| /* | 
 |  *  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> | 
 |  | 
 | #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_SPRG3 | 
 | 	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_SPRG3 | 
 | 	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_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 | 
 | 	   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 */ | 
 | 	mtspr	SPRN_SRR0,r11 | 
 | 	mtspr	SPRN_SRR1,r10 | 
 | 	mtlr	r9 | 
 | 	SYNC | 
 | 	RFI				/* jump to handler, enable MMU */ | 
 |  | 
 | #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 */ | 
 | 	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 */ | 
 | 	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: | 
 | #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 | 
 | 	lis	r4,icache_44x_need_flush@ha | 
 | 	lwz	r5,icache_44x_need_flush@l(r4) | 
 | 	cmplwi	cr0,r5,0 | 
 | 	bne-	2f | 
 | 1: | 
 | #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) | 
 | 	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 | 
 | #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 */ | 
 | 	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_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 | 
 | 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. */ | 
 | 	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 */ | 
 | 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 | 
 | #else | 
 | resume_kernel: | 
 | #endif /* CONFIG_PREEMPT */ | 
 |  | 
 | 	/* interrupts are hard-disabled at this point */ | 
 | restore: | 
 | #ifdef CONFIG_44x | 
 | 	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	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)) | 
 | 	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. | 
 |  * | 
 |  */ | 
 | #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_SPRG3 | 
 | 	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_SPRG3 | 
 | 	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_SPRG3 | 
 | 	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_SPRG3 | 
 | 	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 */ | 
 | 	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,(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_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 | 
 |  | 
 | 	.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_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_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 */ |