summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/entry_32.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/kernel/entry_32.S')
-rw-r--r--arch/powerpc/kernel/entry_32.S1366
1 files changed, 1366 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
new file mode 100644
index 000000000..26b3f853c
--- /dev/null
+++ b/arch/powerpc/kernel/entry_32.S
@@ -0,0 +1,1366 @@
+/*
+ * PowerPC version
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ * Rewritten by Cort Dougan (cort@fsmlabs.com) for PReP
+ * Copyright (C) 1996 Cort Dougan <cort@fsmlabs.com>
+ * 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).
+ *
+ * This file contains the system call entry code, context switch
+ * code, and exception/interrupt return code for PowerPC.
+ *
+ * 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/errno.h>
+#include <linux/err.h>
+#include <linux/sys.h>
+#include <linux/threads.h>
+#include <asm/reg.h>
+#include <asm/page.h>
+#include <asm/mmu.h>
+#include <asm/cputable.h>
+#include <asm/thread_info.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/unistd.h>
+#include <asm/ptrace.h>
+#include <asm/export.h>
+#include <asm/asm-405.h>
+#include <asm/feature-fixups.h>
+#include <asm/barrier.h>
+
+/*
+ * MSR_KERNEL is > 0x10000 on 4xx/Book-E since it include MSR_CE.
+ */
+#if MSR_KERNEL >= 0x10000
+#define LOAD_MSR_KERNEL(r, x) lis r,(x)@h; ori r,r,(x)@l
+#else
+#define LOAD_MSR_KERNEL(r, x) li r,(x)
+#endif
+
+/*
+ * Align to 4k in order to ensure that all functions modyfing srr0/srr1
+ * fit into one page in order to not encounter a TLB miss between the
+ * modification of srr0/srr1 and the associated rfi.
+ */
+ .align 12
+
+#ifdef CONFIG_BOOKE
+ .globl mcheck_transfer_to_handler
+mcheck_transfer_to_handler:
+ mfspr r0,SPRN_DSRR0
+ stw r0,_DSRR0(r11)
+ mfspr r0,SPRN_DSRR1
+ stw r0,_DSRR1(r11)
+ /* fall through */
+
+ .globl debug_transfer_to_handler
+debug_transfer_to_handler:
+ mfspr r0,SPRN_CSRR0
+ stw r0,_CSRR0(r11)
+ mfspr r0,SPRN_CSRR1
+ stw r0,_CSRR1(r11)
+ /* fall through */
+
+ .globl crit_transfer_to_handler
+crit_transfer_to_handler:
+#ifdef CONFIG_PPC_BOOK3E_MMU
+ mfspr r0,SPRN_MAS0
+ stw r0,MAS0(r11)
+ mfspr r0,SPRN_MAS1
+ stw r0,MAS1(r11)
+ mfspr r0,SPRN_MAS2
+ stw r0,MAS2(r11)
+ mfspr r0,SPRN_MAS3
+ stw r0,MAS3(r11)
+ mfspr r0,SPRN_MAS6
+ stw r0,MAS6(r11)
+#ifdef CONFIG_PHYS_64BIT
+ mfspr r0,SPRN_MAS7
+ stw r0,MAS7(r11)
+#endif /* CONFIG_PHYS_64BIT */
+#endif /* CONFIG_PPC_BOOK3E_MMU */
+#ifdef CONFIG_44x
+ mfspr r0,SPRN_MMUCR
+ stw r0,MMUCR(r11)
+#endif
+ mfspr r0,SPRN_SRR0
+ stw r0,_SRR0(r11)
+ mfspr r0,SPRN_SRR1
+ stw r0,_SRR1(r11)
+
+ /* set the stack limit to the current stack
+ * and set the limit to protect the thread_info
+ * struct
+ */
+ mfspr r8,SPRN_SPRG_THREAD
+ lwz r0,KSP_LIMIT(r8)
+ stw r0,SAVED_KSP_LIMIT(r11)
+ rlwimi r0,r1,0,0,(31-THREAD_SHIFT)
+ stw r0,KSP_LIMIT(r8)
+ /* fall through */
+#endif
+
+#ifdef CONFIG_40x
+ .globl crit_transfer_to_handler
+crit_transfer_to_handler:
+ lwz r0,crit_r10@l(0)
+ stw r0,GPR10(r11)
+ lwz r0,crit_r11@l(0)
+ stw r0,GPR11(r11)
+ mfspr r0,SPRN_SRR0
+ stw r0,crit_srr0@l(0)
+ mfspr r0,SPRN_SRR1
+ stw r0,crit_srr1@l(0)
+
+ /* set the stack limit to the current stack
+ * and set the limit to protect the thread_info
+ * struct
+ */
+ mfspr r8,SPRN_SPRG_THREAD
+ lwz r0,KSP_LIMIT(r8)
+ stw r0,saved_ksp_limit@l(0)
+ rlwimi r0,r1,0,0,(31-THREAD_SHIFT)
+ stw r0,KSP_LIMIT(r8)
+ /* fall through */
+#endif
+
+/*
+ * This code finishes saving the registers to the exception frame
+ * and jumps to the appropriate handler for the exception, turning
+ * on address translation.
+ * Note that we rely on the caller having set cr0.eq iff the exception
+ * occurred in kernel mode (i.e. MSR:PR = 0).
+ */
+ .globl transfer_to_handler_full
+transfer_to_handler_full:
+ SAVE_NVGPRS(r11)
+ /* fall through */
+
+ .globl transfer_to_handler
+transfer_to_handler:
+ stw r2,GPR2(r11)
+ stw r12,_NIP(r11)
+ stw r9,_MSR(r11)
+ andi. r2,r9,MSR_PR
+ mfctr r12
+ mfspr r2,SPRN_XER
+ stw r12,_CTR(r11)
+ stw r2,_XER(r11)
+ mfspr r12,SPRN_SPRG_THREAD
+ addi r2,r12,-THREAD
+ tovirt(r2,r2) /* set r2 to current */
+ beq 2f /* if from user, fix up THREAD.regs */
+ addi r11,r1,STACK_FRAME_OVERHEAD
+ stw r11,PT_REGS(r12)
+#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
+ /* Check to see if the dbcr0 register is set up to debug. Use the
+ internal debug mode bit to do this. */
+ lwz r12,THREAD_DBCR0(r12)
+ andis. r12,r12,DBCR0_IDM@h
+ beq+ 3f
+ /* From user and task is ptraced - load up global dbcr0 */
+ li r12,-1 /* clear all pending debug events */
+ mtspr SPRN_DBSR,r12
+ lis r11,global_dbcr0@ha
+ tophys(r11,r11)
+ addi r11,r11,global_dbcr0@l
+#ifdef CONFIG_SMP
+ CURRENT_THREAD_INFO(r9, r1)
+ lwz r9,TI_CPU(r9)
+ slwi r9,r9,3
+ add r11,r11,r9
+#endif
+ lwz r12,0(r11)
+ mtspr SPRN_DBCR0,r12
+ lwz r12,4(r11)
+ addi r12,r12,-1
+ stw r12,4(r11)
+#endif
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+ CURRENT_THREAD_INFO(r9, r1)
+ tophys(r9, r9)
+ ACCOUNT_CPU_USER_ENTRY(r9, r11, r12)
+#endif
+
+ b 3f
+
+2: /* if from kernel, check interrupted DOZE/NAP mode and
+ * check for stack overflow
+ */
+ lwz r9,KSP_LIMIT(r12)
+ cmplw r1,r9 /* if r1 <= ksp_limit */
+ ble- stack_ovf /* then the kernel stack overflowed */
+5:
+#if defined(CONFIG_6xx) || defined(CONFIG_E500)
+ CURRENT_THREAD_INFO(r9, r1)
+ tophys(r9,r9) /* check local flags */
+ lwz r12,TI_LOCAL_FLAGS(r9)
+ mtcrf 0x01,r12
+ bt- 31-TLF_NAPPING,4f
+ bt- 31-TLF_SLEEPING,7f
+#endif /* CONFIG_6xx || CONFIG_E500 */
+ .globl transfer_to_handler_cont
+transfer_to_handler_cont:
+3:
+ mflr r9
+ lwz r11,0(r9) /* virtual address of handler */
+ lwz r9,4(r9) /* where to go when done */
+#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
+ mtspr SPRN_NRI, r0
+#endif
+#ifdef CONFIG_TRACE_IRQFLAGS
+ lis r12,reenable_mmu@h
+ ori r12,r12,reenable_mmu@l
+ mtspr SPRN_SRR0,r12
+ mtspr SPRN_SRR1,r10
+ SYNC
+ RFI
+reenable_mmu: /* re-enable mmu so we can */
+ mfmsr r10
+ lwz r12,_MSR(r1)
+ xor r10,r10,r12
+ andi. r10,r10,MSR_EE /* Did EE change? */
+ beq 1f
+
+ /*
+ * The trace_hardirqs_off will use CALLER_ADDR0 and CALLER_ADDR1.
+ * If from user mode there is only one stack frame on the stack, and
+ * accessing CALLER_ADDR1 will cause oops. So we need create a dummy
+ * stack frame to make trace_hardirqs_off happy.
+ *
+ * This is handy because we also need to save a bunch of GPRs,
+ * r3 can be different from GPR3(r1) at this point, r9 and r11
+ * contains the old MSR and handler address respectively,
+ * r4 & r5 can contain page fault arguments that need to be passed
+ * along as well. r12, CCR, CTR, XER etc... are left clobbered as
+ * they aren't useful past this point (aren't syscall arguments),
+ * the rest is restored from the exception frame.
+ */
+ stwu r1,-32(r1)
+ stw r9,8(r1)
+ stw r11,12(r1)
+ stw r3,16(r1)
+ stw r4,20(r1)
+ stw r5,24(r1)
+ bl trace_hardirqs_off
+ lwz r5,24(r1)
+ lwz r4,20(r1)
+ lwz r3,16(r1)
+ lwz r11,12(r1)
+ lwz r9,8(r1)
+ addi r1,r1,32
+ lwz r0,GPR0(r1)
+ lwz r6,GPR6(r1)
+ lwz r7,GPR7(r1)
+ lwz r8,GPR8(r1)
+1: mtctr r11
+ mtlr r9
+ bctr /* jump to handler */
+#else /* CONFIG_TRACE_IRQFLAGS */
+ mtspr SPRN_SRR0,r11
+ mtspr SPRN_SRR1,r10
+ mtlr r9
+ SYNC
+ RFI /* jump to handler, enable MMU */
+#endif /* CONFIG_TRACE_IRQFLAGS */
+
+#if defined (CONFIG_6xx) || defined(CONFIG_E500)
+4: rlwinm r12,r12,0,~_TLF_NAPPING
+ stw r12,TI_LOCAL_FLAGS(r9)
+ b power_save_ppc32_restore
+
+7: rlwinm r12,r12,0,~_TLF_SLEEPING
+ stw r12,TI_LOCAL_FLAGS(r9)
+ lwz r9,_MSR(r11) /* if sleeping, clear MSR.EE */
+ rlwinm r9,r9,0,~MSR_EE
+ lwz r12,_LINK(r11) /* and return to address in LR */
+ b fast_exception_return
+#endif
+
+/*
+ * On kernel stack overflow, load up an initial stack pointer
+ * and call StackOverflow(regs), which should not return.
+ */
+stack_ovf:
+ /* sometimes we use a statically-allocated stack, which is OK. */
+ lis r12,_end@h
+ ori r12,r12,_end@l
+ cmplw r1,r12
+ ble 5b /* r1 <= &_end is OK */
+ SAVE_NVGPRS(r11)
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ lis r1,init_thread_union@ha
+ addi r1,r1,init_thread_union@l
+ addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
+ lis r9,StackOverflow@ha
+ addi r9,r9,StackOverflow@l
+ LOAD_MSR_KERNEL(r10,MSR_KERNEL)
+#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
+ mtspr SPRN_NRI, r0
+#endif
+ mtspr SPRN_SRR0,r9
+ mtspr SPRN_SRR1,r10
+ SYNC
+ RFI
+
+/*
+ * Handle a system call.
+ */
+ .stabs "arch/powerpc/kernel/",N_SO,0,0,0f
+ .stabs "entry_32.S",N_SO,0,0,0f
+0:
+
+_GLOBAL(DoSyscall)
+ stw r3,ORIG_GPR3(r1)
+ li r12,0
+ stw r12,RESULT(r1)
+ lwz r11,_CCR(r1) /* Clear SO bit in CR */
+ rlwinm r11,r11,0,4,2
+ stw r11,_CCR(r1)
+#ifdef CONFIG_TRACE_IRQFLAGS
+ /* Return from syscalls can (and generally will) hard enable
+ * interrupts. You aren't supposed to call a syscall with
+ * interrupts disabled in the first place. However, to ensure
+ * that we get it right vs. lockdep if it happens, we force
+ * that hard enable here with appropriate tracing if we see
+ * that we have been called with interrupts off
+ */
+ mfmsr r11
+ andi. r12,r11,MSR_EE
+ bne+ 1f
+ /* We came in with interrupts disabled, we enable them now */
+ bl trace_hardirqs_on
+ mfmsr r11
+ lwz r0,GPR0(r1)
+ lwz r3,GPR3(r1)
+ lwz r4,GPR4(r1)
+ ori r11,r11,MSR_EE
+ lwz r5,GPR5(r1)
+ lwz r6,GPR6(r1)
+ lwz r7,GPR7(r1)
+ lwz r8,GPR8(r1)
+ mtmsr r11
+1:
+#endif /* CONFIG_TRACE_IRQFLAGS */
+ CURRENT_THREAD_INFO(r10, r1)
+ lwz r11,TI_FLAGS(r10)
+ andi. r11,r11,_TIF_SYSCALL_DOTRACE
+ bne- syscall_dotrace
+syscall_dotrace_cont:
+ cmplwi 0,r0,NR_syscalls
+ lis r10,sys_call_table@h
+ ori r10,r10,sys_call_table@l
+ slwi r0,r0,2
+ bge- 66f
+
+ barrier_nospec_asm
+ /*
+ * Prevent the load of the handler below (based on the user-passed
+ * system call number) being speculatively executed until the test
+ * against NR_syscalls and branch to .66f above has
+ * committed.
+ */
+
+ lwzx r10,r10,r0 /* Fetch system call handler [ptr] */
+ mtlr r10
+ addi r9,r1,STACK_FRAME_OVERHEAD
+ PPC440EP_ERR42
+ blrl /* Call handler */
+ .globl ret_from_syscall
+ret_from_syscall:
+#ifdef CONFIG_DEBUG_RSEQ
+ /* Check whether the syscall is issued inside a restartable sequence */
+ stw r3,GPR3(r1)
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ bl rseq_syscall
+ lwz r3,GPR3(r1)
+#endif
+ mr r6,r3
+ CURRENT_THREAD_INFO(r12, r1)
+ /* disable interrupts so current_thread_info()->flags can't change */
+ LOAD_MSR_KERNEL(r10,MSR_KERNEL) /* doesn't include MSR_EE */
+ /* Note: We don't bother telling lockdep about it */
+ SYNC
+ MTMSRD(r10)
+ lwz r9,TI_FLAGS(r12)
+ li r8,-MAX_ERRNO
+ andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
+ bne- syscall_exit_work
+ cmplw 0,r3,r8
+ blt+ syscall_exit_cont
+ lwz r11,_CCR(r1) /* Load CR */
+ neg r3,r3
+ oris r11,r11,0x1000 /* Set SO bit in CR */
+ stw r11,_CCR(r1)
+syscall_exit_cont:
+ lwz r8,_MSR(r1)
+#ifdef CONFIG_TRACE_IRQFLAGS
+ /* If we are going to return from the syscall with interrupts
+ * off, we trace that here. It shouldn't happen though but we
+ * want to catch the bugger if it does right ?
+ */
+ andi. r10,r8,MSR_EE
+ bne+ 1f
+ stw r3,GPR3(r1)
+ bl trace_hardirqs_off
+ lwz r3,GPR3(r1)
+1:
+#endif /* CONFIG_TRACE_IRQFLAGS */
+#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
+ /* If the process has its own DBCR0 value, load it up. The internal
+ debug mode bit tells us that dbcr0 should be loaded. */
+ lwz r0,THREAD+THREAD_DBCR0(r2)
+ andis. r10,r0,DBCR0_IDM@h
+ bnel- load_dbcr0
+#endif
+#ifdef CONFIG_44x
+BEGIN_MMU_FTR_SECTION
+ lis r4,icache_44x_need_flush@ha
+ lwz r5,icache_44x_need_flush@l(r4)
+ cmplwi cr0,r5,0
+ bne- 2f
+1:
+END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_47x)
+#endif /* CONFIG_44x */
+BEGIN_FTR_SECTION
+ lwarx r7,0,r1
+END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
+ stwcx. r0,0,r1 /* to clear the reservation */
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+ andi. r4,r8,MSR_PR
+ beq 3f
+ CURRENT_THREAD_INFO(r4, r1)
+ ACCOUNT_CPU_USER_EXIT(r4, r5, r7)
+3:
+#endif
+ lwz r4,_LINK(r1)
+ lwz r5,_CCR(r1)
+ mtlr r4
+ mtcr r5
+ lwz r7,_NIP(r1)
+ lwz r2,GPR2(r1)
+ lwz r1,GPR1(r1)
+#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
+ mtspr SPRN_NRI, r0
+#endif
+ mtspr SPRN_SRR0,r7
+ mtspr SPRN_SRR1,r8
+ SYNC
+ RFI
+#ifdef CONFIG_44x
+2: li r7,0
+ iccci r0,r0
+ stw r7,icache_44x_need_flush@l(r4)
+ b 1b
+#endif /* CONFIG_44x */
+
+66: li r3,-ENOSYS
+ b ret_from_syscall
+
+ .globl ret_from_fork
+ret_from_fork:
+ REST_NVGPRS(r1)
+ bl schedule_tail
+ li r3,0
+ b ret_from_syscall
+
+ .globl ret_from_kernel_thread
+ret_from_kernel_thread:
+ REST_NVGPRS(r1)
+ bl schedule_tail
+ mtlr r14
+ mr r3,r15
+ PPC440EP_ERR42
+ blrl
+ li r3,0
+ b ret_from_syscall
+
+/* Traced system call support */
+syscall_dotrace:
+ SAVE_NVGPRS(r1)
+ li r0,0xc00
+ stw r0,_TRAP(r1)
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ bl do_syscall_trace_enter
+ /*
+ * Restore argument registers possibly just changed.
+ * We use the return value of do_syscall_trace_enter
+ * for call number to look up in the table (r0).
+ */
+ mr r0,r3
+ lwz r3,GPR3(r1)
+ lwz r4,GPR4(r1)
+ lwz r5,GPR5(r1)
+ lwz r6,GPR6(r1)
+ lwz r7,GPR7(r1)
+ lwz r8,GPR8(r1)
+ REST_NVGPRS(r1)
+
+ cmplwi r0,NR_syscalls
+ /* Return code is already in r3 thanks to do_syscall_trace_enter() */
+ bge- ret_from_syscall
+ b syscall_dotrace_cont
+
+syscall_exit_work:
+ andi. r0,r9,_TIF_RESTOREALL
+ beq+ 0f
+ REST_NVGPRS(r1)
+ b 2f
+0: cmplw 0,r3,r8
+ blt+ 1f
+ andi. r0,r9,_TIF_NOERROR
+ bne- 1f
+ lwz r11,_CCR(r1) /* Load CR */
+ neg r3,r3
+ oris r11,r11,0x1000 /* Set SO bit in CR */
+ stw r11,_CCR(r1)
+
+1: stw r6,RESULT(r1) /* Save result */
+ stw r3,GPR3(r1) /* Update return value */
+2: andi. r0,r9,(_TIF_PERSYSCALL_MASK)
+ beq 4f
+
+ /* Clear per-syscall TIF flags if any are set. */
+
+ li r11,_TIF_PERSYSCALL_MASK
+ addi r12,r12,TI_FLAGS
+3: lwarx r8,0,r12
+ andc r8,r8,r11
+#ifdef CONFIG_IBM405_ERR77
+ dcbt 0,r12
+#endif
+ stwcx. r8,0,r12
+ bne- 3b
+ subi r12,r12,TI_FLAGS
+
+4: /* Anything which requires enabling interrupts? */
+ andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP)
+ beq ret_from_except
+
+ /* Re-enable interrupts. There is no need to trace that with
+ * lockdep as we are supposed to have IRQs on at this point
+ */
+ ori r10,r10,MSR_EE
+ SYNC
+ MTMSRD(r10)
+
+ /* Save NVGPRS if they're not saved already */
+ lwz r4,_TRAP(r1)
+ andi. r4,r4,1
+ beq 5f
+ SAVE_NVGPRS(r1)
+ li r4,0xc00
+ stw r4,_TRAP(r1)
+5:
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ bl do_syscall_trace_leave
+ b ret_from_except_full
+
+/*
+ * The fork/clone functions need to copy the full register set into
+ * the child process. Therefore we need to save all the nonvolatile
+ * registers (r13 - r31) before calling the C code.
+ */
+ .globl ppc_fork
+ppc_fork:
+ SAVE_NVGPRS(r1)
+ lwz r0,_TRAP(r1)
+ rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
+ stw r0,_TRAP(r1) /* register set saved */
+ b sys_fork
+
+ .globl ppc_vfork
+ppc_vfork:
+ SAVE_NVGPRS(r1)
+ lwz r0,_TRAP(r1)
+ rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
+ stw r0,_TRAP(r1) /* register set saved */
+ b sys_vfork
+
+ .globl ppc_clone
+ppc_clone:
+ SAVE_NVGPRS(r1)
+ lwz r0,_TRAP(r1)
+ rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
+ stw r0,_TRAP(r1) /* register set saved */
+ b sys_clone
+
+ .globl ppc_swapcontext
+ppc_swapcontext:
+ SAVE_NVGPRS(r1)
+ lwz r0,_TRAP(r1)
+ rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
+ stw r0,_TRAP(r1) /* register set saved */
+ b sys_swapcontext
+
+/*
+ * Top-level page fault handling.
+ * This is in assembler because if do_page_fault tells us that
+ * it is a bad kernel page fault, we want to save the non-volatile
+ * registers before calling bad_page_fault.
+ */
+ .globl handle_page_fault
+handle_page_fault:
+ stw r4,_DAR(r1)
+ addi r3,r1,STACK_FRAME_OVERHEAD
+#ifdef CONFIG_6xx
+ andis. r0,r5,DSISR_DABRMATCH@h
+ bne- handle_dabr_fault
+#endif
+ bl do_page_fault
+ cmpwi r3,0
+ beq+ ret_from_except
+ SAVE_NVGPRS(r1)
+ lwz r0,_TRAP(r1)
+ clrrwi r0,r0,1
+ stw r0,_TRAP(r1)
+ mr r5,r3
+ addi r3,r1,STACK_FRAME_OVERHEAD
+ lwz r4,_DAR(r1)
+ bl bad_page_fault
+ b ret_from_except_full
+
+#ifdef CONFIG_6xx
+ /* We have a data breakpoint exception - handle it */
+handle_dabr_fault:
+ SAVE_NVGPRS(r1)
+ lwz r0,_TRAP(r1)
+ clrrwi r0,r0,1
+ stw r0,_TRAP(r1)
+ bl do_break
+ b ret_from_except_full
+#endif
+
+/*
+ * This routine switches between two different tasks. The process
+ * state of one is saved on its kernel stack. Then the state
+ * of the other is restored from its kernel stack. The memory
+ * management hardware is updated to the second process's state.
+ * Finally, we can return to the second process.
+ * On entry, r3 points to the THREAD for the current task, r4
+ * points to the THREAD for the new task.
+ *
+ * This routine is always called with interrupts disabled.
+ *
+ * Note: there are two ways to get to the "going out" portion
+ * of this code; either by coming in via the entry (_switch)
+ * or via "fork" which must set up an environment equivalent
+ * to the "_switch" path. If you change this , you'll have to
+ * change the fork code also.
+ *
+ * The code which creates the new task context is in 'copy_thread'
+ * in arch/ppc/kernel/process.c
+ */
+_GLOBAL(_switch)
+ stwu r1,-INT_FRAME_SIZE(r1)
+ mflr r0
+ stw r0,INT_FRAME_SIZE+4(r1)
+ /* r3-r12 are caller saved -- Cort */
+ SAVE_NVGPRS(r1)
+ stw r0,_NIP(r1) /* Return to switch caller */
+ mfmsr r11
+ li r0,MSR_FP /* Disable floating-point */
+#ifdef CONFIG_ALTIVEC
+BEGIN_FTR_SECTION
+ oris r0,r0,MSR_VEC@h /* Disable altivec */
+ mfspr r12,SPRN_VRSAVE /* save vrsave register value */
+ stw r12,THREAD+THREAD_VRSAVE(r2)
+END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
+#endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_SPE
+BEGIN_FTR_SECTION
+ oris r0,r0,MSR_SPE@h /* Disable SPE */
+ mfspr r12,SPRN_SPEFSCR /* save spefscr register value */
+ stw r12,THREAD+THREAD_SPEFSCR(r2)
+END_FTR_SECTION_IFSET(CPU_FTR_SPE)
+#endif /* CONFIG_SPE */
+ and. r0,r0,r11 /* FP or altivec or SPE enabled? */
+ beq+ 1f
+ andc r11,r11,r0
+ MTMSRD(r11)
+ isync
+1: stw r11,_MSR(r1)
+ mfcr r10
+ stw r10,_CCR(r1)
+ stw r1,KSP(r3) /* Set old stack pointer */
+
+#ifdef CONFIG_SMP
+ /* We need a sync somewhere here to make sure that if the
+ * previous task gets rescheduled on another CPU, it sees all
+ * stores it has performed on this one.
+ */
+ sync
+#endif /* CONFIG_SMP */
+
+ tophys(r0,r4)
+ mtspr SPRN_SPRG_THREAD,r0 /* Update current THREAD phys addr */
+ lwz r1,KSP(r4) /* Load new stack pointer */
+
+ /* save the old current 'last' for return value */
+ mr r3,r2
+ addi r2,r4,-THREAD /* Update current */
+
+#ifdef CONFIG_ALTIVEC
+BEGIN_FTR_SECTION
+ lwz r0,THREAD+THREAD_VRSAVE(r2)
+ mtspr SPRN_VRSAVE,r0 /* if G4, restore VRSAVE reg */
+END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
+#endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_SPE
+BEGIN_FTR_SECTION
+ lwz r0,THREAD+THREAD_SPEFSCR(r2)
+ mtspr SPRN_SPEFSCR,r0 /* restore SPEFSCR reg */
+END_FTR_SECTION_IFSET(CPU_FTR_SPE)
+#endif /* CONFIG_SPE */
+
+ lwz r0,_CCR(r1)
+ mtcrf 0xFF,r0
+ /* r3-r12 are destroyed -- Cort */
+ REST_NVGPRS(r1)
+
+ lwz r4,_NIP(r1) /* Return to _switch caller in new task */
+ mtlr r4
+ addi r1,r1,INT_FRAME_SIZE
+ blr
+
+ .globl fast_exception_return
+fast_exception_return:
+#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
+ andi. r10,r9,MSR_RI /* check for recoverable interrupt */
+ beq 1f /* if not, we've got problems */
+#endif
+
+2: REST_4GPRS(3, r11)
+ lwz r10,_CCR(r11)
+ REST_GPR(1, r11)
+ mtcr r10
+ lwz r10,_LINK(r11)
+ mtlr r10
+ /* Clear the exception_marker on the stack to avoid confusing stacktrace */
+ li r10, 0
+ stw r10, 8(r11)
+ REST_GPR(10, r11)
+#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
+ mtspr SPRN_NRI, r0
+#endif
+ mtspr SPRN_SRR1,r9
+ mtspr SPRN_SRR0,r12
+ REST_GPR(9, r11)
+ REST_GPR(12, r11)
+ lwz r11,GPR11(r11)
+ SYNC
+ RFI
+
+#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
+/* 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
+
+ .section .bss
+ .align 2
+fee_restarts:
+ .space 4
+ .previous
+
+/* 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
+ lis r10,MSR_KERNEL@h
+ ori r10,r10,MSR_KERNEL@l
+ bl transfer_to_handler_full
+ .long nonrecoverable_exception
+ .long ret_from_except
+#endif
+
+ .globl ret_from_except_full
+ret_from_except_full:
+ REST_NVGPRS(r1)
+ /* fall through */
+
+ .globl ret_from_except
+ret_from_except:
+ /* Hard-disable interrupts so that current_thread_info()->flags
+ * can't change between when we test it and when we return
+ * from the interrupt. */
+ /* Note: We don't bother telling lockdep about it */
+ LOAD_MSR_KERNEL(r10,MSR_KERNEL)
+ SYNC /* Some chip revs have problems here... */
+ MTMSRD(r10) /* disable interrupts */
+
+ lwz r3,_MSR(r1) /* Returning to user mode? */
+ andi. r0,r3,MSR_PR
+ beq resume_kernel
+
+user_exc_return: /* r10 contains MSR_KERNEL here */
+ /* Check current_thread_info()->flags */
+ CURRENT_THREAD_INFO(r9, r1)
+ lwz r9,TI_FLAGS(r9)
+ andi. r0,r9,_TIF_USER_WORK_MASK
+ bne do_work
+
+restore_user:
+#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
+ /* Check whether this process has its own DBCR0 value. The internal
+ debug mode bit tells us that dbcr0 should be loaded. */
+ lwz r0,THREAD+THREAD_DBCR0(r2)
+ andis. r10,r0,DBCR0_IDM@h
+ bnel- load_dbcr0
+#endif
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+ CURRENT_THREAD_INFO(r9, r1)
+ ACCOUNT_CPU_USER_EXIT(r9, r10, r11)
+#endif
+
+ b restore
+
+/* N.B. the only way to get here is from the beq following ret_from_except. */
+resume_kernel:
+ /* check current_thread_info, _TIF_EMULATE_STACK_STORE */
+ CURRENT_THREAD_INFO(r9, r1)
+ lwz r8,TI_FLAGS(r9)
+ andis. r0,r8,_TIF_EMULATE_STACK_STORE@h
+ beq+ 1f
+
+ addi r8,r1,INT_FRAME_SIZE /* Get the kprobed function entry */
+
+ lwz r3,GPR1(r1)
+ subi r3,r3,INT_FRAME_SIZE /* dst: Allocate a trampoline exception frame */
+ mr r4,r1 /* src: current exception frame */
+ mr r1,r3 /* Reroute the trampoline frame to r1 */
+
+ /* Copy from the original to the trampoline. */
+ li r5,INT_FRAME_SIZE/4 /* size: INT_FRAME_SIZE */
+ li r6,0 /* start offset: 0 */
+ mtctr r5
+2: lwzx r0,r6,r4
+ stwx r0,r6,r3
+ addi r6,r6,4
+ bdnz 2b
+
+ /* Do real store operation to complete stwu */
+ lwz r5,GPR1(r1)
+ stw r8,0(r5)
+
+ /* Clear _TIF_EMULATE_STACK_STORE flag */
+ lis r11,_TIF_EMULATE_STACK_STORE@h
+ addi r5,r9,TI_FLAGS
+0: lwarx r8,0,r5
+ andc r8,r8,r11
+#ifdef CONFIG_IBM405_ERR77
+ dcbt 0,r5
+#endif
+ stwcx. r8,0,r5
+ bne- 0b
+1:
+
+#ifdef CONFIG_PREEMPT
+ /* check current_thread_info->preempt_count */
+ lwz r0,TI_PREEMPT(r9)
+ cmpwi 0,r0,0 /* if non-zero, just restore regs and return */
+ bne restore
+ andi. r8,r8,_TIF_NEED_RESCHED
+ beq+ restore
+ lwz r3,_MSR(r1)
+ andi. r0,r3,MSR_EE /* interrupts off? */
+ beq restore /* don't schedule if so */
+#ifdef CONFIG_TRACE_IRQFLAGS
+ /* Lockdep thinks irqs are enabled, we need to call
+ * preempt_schedule_irq with IRQs off, so we inform lockdep
+ * now that we -did- turn them off already
+ */
+ bl trace_hardirqs_off
+#endif
+1: bl preempt_schedule_irq
+ CURRENT_THREAD_INFO(r9, r1)
+ lwz r3,TI_FLAGS(r9)
+ andi. r0,r3,_TIF_NEED_RESCHED
+ bne- 1b
+#ifdef CONFIG_TRACE_IRQFLAGS
+ /* And now, to properly rebalance the above, we tell lockdep they
+ * are being turned back on, which will happen when we return
+ */
+ bl trace_hardirqs_on
+#endif
+#endif /* CONFIG_PREEMPT */
+
+ /* interrupts are hard-disabled at this point */
+restore:
+#ifdef CONFIG_44x
+BEGIN_MMU_FTR_SECTION
+ b 1f
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x)
+ lis r4,icache_44x_need_flush@ha
+ lwz r5,icache_44x_need_flush@l(r4)
+ cmplwi cr0,r5,0
+ beq+ 1f
+ li r6,0
+ iccci r0,r0
+ stw r6,icache_44x_need_flush@l(r4)
+1:
+#endif /* CONFIG_44x */
+
+ lwz r9,_MSR(r1)
+#ifdef CONFIG_TRACE_IRQFLAGS
+ /* Lockdep doesn't know about the fact that IRQs are temporarily turned
+ * off in this assembly code while peeking at TI_FLAGS() and such. However
+ * we need to inform it if the exception turned interrupts off, and we
+ * are about to trun them back on.
+ *
+ * The problem here sadly is that we don't know whether the exceptions was
+ * one that turned interrupts off or not. So we always tell lockdep about
+ * turning them on here when we go back to wherever we came from with EE
+ * on, even if that may meen some redudant calls being tracked. Maybe later
+ * we could encode what the exception did somewhere or test the exception
+ * type in the pt_regs but that sounds overkill
+ */
+ andi. r10,r9,MSR_EE
+ beq 1f
+ /*
+ * Since the ftrace irqsoff latency trace checks CALLER_ADDR1,
+ * which is the stack frame here, we need to force a stack frame
+ * in case we came from user space.
+ */
+ stwu r1,-32(r1)
+ mflr r0
+ stw r0,4(r1)
+ stwu r1,-32(r1)
+ bl trace_hardirqs_on
+ lwz r1,0(r1)
+ lwz r1,0(r1)
+ lwz r9,_MSR(r1)
+1:
+#endif /* CONFIG_TRACE_IRQFLAGS */
+
+ lwz r0,GPR0(r1)
+ lwz r2,GPR2(r1)
+ REST_4GPRS(3, r1)
+ REST_2GPRS(7, r1)
+
+ lwz r10,_XER(r1)
+ lwz r11,_CTR(r1)
+ mtspr SPRN_XER,r10
+ mtctr r11
+
+ PPC405_ERR77(0,r1)
+BEGIN_FTR_SECTION
+ lwarx r11,0,r1
+END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
+ stwcx. r0,0,r1 /* to clear the reservation */
+
+#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
+ andi. r10,r9,MSR_RI /* check if this exception occurred */
+ beql nonrecoverable /* at a bad place (MSR:RI = 0) */
+
+ lwz r10,_CCR(r1)
+ lwz r11,_LINK(r1)
+ mtcrf 0xFF,r10
+ mtlr r11
+
+ /* Clear the exception_marker on the stack to avoid confusing stacktrace */
+ li r10, 0
+ stw r10, 8(r1)
+ /*
+ * Once we put values in SRR0 and SRR1, we are in a state
+ * where exceptions are not recoverable, since taking an
+ * exception will trash SRR0 and SRR1. Therefore we clear the
+ * MSR:RI bit to indicate this. If we do take an exception,
+ * we can't return to the point of the exception but we
+ * can restart the exception exit path at the label
+ * exc_exit_restart below. -- paulus
+ */
+ LOAD_MSR_KERNEL(r10,MSR_KERNEL & ~MSR_RI)
+ SYNC
+ MTMSRD(r10) /* clear the RI bit */
+ .globl exc_exit_restart
+exc_exit_restart:
+ lwz r12,_NIP(r1)
+#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
+ mtspr SPRN_NRI, r0
+#endif
+ mtspr SPRN_SRR0,r12
+ mtspr SPRN_SRR1,r9
+ REST_4GPRS(9, r1)
+ lwz r1,GPR1(r1)
+ .globl exc_exit_restart_end
+exc_exit_restart_end:
+ SYNC
+ RFI
+
+#else /* !(CONFIG_4xx || CONFIG_BOOKE) */
+ /*
+ * This is a bit different on 4xx/Book-E because it doesn't have
+ * the RI bit in the MSR.
+ * The TLB miss handler checks if we have interrupted
+ * the exception exit path and restarts it if so
+ * (well maybe one day it will... :).
+ */
+ lwz r11,_LINK(r1)
+ mtlr r11
+ lwz r10,_CCR(r1)
+ mtcrf 0xff,r10
+ /* Clear the exception_marker on the stack to avoid confusing stacktrace */
+ li r10, 0
+ stw r10, 8(r1)
+ REST_2GPRS(9, r1)
+ .globl exc_exit_restart
+exc_exit_restart:
+ lwz r11,_NIP(r1)
+ lwz r12,_MSR(r1)
+exc_exit_start:
+ mtspr SPRN_SRR0,r11
+ mtspr SPRN_SRR1,r12
+ REST_2GPRS(11, r1)
+ lwz r1,GPR1(r1)
+ .globl exc_exit_restart_end
+exc_exit_restart_end:
+ PPC405_ERR77_SYNC
+ rfi
+ b . /* prevent prefetch past rfi */
+
+/*
+ * Returning from a critical interrupt in user mode doesn't need
+ * to be any different from a normal exception. For a critical
+ * interrupt in the kernel, we just return (without checking for
+ * preemption) since the interrupt may have happened at some crucial
+ * place (e.g. inside the TLB miss handler), and because we will be
+ * running with r1 pointing into critical_stack, not the current
+ * process's kernel stack (and therefore current_thread_info() will
+ * give the wrong answer).
+ * We have to restore various SPRs that may have been in use at the
+ * time of the critical interrupt.
+ *
+ */
+#ifdef CONFIG_40x
+#define PPC_40x_TURN_OFF_MSR_DR \
+ /* avoid any possible TLB misses here by turning off MSR.DR, we \
+ * assume the instructions here are mapped by a pinned TLB entry */ \
+ li r10,MSR_IR; \
+ mtmsr r10; \
+ isync; \
+ tophys(r1, r1);
+#else
+#define PPC_40x_TURN_OFF_MSR_DR
+#endif
+
+#define RET_FROM_EXC_LEVEL(exc_lvl_srr0, exc_lvl_srr1, exc_lvl_rfi) \
+ REST_NVGPRS(r1); \
+ lwz r3,_MSR(r1); \
+ andi. r3,r3,MSR_PR; \
+ LOAD_MSR_KERNEL(r10,MSR_KERNEL); \
+ bne user_exc_return; \
+ lwz r0,GPR0(r1); \
+ lwz r2,GPR2(r1); \
+ REST_4GPRS(3, r1); \
+ REST_2GPRS(7, r1); \
+ lwz r10,_XER(r1); \
+ lwz r11,_CTR(r1); \
+ mtspr SPRN_XER,r10; \
+ mtctr r11; \
+ PPC405_ERR77(0,r1); \
+ stwcx. r0,0,r1; /* to clear the reservation */ \
+ lwz r11,_LINK(r1); \
+ mtlr r11; \
+ lwz r10,_CCR(r1); \
+ mtcrf 0xff,r10; \
+ PPC_40x_TURN_OFF_MSR_DR; \
+ lwz r9,_DEAR(r1); \
+ lwz r10,_ESR(r1); \
+ mtspr SPRN_DEAR,r9; \
+ mtspr SPRN_ESR,r10; \
+ lwz r11,_NIP(r1); \
+ lwz r12,_MSR(r1); \
+ mtspr exc_lvl_srr0,r11; \
+ mtspr exc_lvl_srr1,r12; \
+ lwz r9,GPR9(r1); \
+ lwz r12,GPR12(r1); \
+ lwz r10,GPR10(r1); \
+ lwz r11,GPR11(r1); \
+ lwz r1,GPR1(r1); \
+ PPC405_ERR77_SYNC; \
+ exc_lvl_rfi; \
+ b .; /* prevent prefetch past exc_lvl_rfi */
+
+#define RESTORE_xSRR(exc_lvl_srr0, exc_lvl_srr1) \
+ lwz r9,_##exc_lvl_srr0(r1); \
+ lwz r10,_##exc_lvl_srr1(r1); \
+ mtspr SPRN_##exc_lvl_srr0,r9; \
+ mtspr SPRN_##exc_lvl_srr1,r10;
+
+#if defined(CONFIG_PPC_BOOK3E_MMU)
+#ifdef CONFIG_PHYS_64BIT
+#define RESTORE_MAS7 \
+ lwz r11,MAS7(r1); \
+ mtspr SPRN_MAS7,r11;
+#else
+#define RESTORE_MAS7
+#endif /* CONFIG_PHYS_64BIT */
+#define RESTORE_MMU_REGS \
+ lwz r9,MAS0(r1); \
+ lwz r10,MAS1(r1); \
+ lwz r11,MAS2(r1); \
+ mtspr SPRN_MAS0,r9; \
+ lwz r9,MAS3(r1); \
+ mtspr SPRN_MAS1,r10; \
+ lwz r10,MAS6(r1); \
+ mtspr SPRN_MAS2,r11; \
+ mtspr SPRN_MAS3,r9; \
+ mtspr SPRN_MAS6,r10; \
+ RESTORE_MAS7;
+#elif defined(CONFIG_44x)
+#define RESTORE_MMU_REGS \
+ lwz r9,MMUCR(r1); \
+ mtspr SPRN_MMUCR,r9;
+#else
+#define RESTORE_MMU_REGS
+#endif
+
+#ifdef CONFIG_40x
+ .globl ret_from_crit_exc
+ret_from_crit_exc:
+ mfspr r9,SPRN_SPRG_THREAD
+ lis r10,saved_ksp_limit@ha;
+ lwz r10,saved_ksp_limit@l(r10);
+ tovirt(r9,r9);
+ stw r10,KSP_LIMIT(r9)
+ lis r9,crit_srr0@ha;
+ lwz r9,crit_srr0@l(r9);
+ lis r10,crit_srr1@ha;
+ lwz r10,crit_srr1@l(r10);
+ mtspr SPRN_SRR0,r9;
+ mtspr SPRN_SRR1,r10;
+ RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, PPC_RFCI)
+#endif /* CONFIG_40x */
+
+#ifdef CONFIG_BOOKE
+ .globl ret_from_crit_exc
+ret_from_crit_exc:
+ mfspr r9,SPRN_SPRG_THREAD
+ lwz r10,SAVED_KSP_LIMIT(r1)
+ stw r10,KSP_LIMIT(r9)
+ RESTORE_xSRR(SRR0,SRR1);
+ RESTORE_MMU_REGS;
+ RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, PPC_RFCI)
+
+ .globl ret_from_debug_exc
+ret_from_debug_exc:
+ mfspr r9,SPRN_SPRG_THREAD
+ lwz r10,SAVED_KSP_LIMIT(r1)
+ stw r10,KSP_LIMIT(r9)
+ lwz r9,THREAD_INFO-THREAD(r9)
+ CURRENT_THREAD_INFO(r10, r1)
+ lwz r10,TI_PREEMPT(r10)
+ stw r10,TI_PREEMPT(r9)
+ RESTORE_xSRR(SRR0,SRR1);
+ RESTORE_xSRR(CSRR0,CSRR1);
+ RESTORE_MMU_REGS;
+ RET_FROM_EXC_LEVEL(SPRN_DSRR0, SPRN_DSRR1, PPC_RFDI)
+
+ .globl ret_from_mcheck_exc
+ret_from_mcheck_exc:
+ mfspr r9,SPRN_SPRG_THREAD
+ lwz r10,SAVED_KSP_LIMIT(r1)
+ stw r10,KSP_LIMIT(r9)
+ RESTORE_xSRR(SRR0,SRR1);
+ RESTORE_xSRR(CSRR0,CSRR1);
+ RESTORE_xSRR(DSRR0,DSRR1);
+ RESTORE_MMU_REGS;
+ RET_FROM_EXC_LEVEL(SPRN_MCSRR0, SPRN_MCSRR1, PPC_RFMCI)
+#endif /* CONFIG_BOOKE */
+
+/*
+ * Load the DBCR0 value for a task that is being ptraced,
+ * having first saved away the global DBCR0. Note that r0
+ * has the dbcr0 value to set upon entry to this.
+ */
+load_dbcr0:
+ mfmsr r10 /* first disable debug exceptions */
+ rlwinm r10,r10,0,~MSR_DE
+ mtmsr r10
+ isync
+ mfspr r10,SPRN_DBCR0
+ lis r11,global_dbcr0@ha
+ addi r11,r11,global_dbcr0@l
+#ifdef CONFIG_SMP
+ CURRENT_THREAD_INFO(r9, r1)
+ lwz r9,TI_CPU(r9)
+ slwi r9,r9,3
+ add r11,r11,r9
+#endif
+ stw r10,0(r11)
+ mtspr SPRN_DBCR0,r0
+ lwz r10,4(r11)
+ addi r10,r10,1
+ stw r10,4(r11)
+ li r11,-1
+ mtspr SPRN_DBSR,r11 /* clear all pending debug events */
+ blr
+
+ .section .bss
+ .align 4
+global_dbcr0:
+ .space 8*NR_CPUS
+ .previous
+#endif /* !(CONFIG_4xx || CONFIG_BOOKE) */
+
+do_work: /* r10 contains MSR_KERNEL here */
+ andi. r0,r9,_TIF_NEED_RESCHED
+ beq do_user_signal
+
+do_resched: /* r10 contains MSR_KERNEL here */
+ /* Note: We don't need to inform lockdep that we are enabling
+ * interrupts here. As far as it knows, they are already enabled
+ */
+ ori r10,r10,MSR_EE
+ SYNC
+ MTMSRD(r10) /* hard-enable interrupts */
+ bl schedule
+recheck:
+ /* Note: And we don't tell it we are disabling them again
+ * neither. Those disable/enable cycles used to peek at
+ * TI_FLAGS aren't advertised.
+ */
+ LOAD_MSR_KERNEL(r10,MSR_KERNEL)
+ SYNC
+ MTMSRD(r10) /* disable interrupts */
+ CURRENT_THREAD_INFO(r9, r1)
+ lwz r9,TI_FLAGS(r9)
+ andi. r0,r9,_TIF_NEED_RESCHED
+ bne- do_resched
+ andi. r0,r9,_TIF_USER_WORK_MASK
+ beq restore_user
+do_user_signal: /* r10 contains MSR_KERNEL here */
+ ori r10,r10,MSR_EE
+ SYNC
+ MTMSRD(r10) /* hard-enable interrupts */
+ /* save r13-r31 in the exception frame, if not already done */
+ lwz r3,_TRAP(r1)
+ andi. r0,r3,1
+ beq 2f
+ SAVE_NVGPRS(r1)
+ rlwinm r3,r3,0,0,30
+ stw r3,_TRAP(r1)
+2: addi r3,r1,STACK_FRAME_OVERHEAD
+ mr r4,r9
+ bl do_notify_resume
+ REST_NVGPRS(r1)
+ b recheck
+
+/*
+ * We come here when we are at the end of handling an exception
+ * that occurred at a place where taking an exception will lose
+ * state information, such as the contents of SRR0 and SRR1.
+ */
+nonrecoverable:
+ lis r10,exc_exit_restart_end@ha
+ addi r10,r10,exc_exit_restart_end@l
+ cmplw r12,r10
+ bge 3f
+ lis r11,exc_exit_restart@ha
+ addi r11,r11,exc_exit_restart@l
+ cmplw r12,r11
+ blt 3f
+ lis r10,ee_restarts@ha
+ lwz r12,ee_restarts@l(r10)
+ addi r12,r12,1
+ stw r12,ee_restarts@l(r10)
+ mr r12,r11 /* restart at exc_exit_restart */
+ blr
+3: /* OK, we can't recover, kill this process */
+ /* but the 601 doesn't implement the RI bit, so assume it's OK */
+BEGIN_FTR_SECTION
+ blr
+END_FTR_SECTION_IFSET(CPU_FTR_601)
+ lwz r3,_TRAP(r1)
+ andi. r0,r3,1
+ beq 4f
+ SAVE_NVGPRS(r1)
+ rlwinm r3,r3,0,0,30
+ stw r3,_TRAP(r1)
+4: addi r3,r1,STACK_FRAME_OVERHEAD
+ bl nonrecoverable_exception
+ /* shouldn't return */
+ b 4b
+
+ .section .bss
+ .align 2
+ee_restarts:
+ .space 4
+ .previous
+
+/*
+ * PROM code for specific machines follows. Put it
+ * here so it's easy to add arch-specific sections later.
+ * -- Cort
+ */
+#ifdef CONFIG_PPC_RTAS
+/*
+ * On CHRP, the Run-Time Abstraction Services (RTAS) have to be
+ * called with the MMU off.
+ */
+_GLOBAL(enter_rtas)
+ stwu r1,-INT_FRAME_SIZE(r1)
+ mflr r0
+ stw r0,INT_FRAME_SIZE+4(r1)
+ LOAD_REG_ADDR(r4, rtas)
+ lis r6,1f@ha /* physical return address for rtas */
+ addi r6,r6,1f@l
+ tophys(r6,r6)
+ tophys(r7,r1)
+ lwz r8,RTASENTRY(r4)
+ lwz r4,RTASBASE(r4)
+ mfmsr r9
+ stw r9,8(r1)
+ LOAD_MSR_KERNEL(r0,MSR_KERNEL)
+ SYNC /* disable interrupts so SRR0/1 */
+ MTMSRD(r0) /* don't get trashed */
+ li r9,MSR_KERNEL & ~(MSR_IR|MSR_DR)
+ mtlr r6
+ mtspr SPRN_SPRG_RTAS,r7
+ mtspr SPRN_SRR0,r8
+ mtspr SPRN_SRR1,r9
+ RFI
+1: tophys(r9,r1)
+ lwz r8,INT_FRAME_SIZE+4(r9) /* get return address */
+ lwz r9,8(r9) /* original msr value */
+ addi r1,r1,INT_FRAME_SIZE
+ li r0,0
+ mtspr SPRN_SPRG_RTAS,r0
+ mtspr SPRN_SRR0,r8
+ mtspr SPRN_SRR1,r9
+ RFI /* return to caller */
+
+ .globl machine_check_in_rtas
+machine_check_in_rtas:
+ twi 31,0,0
+ /* XXX load up BATs and panic */
+
+#endif /* CONFIG_PPC_RTAS */