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linux-2.4.29操作系统的源码

	mfspr	13,SPRG3		/* Get paca address */
	lhz	r24,PACAPACAINDEX(r13)	/* Get processor # */
	cmpi	0,r24,0			/* Are we processor 0? */
	beq	.__start_initialization_iSeries	/* Start up the first processor */
	mfspr	r4,CTRLF
	li	r5,RUNLATCH		/* Turn off the run light */
	andc	r4,r4,r5
	mtspr	CTRLT,r4

1:
	HMT_LOW
#ifdef CONFIG_SMP
	lbz	r23,PACAPROCSTART(r13)	/* Test if this processor
					 * should start */
	sync
	LOADADDR(r3,current_set)
	sldi	r28,r24,4		/* get current_set[cpu#] */
	ldx	r3,r3,r28
	addi	r1,r3,TASK_UNION_SIZE
	subi	r1,r1,STACK_FRAME_OVERHEAD

	cmpi	0,r23,0
	beq	iseries_secondary_smp_loop	/* Loop until told to go */
#ifdef SECONDARY_PROCESSORS
	bne	.__secondary_start		/* Loop until told to go */
#endif
iseries_secondary_smp_loop:
	/* Let the Hypervisor know we are alive */
	/* 8002 is a call to HvCallCfg::getLps, a harmless Hypervisor function */
	lis	r3,0x8002
	rldicr	r3,r3,32,15		/* r0 = (r3 << 32) & 0xffff000000000000 */
#else /* CONFIG_SMP */
	/* Yield the processor.  This is required for non-SMP kernels
	   which are running on multi-threaded machines. */
	lis	r3,0x8000
	rldicr	r3,r3,32,15		/* r3 = (r3 << 32) & 0xffff000000000000 */
	addi	r3,r3,18		/* r3 = 0x8000000000000012 which is "yield" */
	li	r4,0			/* "yield timed" */
	li	r5,-1			/* "yield forever" */
#endif /* CONFIG_SMP */
	li	r0,-1			/* r0=-1 indicates a Hypervisor call */
	sc				/* Invoke the hypervisor via a system call */
	mfspr	r13,SPRG3		/* Put r13 back - why???? */
	b	1b			/* If SMP not configured, secondaries
					 * loop forever */

	.globl HardwareInterrupt_Iseries_masked
HardwareInterrupt_Iseries_masked:
	b	maskable_exception_exit

	.globl PerformanceMonitor_Iseries_masked
PerformanceMonitor_Iseries_masked:
	li	r22,1
	stb	r22,PACALPPACA+LPPACAPDCINT(r20)
	b	maskable_exception_exit

	.globl Decrementer_Iseries_masked
Decrementer_Iseries_masked:
	li	r22,1
	stb	r22,PACALPPACA+LPPACADECRINT(r20)
	lwz	r22,PACADEFAULTDECR(r20)
	mtspr	DEC,r22
maskable_exception_exit:
	mtcrf	0xff,r23		/* Restore regs and free exception frame */
	ld	r22,EX_SRR0(r21)
	ld	r23,EX_SRR1(r21)
	mtspr	SRR0,r22
	mtspr	SRR1,r23
	ld	r22,EX_R22(r21)
	ld	r23,EX_R23(r21)
	mfspr	r21,SPRG1
	mfspr	r20,SPRG2
	rfid

/*
 * Data area reserved for FWNMI option.
 */
        .= 0x7000
	.globl fwnmi_data_area
fwnmi_data_area:

/*
 * Vectors for the FWNMI option.  Share common code.
 */
	. = 0x8000
	.globl SystemReset_FWNMI
SystemReset_FWNMI:
	EXCEPTION_PROLOG_PSERIES(0x100, SystemReset_common)
	.globl MachineCheck_FWNMI
MachineCheck_FWNMI:
	EXCEPTION_PROLOG_PSERIES(0x200, MachineCheck_common)

	/*
	 * Space for the initial segment table
	 * For LPAR, the hypervisor must fill in at least one entry
	 * before we get control (with relocate on)
	 */
	. = STAB0_PHYS_ADDR
	.globl __start_stab
__start_stab:

	. = (STAB0_PHYS_ADDR + PAGE_SIZE)
	.globl __end_stab
__end_stab:


/*** Common interrupt handlers ***/

	STD_EXCEPTION_COMMON( 0x100, SystemReset, .SystemResetException )
	STD_EXCEPTION_COMMON( 0x200, MachineCheck, .MachineCheckException )
	STD_EXCEPTION_COMMON( 0x900, Decrementer, .timer_interrupt )
	STD_EXCEPTION_COMMON( 0xa00, Trap_0a, .UnknownException )
	STD_EXCEPTION_COMMON( 0xb00, Trap_0b, .UnknownException )
	STD_EXCEPTION_COMMON( 0xd00, SingleStep, .SingleStepException )
	STD_EXCEPTION_COMMON( 0xe00, Trap_0e, .UnknownException )

	.globl AltiVecUnavailable_common
AltiVecUnavailable_common:
	EXCEPTION_PROLOG_COMMON
#ifdef CONFIG_ALTIVEC
	bne	.load_up_altivec	/* if from user, just load it up */
#endif
	addi	r3,r1,STACK_FRAME_OVERHEAD
	DO_COPY_EE()
	li	r6,0xf20
	bl      .save_remaining_regs
#ifndef CONFIG_ALTIVEC
	beq    1f
	bl     .IllegalAltiVecInstruction
	b      .ret_from_except
1:
#endif
	bl      .KernelAltiVecUnavailableException
	BUG_OPCODE

	.global AltiVecAssist_common
AltiVecAssist_common:
	EXCEPTION_PROLOG_COMMON
	addi	r3,r1,STACK_FRAME_OVERHEAD
	DO_COPY_EE()
	li	r6,0x1700
	bl	.save_remaining_regs
	bl	.AltiVecAssistException
	b	.ret_from_except

	.global ThermalInterrupt_common
ThermalInterrupt_common:
	EXCEPTION_PROLOG_COMMON
	addi	r3,r1,STACK_FRAME_OVERHEAD
	DO_COPY_EE()
	li	r6,0x1800
	bl      .save_remaining_regs
	bl	.ThermalInterrupt
	BUG_OPCODE


	STD_EXCEPTION_COMMON(0x1300, InstructionBreakpoint, .InstructionBreakpointException )

/*
 * Return from an exception which is handled without calling
 * save_remaining_regs.  The caller is assumed to have done
 * EXCEPTION_PROLOG_COMMON.
 */
fast_exception_return:
	ld      r3,_CCR(r1)
	ld      r4,_LINK(r1)
	ld      r5,_CTR(r1)
	ld      r6,_XER(r1)
	mtcr    r3
	mtlr    r4
	mtctr   r5
	mtspr   XER,r6
	REST_GPR(0, r1)
	REST_8GPRS(2, r1)
	REST_4GPRS(10, r1)

	mfmsr	r20
	li	r21, MSR_RI
	andc	r20,r20,r21
	mtmsrd	r20,1

	mtspr   SRR1,r23
	mtspr   SRR0,r22
	REST_4GPRS(20, r1)
	ld      r1,GPR1(r1)
	rfid

/*
 * Here r20 points to the PACA, r21 to the exception frame,
 * r23 contains the saved CR.
 * r20 - r23, SRR0 and SRR1 are saved in the exception frame.
 */
	.globl DataAccess_common
DataAccess_common:
	mfspr   r22,DSISR
	andis.  r22,r22,0x0020
	beq	1f
	mfspr   r22,DAR			/* if it's a segment table miss, */
	srdi    r22,r22,60		/* check if it is in kernel region */
	cmpi    0,r22,0xc		/* and call do_stab_bolted if so */
	beq     .do_stab_bolted
	cmpi    0,r22,0xb
	beq     .do_stab_bolted

1:
	EXCEPTION_PROLOG_COMMON
	ld      r3,_DSISR(r1)
	andis.	r0,r3,0xa450		/* weird error? */
	bne	1f			/* if not, try to put a PTE */
	andis.	r0,r3,0x0020		/* Is it a page table fault? */
	rlwinm	r4,r3,32-23,29,29	/* DSISR_STORE -> _PAGE_RW */
	ld      r3,_DAR(r1)             /* into the hash table */

	beq	2f			/* If so handle it */
	li	r4,0x300                /* Trap number */
	bl	.do_stab_SI
	b	1f

2:	li	r5,0x300
	bl	.do_hash_page_DSI 	/* Try to handle as hpte fault */
1:
	ld      r4,_DAR(r1)
	ld      r5,_DSISR(r1)
	addi	r3,r1,STACK_FRAME_OVERHEAD
	DO_COPY_EE()
	li	r6,0x300
	bl      .save_remaining_regs
	bl      .do_page_fault
	b       .ret_from_except

	.globl DataAccessSLB_common
DataAccessSLB_common:
	mfspr   r22,DAR
	srdi    r22,r22,60
	cmpi    0,r22,0xc
	beq     .do_slb_bolted
	cmpi    0,r22,0xb
	beq     .do_slb_bolted

	EXCEPTION_PROLOG_COMMON
	ld      r3,_DAR(r1)
	li      r4,0x380                /* Exception vector  */
	bl	.ste_allocate
	or.	r3,r3,r3		/* Check return code */
	beq     fast_exception_return   /* Return if we succeeded */
	addi	r3,r1,STACK_FRAME_OVERHEAD
	DO_COPY_EE()
	li	r6,0x380
	li	r5,0
	bl      .save_remaining_regs
	bl      .do_page_fault
	b       .ret_from_except

	.globl InstructionAccess_common
InstructionAccess_common:
	EXCEPTION_PROLOG_COMMON

	andis.	r0,r23,0x0020		/* no ste found? */
	beq	2f
	mr	r3,r22			/* SRR0 at interrupt */
	li	r4,0x400		/* Trap number       */
	bl	.do_stab_SI
	b	1f

2:	andis.	r0,r23,0x4000		/* no pte found? */
	beq	1f			/* if so, try to put a PTE */
	mr	r3,r22			/* into the hash table */
	bl	.do_hash_page_ISI	/* Try to handle as hpte fault */
1:
	mr	r4,r22
	rlwinm	r5,r23,0,4,4		/* We only care about PR in error_code */
	addi	r3,r1,STACK_FRAME_OVERHEAD
	DO_COPY_EE()
	li	r6,0x400
	bl      .save_remaining_regs
	bl      .do_page_fault
	b       .ret_from_except

	.globl InstructionAccessSLB_common
InstructionAccessSLB_common:
	EXCEPTION_PROLOG_COMMON
	mr      r3,r22                  /* SRR0 = NIA        */
	li	r4,0x480                /* Exception vector  */
	bl	.ste_allocate
	or.	r3,r3,r3		/* Check return code */
	beq     fast_exception_return   /* Return if we succeeded */

	addi	r3,r1,STACK_FRAME_OVERHEAD
	DO_COPY_EE()
	li	r6,0x480
	li	r5,0
	bl      .save_remaining_regs
	bl      .do_page_fault
	b       .ret_from_except

	.globl HardwareInterrupt_common
HardwareInterrupt_common:
	EXCEPTION_PROLOG_COMMON
HardwareInterrupt_entry:
	addi	r3,r1,STACK_FRAME_OVERHEAD
	li	r20,0
	li	r6,0x500
	bl      .save_remaining_regs
	/* Determine if need to run do_irq on a hardware interrupt stack  */
	/*   The first invocation of do_irq will occur on the kernel      */
	/*   stack in the current stack                                   */
	/*   All other invocations of do_irq will run on the hardware     */
	/*   interrupt stack associated with the PACA of the current      */
	/*   processor.                                                   */
	/*                                                                */
	/*  The call to do_irq will preserve the value of r14 - r31       */
	/*                                                                */
	mfspr	r20,SPRG3 		    /* get paca                   */
	lbz     r21,PACAHRDWINTCOUNT(r20)    /* get hardware interrupt cnt */
	cmpi    0,r21,0                     /*                            */
	addi    r21,r21,1                   /* incr hardware interrupt cnt*/
	stb     r21,PACAHRDWINTCOUNT(r20)   /*                            */
	bne     2f                          /*                            */

	mr      r14,r1                      /* preserve current r1        */
	ld      r1,PACAHRDWINTSTACK(r20)    /*                            */
	std     r14,0(r1)                   /* set the back chain         */
	bl      .do_IRQ
	lbz     r22,PACAHRDWINTCOUNT(r20)   /* get hardware interrupt cnt */
	cmp     0,r22,r21                   /* debug test                 */
	bne     3f
	subi    r21,r21,1
	stb     r21,PACAHRDWINTCOUNT(r20)   /*                            */
	mr      r1,r14                      /*                            */
	b       .ret_from_except

2:
	bl      .do_IRQ

	lbz     r22,PACAHRDWINTCOUNT(r20)   /* get hardware interrupt cnt */
	cmp     0,r22,r21                   /* debug test                 */
	bne     3f                          /*                            */
	subi    r21,r21,1                   /* decr hardware interrupt cnt*/
	stb     r21,PACAHRDWINTCOUNT(r20)   /*                            */

	b       .ret_from_except

3:
	/* error - counts out of sync                                      */
#ifdef CONFIG_XMON
	bl	.xmon
#endif
#ifdef CONFIG_KDB
        /*          kdb(KDB_REASON_FAULT,regs->trap,regs); */
	li      r3,1
	li 	r4,0x200
	li      r5,0
	bl	.kdb
#endif
4:	b	4b


	.globl Alignment_common
Alignment_common:
	EXCEPTION_PROLOG_COMMON
	addi	r3,r1,STACK_FRAME_OVERHEAD
	DO_COPY_EE()
	li	r6,0x600
	bl      .save_remaining_regs
	bl      .AlignmentException
	b       .ret_from_except

	.globl ProgramCheck_common
ProgramCheck_common:
	EXCEPTION_PROLOG_COMMON
	addi	r3,r1,STACK_FRAME_OVERHEAD
	DO_COPY_EE()
	li	r6,0x700
	bl      .save_remaining_regs
	bl      .ProgramCheckException
	b       .ret_from_except

	.globl FPUnavailable_common
FPUnavailable_common:
	EXCEPTION_PROLOG_COMMON
	bne	.load_up_fpu		/* if from user, just load it up */
	addi	r3,r1,STACK_FRAME_OVERHEAD
	DO_COPY_EE()
	li	r6,0x800
	bl      .save_remaining_regs
	bl      .KernelFPUnavailableException
	BUG_OPCODE

	.globl SystemCall_common
SystemCall_common:
	EXCEPTION_PROLOG_COMMON
#ifdef CONFIG_PPC_ISERIES
	cmpi	0,r0,0x5555		/* Special syscall to handle pending */
	bne+	1f			/* interrupts */
	andi.	r6,r23,MSR_PR		/* Only allowed from kernel */
	beq+	HardwareInterrupt_entry
1:
#endif
	std	r3,ORIG_GPR3(r1)
	DO_COPY_EE()
	li	r6,0xC00
	bl      .save_remaining_regs
	bl      .DoSyscall
	b       .ret_from_except

	.globl PerformanceMonitor_common
PerformanceMonitor_common:	
	EXCEPTION_PROLOG_COMMON
	bl	.PerformanceMonitorException
	b	fast_exception_return
	
_GLOBAL(PerformanceMonitorException)
	sync
	mfspr	r7,SPRG3
	lbz	r8,PACAPROFMODE(r7)
	cmpi	0,r8,PMC_STATE_PROFILE_KERN
	beq 	5f
	cmpi	0,r8,PMC_STATE_TRACE_KERN
	beq 	6f
	cmpi	0,r8,PMC_STATE_TRACE_USER
	beq 	9f
	cmpi	0,r8,PMC_STATE_TIMESLICE
	beq 	10f
	blr

	/* PMC Profile Kernel */
5:	mfspr   r9,SIAR	
	srdi    r8,r9,60
	cmpi    0,r8,0xc
	beq     3f
	li	r9,0xc
	sldi	r9,r9,60
3:      ld	r8,PACAPROFSTEXT(r7)	/* _stext */
	subf	r9,r8,r9		/* offset into kernel */
	lwz	r8,PACAPROFSHIFT(r7)
	srd	r9,r9,r8
	lwz	r8,PACAPROFLEN(r7)	/* length of profile table (-1) */
	srdi	r8,r8,2
	cmpd	r9,r8		/* off end? */
	ble	1f
	mr	r9,r8			/* force into last entry */
	srdi	r9,r9,2
1:	sldi	r9,r9,2		/* convert to offset into buffer */
	ld	r8,PACAPROFBUFFER(r7)	/* profile buffer */
	add	r8,r8,r9
2:	lwarx	r9,0,r8		/* atomically increment */
	addi	r9,r9,1
	stwcx.	r9,0,r8
	bne-	2b
	addi	r10,r7,PACAPMC1
	addi	r7,r7,PACAPMCC1
	b	7f

	/* PMC Trace Kernel */
6:	LOADADDR(r11, perfmon_base)
  	addi	r8,r11,32
	ld	r12,24(r11)
	subi	r12,r12,1
8:	ldarx	r10,0,r8
	addi	r9,r10,16
	and	r9,r9,r12
	stdcx.	r9,0,r8
	bne-	8b
	ld	r9,16(r11)	/* profile buffer */