|  | /* | 
|  | *  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/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/ftrace.h> | 
|  | #include <asm/ptrace.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 | 
|  | .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) | 
|  |  | 
|  | 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) | 
|  |  | 
|  | 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 | 
|  | rlwinm	r9,r1,0,0,(31-THREAD_SHIFT) | 
|  | 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 | 
|  | 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) | 
|  | rlwinm	r9,r1,0,0,31-THREAD_SHIFT | 
|  | 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 */ | 
|  | #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 | 
|  |  | 
|  | /* Save handler and return address into the 2 unused words | 
|  | * of the STACK_FRAME_OVERHEAD (sneak sneak sneak). Everything | 
|  | * else can be recovered from the pt_regs except r3 which for | 
|  | * normal interrupts has been set to pt_regs and for syscalls | 
|  | * is an argument, so we temporarily use ORIG_GPR3 to save it | 
|  | */ | 
|  | stw	r9,8(r1) | 
|  | stw	r11,12(r1) | 
|  | stw	r3,ORIG_GPR3(r1) | 
|  | /* | 
|  | * 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. | 
|  | */ | 
|  | andi.	r12,r12,MSR_PR | 
|  | beq	11f | 
|  | stwu	r1,-16(r1) | 
|  | bl	trace_hardirqs_off | 
|  | addi	r1,r1,16 | 
|  | b	12f | 
|  |  | 
|  | 11: | 
|  | bl	trace_hardirqs_off | 
|  | 12: | 
|  | lwz	r0,GPR0(r1) | 
|  | lwz	r3,ORIG_GPR3(r1) | 
|  | lwz	r4,GPR4(r1) | 
|  | lwz	r5,GPR5(r1) | 
|  | lwz	r6,GPR6(r1) | 
|  | lwz	r7,GPR7(r1) | 
|  | lwz	r8,GPR8(r1) | 
|  | lwz	r9,8(r1) | 
|  | lwz	r11,12(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) | 
|  | FIX_SRR1(r10,r12) | 
|  | 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 SHOW_SYSCALLS | 
|  | bl	do_show_syscall | 
|  | #endif /* SHOW_SYSCALLS */ | 
|  | #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 */ | 
|  | rlwinm	r10,r1,0,0,(31-THREAD_SHIFT)	/* current_thread_info() */ | 
|  | lwz	r11,TI_FLAGS(r10) | 
|  | andi.	r11,r11,_TIF_SYSCALL_T_OR_A | 
|  | 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 | 
|  | PPC440EP_ERR42 | 
|  | blrl			/* Call handler */ | 
|  | .globl	ret_from_syscall | 
|  | ret_from_syscall: | 
|  | #ifdef SHOW_SYSCALLS | 
|  | bl	do_show_syscall_exit | 
|  | #endif | 
|  | mr	r6,r3 | 
|  | rlwinm	r12,r1,0,0,(31-THREAD_SHIFT)	/* current_thread_info() */ | 
|  | /* 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,-_LAST_ERRNO | 
|  | andi.	r0,r9,(_TIF_SYSCALL_T_OR_A|_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 */ | 
|  | lwz	r4,_LINK(r1) | 
|  | lwz	r5,_CCR(r1) | 
|  | mtlr	r4 | 
|  | mtcr	r5 | 
|  | lwz	r7,_NIP(r1) | 
|  | FIX_SRR1(r8, r0) | 
|  | lwz	r2,GPR2(r1) | 
|  | lwz	r1,GPR1(r1) | 
|  | 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 | 
|  |  | 
|  | /* 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) | 
|  | 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_T_OR_A|_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 | 
|  |  | 
|  | #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 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 | 
|  | 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 | 
|  | 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) | 
|  | CLR_TOP32(r0) | 
|  | 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 | 
|  | 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 | 
|  |  | 
|  | #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 */ | 
|  | rlwinm	r9,r1,0,0,(31-THREAD_SHIFT) | 
|  | 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_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,(31-THREAD_SHIFT) | 
|  | 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 */ | 
|  | #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 | 
|  | rlwinm	r9,r1,0,0,(31-THREAD_SHIFT) | 
|  | 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 | 
|  | #else | 
|  | resume_kernel: | 
|  | #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 | 
|  |  | 
|  | /* | 
|  | * 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) | 
|  | 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. | 
|  | * | 
|  | */ | 
|  | #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) | 
|  | rlwinm	r10,r1,0,0,(31-THREAD_SHIFT) | 
|  | 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 | 
|  | rlwinm	r9,r1,0,0,(31-THREAD_SHIFT) | 
|  | 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 */ | 
|  | rlwinm	r9,r1,0,0,(31-THREAD_SHIFT) | 
|  | 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 */ | 
|  | FIX_SRR1(r9,r0) | 
|  | 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 */ | 
|  |  | 
|  | #ifdef CONFIG_FUNCTION_TRACER | 
|  | #ifdef CONFIG_DYNAMIC_FTRACE | 
|  | _GLOBAL(mcount) | 
|  | _GLOBAL(_mcount) | 
|  | /* | 
|  | * It is required that _mcount on PPC32 must preserve the | 
|  | * link register. But we have r0 to play with. We use r0 | 
|  | * to push the return address back to the caller of mcount | 
|  | * into the ctr register, restore the link register and | 
|  | * then jump back using the ctr register. | 
|  | */ | 
|  | mflr	r0 | 
|  | mtctr	r0 | 
|  | lwz	r0, 4(r1) | 
|  | mtlr	r0 | 
|  | bctr | 
|  |  | 
|  | _GLOBAL(ftrace_caller) | 
|  | MCOUNT_SAVE_FRAME | 
|  | /* r3 ends up with link register */ | 
|  | subi	r3, r3, MCOUNT_INSN_SIZE | 
|  | .globl ftrace_call | 
|  | ftrace_call: | 
|  | bl	ftrace_stub | 
|  | nop | 
|  | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | 
|  | .globl ftrace_graph_call | 
|  | ftrace_graph_call: | 
|  | b	ftrace_graph_stub | 
|  | _GLOBAL(ftrace_graph_stub) | 
|  | #endif | 
|  | MCOUNT_RESTORE_FRAME | 
|  | /* old link register ends up in ctr reg */ | 
|  | bctr | 
|  | #else | 
|  | _GLOBAL(mcount) | 
|  | _GLOBAL(_mcount) | 
|  |  | 
|  | MCOUNT_SAVE_FRAME | 
|  |  | 
|  | subi	r3, r3, MCOUNT_INSN_SIZE | 
|  | LOAD_REG_ADDR(r5, ftrace_trace_function) | 
|  | lwz	r5,0(r5) | 
|  |  | 
|  | mtctr	r5 | 
|  | bctrl | 
|  | nop | 
|  |  | 
|  | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | 
|  | b	ftrace_graph_caller | 
|  | #endif | 
|  | MCOUNT_RESTORE_FRAME | 
|  | bctr | 
|  | #endif | 
|  |  | 
|  | _GLOBAL(ftrace_stub) | 
|  | blr | 
|  |  | 
|  | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | 
|  | _GLOBAL(ftrace_graph_caller) | 
|  | /* load r4 with local address */ | 
|  | lwz	r4, 44(r1) | 
|  | subi	r4, r4, MCOUNT_INSN_SIZE | 
|  |  | 
|  | /* get the parent address */ | 
|  | addi	r3, r1, 52 | 
|  |  | 
|  | bl	prepare_ftrace_return | 
|  | nop | 
|  |  | 
|  | MCOUNT_RESTORE_FRAME | 
|  | /* old link register ends up in ctr reg */ | 
|  | bctr | 
|  |  | 
|  | _GLOBAL(return_to_handler) | 
|  | /* need to save return values */ | 
|  | stwu	r1, -32(r1) | 
|  | stw	r3, 20(r1) | 
|  | stw	r4, 16(r1) | 
|  | stw	r31, 12(r1) | 
|  | mr	r31, r1 | 
|  |  | 
|  | bl	ftrace_return_to_handler | 
|  | nop | 
|  |  | 
|  | /* return value has real return address */ | 
|  | mtlr	r3 | 
|  |  | 
|  | lwz	r3, 20(r1) | 
|  | lwz	r4, 16(r1) | 
|  | lwz	r31,12(r1) | 
|  | lwz	r1, 0(r1) | 
|  |  | 
|  | /* Jump back to real return address */ | 
|  | blr | 
|  | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ | 
|  |  | 
|  | #endif /* CONFIG_MCOUNT */ |