Linux-2.6.12-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!
diff --git a/arch/ppc/kernel/entry.S b/arch/ppc/kernel/entry.S
new file mode 100644
index 0000000..035217d
--- /dev/null
+++ b/arch/ppc/kernel/entry.S
@@ -0,0 +1,969 @@
+/*
+ * 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/config.h>
+#include <linux/errno.h>
+#include <linux/sys.h>
+#include <linux/threads.h>
+#include <asm/processor.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/offsets.h>
+#include <asm/unistd.h>
+
+#undef SHOW_SYSCALLS
+#undef SHOW_SYSCALLS_TASK
+
+/*
+ * 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
+
+#ifdef CONFIG_BOOKE
+#include "head_booke.h"
+ .globl mcheck_transfer_to_handler
+mcheck_transfer_to_handler:
+ mtspr MCHECK_SPRG,r8
+ BOOKE_LOAD_MCHECK_STACK
+ lwz r0,GPR10-INT_FRAME_SIZE(r8)
+ stw r0,GPR10(r11)
+ lwz r0,GPR11-INT_FRAME_SIZE(r8)
+ stw r0,GPR11(r11)
+ mfspr r8,MCHECK_SPRG
+ b transfer_to_handler_full
+
+ .globl crit_transfer_to_handler
+crit_transfer_to_handler:
+ mtspr CRIT_SPRG,r8
+ BOOKE_LOAD_CRIT_STACK
+ lwz r0,GPR10-INT_FRAME_SIZE(r8)
+ stw r0,GPR10(r11)
+ lwz r0,GPR11-INT_FRAME_SIZE(r8)
+ stw r0,GPR11(r11)
+ mfspr r8,CRIT_SPRG
+ /* 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)
+ /* 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_SPRG3
+ 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
+ single-step bit to do this. */
+ lwz r12,THREAD_DBCR0(r12)
+ andis. r12,r12,DBCR0_IC@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
+ lwz r12,0(r11)
+ mtspr SPRN_DBCR0,r12
+ lwz r12,4(r11)
+ addi r12,r12,-1
+ stw r12,4(r11)
+#endif
+ b 3f
+2: /* if from kernel, check interrupted DOZE/NAP mode and
+ * check for stack overflow
+ */
+#ifdef CONFIG_6xx
+ mfspr r11,SPRN_HID0
+ mtcr r11
+BEGIN_FTR_SECTION
+ bt- 8,power_save_6xx_restore /* Check DOZE */
+END_FTR_SECTION_IFSET(CPU_FTR_CAN_DOZE)
+BEGIN_FTR_SECTION
+ bt- 9,power_save_6xx_restore /* Check NAP */
+END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
+#endif /* CONFIG_6xx */
+ .globl transfer_to_handler_cont
+transfer_to_handler_cont:
+ lwz r11,THREAD_INFO-THREAD(r12)
+ cmplw r1,r11 /* if r1 <= current->thread_info */
+ ble- stack_ovf /* then the kernel stack overflowed */
+3:
+ mflr r9
+ lwz r11,0(r9) /* virtual address of handler */
+ lwz r9,4(r9) /* where to go when done */
+ FIX_SRR1(r10,r12)
+ mtspr SPRN_SRR0,r11
+ mtspr SPRN_SRR1,r10
+ mtlr r9
+ SYNC
+ RFI /* jump to handler, enable MMU */
+
+/*
+ * 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 r11,_end@h
+ ori r11,r11,_end@l
+ cmplw r1,r11
+ ble 3b /* 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)
+ FIX_SRR1(r10,r12)
+ mtspr SPRN_SRR0,r9
+ mtspr SPRN_SRR1,r10
+ SYNC
+ RFI
+
+/*
+ * Handle a system call.
+ */
+ .stabs "arch/ppc/kernel/",N_SO,0,0,0f
+ .stabs "entry.S",N_SO,0,0,0f
+0:
+
+_GLOBAL(DoSyscall)
+ stw r0,THREAD+LAST_SYSCALL(r2)
+ 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 SHOW_SYSCALLS
+ bl do_show_syscall
+#endif /* SHOW_SYSCALLS */
+ rlwinm r10,r1,0,0,18 /* current_thread_info() */
+ lwz r11,TI_LOCAL_FLAGS(r10)
+ rlwinm r11,r11,0,~_TIFL_FORCE_NOERROR
+ stw r11,TI_LOCAL_FLAGS(r10)
+ lwz r11,TI_FLAGS(r10)
+ andi. r11,r11,_TIF_SYSCALL_TRACE
+ 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
+ lwzx r10,r10,r0 /* Fetch system call handler [ptr] */
+ mtlr r10
+ addi r9,r1,STACK_FRAME_OVERHEAD
+ blrl /* Call handler */
+ .globl ret_from_syscall
+ret_from_syscall:
+#ifdef SHOW_SYSCALLS
+ bl do_show_syscall_exit
+#endif
+ mr r6,r3
+ li r11,-_LAST_ERRNO
+ cmplw 0,r3,r11
+ rlwinm r12,r1,0,0,18 /* current_thread_info() */
+ blt+ 30f
+ lwz r11,TI_LOCAL_FLAGS(r12)
+ andi. r11,r11,_TIFL_FORCE_NOERROR
+ bne 30f
+ neg r3,r3
+ lwz r10,_CCR(r1) /* Set SO bit in CR */
+ oris r10,r10,0x1000
+ stw r10,_CCR(r1)
+
+ /* disable interrupts so current_thread_info()->flags can't change */
+30: LOAD_MSR_KERNEL(r10,MSR_KERNEL) /* doesn't include MSR_EE */
+ SYNC
+ MTMSRD(r10)
+ lwz r9,TI_FLAGS(r12)
+ andi. r0,r9,(_TIF_SYSCALL_TRACE|_TIF_SIGPENDING|_TIF_NEED_RESCHED)
+ bne- syscall_exit_work
+syscall_exit_cont:
+#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
+ /* If the process has its own DBCR0 value, load it up. The single
+ step bit tells us that dbcr0 should be loaded. */
+ lwz r0,THREAD+THREAD_DBCR0(r2)
+ andis. r10,r0,DBCR0_IC@h
+ bnel- load_dbcr0
+#endif
+ stwcx. r0,0,r1 /* to clear the reservation */
+ lwz r4,_LINK(r1)
+ lwz r5,_CCR(r1)
+ mtlr r4
+ mtcr r5
+ lwz r7,_NIP(r1)
+ lwz r8,_MSR(r1)
+ FIX_SRR1(r8, r0)
+ lwz r2,GPR2(r1)
+ lwz r1,GPR1(r1)
+ mtspr SPRN_SRR0,r7
+ mtspr SPRN_SRR1,r8
+ SYNC
+ RFI
+
+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
+
+/* Traced system call support */
+syscall_dotrace:
+ SAVE_NVGPRS(r1)
+ li r0,0xc00
+ stw r0,TRAP(r1)
+ bl do_syscall_trace
+ lwz r0,GPR0(r1) /* Restore original registers */
+ 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)
+ b syscall_dotrace_cont
+
+syscall_exit_work:
+ stw r6,RESULT(r1) /* Save result */
+ stw r3,GPR3(r1) /* Update return value */
+ andi. r0,r9,_TIF_SYSCALL_TRACE
+ beq 5f
+ ori r10,r10,MSR_EE
+ SYNC
+ MTMSRD(r10) /* re-enable interrupts */
+ lwz r4,TRAP(r1)
+ andi. r4,r4,1
+ beq 4f
+ SAVE_NVGPRS(r1)
+ li r4,0xc00
+ stw r4,TRAP(r1)
+4:
+ bl do_syscall_trace
+ REST_NVGPRS(r1)
+2:
+ lwz r3,GPR3(r1)
+ LOAD_MSR_KERNEL(r10,MSR_KERNEL) /* doesn't include MSR_EE */
+ SYNC
+ MTMSRD(r10) /* disable interrupts again */
+ rlwinm r12,r1,0,0,18 /* current_thread_info() */
+ lwz r9,TI_FLAGS(r12)
+5:
+ andi. r0,r9,_TIF_NEED_RESCHED
+ bne 1f
+ lwz r5,_MSR(r1)
+ andi. r5,r5,MSR_PR
+ beq syscall_exit_cont
+ andi. r0,r9,_TIF_SIGPENDING
+ beq syscall_exit_cont
+ b do_user_signal
+1:
+ ori r10,r10,MSR_EE
+ SYNC
+ MTMSRD(r10) /* re-enable interrupts */
+ bl schedule
+ b 2b
+
+#ifdef SHOW_SYSCALLS
+do_show_syscall:
+#ifdef SHOW_SYSCALLS_TASK
+ lis r11,show_syscalls_task@ha
+ lwz r11,show_syscalls_task@l(r11)
+ cmp 0,r2,r11
+ bnelr
+#endif
+ stw r31,GPR31(r1)
+ mflr r31
+ lis r3,7f@ha
+ addi r3,r3,7f@l
+ lwz r4,GPR0(r1)
+ lwz r5,GPR3(r1)
+ lwz r6,GPR4(r1)
+ lwz r7,GPR5(r1)
+ lwz r8,GPR6(r1)
+ lwz r9,GPR7(r1)
+ bl printk
+ lis r3,77f@ha
+ addi r3,r3,77f@l
+ lwz r4,GPR8(r1)
+ mr r5,r2
+ bl printk
+ lwz r0,GPR0(r1)
+ lwz r3,GPR3(r1)
+ lwz r4,GPR4(r1)
+ lwz r5,GPR5(r1)
+ lwz r6,GPR6(r1)
+ lwz r7,GPR7(r1)
+ lwz r8,GPR8(r1)
+ mtlr r31
+ lwz r31,GPR31(r1)
+ blr
+
+do_show_syscall_exit:
+#ifdef SHOW_SYSCALLS_TASK
+ lis r11,show_syscalls_task@ha
+ lwz r11,show_syscalls_task@l(r11)
+ cmp 0,r2,r11
+ bnelr
+#endif
+ stw r31,GPR31(r1)
+ mflr r31
+ stw r3,RESULT(r1) /* Save result */
+ mr r4,r3
+ lis r3,79f@ha
+ addi r3,r3,79f@l
+ bl printk
+ lwz r3,RESULT(r1)
+ mtlr r31
+ lwz r31,GPR31(r1)
+ blr
+
+7: .string "syscall %d(%x, %x, %x, %x, %x, "
+77: .string "%x), current=%p\n"
+79: .string " -> %x\n"
+ .align 2,0
+
+#ifdef SHOW_SYSCALLS_TASK
+ .data
+ .globl show_syscalls_task
+show_syscalls_task:
+ .long -1
+ .text
+#endif
+#endif /* SHOW_SYSCALLS */
+
+/*
+ * The sigsuspend and rt_sigsuspend system calls can call do_signal
+ * and thus put the process into the stopped state where we might
+ * want to examine its user state with ptrace. Therefore we need
+ * to save all the nonvolatile registers (r13 - r31) before calling
+ * the C code.
+ */
+ .globl ppc_sigsuspend
+ppc_sigsuspend:
+ 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_sigsuspend
+
+ .globl ppc_rt_sigsuspend
+ppc_rt_sigsuspend:
+ SAVE_NVGPRS(r1)
+ lwz r0,TRAP(r1)
+ rlwinm r0,r0,0,0,30
+ stw r0,TRAP(r1)
+ b sys_rt_sigsuspend
+
+ .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
+ 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
+
+/*
+ * 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
+ oris r0,r0,MSR_SPE@h /* Disable SPE */
+ mfspr r12,SPRN_SPEFSCR /* save spefscr register value */
+ stw r12,THREAD+THREAD_SPEFSCR(r2)
+#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)
+ CLR_TOP32(r0)
+ mtspr SPRN_SPRG3,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
+ lwz r0,THREAD+THREAD_SPEFSCR(r2)
+ mtspr SPRN_SPEFSCR,r0 /* restore SPEFSCR reg */
+#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 sigreturn_exit
+sigreturn_exit:
+ subi r1,r3,STACK_FRAME_OVERHEAD
+ rlwinm r12,r1,0,0,18 /* current_thread_info() */
+ lwz r9,TI_FLAGS(r12)
+ andi. r0,r9,_TIF_SYSCALL_TRACE
+ bnel- do_syscall_trace
+ /* fall through */
+
+ .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. */
+ 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 */
+ rlwinm r9,r1,0,0,18
+ lwz r9,TI_FLAGS(r9)
+ andi. r0,r9,(_TIF_SIGPENDING|_TIF_NEED_RESCHED)
+ bne do_work
+
+restore_user:
+#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
+ /* Check whether this process has its own DBCR0 value. The single
+ step bit tells us that dbcr0 should be loaded. */
+ lwz r0,THREAD+THREAD_DBCR0(r2)
+ andis. r10,r0,DBCR0_IC@h
+ bnel- load_dbcr0
+#endif
+
+#ifdef CONFIG_PREEMPT
+ b restore
+
+/* N.B. the only way to get here is from the beq following ret_from_except. */
+resume_kernel:
+ /* check current_thread_info->preempt_count */
+ rlwinm r9,r1,0,0,18
+ lwz r0,TI_PREEMPT(r9)
+ cmpwi 0,r0,0 /* if non-zero, just restore regs and return */
+ bne restore
+ lwz r0,TI_FLAGS(r9)
+ andi. r0,r0,_TIF_NEED_RESCHED
+ beq+ restore
+ andi. r0,r3,MSR_EE /* interrupts off? */
+ beq restore /* don't schedule if so */
+1: bl preempt_schedule_irq
+ rlwinm r9,r1,0,0,18
+ lwz r3,TI_FLAGS(r9)
+ andi. r0,r3,_TIF_NEED_RESCHED
+ bne- 1b
+#else
+resume_kernel:
+#endif /* CONFIG_PREEMPT */
+
+ /* interrupts are hard-disabled at this point */
+restore:
+ 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 */
+
+#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
+ lwz r9,_MSR(r1)
+ 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
+
+ /*
+ * 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 r9,_MSR(r1)
+ lwz r12,_NIP(r1)
+ FIX_SRR1(r9,r10)
+ 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
+ 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.
+ *
+ */
+ .globl ret_from_crit_exc
+ret_from_crit_exc:
+ 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
+#ifdef CONFIG_40x
+ /* 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)
+#endif
+ 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 SPRN_CSRR0,r11
+ mtspr SPRN_CSRR1,r12
+ lwz r9,GPR9(r1)
+ lwz r12,GPR12(r1)
+ lwz r10,GPR10(r1)
+ lwz r11,GPR11(r1)
+ lwz r1,GPR1(r1)
+ PPC405_ERR77_SYNC
+ rfci
+ b . /* prevent prefetch past rfci */
+
+#ifdef CONFIG_BOOKE
+/*
+ * Return from a machine check interrupt, similar to a critical
+ * interrupt.
+ */
+ .globl ret_from_mcheck_exc
+ret_from_mcheck_exc:
+ 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
+
+ stwcx. r0,0,r1 /* to clear the reservation */
+
+ lwz r11,_LINK(r1)
+ mtlr r11
+ lwz r10,_CCR(r1)
+ mtcrf 0xff,r10
+ 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 SPRN_MCSRR0,r11
+ mtspr SPRN_MCSRR1,r12
+ lwz r9,GPR9(r1)
+ lwz r12,GPR12(r1)
+ lwz r10,GPR10(r1)
+ lwz r11,GPR11(r1)
+ lwz r1,GPR1(r1)
+ 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
+ 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
+
+ .comm global_dbcr0,8
+#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 */
+ ori r10,r10,MSR_EE
+ SYNC
+ MTMSRD(r10) /* hard-enable interrupts */
+ bl schedule
+recheck:
+ LOAD_MSR_KERNEL(r10,MSR_KERNEL)
+ SYNC
+ MTMSRD(r10) /* disable interrupts */
+ rlwinm r9,r1,0,0,18
+ lwz r9,TI_FLAGS(r9)
+ andi. r0,r9,_TIF_NEED_RESCHED
+ bne- do_resched
+ andi. r0,r9,_TIF_SIGPENDING
+ 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: li r3,0
+ addi r4,r1,STACK_FRAME_OVERHEAD
+ bl do_signal
+ 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
+
+ .comm ee_restarts,4
+
+/*
+ * PROM code for specific machines follows. Put it
+ * here so it's easy to add arch-specific sections later.
+ * -- Cort
+ */
+#ifdef CONFIG_PPC_OF
+/*
+ * 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)
+ lis r4,rtas_data@ha
+ lwz r4,rtas_data@l(r4)
+ lis r6,1f@ha /* physical return address for rtas */
+ addi r6,r6,1f@l
+ tophys(r6,r6)
+ tophys(r7,r1)
+ lis r8,rtas_entry@ha
+ lwz r8,rtas_entry@l(r8)
+ 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
+ CLR_TOP32(r7)
+ mtspr SPRN_SPRG2,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 */
+ FIX_SRR1(r9,r0)
+ addi r1,r1,INT_FRAME_SIZE
+ li r0,0
+ mtspr SPRN_SPRG2,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_OF */