/* * arch/ppc/kernel/head_e500.S * * Kernel execution entry point code. * * Copyright (c) 1995-1996 Gary Thomas * Initial PowerPC version. * Copyright (c) 1996 Cort Dougan * Rewritten for PReP * Copyright (c) 1996 Paul Mackerras * Low-level exception handers, MMU support, and rewrite. * Copyright (c) 1997 Dan Malek * PowerPC 8xx modifications. * Copyright (c) 1998-1999 TiVo, Inc. * PowerPC 403GCX modifications. * Copyright (c) 1999 Grant Erickson * 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 2002-2004 MontaVista Software, Inc. * PowerPC 44x support, Matt Porter * Copyright 2004 Freescale Semiconductor, Inc * PowerPC e500 modifications, Kumar Gala * * 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 #include #include #include #include #include #include #include #include /* * Macros */ #define SET_IVOR(vector_number, vector_label) \ li r26,vector_label@l; \ mtspr SPRN_IVOR##vector_number,r26; \ sync /* 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 */ /* We try to not make any assumptions about how the boot loader * setup or used the TLBs. We invalidate all mappings from the * boot loader and load a single entry in TLB1[0] to map the * first 16M of kernel memory. Any boot info passed from the * bootloader needs to live in this first 16M. * * Requirement on bootloader: * - The page we're executing in needs to reside in TLB1 and * have IPROT=1. If not an invalidate broadcast could * evict the entry we're currently executing in. * * r3 = Index of TLB1 were executing in * r4 = Current MSR[IS] * r5 = Index of TLB1 temp mapping * * Later in mapin_ram we will correctly map lowmem, and resize TLB1[0] * if needed */ /* 1. Find the index of the entry we're executing in */ bl invstr /* Find our address */ invstr: mflr r6 /* Make it accessible */ mfmsr r7 rlwinm r4,r7,27,31,31 /* extract MSR[IS] */ mfspr r7, SPRN_PID0 slwi r7,r7,16 or r7,r7,r4 mtspr SPRN_MAS6,r7 tlbsx 0,r6 /* search MSR[IS], SPID=PID0 */ mfspr r7,SPRN_MAS1 andis. r7,r7,MAS1_VALID@h bne match_TLB mfspr r7,SPRN_PID1 slwi r7,r7,16 or r7,r7,r4 mtspr SPRN_MAS6,r7 tlbsx 0,r6 /* search MSR[IS], SPID=PID1 */ mfspr r7,SPRN_MAS1 andis. r7,r7,MAS1_VALID@h bne match_TLB mfspr r7, SPRN_PID2 slwi r7,r7,16 or r7,r7,r4 mtspr SPRN_MAS6,r7 tlbsx 0,r6 /* Fall through, we had to match */ match_TLB: mfspr r7,SPRN_MAS0 rlwinm r3,r7,16,28,31 /* Extract MAS0(Entry) */ mfspr r7,SPRN_MAS1 /* Insure IPROT set */ oris r7,r7,MAS1_IPROT@h mtspr SPRN_MAS1,r7 tlbwe /* 2. Invalidate all entries except the entry we're executing in */ mfspr r9,SPRN_TLB1CFG andi. r9,r9,0xfff li r6,0 /* Set Entry counter to 0 */ 1: lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */ rlwimi r7,r6,16,12,15 /* Setup MAS0 = TLBSEL | ESEL(r6) */ mtspr SPRN_MAS0,r7 tlbre mfspr r7,SPRN_MAS1 rlwinm r7,r7,0,2,31 /* Clear MAS1 Valid and IPROT */ cmpw r3,r6 beq skpinv /* Dont update the current execution TLB */ mtspr SPRN_MAS1,r7 tlbwe isync skpinv: addi r6,r6,1 /* Increment */ cmpw r6,r9 /* Are we done? */ bne 1b /* If not, repeat */ /* Invalidate TLB0 */ li r6,0x04 tlbivax 0,r6 #ifdef CONFIG_SMP tlbsync #endif /* Invalidate TLB1 */ li r6,0x0c tlbivax 0,r6 #ifdef CONFIG_SMP tlbsync #endif msync /* 3. Setup a temp mapping and jump to it */ andi. r5, r3, 0x1 /* Find an entry not used and is non-zero */ addi r5, r5, 0x1 lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */ rlwimi r7,r3,16,12,15 /* Setup MAS0 = TLBSEL | ESEL(r3) */ mtspr SPRN_MAS0,r7 tlbre /* Just modify the entry ID and EPN for the temp mapping */ lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */ rlwimi r7,r5,16,12,15 /* Setup MAS0 = TLBSEL | ESEL(r5) */ mtspr SPRN_MAS0,r7 xori r6,r4,1 /* Setup TMP mapping in the other Address space */ slwi r6,r6,12 oris r6,r6,(MAS1_VALID|MAS1_IPROT)@h ori r6,r6,(MAS1_TSIZE(BOOKE_PAGESZ_4K))@l mtspr SPRN_MAS1,r6 mfspr r6,SPRN_MAS2 li r7,0 /* temp EPN = 0 */ rlwimi r7,r6,0,20,31 mtspr SPRN_MAS2,r7 tlbwe xori r6,r4,1 slwi r6,r6,5 /* setup new context with other address space */ bl 1f /* Find our address */ 1: mflr r9 rlwimi r7,r9,0,20,31 addi r7,r7,24 mtspr SRR0,r7 mtspr SRR1,r6 rfi /* 4. Clear out PIDs & Search info */ li r6,0 mtspr SPRN_PID0,r6 mtspr SPRN_PID1,r6 mtspr SPRN_PID2,r6 mtspr SPRN_MAS6,r6 /* 5. Invalidate mapping we started in */ lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */ rlwimi r7,r3,16,12,15 /* Setup MAS0 = TLBSEL | ESEL(r3) */ mtspr SPRN_MAS0,r7 tlbre li r6,0 mtspr SPRN_MAS1,r6 tlbwe /* Invalidate TLB1 */ li r9,0x0c tlbivax 0,r9 #ifdef CONFIG_SMP tlbsync #endif msync /* 6. Setup KERNELBASE mapping in TLB1[0] */ lis r6,0x1000 /* Set MAS0(TLBSEL) = TLB1(1), ESEL = 0 */ mtspr SPRN_MAS0,r6 lis r6,(MAS1_VALID|MAS1_IPROT)@h ori r6,r6,(MAS1_TSIZE(BOOKE_PAGESZ_16M))@l mtspr SPRN_MAS1,r6 li r7,0 lis r6,KERNELBASE@h ori r6,r6,KERNELBASE@l rlwimi r6,r7,0,20,31 mtspr SPRN_MAS2,r6 li r7,(MAS3_SX|MAS3_SW|MAS3_SR) mtspr SPRN_MAS3,r7 tlbwe /* 7. Jump to KERNELBASE mapping */ li r7,0 bl 1f /* Find our address */ 1: mflr r9 rlwimi r6,r9,0,20,31 addi r6,r6,24 mtspr SRR0,r6 mtspr SRR1,r7 rfi /* start execution out of TLB1[0] entry */ /* 8. Clear out the temp mapping */ lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */ rlwimi r7,r5,16,12,15 /* Setup MAS0 = TLBSEL | ESEL(r5) */ mtspr SPRN_MAS0,r7 tlbre mtspr SPRN_MAS1,r8 tlbwe /* Invalidate TLB1 */ li r9,0x0c tlbivax 0,r9 #ifdef CONFIG_SMP tlbsync #endif msync /* 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); SET_IVOR(32, SPEUnavailable); SET_IVOR(33, SPEFloatingPointData); SET_IVOR(34, SPEFloatingPointRound); SET_IVOR(35, PerformanceMonitor); /* Establish the interrupt vector base */ lis r4,interrupt_base@h /* IVPR only uses the high 16-bits */ mtspr SPRN_IVPR,r4 /* Setup the defaults for TLB entries */ li r2,MAS4_TSIZED(BOOKE_PAGESZ_4K) mtspr SPRN_MAS4, r2 #if 0 /* Enable DOZE */ mfspr r2,SPRN_HID0 oris r2,r2,HID0_DOZE@h mtspr SPRN_HID0, r2 #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 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 mfspr r3,SPRN_TLB1CFG andi. r3,r3,0xfff lis r4,num_tlbcam_entries@ha stw r3,num_tlbcam_entries@l(r4) /* * 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 SRR0,r4 mtspr 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. */ #define NORMAL_EXCEPTION_PROLOG \ mtspr SPRN_SPRG0,r10; /* save two registers to work with */\ mtspr SPRN_SPRG1,r11; \ mtspr SPRN_SPRG4W,r1; \ mfcr r10; /* save CR in r10 for now */\ mfspr r11,SPRN_SRR1; /* check whether user or kernel */\ andi. r11,r11,MSR_PR; \ beq 1f; \ mfspr r1,SPRG3; /* if from user, start at top of */\ lwz r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack */\ addi r1,r1,THREAD_SIZE; \ 1: subi r1,r1,INT_FRAME_SIZE; /* Allocate an exception frame */\ tophys(r11,r1); \ stw r10,_CCR(r11); /* save various registers */\ stw r12,GPR12(r11); \ stw r9,GPR9(r11); \ mfspr r10,SPRG0; \ stw r10,GPR10(r11); \ mfspr r12,SPRG1; \ stw r12,GPR11(r11); \ mflr r10; \ stw r10,_LINK(r11); \ mfspr r10,SPRG4R; \ mfspr r12,SRR0; \ stw r10,GPR1(r11); \ mfspr r9,SRR1; \ stw r10,0(r11); \ rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\ stw r0,GPR0(r11); \ SAVE_4GPRS(3, r11); \ SAVE_2GPRS(7, r11) /* * Exception prolog for critical exceptions. This is a little different * from the normal exception prolog above since a critical exception * can potentially occur at any point during normal exception processing. * Thus we cannot use the same SPRG registers as the normal prolog above. * Instead we use a couple of words of memory at low physical addresses. * This is OK since we don't support SMP on these processors. For Book E * processors, we also have a reserved register (SPRG2) that is only used * in critical exceptions so we can free up a GPR to use as the base for * indirect access to the critical exception save area. This is necessary * since the MMU is always on and the save area is offset from KERNELBASE. */ #define CRITICAL_EXCEPTION_PROLOG \ mtspr SPRG2,r8; /* SPRG2 only used in criticals */ \ lis r8,crit_save@ha; \ stw r10,crit_r10@l(r8); \ stw r11,crit_r11@l(r8); \ mfspr r10,SPRG0; \ stw r10,crit_sprg0@l(r8); \ mfspr r10,SPRG1; \ stw r10,crit_sprg1@l(r8); \ mfspr r10,SPRG4R; \ stw r10,crit_sprg4@l(r8); \ mfspr r10,SPRG5R; \ stw r10,crit_sprg5@l(r8); \ mfspr r10,SPRG7R; \ stw r10,crit_sprg7@l(r8); \ mfspr r10,SPRN_PID; \ stw r10,crit_pid@l(r8); \ mfspr r10,SRR0; \ stw r10,crit_srr0@l(r8); \ mfspr r10,SRR1; \ stw r10,crit_srr1@l(r8); \ mfspr r8,SPRG2; /* SPRG2 only used in criticals */ \ mfcr r10; /* save CR in r10 for now */\ mfspr r11,SPRN_CSRR1; /* check whether user or kernel */\ andi. r11,r11,MSR_PR; \ lis r11,critical_stack_top@h; \ ori r11,r11,critical_stack_top@l; \ beq 1f; \ /* COMING FROM USER MODE */ \ mfspr r11,SPRG3; /* if from user, start at top of */\ lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\ addi r11,r11,THREAD_SIZE; \ 1: subi r11,r11,INT_FRAME_SIZE; /* Allocate an exception frame */\ stw r10,_CCR(r11); /* save various registers */\ stw r12,GPR12(r11); \ stw r9,GPR9(r11); \ mflr r10; \ stw r10,_LINK(r11); \ mfspr r12,SPRN_DEAR; /* save DEAR and ESR in the frame */\ stw r12,_DEAR(r11); /* since they may have had stuff */\ mfspr r9,SPRN_ESR; /* in them at the point where the */\ stw r9,_ESR(r11); /* exception was taken */\ mfspr r12,CSRR0; \ stw r1,GPR1(r11); \ mfspr r9,CSRR1; \ stw r1,0(r11); \ tovirt(r1,r11); \ rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\ stw r0,GPR0(r11); \ SAVE_4GPRS(3, r11); \ SAVE_2GPRS(7, r11) /* * Exception prolog for machine check exceptions. This is similar to * the critical exception prolog, except that machine check exceptions * have their own save area. For Book E processors, we also have a * reserved register (SPRG6) that is only used in machine check exceptions * so we can free up a GPR to use as the base for indirect access to the * machine check exception save area. This is necessary since the MMU * is always on and the save area is offset from KERNELBASE. */ #define MCHECK_EXCEPTION_PROLOG \ mtspr SPRG6W,r8; /* SPRG6 used in machine checks */ \ lis r8,mcheck_save@ha; \ stw r10,mcheck_r10@l(r8); \ stw r11,mcheck_r11@l(r8); \ mfspr r10,SPRG0; \ stw r10,mcheck_sprg0@l(r8); \ mfspr r10,SPRG1; \ stw r10,mcheck_sprg1@l(r8); \ mfspr r10,SPRG4R; \ stw r10,mcheck_sprg4@l(r8); \ mfspr r10,SPRG5R; \ stw r10,mcheck_sprg5@l(r8); \ mfspr r10,SPRG7R; \ stw r10,mcheck_sprg7@l(r8); \ mfspr r10,SPRN_PID; \ stw r10,mcheck_pid@l(r8); \ mfspr r10,SRR0; \ stw r10,mcheck_srr0@l(r8); \ mfspr r10,SRR1; \ stw r10,mcheck_srr1@l(r8); \ mfspr r10,CSRR0; \ stw r10,mcheck_csrr0@l(r8); \ mfspr r10,CSRR1; \ stw r10,mcheck_csrr1@l(r8); \ mfspr r8,SPRG6R; /* SPRG6 used in machine checks */ \ mfcr r10; /* save CR in r10 for now */\ mfspr r11,SPRN_MCSRR1; /* check whether user or kernel */\ andi. r11,r11,MSR_PR; \ lis r11,mcheck_stack_top@h; \ ori r11,r11,mcheck_stack_top@l; \ beq 1f; \ /* COMING FROM USER MODE */ \ mfspr r11,SPRG3; /* if from user, start at top of */\ lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\ addi r11,r11,THREAD_SIZE; \ 1: subi r11,r11,INT_FRAME_SIZE; /* Allocate an exception frame */\ stw r10,_CCR(r11); /* save various registers */\ stw r12,GPR12(r11); \ stw r9,GPR9(r11); \ mflr r10; \ stw r10,_LINK(r11); \ mfspr r12,SPRN_DEAR; /* save DEAR and ESR in the frame */\ stw r12,_DEAR(r11); /* since they may have had stuff */\ mfspr r9,SPRN_ESR; /* in them at the point where the */\ stw r9,_ESR(r11); /* exception was taken */\ mfspr r12,MCSRR0; \ stw r1,GPR1(r11); \ mfspr r9,MCSRR1; \ stw r1,0(r11); \ tovirt(r1,r11); \ rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\ stw r0,GPR0(r11); \ SAVE_4GPRS(3, r11); \ SAVE_2GPRS(7, r11) /* * Exception vectors. */ #define START_EXCEPTION(label) \ .align 5; \ label: #define FINISH_EXCEPTION(func) \ bl transfer_to_handler_full; \ .long func; \ .long ret_from_except_full #define EXCEPTION(n, label, hdlr, xfer) \ START_EXCEPTION(label); \ NORMAL_EXCEPTION_PROLOG; \ addi r3,r1,STACK_FRAME_OVERHEAD; \ xfer(n, hdlr) #define CRITICAL_EXCEPTION(n, label, hdlr) \ START_EXCEPTION(label); \ CRITICAL_EXCEPTION_PROLOG; \ addi r3,r1,STACK_FRAME_OVERHEAD; \ EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \ NOCOPY, transfer_to_handler_full, \ ret_from_except_full) #define MCHECK_EXCEPTION(n, label, hdlr) \ START_EXCEPTION(label); \ MCHECK_EXCEPTION_PROLOG; \ mfspr r5,SPRN_ESR; \ stw r5,_ESR(r11); \ addi r3,r1,STACK_FRAME_OVERHEAD; \ EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \ NOCOPY, mcheck_transfer_to_handler, \ ret_from_mcheck_exc) #define EXC_XFER_TEMPLATE(hdlr, trap, msr, copyee, tfer, ret) \ li r10,trap; \ stw r10,TRAP(r11); \ lis r10,msr@h; \ ori r10,r10,msr@l; \ copyee(r10, r9); \ bl tfer; \ .long hdlr; \ .long ret #define COPY_EE(d, s) rlwimi d,s,0,16,16 #define NOCOPY(d, s) #define EXC_XFER_STD(n, hdlr) \ EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, NOCOPY, transfer_to_handler_full, \ ret_from_except_full) #define EXC_XFER_LITE(n, hdlr) \ EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \ ret_from_except) #define EXC_XFER_EE(n, hdlr) \ EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, COPY_EE, transfer_to_handler_full, \ ret_from_except_full) #define EXC_XFER_EE_LITE(n, hdlr) \ EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, COPY_EE, transfer_to_handler, \ ret_from_except) interrupt_base: /* Critical Input Interrupt */ CRITICAL_EXCEPTION(0x0100, CriticalInput, UnknownException) /* Machine Check Interrupt */ MCHECK_EXCEPTION(0x0200, MachineCheck, MachineCheckException) /* Data Storage Interrupt */ START_EXCEPTION(DataStorage) mtspr SPRG0, r10 /* Save some working registers */ mtspr SPRG1, r11 mtspr SPRG4W, r12 mtspr SPRG5W, r13 mfcr r11 mtspr 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 ori r11, r11, TASK_SIZE@l cmplw 0, r10, r11 bge 2f /* Get the PGD for the current thread */ 3: mfspr r11,SPRG3 lwz r11,PGDIR(r11) 4: rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */ lwz r11, 0(r11) /* Get L1 entry */ rlwinm. r12, r11, 0, 0, 19 /* Extract L2 (pte) base address */ beq 2f /* Bail if no table */ rlwimi r12, r10, 22, 20, 29 /* Compute PTE address */ lwz r11, 0(r12) /* Get Linux PTE */ /* Are _PAGE_USER & _PAGE_RW set & _PAGE_HWWRITE not? */ andi. r13, r11, _PAGE_RW|_PAGE_USER|_PAGE_HWWRITE cmpwi 0, r13, _PAGE_RW|_PAGE_USER bne 2f /* Bail if not */ /* Update 'changed'. */ ori r11, r11, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE stw r11, 0(r12) /* Update Linux page table */ /* MAS2 not updated as the entry does exist in the tlb, this fault taken to detect state transition (eg: COW -> DIRTY) */ lis r12, MAS3_RPN@h ori r12, r12, _PAGE_HWEXEC | MAS3_RPN@l and r11, r11, r12 rlwimi r11, r11, 31, 27, 27 /* SX <- _PAGE_HWEXEC */ ori r11, r11, (MAS3_UW|MAS3_SW|MAS3_UR|MAS3_SR)@l /* set static perms */ /* update search PID in MAS6, AS = 0 */ mfspr r12, SPRN_PID0 slwi r12, r12, 16 mtspr SPRN_MAS6, r12 /* find the TLB index that caused the fault. It has to be here. */ tlbsx 0, r10 mtspr SPRN_MAS3,r11 tlbwe /* Done...restore registers and get out of here. */ mfspr r11, SPRG7R mtcr r11 mfspr r13, SPRG5R mfspr r12, SPRG4R mfspr r11, SPRG1 mfspr r10, SPRG0 rfi /* Force context change */ 2: /* * The bailout. Restore registers to pre-exception conditions * and call the heavyweights to help us out. */ mfspr r11, SPRG7R mtcr r11 mfspr r13, SPRG5R mfspr r12, SPRG4R mfspr r11, SPRG1 mfspr r10, SPRG0 b data_access /* Instruction Storage Interrupt */ START_EXCEPTION(InstructionStorage) NORMAL_EXCEPTION_PROLOG mfspr r5,SPRN_ESR /* Grab the ESR and save it */ stw r5,_ESR(r11) mr r4,r12 /* Pass SRR0 as arg2 */ li r5,0 /* Pass zero as arg3 */ EXC_XFER_EE_LITE(0x0400, handle_page_fault) /* External Input Interrupt */ EXCEPTION(0x0500, ExternalInput, do_IRQ, EXC_XFER_LITE) /* Alignment Interrupt */ START_EXCEPTION(Alignment) NORMAL_EXCEPTION_PROLOG mfspr r4,SPRN_DEAR /* Grab the DEAR and save it */ stw r4,_DEAR(r11) addi r3,r1,STACK_FRAME_OVERHEAD EXC_XFER_EE(0x0600, AlignmentException) /* Program Interrupt */ START_EXCEPTION(Program) NORMAL_EXCEPTION_PROLOG mfspr r4,SPRN_ESR /* Grab the ESR and save it */ stw r4,_ESR(r11) addi r3,r1,STACK_FRAME_OVERHEAD EXC_XFER_STD(0x0700, ProgramCheckException) /* Floating Point Unavailable Interrupt */ EXCEPTION(0x0800, 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(0x2900, AuxillaryProcessorUnavailable, UnknownException, EXC_XFER_EE) /* Decrementer Interrupt */ START_EXCEPTION(Decrementer) NORMAL_EXCEPTION_PROLOG lis r0,TSR_DIS@h /* Setup the DEC interrupt mask */ mtspr SPRN_TSR,r0 /* Clear the DEC interrupt */ addi r3,r1,STACK_FRAME_OVERHEAD EXC_XFER_LITE(0x0900, timer_interrupt) /* Fixed Internal Timer Interrupt */ /* TODO: Add FIT support */ EXCEPTION(0x3100, FixedIntervalTimer, UnknownException, EXC_XFER_EE) /* Watchdog Timer Interrupt */ /* TODO: Add watchdog support */ CRITICAL_EXCEPTION(0x3200, WatchdogTimer, UnknownException) /* Data TLB Error Interrupt */ START_EXCEPTION(DataTLBError) mtspr SPRG0, r10 /* Save some working registers */ mtspr SPRG1, r11 mtspr SPRG4W, r12 mtspr SPRG5W, r13 mfcr r11 mtspr 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 ori r11, r11, TASK_SIZE@l cmplw 5, r10, r11 blt 5, 3f lis r11, swapper_pg_dir@h ori r11, r11, swapper_pg_dir@l mfspr r12,SPRN_MAS1 /* Set TID to 0 */ li r13,MAS1_TID@l andc r12,r12,r13 mtspr SPRN_MAS1,r12 b 4f /* Get the PGD for the current thread */ 3: mfspr r11,SPRG3 lwz r11,PGDIR(r11) 4: rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */ lwz r11, 0(r11) /* Get L1 entry */ rlwinm. r12, r11, 0, 0, 19 /* Extract L2 (pte) base address */ beq 2f /* Bail if no table */ rlwimi r12, r10, 22, 20, 29 /* Compute PTE address */ lwz r11, 0(r12) /* Get Linux PTE */ andi. r13, r11, _PAGE_PRESENT beq 2f ori r11, r11, _PAGE_ACCESSED stw r11, 0(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, SPRG7R mtcr r11 mfspr r13, SPRG5R mfspr r12, SPRG4R mfspr r11, SPRG1 mfspr r10, 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 SPRG0, r10 /* Save some working registers */ mtspr SPRG1, r11 mtspr SPRG4W, r12 mtspr SPRG5W, r13 mfcr r11 mtspr SPRG7W, r11 mfspr r10, SRR0 /* Get faulting address */ /* If we are faulting a kernel address, we have to use the * kernel page tables. */ lis r11, TASK_SIZE@h ori r11, r11, TASK_SIZE@l cmplw 5, r10, r11 blt 5, 3f lis r11, swapper_pg_dir@h ori r11, r11, swapper_pg_dir@l mfspr r12,SPRN_MAS1 /* Set TID to 0 */ li r13,MAS1_TID@l andc r12,r12,r13 mtspr SPRN_MAS1,r12 b 4f /* Get the PGD for the current thread */ 3: mfspr r11,SPRG3 lwz r11,PGDIR(r11) 4: rlwimi r11, r10, 12, 20, 29 /* Create L1 (pgdir/pmd) address */ lwz r11, 0(r11) /* Get L1 entry */ rlwinm. r12, r11, 0, 0, 19 /* Extract L2 (pte) base address */ beq 2f /* Bail if no table */ rlwimi r12, r10, 22, 20, 29 /* Compute PTE address */ lwz r11, 0(r12) /* Get Linux PTE */ andi. r13, r11, _PAGE_PRESENT beq 2f ori r11, r11, _PAGE_ACCESSED stw r11, 0(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, SPRG7R mtcr r11 mfspr r13, SPRG5R mfspr r12, SPRG4R mfspr r11, SPRG1 mfspr r10, SPRG0 b InstructionStorage #ifdef CONFIG_SPE /* SPE Unavailable */ START_EXCEPTION(SPEUnavailable) NORMAL_EXCEPTION_PROLOG bne load_up_spe addi r3,r1,STACK_FRAME_OVERHEAD EXC_XFER_EE_LITE(0x2010, KernelSPE) #else EXCEPTION(0x2020, SPEUnavailable, UnknownException, EXC_XFER_EE) #endif /* CONFIG_SPE */ /* SPE Floating Point Data */ #ifdef CONFIG_SPE EXCEPTION(0x2030, SPEFloatingPointData, SPEFloatingPointException, EXC_XFER_EE); #else EXCEPTION(0x2040, SPEFloatingPointData, UnknownException, EXC_XFER_EE) #endif /* CONFIG_SPE */ /* SPE Floating Point Round */ EXCEPTION(0x2050, SPEFloatingPointRound, UnknownException, EXC_XFER_EE) /* Performance Monitor */ EXCEPTION(0x2060, PerformanceMonitor, UnknownException, EXC_XFER_EE) /* Check for a single step debug exception while in an exception * handler before state has been saved. This is to catch the case * where an instruction that we are trying to single step causes * an exception (eg ITLB/DTLB miss) and thus the first instruction of * the exception handler generates a single step debug exception. * * If we get a debug trap on the first instruction of an exception handler, * we reset the MSR_DE in the _exception handler's_ MSR (the debug trap is * a critical exception, so we are using SPRN_CSRR1 to manipulate the MSR). * The exception handler was handling a non-critical interrupt, so it will * save (and later restore) the MSR via SPRN_SRR1, which will still have * the MSR_DE bit set. */ /* Debug Interrupt */ START_EXCEPTION(Debug) CRITICAL_EXCEPTION_PROLOG /* * If this is a single step or branch-taken exception in an * exception entry sequence, it was probably meant to apply to * the code where the exception occurred (since exception entry * doesn't turn off DE automatically). We simulate the effect * of turning off DE on entry to an exception handler by turning * off DE in the CSRR1 value and clearing the debug status. */ mfspr r10,SPRN_DBSR /* check single-step/branch taken */ andis. r10,r10,(DBSR_IC|DBSR_BT)@h beq+ 1f andi. r0,r9,MSR_PR /* check supervisor */ beq 2f /* branch if we need to fix it up... */ /* continue normal handling for a critical exception... */ 1: mfspr r4,SPRN_DBSR addi r3,r1,STACK_FRAME_OVERHEAD EXC_XFER_TEMPLATE(DebugException, 0x2002, \ (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \ NOCOPY, crit_transfer_to_handler, ret_from_crit_exc) /* here it looks like we got an inappropriate debug exception. */ 2: rlwinm r9,r9,0,~MSR_DE /* clear DE in the CSRR1 value */ mtspr SPRN_DBSR,r10 /* clear the IC/BT debug intr status */ /* restore state and get out */ lwz r10,_CCR(r11) lwz r0,GPR0(r11) lwz r1,GPR1(r11) mtcrf 0x80,r10 mtspr CSRR0,r12 mtspr CSRR1,r9 lwz r9,GPR9(r11) mtspr SPRG2,r8; /* SPRG2 only used in criticals */ lis r8,crit_save@ha; lwz r10,crit_r10@l(r8) lwz r11,crit_r11@l(r8) mfspr r8,SPRG2 rfci b . /* * 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 */ andis. r10,r5,(ESR_ILK|ESR_DLK)@h bne 1f EXC_XFER_EE_LITE(0x0300, handle_page_fault) 1: addi r3,r1,STACK_FRAME_OVERHEAD EXC_XFER_EE_LITE(0x0300, CacheLockingException) /* * Both the instruction and data TLB miss get to this * point to load the TLB. * r10 - EA of fault * r11 - TLB (info from Linux PTE) * r12, r13 - available to use * CR5 - results of addr < TASK_SIZE * MAS0, MAS1 - loaded with proper value when we get here * MAS2, MAS3 - will need additional info from Linux PTE * 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). * Many of these bits are software only. Bits we don't set * here we (properly should) assume have the appropriate value. */ mfspr r12, SPRN_MAS2 rlwimi r12, r11, 26, 27, 31 /* extract WIMGE from pte */ mtspr SPRN_MAS2, r12 bge 5, 1f /* addr > TASK_SIZE */ li r10, (MAS3_UX | MAS3_UW | MAS3_UR) andi. r13, r11, (_PAGE_USER | _PAGE_HWWRITE | _PAGE_HWEXEC) andi. r12, r11, _PAGE_USER /* Test for _PAGE_USER */ iseleq r12, 0, r10 and r10, r12, r13 srwi r12, r10, 1 or r12, r12, r10 /* Copy user perms into supervisor */ b 2f /* addr <= TASK_SIZE */ 1: rlwinm r12, r11, 31, 29, 29 /* Extract _PAGE_HWWRITE into SW */ ori r12, r12, (MAS3_SX | MAS3_SR) 2: rlwimi r11, r12, 0, 20, 31 /* Extract RPN from PTE and merge with perms */ mtspr SPRN_MAS3, r11 tlbwe /* Done...restore registers and get out of here. */ mfspr r11, SPRG7R mtcr r11 mfspr r13, SPRG5R mfspr r12, SPRG4R mfspr r11, SPRG1 mfspr r10, SPRG0 rfi /* Force context change */ #ifdef CONFIG_SPE /* Note that the SPE support is closely modeled after the AltiVec * support. Changes to one are likely to be applicable to the * other! */ load_up_spe: /* * Disable SPE for the task which had SPE previously, * and save its SPE registers in its thread_struct. * Enables SPE for use in the kernel on return. * On SMP we know the SPE units are free, since we give it up every * switch. -- Kumar */ mfmsr r5 oris r5,r5,MSR_SPE@h mtmsr r5 /* enable use of SPE now */ isync /* * For SMP, we don't do lazy SPE switching because it just gets too * horrendously complex, especially when a task switches from one CPU * to another. Instead we call giveup_spe in switch_to. */ #ifndef CONFIG_SMP lis r3,last_task_used_spe@ha lwz r4,last_task_used_spe@l(r3) cmpi 0,r4,0 beq 1f addi r4,r4,THREAD /* want THREAD of last_task_used_spe */ SAVE_32EVR(0,r10,r4) evxor evr10, evr10, evr10 /* clear out evr10 */ evmwumiaa evr10, evr10, evr10 /* evr10 <- ACC = 0 * 0 + ACC */ li r5,THREAD_ACC evstddx evr10, r4, r5 /* save off accumulator */ lwz r5,PT_REGS(r4) lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5) lis r10,MSR_SPE@h andc r4,r4,r10 /* disable SPE for previous task */ stw r4,_MSR-STACK_FRAME_OVERHEAD(r5) 1: #endif /* CONFIG_SMP */ /* enable use of SPE after return */ oris r9,r9,MSR_SPE@h mfspr r5,SPRG3 /* current task's THREAD (phys) */ li r4,1 li r10,THREAD_ACC stw r4,THREAD_USED_SPE(r5) evlddx evr4,r10,r5 evmra evr4,evr4 REST_32EVR(0,r10,r5) #ifndef CONFIG_SMP subi r4,r5,THREAD stw r4,last_task_used_spe@l(r3) #endif /* CONFIG_SMP */ /* restore registers and return */ 2: REST_4GPRS(3, r11) lwz r10,_CCR(r11) REST_GPR(1, r11) mtcr r10 lwz r10,_LINK(r11) mtlr r10 REST_GPR(10, r11) mtspr SRR1,r9 mtspr SRR0,r12 REST_GPR(9, r11) REST_GPR(12, r11) lwz r11,GPR11(r11) SYNC rfi /* * SPE unavailable trap from kernel - print a message, but let * the task use SPE in the kernel until it returns to user mode. */ KernelSPE: lwz r3,_MSR(r1) oris r3,r3,MSR_SPE@h stw r3,_MSR(r1) /* enable use of SPE after return */ lis r3,87f@h ori r3,r3,87f@l mr r4,r2 /* current */ lwz r5,_NIP(r1) bl printk b ret_from_except 87: .string "SPE used in kernel (task=%p, pc=%x) \n" .align 4,0 #endif /* CONFIG_SPE */ /* * Global functions */ /* * extern void loadcam_entry(unsigned int index) * * Load TLBCAM[index] entry in to the L2 CAM MMU */ _GLOBAL(loadcam_entry) lis r4,TLBCAM@ha addi r4,r4,TLBCAM@l mulli r5,r3,20 add r3,r5,r4 lwz r4,0(r3) mtspr SPRN_MAS0,r4 lwz r4,4(r3) mtspr SPRN_MAS1,r4 lwz r4,8(r3) mtspr SPRN_MAS2,r4 lwz r4,12(r3) mtspr SPRN_MAS3,r4 tlbwe isync blr /* * extern void giveup_altivec(struct task_struct *prev) * * The e500 core does not have an AltiVec unit. */ _GLOBAL(giveup_altivec) blr #ifdef CONFIG_SPE /* * extern void giveup_spe(struct task_struct *prev) * */ _GLOBAL(giveup_spe) mfmsr r5 oris r5,r5,MSR_SPE@h SYNC mtmsr r5 /* enable use of SPE now */ isync cmpi 0,r3,0 beqlr- /* if no previous owner, done */ addi r3,r3,THREAD /* want THREAD of task */ lwz r5,PT_REGS(r3) cmpi 0,r5,0 SAVE_32EVR(0, r4, r3) evxor evr6, evr6, evr6 /* clear out evr6 */ evmwumiaa evr6, evr6, evr6 /* evr6 <- ACC = 0 * 0 + ACC */ li r4,THREAD_ACC evstddx evr6, r4, r3 /* save off accumulator */ beq 1f lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5) lis r3,MSR_SPE@h andc r4,r4,r3 /* disable SPE for previous task */ stw r4,_MSR-STACK_FRAME_OVERHEAD(r5) 1: #ifndef CONFIG_SMP li r5,0 lis r4,last_task_used_spe@ha stw r5,last_task_used_spe@l(r4) #endif /* CONFIG_SMP */ blr #endif /* CONFIG_SPE */ /* * extern void giveup_fpu(struct task_struct *prev) * * The e500 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) li r13,0 mtspr SPRN_DBCR0,r13 /* disable all debug events */ mfmsr r13 ori r13,r13,MSR_DE@l /* Enable Debug Events */ mtmsr r13 mfspr r13,SPRN_DBCR0 lis r13,(DBCR0_IDM|DBCR0_RST_CHIP)@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 _GLOBAL(swapper_pg_dir) .space 4096 .section .bss /* Stack for handling critical exceptions from kernel mode */ critical_stack_bottom: .space 4096 critical_stack_top: .previous /* Stack for handling machine check exceptions from kernel mode */ mcheck_stack_bottom: .space 4096 mcheck_stack_top: .previous /* * This area is used for temporarily saving registers during the * critical and machine check exception prologs. It must always * follow the page aligned allocations, so it starts on a page * boundary, ensuring that all crit_save areas are in a single * page. */ /* crit_save */ _GLOBAL(crit_save) .space 4 _GLOBAL(crit_r10) .space 4 _GLOBAL(crit_r11) .space 4 _GLOBAL(crit_sprg0) .space 4 _GLOBAL(crit_sprg1) .space 4 _GLOBAL(crit_sprg4) .space 4 _GLOBAL(crit_sprg5) .space 4 _GLOBAL(crit_sprg7) .space 4 _GLOBAL(crit_pid) .space 4 _GLOBAL(crit_srr0) .space 4 _GLOBAL(crit_srr1) .space 4 /* mcheck_save */ _GLOBAL(mcheck_save) .space 4 _GLOBAL(mcheck_r10) .space 4 _GLOBAL(mcheck_r11) .space 4 _GLOBAL(mcheck_sprg0) .space 4 _GLOBAL(mcheck_sprg1) .space 4 _GLOBAL(mcheck_sprg4) .space 4 _GLOBAL(mcheck_sprg5) .space 4 _GLOBAL(mcheck_sprg7) .space 4 _GLOBAL(mcheck_pid) .space 4 _GLOBAL(mcheck_srr0) .space 4 _GLOBAL(mcheck_srr1) .space 4 _GLOBAL(mcheck_csrr0) .space 4 _GLOBAL(mcheck_csrr1) .space 4 /* * 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