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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ppc/kernel/head.S
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/ppc/kernel/head.S')
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diff --git a/arch/ppc/kernel/head.S b/arch/ppc/kernel/head.S
new file mode 100644
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+/*
+ * PowerPC version
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
+ * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
+ * Adapted for Power Macintosh by Paul Mackerras.
+ * Low-level exception handlers and MMU support
+ * rewritten by Paul Mackerras.
+ * Copyright (C) 1996 Paul Mackerras.
+ * MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net).
+ * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
+ *
+ * This file contains the low-level support and setup for the
+ * PowerPC platform, including trap and interrupt dispatch.
+ * (The PPC 8xx embedded CPUs use head_8xx.S instead.)
+ *
+ * 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/cputable.h>
+#include <asm/cache.h>
+#include <asm/thread_info.h>
+#include <asm/ppc_asm.h>
+#include <asm/offsets.h>
+
+#ifdef CONFIG_APUS
+#include <asm/amigappc.h>
+#endif
+
+#ifdef CONFIG_PPC64BRIDGE
+#define LOAD_BAT(n, reg, RA, RB) \
+ ld RA,(n*32)+0(reg); \
+ ld RB,(n*32)+8(reg); \
+ mtspr SPRN_IBAT##n##U,RA; \
+ mtspr SPRN_IBAT##n##L,RB; \
+ ld RA,(n*32)+16(reg); \
+ ld RB,(n*32)+24(reg); \
+ mtspr SPRN_DBAT##n##U,RA; \
+ mtspr SPRN_DBAT##n##L,RB; \
+
+#else /* CONFIG_PPC64BRIDGE */
+
+/* 601 only have IBAT; cr0.eq is set on 601 when using this macro */
+#define LOAD_BAT(n, reg, RA, RB) \
+ /* see the comment for clear_bats() -- Cort */ \
+ li RA,0; \
+ mtspr SPRN_IBAT##n##U,RA; \
+ mtspr SPRN_DBAT##n##U,RA; \
+ lwz RA,(n*16)+0(reg); \
+ lwz RB,(n*16)+4(reg); \
+ mtspr SPRN_IBAT##n##U,RA; \
+ mtspr SPRN_IBAT##n##L,RB; \
+ beq 1f; \
+ lwz RA,(n*16)+8(reg); \
+ lwz RB,(n*16)+12(reg); \
+ mtspr SPRN_DBAT##n##U,RA; \
+ mtspr SPRN_DBAT##n##L,RB; \
+1:
+#endif /* CONFIG_PPC64BRIDGE */
+
+ .text
+ .stabs "arch/ppc/kernel/",N_SO,0,0,0f
+ .stabs "head.S",N_SO,0,0,0f
+0:
+ .globl _stext
+_stext:
+
+/*
+ * _start is defined this way because the XCOFF loader in the OpenFirmware
+ * on the powermac expects the entry point to be a procedure descriptor.
+ */
+ .text
+ .globl _start
+_start:
+ /*
+ * These are here for legacy reasons, the kernel used to
+ * need to look like a coff function entry for the pmac
+ * but we're always started by some kind of bootloader now.
+ * -- Cort
+ */
+ nop /* used by __secondary_hold on prep (mtx) and chrp smp */
+ nop /* used by __secondary_hold on prep (mtx) and chrp smp */
+ nop
+
+/* PMAC
+ * Enter here with the kernel text, data and bss loaded starting at
+ * 0, running with virtual == physical mapping.
+ * r5 points to the prom entry point (the client interface handler
+ * address). Address translation is turned on, with the prom
+ * managing the hash table. Interrupts are disabled. The stack
+ * pointer (r1) points to just below the end of the half-meg region
+ * from 0x380000 - 0x400000, which is mapped in already.
+ *
+ * If we are booted from MacOS via BootX, we enter with the kernel
+ * image loaded somewhere, and the following values in registers:
+ * r3: 'BooX' (0x426f6f58)
+ * r4: virtual address of boot_infos_t
+ * r5: 0
+ *
+ * APUS
+ * r3: 'APUS'
+ * r4: physical address of memory base
+ * Linux/m68k style BootInfo structure at &_end.
+ *
+ * PREP
+ * This is jumped to on prep systems right after the kernel is relocated
+ * to its proper place in memory by the boot loader. The expected layout
+ * of the regs is:
+ * r3: ptr to residual data
+ * r4: initrd_start or if no initrd then 0
+ * r5: initrd_end - unused if r4 is 0
+ * r6: Start of command line string
+ * r7: End of command line string
+ *
+ * This just gets a minimal mmu environment setup so we can call
+ * start_here() to do the real work.
+ * -- Cort
+ */
+
+ .globl __start
+__start:
+/*
+ * We have to do any OF calls before we map ourselves to KERNELBASE,
+ * because OF may have I/O devices mapped into that area
+ * (particularly on CHRP).
+ */
+ mr r31,r3 /* save parameters */
+ mr r30,r4
+ mr r29,r5
+ mr r28,r6
+ mr r27,r7
+ li r24,0 /* cpu # */
+
+/*
+ * early_init() does the early machine identification and does
+ * the necessary low-level setup and clears the BSS
+ * -- Cort <cort@fsmlabs.com>
+ */
+ bl early_init
+
+/*
+ * On POWER4, we first need to tweak some CPU configuration registers
+ * like real mode cache inhibit or exception base
+ */
+#ifdef CONFIG_POWER4
+ bl __970_cpu_preinit
+#endif /* CONFIG_POWER4 */
+
+#ifdef CONFIG_APUS
+/* On APUS the __va/__pa constants need to be set to the correct
+ * values before continuing.
+ */
+ mr r4,r30
+ bl fix_mem_constants
+#endif /* CONFIG_APUS */
+
+/* Switch MMU off, clear BATs and flush TLB. At this point, r3 contains
+ * the physical address we are running at, returned by early_init()
+ */
+ bl mmu_off
+__after_mmu_off:
+#ifndef CONFIG_POWER4
+ bl clear_bats
+ bl flush_tlbs
+
+ bl initial_bats
+#if !defined(CONFIG_APUS) && defined(CONFIG_BOOTX_TEXT)
+ bl setup_disp_bat
+#endif
+#else /* CONFIG_POWER4 */
+ bl reloc_offset
+ bl initial_mm_power4
+#endif /* CONFIG_POWER4 */
+
+/*
+ * Call setup_cpu for CPU 0 and initialize 6xx Idle
+ */
+ bl reloc_offset
+ li r24,0 /* cpu# */
+ bl call_setup_cpu /* Call setup_cpu for this CPU */
+#ifdef CONFIG_6xx
+ bl reloc_offset
+ bl init_idle_6xx
+#endif /* CONFIG_6xx */
+#ifdef CONFIG_POWER4
+ bl reloc_offset
+ bl init_idle_power4
+#endif /* CONFIG_POWER4 */
+
+
+#ifndef CONFIG_APUS
+/*
+ * We need to run with _start at physical address 0.
+ * On CHRP, we are loaded at 0x10000 since OF on CHRP uses
+ * the exception vectors at 0 (and therefore this copy
+ * overwrites OF's exception vectors with our own).
+ * If the MMU is already turned on, we copy stuff to KERNELBASE,
+ * otherwise we copy it to 0.
+ */
+ bl reloc_offset
+ mr r26,r3
+ addis r4,r3,KERNELBASE@h /* current address of _start */
+ cmpwi 0,r4,0 /* are we already running at 0? */
+ bne relocate_kernel
+#endif /* CONFIG_APUS */
+/*
+ * we now have the 1st 16M of ram mapped with the bats.
+ * prep needs the mmu to be turned on here, but pmac already has it on.
+ * this shouldn't bother the pmac since it just gets turned on again
+ * as we jump to our code at KERNELBASE. -- Cort
+ * Actually no, pmac doesn't have it on any more. BootX enters with MMU
+ * off, and in other cases, we now turn it off before changing BATs above.
+ */
+turn_on_mmu:
+ mfmsr r0
+ ori r0,r0,MSR_DR|MSR_IR
+ mtspr SPRN_SRR1,r0
+ lis r0,start_here@h
+ ori r0,r0,start_here@l
+ mtspr SPRN_SRR0,r0
+ SYNC
+ RFI /* enables MMU */
+
+/*
+ * We need __secondary_hold as a place to hold the other cpus on
+ * an SMP machine, even when we are running a UP kernel.
+ */
+ . = 0xc0 /* for prep bootloader */
+ li r3,1 /* MTX only has 1 cpu */
+ .globl __secondary_hold
+__secondary_hold:
+ /* tell the master we're here */
+ stw r3,4(0)
+#ifdef CONFIG_SMP
+100: lwz r4,0(0)
+ /* wait until we're told to start */
+ cmpw 0,r4,r3
+ bne 100b
+ /* our cpu # was at addr 0 - go */
+ mr r24,r3 /* cpu # */
+ b __secondary_start
+#else
+ b .
+#endif /* CONFIG_SMP */
+
+/*
+ * Exception entry code. This code runs with address translation
+ * turned off, i.e. using physical addresses.
+ * We assume sprg3 has the physical address of the current
+ * task's thread_struct.
+ */
+#define EXCEPTION_PROLOG \
+ mtspr SPRN_SPRG0,r10; \
+ mtspr SPRN_SPRG1,r11; \
+ mfcr r10; \
+ EXCEPTION_PROLOG_1; \
+ EXCEPTION_PROLOG_2
+
+#define EXCEPTION_PROLOG_1 \
+ mfspr r11,SPRN_SRR1; /* check whether user or kernel */ \
+ andi. r11,r11,MSR_PR; \
+ tophys(r11,r1); /* use tophys(r1) if kernel */ \
+ beq 1f; \
+ mfspr r11,SPRN_SPRG3; \
+ lwz r11,THREAD_INFO-THREAD(r11); \
+ addi r11,r11,THREAD_SIZE; \
+ tophys(r11,r11); \
+1: subi r11,r11,INT_FRAME_SIZE /* alloc exc. frame */
+
+
+#define EXCEPTION_PROLOG_2 \
+ CLR_TOP32(r11); \
+ stw r10,_CCR(r11); /* save registers */ \
+ stw r12,GPR12(r11); \
+ stw r9,GPR9(r11); \
+ mfspr r10,SPRN_SPRG0; \
+ stw r10,GPR10(r11); \
+ mfspr r12,SPRN_SPRG1; \
+ stw r12,GPR11(r11); \
+ mflr r10; \
+ stw r10,_LINK(r11); \
+ mfspr r12,SPRN_SRR0; \
+ mfspr r9,SPRN_SRR1; \
+ stw r1,GPR1(r11); \
+ stw r1,0(r11); \
+ tovirt(r1,r11); /* set new kernel sp */ \
+ li r10,MSR_KERNEL & ~(MSR_IR|MSR_DR); /* can take exceptions */ \
+ MTMSRD(r10); /* (except for mach check in rtas) */ \
+ stw r0,GPR0(r11); \
+ SAVE_4GPRS(3, r11); \
+ SAVE_2GPRS(7, r11)
+
+/*
+ * Note: code which follows this uses cr0.eq (set if from kernel),
+ * r11, r12 (SRR0), and r9 (SRR1).
+ *
+ * Note2: once we have set r1 we are in a position to take exceptions
+ * again, and we could thus set MSR:RI at that point.
+ */
+
+/*
+ * Exception vectors.
+ */
+#define EXCEPTION(n, label, hdlr, xfer) \
+ . = n; \
+label: \
+ EXCEPTION_PROLOG; \
+ addi r3,r1,STACK_FRAME_OVERHEAD; \
+ xfer(n, hdlr)
+
+#define EXC_XFER_TEMPLATE(n, hdlr, trap, copyee, tfer, ret) \
+ li r10,trap; \
+ stw r10,TRAP(r11); \
+ li r10,MSR_KERNEL; \
+ copyee(r10, r9); \
+ bl tfer; \
+i##n: \
+ .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(n, hdlr, n, NOCOPY, transfer_to_handler_full, \
+ ret_from_except_full)
+
+#define EXC_XFER_LITE(n, hdlr) \
+ EXC_XFER_TEMPLATE(n, hdlr, n+1, NOCOPY, transfer_to_handler, \
+ ret_from_except)
+
+#define EXC_XFER_EE(n, hdlr) \
+ EXC_XFER_TEMPLATE(n, hdlr, n, COPY_EE, transfer_to_handler_full, \
+ ret_from_except_full)
+
+#define EXC_XFER_EE_LITE(n, hdlr) \
+ EXC_XFER_TEMPLATE(n, hdlr, n+1, COPY_EE, transfer_to_handler, \
+ ret_from_except)
+
+/* System reset */
+/* core99 pmac starts the seconary here by changing the vector, and
+ putting it back to what it was (UnknownException) when done. */
+#if defined(CONFIG_GEMINI) && defined(CONFIG_SMP)
+ . = 0x100
+ b __secondary_start_gemini
+#else
+ EXCEPTION(0x100, Reset, UnknownException, EXC_XFER_STD)
+#endif
+
+/* Machine check */
+/*
+ * On CHRP, this is complicated by the fact that we could get a
+ * machine check inside RTAS, and we have no guarantee that certain
+ * critical registers will have the values we expect. The set of
+ * registers that might have bad values includes all the GPRs
+ * and all the BATs. We indicate that we are in RTAS by putting
+ * a non-zero value, the address of the exception frame to use,
+ * in SPRG2. The machine check handler checks SPRG2 and uses its
+ * value if it is non-zero. If we ever needed to free up SPRG2,
+ * we could use a field in the thread_info or thread_struct instead.
+ * (Other exception handlers assume that r1 is a valid kernel stack
+ * pointer when we take an exception from supervisor mode.)
+ * -- paulus.
+ */
+ . = 0x200
+ mtspr SPRN_SPRG0,r10
+ mtspr SPRN_SPRG1,r11
+ mfcr r10
+#ifdef CONFIG_PPC_CHRP
+ mfspr r11,SPRN_SPRG2
+ cmpwi 0,r11,0
+ bne 7f
+#endif /* CONFIG_PPC_CHRP */
+ EXCEPTION_PROLOG_1
+7: EXCEPTION_PROLOG_2
+ addi r3,r1,STACK_FRAME_OVERHEAD
+#ifdef CONFIG_PPC_CHRP
+ mfspr r4,SPRN_SPRG2
+ cmpwi cr1,r4,0
+ bne cr1,1f
+#endif
+ EXC_XFER_STD(0x200, MachineCheckException)
+#ifdef CONFIG_PPC_CHRP
+1: b machine_check_in_rtas
+#endif
+
+/* Data access exception. */
+ . = 0x300
+#ifdef CONFIG_PPC64BRIDGE
+ b DataAccess
+DataAccessCont:
+#else
+DataAccess:
+ EXCEPTION_PROLOG
+#endif /* CONFIG_PPC64BRIDGE */
+ mfspr r10,SPRN_DSISR
+ andis. r0,r10,0xa470 /* weird error? */
+ bne 1f /* if not, try to put a PTE */
+ mfspr r4,SPRN_DAR /* into the hash table */
+ rlwinm r3,r10,32-15,21,21 /* DSISR_STORE -> _PAGE_RW */
+ bl hash_page
+1: stw r10,_DSISR(r11)
+ mr r5,r10
+ mfspr r4,SPRN_DAR
+ EXC_XFER_EE_LITE(0x300, handle_page_fault)
+
+#ifdef CONFIG_PPC64BRIDGE
+/* SLB fault on data access. */
+ . = 0x380
+ b DataSegment
+#endif /* CONFIG_PPC64BRIDGE */
+
+/* Instruction access exception. */
+ . = 0x400
+#ifdef CONFIG_PPC64BRIDGE
+ b InstructionAccess
+InstructionAccessCont:
+#else
+InstructionAccess:
+ EXCEPTION_PROLOG
+#endif /* CONFIG_PPC64BRIDGE */
+ andis. r0,r9,0x4000 /* no pte found? */
+ beq 1f /* if so, try to put a PTE */
+ li r3,0 /* into the hash table */
+ mr r4,r12 /* SRR0 is fault address */
+ bl hash_page
+1: mr r4,r12
+ mr r5,r9
+ EXC_XFER_EE_LITE(0x400, handle_page_fault)
+
+#ifdef CONFIG_PPC64BRIDGE
+/* SLB fault on instruction access. */
+ . = 0x480
+ b InstructionSegment
+#endif /* CONFIG_PPC64BRIDGE */
+
+/* External interrupt */
+ EXCEPTION(0x500, HardwareInterrupt, do_IRQ, EXC_XFER_LITE)
+
+/* Alignment exception */
+ . = 0x600
+Alignment:
+ EXCEPTION_PROLOG
+ mfspr r4,SPRN_DAR
+ stw r4,_DAR(r11)
+ mfspr r5,SPRN_DSISR
+ stw r5,_DSISR(r11)
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ EXC_XFER_EE(0x600, AlignmentException)
+
+/* Program check exception */
+ EXCEPTION(0x700, ProgramCheck, ProgramCheckException, EXC_XFER_STD)
+
+/* Floating-point unavailable */
+ . = 0x800
+FPUnavailable:
+ EXCEPTION_PROLOG
+ bne load_up_fpu /* if from user, just load it up */
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ EXC_XFER_EE_LITE(0x800, KernelFP)
+
+/* Decrementer */
+ EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)
+
+ EXCEPTION(0xa00, Trap_0a, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0xb00, Trap_0b, UnknownException, EXC_XFER_EE)
+
+/* System call */
+ . = 0xc00
+SystemCall:
+ EXCEPTION_PROLOG
+ EXC_XFER_EE_LITE(0xc00, DoSyscall)
+
+/* Single step - not used on 601 */
+ EXCEPTION(0xd00, SingleStep, SingleStepException, EXC_XFER_STD)
+ EXCEPTION(0xe00, Trap_0e, UnknownException, EXC_XFER_EE)
+
+/*
+ * The Altivec unavailable trap is at 0x0f20. Foo.
+ * We effectively remap it to 0x3000.
+ * We include an altivec unavailable exception vector even if
+ * not configured for Altivec, so that you can't panic a
+ * non-altivec kernel running on a machine with altivec just
+ * by executing an altivec instruction.
+ */
+ . = 0xf00
+ b Trap_0f
+
+ . = 0xf20
+ b AltiVecUnavailable
+
+Trap_0f:
+ EXCEPTION_PROLOG
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ EXC_XFER_EE(0xf00, UnknownException)
+
+/*
+ * Handle TLB miss for instruction on 603/603e.
+ * Note: we get an alternate set of r0 - r3 to use automatically.
+ */
+ . = 0x1000
+InstructionTLBMiss:
+/*
+ * r0: stored ctr
+ * r1: linux style pte ( later becomes ppc hardware pte )
+ * r2: ptr to linux-style pte
+ * r3: scratch
+ */
+ mfctr r0
+ /* Get PTE (linux-style) and check access */
+ mfspr r3,SPRN_IMISS
+ lis r1,KERNELBASE@h /* check if kernel address */
+ cmplw 0,r3,r1
+ mfspr r2,SPRN_SPRG3
+ li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
+ lwz r2,PGDIR(r2)
+ blt+ 112f
+ lis r2,swapper_pg_dir@ha /* if kernel address, use */
+ addi r2,r2,swapper_pg_dir@l /* kernel page table */
+ mfspr r1,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
+ rlwinm r1,r1,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
+112: tophys(r2,r2)
+ rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
+ lwz r2,0(r2) /* get pmd entry */
+ rlwinm. r2,r2,0,0,19 /* extract address of pte page */
+ beq- InstructionAddressInvalid /* return if no mapping */
+ rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
+ lwz r3,0(r2) /* get linux-style pte */
+ andc. r1,r1,r3 /* check access & ~permission */
+ bne- InstructionAddressInvalid /* return if access not permitted */
+ ori r3,r3,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
+ /*
+ * NOTE! We are assuming this is not an SMP system, otherwise
+ * we would need to update the pte atomically with lwarx/stwcx.
+ */
+ stw r3,0(r2) /* update PTE (accessed bit) */
+ /* Convert linux-style PTE to low word of PPC-style PTE */
+ rlwinm r1,r3,32-10,31,31 /* _PAGE_RW -> PP lsb */
+ rlwinm r2,r3,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
+ and r1,r1,r2 /* writable if _RW and _DIRTY */
+ rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
+ rlwimi r3,r3,32-1,31,31 /* _PAGE_USER -> PP lsb */
+ ori r1,r1,0xe14 /* clear out reserved bits and M */
+ andc r1,r3,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
+ mtspr SPRN_RPA,r1
+ mfspr r3,SPRN_IMISS
+ tlbli r3
+ mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
+ mtcrf 0x80,r3
+ rfi
+InstructionAddressInvalid:
+ mfspr r3,SPRN_SRR1
+ rlwinm r1,r3,9,6,6 /* Get load/store bit */
+
+ addis r1,r1,0x2000
+ mtspr SPRN_DSISR,r1 /* (shouldn't be needed) */
+ mtctr r0 /* Restore CTR */
+ andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
+ or r2,r2,r1
+ mtspr SPRN_SRR1,r2
+ mfspr r1,SPRN_IMISS /* Get failing address */
+ rlwinm. r2,r2,0,31,31 /* Check for little endian access */
+ rlwimi r2,r2,1,30,30 /* change 1 -> 3 */
+ xor r1,r1,r2
+ mtspr SPRN_DAR,r1 /* Set fault address */
+ mfmsr r0 /* Restore "normal" registers */
+ xoris r0,r0,MSR_TGPR>>16
+ mtcrf 0x80,r3 /* Restore CR0 */
+ mtmsr r0
+ b InstructionAccess
+
+/*
+ * Handle TLB miss for DATA Load operation on 603/603e
+ */
+ . = 0x1100
+DataLoadTLBMiss:
+/*
+ * r0: stored ctr
+ * r1: linux style pte ( later becomes ppc hardware pte )
+ * r2: ptr to linux-style pte
+ * r3: scratch
+ */
+ mfctr r0
+ /* Get PTE (linux-style) and check access */
+ mfspr r3,SPRN_DMISS
+ lis r1,KERNELBASE@h /* check if kernel address */
+ cmplw 0,r3,r1
+ mfspr r2,SPRN_SPRG3
+ li r1,_PAGE_USER|_PAGE_PRESENT /* low addresses tested as user */
+ lwz r2,PGDIR(r2)
+ blt+ 112f
+ lis r2,swapper_pg_dir@ha /* if kernel address, use */
+ addi r2,r2,swapper_pg_dir@l /* kernel page table */
+ mfspr r1,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
+ rlwinm r1,r1,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
+112: tophys(r2,r2)
+ rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
+ lwz r2,0(r2) /* get pmd entry */
+ rlwinm. r2,r2,0,0,19 /* extract address of pte page */
+ beq- DataAddressInvalid /* return if no mapping */
+ rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
+ lwz r3,0(r2) /* get linux-style pte */
+ andc. r1,r1,r3 /* check access & ~permission */
+ bne- DataAddressInvalid /* return if access not permitted */
+ ori r3,r3,_PAGE_ACCESSED /* set _PAGE_ACCESSED in pte */
+ /*
+ * NOTE! We are assuming this is not an SMP system, otherwise
+ * we would need to update the pte atomically with lwarx/stwcx.
+ */
+ stw r3,0(r2) /* update PTE (accessed bit) */
+ /* Convert linux-style PTE to low word of PPC-style PTE */
+ rlwinm r1,r3,32-10,31,31 /* _PAGE_RW -> PP lsb */
+ rlwinm r2,r3,32-7,31,31 /* _PAGE_DIRTY -> PP lsb */
+ and r1,r1,r2 /* writable if _RW and _DIRTY */
+ rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
+ rlwimi r3,r3,32-1,31,31 /* _PAGE_USER -> PP lsb */
+ ori r1,r1,0xe14 /* clear out reserved bits and M */
+ andc r1,r3,r1 /* PP = user? (rw&dirty? 2: 3): 0 */
+ mtspr SPRN_RPA,r1
+ mfspr r3,SPRN_DMISS
+ tlbld r3
+ mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
+ mtcrf 0x80,r3
+ rfi
+DataAddressInvalid:
+ mfspr r3,SPRN_SRR1
+ rlwinm r1,r3,9,6,6 /* Get load/store bit */
+ addis r1,r1,0x2000
+ mtspr SPRN_DSISR,r1
+ mtctr r0 /* Restore CTR */
+ andi. r2,r3,0xFFFF /* Clear upper bits of SRR1 */
+ mtspr SPRN_SRR1,r2
+ mfspr r1,SPRN_DMISS /* Get failing address */
+ rlwinm. r2,r2,0,31,31 /* Check for little endian access */
+ beq 20f /* Jump if big endian */
+ xori r1,r1,3
+20: mtspr SPRN_DAR,r1 /* Set fault address */
+ mfmsr r0 /* Restore "normal" registers */
+ xoris r0,r0,MSR_TGPR>>16
+ mtcrf 0x80,r3 /* Restore CR0 */
+ mtmsr r0
+ b DataAccess
+
+/*
+ * Handle TLB miss for DATA Store on 603/603e
+ */
+ . = 0x1200
+DataStoreTLBMiss:
+/*
+ * r0: stored ctr
+ * r1: linux style pte ( later becomes ppc hardware pte )
+ * r2: ptr to linux-style pte
+ * r3: scratch
+ */
+ mfctr r0
+ /* Get PTE (linux-style) and check access */
+ mfspr r3,SPRN_DMISS
+ lis r1,KERNELBASE@h /* check if kernel address */
+ cmplw 0,r3,r1
+ mfspr r2,SPRN_SPRG3
+ li r1,_PAGE_RW|_PAGE_USER|_PAGE_PRESENT /* access flags */
+ lwz r2,PGDIR(r2)
+ blt+ 112f
+ lis r2,swapper_pg_dir@ha /* if kernel address, use */
+ addi r2,r2,swapper_pg_dir@l /* kernel page table */
+ mfspr r1,SPRN_SRR1 /* and MSR_PR bit from SRR1 */
+ rlwinm r1,r1,32-12,29,29 /* shift MSR_PR to _PAGE_USER posn */
+112: tophys(r2,r2)
+ rlwimi r2,r3,12,20,29 /* insert top 10 bits of address */
+ lwz r2,0(r2) /* get pmd entry */
+ rlwinm. r2,r2,0,0,19 /* extract address of pte page */
+ beq- DataAddressInvalid /* return if no mapping */
+ rlwimi r2,r3,22,20,29 /* insert next 10 bits of address */
+ lwz r3,0(r2) /* get linux-style pte */
+ andc. r1,r1,r3 /* check access & ~permission */
+ bne- DataAddressInvalid /* return if access not permitted */
+ ori r3,r3,_PAGE_ACCESSED|_PAGE_DIRTY
+ /*
+ * NOTE! We are assuming this is not an SMP system, otherwise
+ * we would need to update the pte atomically with lwarx/stwcx.
+ */
+ stw r3,0(r2) /* update PTE (accessed/dirty bits) */
+ /* Convert linux-style PTE to low word of PPC-style PTE */
+ rlwimi r3,r3,32-1,30,30 /* _PAGE_USER -> PP msb */
+ li r1,0xe15 /* clear out reserved bits and M */
+ andc r1,r3,r1 /* PP = user? 2: 0 */
+ mtspr SPRN_RPA,r1
+ mfspr r3,SPRN_DMISS
+ tlbld r3
+ mfspr r3,SPRN_SRR1 /* Need to restore CR0 */
+ mtcrf 0x80,r3
+ rfi
+
+#ifndef CONFIG_ALTIVEC
+#define AltivecAssistException UnknownException
+#endif
+
+ EXCEPTION(0x1300, Trap_13, InstructionBreakpoint, EXC_XFER_EE)
+ EXCEPTION(0x1400, SMI, SMIException, EXC_XFER_EE)
+ EXCEPTION(0x1500, Trap_15, UnknownException, EXC_XFER_EE)
+#ifdef CONFIG_POWER4
+ EXCEPTION(0x1600, Trap_16, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1700, Trap_17, AltivecAssistException, EXC_XFER_EE)
+ EXCEPTION(0x1800, Trap_18, TAUException, EXC_XFER_STD)
+#else /* !CONFIG_POWER4 */
+ EXCEPTION(0x1600, Trap_16, AltivecAssistException, EXC_XFER_EE)
+ EXCEPTION(0x1700, Trap_17, TAUException, EXC_XFER_STD)
+ EXCEPTION(0x1800, Trap_18, UnknownException, EXC_XFER_EE)
+#endif /* CONFIG_POWER4 */
+ EXCEPTION(0x1900, Trap_19, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1a00, Trap_1a, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1b00, Trap_1b, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1c00, Trap_1c, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1d00, Trap_1d, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1e00, Trap_1e, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x1f00, Trap_1f, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2000, RunMode, RunModeException, EXC_XFER_EE)
+ EXCEPTION(0x2100, Trap_21, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2200, Trap_22, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2300, Trap_23, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2400, Trap_24, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2500, Trap_25, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2600, Trap_26, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2700, Trap_27, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2800, Trap_28, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2900, Trap_29, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2a00, Trap_2a, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2b00, Trap_2b, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2c00, Trap_2c, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2d00, Trap_2d, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2e00, Trap_2e, UnknownException, EXC_XFER_EE)
+ EXCEPTION(0x2f00, MOLTrampoline, UnknownException, EXC_XFER_EE_LITE)
+
+ .globl mol_trampoline
+ .set mol_trampoline, i0x2f00
+
+ . = 0x3000
+
+AltiVecUnavailable:
+ EXCEPTION_PROLOG
+#ifdef CONFIG_ALTIVEC
+ bne load_up_altivec /* if from user, just load it up */
+#endif /* CONFIG_ALTIVEC */
+ EXC_XFER_EE_LITE(0xf20, AltivecUnavailException)
+
+#ifdef CONFIG_PPC64BRIDGE
+DataAccess:
+ EXCEPTION_PROLOG
+ b DataAccessCont
+
+InstructionAccess:
+ EXCEPTION_PROLOG
+ b InstructionAccessCont
+
+DataSegment:
+ EXCEPTION_PROLOG
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ mfspr r4,SPRN_DAR
+ stw r4,_DAR(r11)
+ EXC_XFER_STD(0x380, UnknownException)
+
+InstructionSegment:
+ EXCEPTION_PROLOG
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ EXC_XFER_STD(0x480, UnknownException)
+#endif /* CONFIG_PPC64BRIDGE */
+
+/*
+ * This task wants to use the FPU now.
+ * On UP, disable FP for the task which had the FPU previously,
+ * and save its floating-point registers in its thread_struct.
+ * Load up this task's FP registers from its thread_struct,
+ * enable the FPU for the current task and return to the task.
+ */
+load_up_fpu:
+ mfmsr r5
+ ori r5,r5,MSR_FP
+#ifdef CONFIG_PPC64BRIDGE
+ clrldi r5,r5,1 /* turn off 64-bit mode */
+#endif /* CONFIG_PPC64BRIDGE */
+ SYNC
+ MTMSRD(r5) /* enable use of fpu now */
+ isync
+/*
+ * For SMP, we don't do lazy FPU switching because it just gets too
+ * horrendously complex, especially when a task switches from one CPU
+ * to another. Instead we call giveup_fpu in switch_to.
+ */
+#ifndef CONFIG_SMP
+ tophys(r6,0) /* get __pa constant */
+ addis r3,r6,last_task_used_math@ha
+ lwz r4,last_task_used_math@l(r3)
+ cmpwi 0,r4,0
+ beq 1f
+ add r4,r4,r6
+ addi r4,r4,THREAD /* want last_task_used_math->thread */
+ SAVE_32FPRS(0, r4)
+ mffs fr0
+ stfd fr0,THREAD_FPSCR-4(r4)
+ lwz r5,PT_REGS(r4)
+ add r5,r5,r6
+ lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+ li r10,MSR_FP|MSR_FE0|MSR_FE1
+ andc r4,r4,r10 /* disable FP for previous task */
+ stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+1:
+#endif /* CONFIG_SMP */
+ /* enable use of FP after return */
+ mfspr r5,SPRN_SPRG3 /* current task's THREAD (phys) */
+ lwz r4,THREAD_FPEXC_MODE(r5)
+ ori r9,r9,MSR_FP /* enable FP for current */
+ or r9,r9,r4
+ lfd fr0,THREAD_FPSCR-4(r5)
+ mtfsf 0xff,fr0
+ REST_32FPRS(0, r5)
+#ifndef CONFIG_SMP
+ subi r4,r5,THREAD
+ sub r4,r4,r6
+ stw r4,last_task_used_math@l(r3)
+#endif /* CONFIG_SMP */
+ /* restore registers and return */
+ /* we haven't used ctr or xer or lr */
+ /* fall through to fast_exception_return */
+
+ .globl fast_exception_return
+fast_exception_return:
+ andi. r10,r9,MSR_RI /* check for recoverable interrupt */
+ beq 1f /* if not, we've got problems */
+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 SPRN_SRR1,r9
+ mtspr SPRN_SRR0,r12
+ REST_GPR(9, r11)
+ REST_GPR(12, r11)
+ lwz r11,GPR11(r11)
+ SYNC
+ RFI
+
+/* check if the exception happened in a restartable section */
+1: lis r3,exc_exit_restart_end@ha
+ addi r3,r3,exc_exit_restart_end@l
+ cmplw r12,r3
+ bge 3f
+ lis r4,exc_exit_restart@ha
+ addi r4,r4,exc_exit_restart@l
+ cmplw r12,r4
+ blt 3f
+ lis r3,fee_restarts@ha
+ tophys(r3,r3)
+ lwz r5,fee_restarts@l(r3)
+ addi r5,r5,1
+ stw r5,fee_restarts@l(r3)
+ mr r12,r4 /* restart at exc_exit_restart */
+ b 2b
+
+ .comm fee_restarts,4
+
+/* aargh, a nonrecoverable interrupt, panic */
+/* aargh, we don't know which trap this is */
+/* but the 601 doesn't implement the RI bit, so assume it's OK */
+3:
+BEGIN_FTR_SECTION
+ b 2b
+END_FTR_SECTION_IFSET(CPU_FTR_601)
+ li r10,-1
+ stw r10,TRAP(r11)
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ li r10,MSR_KERNEL
+ bl transfer_to_handler_full
+ .long nonrecoverable_exception
+ .long ret_from_except
+
+/*
+ * FP unavailable trap from kernel - print a message, but let
+ * the task use FP in the kernel until it returns to user mode.
+ */
+KernelFP:
+ lwz r3,_MSR(r1)
+ ori r3,r3,MSR_FP
+ stw r3,_MSR(r1) /* enable use of FP after return */
+ lis r3,86f@h
+ ori r3,r3,86f@l
+ mr r4,r2 /* current */
+ lwz r5,_NIP(r1)
+ bl printk
+ b ret_from_except
+86: .string "floating point used in kernel (task=%p, pc=%x)\n"
+ .align 4,0
+
+#ifdef CONFIG_ALTIVEC
+/* Note that the AltiVec support is closely modeled after the FP
+ * support. Changes to one are likely to be applicable to the
+ * other! */
+load_up_altivec:
+/*
+ * Disable AltiVec for the task which had AltiVec previously,
+ * and save its AltiVec registers in its thread_struct.
+ * Enables AltiVec for use in the kernel on return.
+ * On SMP we know the AltiVec units are free, since we give it up every
+ * switch. -- Kumar
+ */
+ mfmsr r5
+ oris r5,r5,MSR_VEC@h
+ MTMSRD(r5) /* enable use of AltiVec now */
+ isync
+/*
+ * For SMP, we don't do lazy AltiVec switching because it just gets too
+ * horrendously complex, especially when a task switches from one CPU
+ * to another. Instead we call giveup_altivec in switch_to.
+ */
+#ifndef CONFIG_SMP
+ tophys(r6,0)
+ addis r3,r6,last_task_used_altivec@ha
+ lwz r4,last_task_used_altivec@l(r3)
+ cmpwi 0,r4,0
+ beq 1f
+ add r4,r4,r6
+ addi r4,r4,THREAD /* want THREAD of last_task_used_altivec */
+ SAVE_32VR(0,r10,r4)
+ mfvscr vr0
+ li r10,THREAD_VSCR
+ stvx vr0,r10,r4
+ lwz r5,PT_REGS(r4)
+ add r5,r5,r6
+ lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+ lis r10,MSR_VEC@h
+ andc r4,r4,r10 /* disable altivec for previous task */
+ stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+1:
+#endif /* CONFIG_SMP */
+ /* enable use of AltiVec after return */
+ oris r9,r9,MSR_VEC@h
+ mfspr r5,SPRN_SPRG3 /* current task's THREAD (phys) */
+ li r4,1
+ li r10,THREAD_VSCR
+ stw r4,THREAD_USED_VR(r5)
+ lvx vr0,r10,r5
+ mtvscr vr0
+ REST_32VR(0,r10,r5)
+#ifndef CONFIG_SMP
+ subi r4,r5,THREAD
+ sub r4,r4,r6
+ stw r4,last_task_used_altivec@l(r3)
+#endif /* CONFIG_SMP */
+ /* restore registers and return */
+ /* we haven't used ctr or xer or lr */
+ b fast_exception_return
+
+/*
+ * AltiVec unavailable trap from kernel - print a message, but let
+ * the task use AltiVec in the kernel until it returns to user mode.
+ */
+KernelAltiVec:
+ lwz r3,_MSR(r1)
+ oris r3,r3,MSR_VEC@h
+ stw r3,_MSR(r1) /* enable use of AltiVec 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 "AltiVec used in kernel (task=%p, pc=%x) \n"
+ .align 4,0
+
+/*
+ * giveup_altivec(tsk)
+ * Disable AltiVec for the task given as the argument,
+ * and save the AltiVec registers in its thread_struct.
+ * Enables AltiVec for use in the kernel on return.
+ */
+
+ .globl giveup_altivec
+giveup_altivec:
+ mfmsr r5
+ oris r5,r5,MSR_VEC@h
+ SYNC
+ MTMSRD(r5) /* enable use of AltiVec now */
+ isync
+ cmpwi 0,r3,0
+ beqlr- /* if no previous owner, done */
+ addi r3,r3,THREAD /* want THREAD of task */
+ lwz r5,PT_REGS(r3)
+ cmpwi 0,r5,0
+ SAVE_32VR(0, r4, r3)
+ mfvscr vr0
+ li r4,THREAD_VSCR
+ stvx vr0,r4,r3
+ beq 1f
+ lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+ lis r3,MSR_VEC@h
+ andc r4,r4,r3 /* disable AltiVec for previous task */
+ stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+1:
+#ifndef CONFIG_SMP
+ li r5,0
+ lis r4,last_task_used_altivec@ha
+ stw r5,last_task_used_altivec@l(r4)
+#endif /* CONFIG_SMP */
+ blr
+#endif /* CONFIG_ALTIVEC */
+
+/*
+ * giveup_fpu(tsk)
+ * Disable FP for the task given as the argument,
+ * and save the floating-point registers in its thread_struct.
+ * Enables the FPU for use in the kernel on return.
+ */
+ .globl giveup_fpu
+giveup_fpu:
+ mfmsr r5
+ ori r5,r5,MSR_FP
+ SYNC_601
+ ISYNC_601
+ MTMSRD(r5) /* enable use of fpu now */
+ SYNC_601
+ isync
+ cmpwi 0,r3,0
+ beqlr- /* if no previous owner, done */
+ addi r3,r3,THREAD /* want THREAD of task */
+ lwz r5,PT_REGS(r3)
+ cmpwi 0,r5,0
+ SAVE_32FPRS(0, r3)
+ mffs fr0
+ stfd fr0,THREAD_FPSCR-4(r3)
+ beq 1f
+ lwz r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+ li r3,MSR_FP|MSR_FE0|MSR_FE1
+ andc r4,r4,r3 /* disable FP for previous task */
+ stw r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+1:
+#ifndef CONFIG_SMP
+ li r5,0
+ lis r4,last_task_used_math@ha
+ stw r5,last_task_used_math@l(r4)
+#endif /* CONFIG_SMP */
+ blr
+
+/*
+ * This code is jumped to from the startup code to copy
+ * the kernel image to physical address 0.
+ */
+relocate_kernel:
+ addis r9,r26,klimit@ha /* fetch klimit */
+ lwz r25,klimit@l(r9)
+ addis r25,r25,-KERNELBASE@h
+ li r3,0 /* Destination base address */
+ li r6,0 /* Destination offset */
+ li r5,0x4000 /* # bytes of memory to copy */
+ bl copy_and_flush /* copy the first 0x4000 bytes */
+ addi r0,r3,4f@l /* jump to the address of 4f */
+ mtctr r0 /* in copy and do the rest. */
+ bctr /* jump to the copy */
+4: mr r5,r25
+ bl copy_and_flush /* copy the rest */
+ b turn_on_mmu
+
+/*
+ * Copy routine used to copy the kernel to start at physical address 0
+ * and flush and invalidate the caches as needed.
+ * r3 = dest addr, r4 = source addr, r5 = copy limit, r6 = start offset
+ * on exit, r3, r4, r5 are unchanged, r6 is updated to be >= r5.
+ */
+copy_and_flush:
+ addi r5,r5,-4
+ addi r6,r6,-4
+4: li r0,L1_CACHE_LINE_SIZE/4
+ mtctr r0
+3: addi r6,r6,4 /* copy a cache line */
+ lwzx r0,r6,r4
+ stwx r0,r6,r3
+ bdnz 3b
+ dcbst r6,r3 /* write it to memory */
+ sync
+ icbi r6,r3 /* flush the icache line */
+ cmplw 0,r6,r5
+ blt 4b
+ sync /* additional sync needed on g4 */
+ isync
+ addi r5,r5,4
+ addi r6,r6,4
+ blr
+
+#ifdef CONFIG_APUS
+/*
+ * On APUS the physical base address of the kernel is not known at compile
+ * time, which means the __pa/__va constants used are incorrect. In the
+ * __init section is recorded the virtual addresses of instructions using
+ * these constants, so all that has to be done is fix these before
+ * continuing the kernel boot.
+ *
+ * r4 = The physical address of the kernel base.
+ */
+fix_mem_constants:
+ mr r10,r4
+ addis r10,r10,-KERNELBASE@h /* virt_to_phys constant */
+ neg r11,r10 /* phys_to_virt constant */
+
+ lis r12,__vtop_table_begin@h
+ ori r12,r12,__vtop_table_begin@l
+ add r12,r12,r10 /* table begin phys address */
+ lis r13,__vtop_table_end@h
+ ori r13,r13,__vtop_table_end@l
+ add r13,r13,r10 /* table end phys address */
+ subi r12,r12,4
+ subi r13,r13,