| empty_zero_page: |
| .space 4096 |
| |
| /* |
| * To support >32-bit physical addresses, we use an 8KB pgdir. |
| */ |
| .globl swapper_pg_dir |
| 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 |
| .globl exception_stack_top |
| 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. |
| */ |
| .globl cmd_line |
| 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 |