| /* |
| * 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/ptrace.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 |
| mr r31,r3 /* save device tree ptr */ |
| li r24,0 /* CPU number */ |
| |
| #ifdef CONFIG_RELOCATABLE |
| /* |
| * Relocate ourselves to the current runtime address. |
| * This is called only by the Boot CPU. |
| * "relocate" is called with our current runtime virutal |
| * address. |
| * r21 will be loaded with the physical runtime address of _stext |
| */ |
| bl 0f /* Get our runtime address */ |
| 0: mflr r21 /* Make it accessible */ |
| addis r21,r21,(_stext - 0b)@ha |
| addi r21,r21,(_stext - 0b)@l /* Get our current runtime base */ |
| |
| /* |
| * We have the runtime (virutal) address of our base. |
| * We calculate our shift of offset from a 256M page. |
| * We could map the 256M page we belong to at PAGE_OFFSET and |
| * get going from there. |
| */ |
| lis r4,KERNELBASE@h |
| ori r4,r4,KERNELBASE@l |
| rlwinm r6,r21,0,4,31 /* r6 = PHYS_START % 256M */ |
| rlwinm r5,r4,0,4,31 /* r5 = KERNELBASE % 256M */ |
| subf r3,r5,r6 /* r3 = r6 - r5 */ |
| add r3,r4,r3 /* Required Virutal Address */ |
| |
| bl relocate |
| #endif |
| |
| 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 |
| |
| #ifdef CONFIG_RELOCATABLE |
| /* |
| * Relocatable kernel support based on processing of dynamic |
| * relocation entries. |
| * |
| * r25 will contain RPN/ERPN for the start address of memory |
| * r21 will contain the current offset of _stext |
| */ |
| lis r3,kernstart_addr@ha |
| la r3,kernstart_addr@l(r3) |
| |
| /* |
| * Compute the kernstart_addr. |
| * kernstart_addr => (r6,r8) |
| * kernstart_addr & ~0xfffffff => (r6,r7) |
| */ |
| rlwinm r6,r25,0,28,31 /* ERPN. Bits 32-35 of Address */ |
| rlwinm r7,r25,0,0,3 /* RPN - assuming 256 MB page size */ |
| rlwinm r8,r21,0,4,31 /* r8 = (_stext & 0xfffffff) */ |
| or r8,r7,r8 /* Compute the lower 32bit of kernstart_addr */ |
| |
| /* Store kernstart_addr */ |
| stw r6,0(r3) /* higher 32bit */ |
| stw r8,4(r3) /* lower 32bit */ |
| |
| /* |
| * Compute the virt_phys_offset : |
| * virt_phys_offset = stext.run - kernstart_addr |
| * |
| * stext.run = (KERNELBASE & ~0xfffffff) + (kernstart_addr & 0xfffffff) |
| * When we relocate, we have : |
| * |
| * (kernstart_addr & 0xfffffff) = (stext.run & 0xfffffff) |
| * |
| * hence: |
| * virt_phys_offset = (KERNELBASE & ~0xfffffff) - (kernstart_addr & ~0xfffffff) |
| * |
| */ |
| |
| /* KERNELBASE&~0xfffffff => (r4,r5) */ |
| li r4, 0 /* higer 32bit */ |
| lis r5,KERNELBASE@h |
| rlwinm r5,r5,0,0,3 /* Align to 256M, lower 32bit */ |
| |
| /* |
| * 64bit subtraction. |
| */ |
| subfc r5,r7,r5 |
| subfe r4,r6,r4 |
| |
| /* Store virt_phys_offset */ |
| lis r3,virt_phys_offset@ha |
| la r3,virt_phys_offset@l(r3) |
| |
| stw r4,0(r3) |
| stw r5,4(r3) |
| |
| #elif defined(CONFIG_DYNAMIC_MEMSTART) |
| /* |
| * Mapping based, page aligned dynamic kernel loading. |
| * |
| * r25 will contain RPN/ERPN for the start address of memory |
| * |
| * Add the difference between KERNELBASE and PAGE_OFFSET to the |
| * start of physical memory to get kernstart_addr. |
| */ |
| lis r3,kernstart_addr@ha |
| la r3,kernstart_addr@l(r3) |
| |
| lis r4,KERNELBASE@h |
| ori r4,r4,KERNELBASE@l |
| lis r5,PAGE_OFFSET@h |
| ori r5,r5,PAGE_OFFSET@l |
| subf r4,r5,r4 |
| |
| rlwinm r6,r25,0,28,31 /* ERPN */ |
| rlwinm r7,r25,0,0,3 /* RPN - assuming 256 MB page size */ |
| add r7,r7,r4 |
| |
| stw r6,0(r3) |
| stw r7,4(r3) |
| #endif |
| |
| /* |
| * Decide what sort of machine this is and initialize the MMU. |
| */ |
| li r3,0 |
| mr r4,r31 |
| 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, CRITICAL, CriticalInput, unknown_exception) |
| |
| /* Machine Check Interrupt */ |
| CRITICAL_EXCEPTION(0x0200, MACHINE_CHECK, 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, BOOKE_INTERRUPT_EXTERNAL, 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, BOOKE_INTERRUPT_FP_UNAVAIL, \ |
| FloatingPointUnavailable, unknown_exception, EXC_XFER_EE) |
| #endif |
| /* System Call Interrupt */ |
| START_EXCEPTION(SystemCall) |
| NORMAL_EXCEPTION_PROLOG(BOOKE_INTERRUPT_SYSCALL) |
| EXC_XFER_EE_LITE(0x0c00, DoSyscall) |
| |
| /* Auxiliary Processor Unavailable Interrupt */ |
| EXCEPTION(0x2020, BOOKE_INTERRUPT_AP_UNAVAIL, \ |
| AuxillaryProcessorUnavailable, unknown_exception, EXC_XFER_EE) |
| |
| /* Decrementer Interrupt */ |
| DECREMENTER_EXCEPTION |
| |
| /* Fixed Internal Timer Interrupt */ |
| /* TODO: Add FIT support */ |
| EXCEPTION(0x1010, BOOKE_INTERRUPT_FIT, FixedIntervalTimer, \ |
| unknown_exception, EXC_XFER_EE) |
| |
| /* Watchdog Timer Interrupt */ |
| /* TODO: Add watchdog support */ |
| #ifdef CONFIG_BOOKE_WDT |
| CRITICAL_EXCEPTION(0x1020, WATCHDOG, WatchdogTimer, WatchdogException) |
| #else |
| CRITICAL_EXCEPTION(0x1020, WATCHDOG, 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_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_476FPE@h |
| beq head_start_47x |
| 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. |
| */ |
| #ifdef CONFIG_NONSTATIC_KERNEL |
| /* |
| * In case of a NONSTATIC_KERNEL we reuse the TLB XLAT |
| * entries of the initial mapping set by the boot loader. |
| * The XLAT entry is stored in r25 |
| */ |
| |
| /* Read the XLAT entry for our current mapping */ |
| tlbre r25,r23,PPC44x_TLB_XLAT |
| |
| lis r3,KERNELBASE@h |
| ori r3,r3,KERNELBASE@l |
| |
| /* Use our current RPN entry */ |
| mr r4,r25 |
| #else |
| |
| 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 */ |
| #endif |
| |
| /* 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 |
| |
| /* 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 - use r25. RPN is the same as the original entry */ |
| |
| /* 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 r25,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 |
| |
| /* |
| * If the kernel was loaded at a non-zero 256 MB page, we need to |
| * mask off the most significant 4 bits to get the relative address |
| * from the start of physical memory |
| */ |
| rlwinm r22,r22,0,4,31 |
| addis r22,r22,PAGE_OFFSET@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 */ |
