head.s

linux-2.4.29操作系统的源码

 *   1. Processor number
 *   2. Segment table pointer (virtual address)
 * On entry the following are set:
 *   r1    = stack pointer.  vaddr for iSeries, raddr (temp stack) for pSeries
 *   r24   = cpu# (in Linux terms)
 *   r13   = paca virtual address
 *   SPRG3 = paca virtual address
 */
_GLOBAL(__secondary_start)

	HMT_MEDIUM			/* Set thread priority to MEDIUM */

	/* set up the TOC (virtual address) */
	LOADADDR(r2,__toc_start)
	addi    r2,r2,0x4000
	addi    r2,r2,0x4000

	std	r2,PACATOC(r13)
	li	r6,0
	std	r6,PACAKSAVE(r13)
	stb	r6,PACAPROCENABLED(r13)

#ifndef CONFIG_PPC_ISERIES
	/* Initialize the page table pointer register. */
	LOADADDR(r6,_SDR1)
	ld	r6,0(r6)		/* get the value of _SDR1 */
	mtspr	SDR1,r6			/* set the htab location  */
#endif
	/* Initialize the first segment table (or SLB) entry                */
	ld	r3,PACASTABVIRT(r13)    /* get addr of segment table        */
	bl	.stab_initialize

	/* Initialize the kernel stack.  Just a repeat for iSeries.         */
	LOADADDR(r3,current_set)
	sldi	r28,r24,4		/* get current_set[cpu#] */
	ldx	r28,r3,r28
	std	r28,PACACURRENT(r13)
	addi	r1,r28,TASK_UNION_SIZE
	subi	r1,r1,STACK_FRAME_OVERHEAD

	ld	r3,PACASTABREAL(r13)    /* get raddr of segment table       */
	ori	r4,r3,1			/* turn on valid bit                */

#ifdef CONFIG_PPC_ISERIES
	li	r0,-1			/* hypervisor call */
	li	r3,1
	sldi	r3,r3,63		/* 0x8000000000000000 */
	ori	r3,r3,4			/* 0x8000000000000004 */
	sc				/* HvCall_setASR */
#else
	/* set the ASR */
	li	r3,0x5000	/* r3 = ptr to systemcfg  */
	lwz   	r3,PLATFORM(r3) /* r3 = platform flags */
	cmpldi 	r3,PLATFORM_PSERIES_LPAR
	bne   	98f
	mfspr	r3,PVR
	srwi	r3,r3,16
	cmpwi	r3,0x37         /* SStar  */
	beq	97f
	cmpwi	r3,0x36         /* IStar  */
	beq	97f
	cmpwi	r3,0x34         /* Pulsar */
	bne	98f
97:	li	r3,H_SET_ASR    /* hcall = H_SET_ASR */
	HSC     		/* Invoking hcall */
	b	99f
98:                             /* !(rpa hypervisor) || !(sstar) */
	mtasr	r4	        /* set the stab location         */
99:
#endif
	li	r7,0
	mtlr	r7

	/* enable MMU and jump to start_secondary */
	LOADADDR(r3,.start_secondary_prolog)
	SET_REG_TO_CONST(r4, MSR_KERNEL)
#ifdef DO_SOFT_DISABLE
	ori	r4,r4,MSR_EE
#endif
	mtspr	SRR0,r3
	mtspr	SRR1,r4
	rfid

/* 
 * Running with relocation on at this point.  All we want to do is
 * zero the stack back-chain pointer before going into C code.
 */
_GLOBAL(start_secondary_prolog)
	li	r3,0
	std	r3,0(r1)                /* Zero the stack frame pointer     */
	bl	.start_secondary
#endif /* CONFIG_SMP */

/*
 * This subroutine clobbers r11, r12 and the LR
 */
_GLOBAL(enable_64b_mode)
	mfmsr   r11                      /* grab the current MSR */
	li      r12,1
	rldicr  r12,r12,MSR_SF_LG,(63-MSR_SF_LG)
	or      r11,r11,r12
	li      r12,1
	rldicr  r12,r12,MSR_ISF_LG,(63-MSR_ISF_LG)
	or      r11,r11,r12
	mtmsrd  r11
	isync
	blr

/*
 * This subroutine clobbers r11, r12 and the LR
 */
_GLOBAL(enable_32b_mode)
	mfmsr   r11                      /* grab the current MSR */
	li      r12,1
	rldicr  r12,r12,MSR_SF_LG,(63-MSR_SF_LG)
	andc	r11,r11,r12
	li      r12,1
	rldicr  r12,r12,MSR_ISF_LG,(63-MSR_ISF_LG)
	andc	r11,r11,r12
	mtmsrd  r11
	isync
	blr

/*
 * This is where the main kernel code starts.
 */
_STATIC(start_here_pSeries)
	/* get a new offset, now that the kernel has moved. */
	bl	.reloc_offset
	mr	r26,r3

	mfmsr	r6
	ori	r6,r6,MSR_RI
	mtmsrd	r6			/* RI on */

	/* setup the systemcfg pointer which is needed by *tab_initialize  */
	LOADADDR(r6,systemcfg)
	sub	r6,r6,r26                /* addr of the variable systemcfg */
	li	r27,0x5000
	std	r27,0(r6)	 	 /* set the value of systemcfg     */

	/* setup the naca pointer which is needed by *tab_initialize       */
	LOADADDR(r6,naca)
	sub	r6,r6,r26                /* addr of the variable naca      */
	li	r27,0x4000
	std	r27,0(r6)	 	 /* set the value of naca          */

#ifdef CONFIG_HMT
	/* Start up the second thread on cpu 0 */
	mfspr	r3,PVR
	srwi	r3,r3,16
	cmpwi	r3,0x34                 /* Pulsar  */
	beq	90f
	cmpwi	r3,0x36                 /* Icestar */
	beq	90f
	cmpwi	r3,0x37                 /* SStar   */
	beq	90f
	b	91f                     /* HMT not supported */
90:	li      r3,0
	bl	.hmt_start_secondary
91:
#endif

#ifdef CONFIG_SMP
	/* All secondary cpus are now spinning on a common
	 * spinloop, release them all now so they can start
	 * to spin on their individual paca spinloops.
	 * For non SMP kernels, the secondary cpus never
	 * get out of the common spinloop.
	 */
	li	r3,1
	LOADADDR(r5,__secondary_hold_spinloop)
	tophys(r4,r5)
	std     r3,0(r4)
#endif

	/* The following gets the stack and TOC set up with the regs */
	/* pointing to the real addr of the kernel stack.  This is   */
	/* all done to support the C function call below which sets  */
	/* up the htab.  This is done because we have relocated the  */
	/* kernel but are still running in real mode. */

	/* real ptr to current */
	LOADADDR(r3,init_task_union)
	sub	r3,r3,r26

	/* set up a stack pointer (physical address) */
	addi	r1,r3,TASK_UNION_SIZE
	li	r0,0
	stdu	r0,-STACK_FRAME_OVERHEAD(r1)

	LOADADDR(r3,cpu_specs)
	sub	r3,r3,r26
	LOADADDR(r4,cur_cpu_spec)
	sub	r4,r4,r26
	mr	r5,r26
	bl	.identify_cpu

	/* set up the TOC (physical address) */
	LOADADDR(r2,__toc_start)
	addi    r2,r2,0x4000
	addi    r2,r2,0x4000
	sub	r2,r2,r26

	/* Get the pointer to the segment table which is used by           */
	/* stab_initialize                                                 */
	li	r27,0x4000
	ld	r6,PACA(r27)            /* Get the base paca pointer       */
	sub	r13,r6,r26		/* convert to physical addr         */
	mtspr	SPRG3,r13		/* PPPBBB: Temp... -Peter */
	ld	r3,PACASTABREAL(r13)
	ori	r4,r3,1			/* turn on valid bit                */

	/* set the ASR */
	li	r3,0x5000	/* r3 = ptr to systemcfg */
	lwz   	r3,PLATFORM(r3) /* r3 = platform flags */
	cmpldi 	r3,PLATFORM_PSERIES_LPAR
	bne   	98f
	mfspr	r3,PVR
	srwi	r3,r3,16
	cmpwi	r3,0x37         /* SStar */
	beq	97f
	cmpwi	r3,0x36         /* IStar  */
	beq	97f
	cmpwi	r3,0x34         /* Pulsar */
	bne	98f
97:	li	r3,H_SET_ASR    /* hcall = H_SET_ASR */
	HSC     	        /* Invoking hcall */
	b     	99f
98:                 /* This is not a hypervisor machine */
	mtasr	r4			/* set the stab location            */
99:
	mfspr	r6,SPRG3
	ld	r3,PACASTABREAL(r6)     /* restore r3 for stab_initialize */

	/* Initialize an initial memory mapping and turn on relocation.   */
	bl	.stab_initialize
	bl	.htab_initialize

	li	r3,0x5000	/* r3 = ptr to systemcfg */
	lwz	r3,PLATFORM(r3) /* r3 = platform flags */
	cmpldi r3,PLATFORM_PSERIES
	bne    98f
	LOADADDR(r6,_SDR1)		/* Only if NOT LPAR */
	sub	r6,r6,r26
	ld	r6,0(r6)		/* get the value of _SDR1 */
	mtspr	SDR1,r6			/* set the htab location  */
98: 
	LOADADDR(r3,.start_here_common)
	SET_REG_TO_CONST(r4, MSR_KERNEL)
	mtspr	SRR0,r3
	mtspr	SRR1,r4
	rfid

	/* This is where all platforms converge execution */
_STATIC(start_here_common)
	/* relocation is on at this point */

	/* Clear out the BSS */
	LOADADDR(r11,_end)

	LOADADDR(r8,__bss_start)

	sub	r11,r11,r8        /* bss size                        */
	addi	r11,r11,7         /* round up to an even double word */
	rldicl. r11,r11,61,3      /* shift right by 3                */
	beq	4f
	addi	r8,r8,-8
	li	r0,0
	mtctr	r11		  /* zero this many doublewords      */
3:	stdu	r0,8(r8)
	bdnz	3b
4:

	/* The following code sets up the SP and TOC now that we are */
	/* running with translation enabled. */

	/* ptr to current */
	LOADADDR(r3,init_task_union)

	/* set up the stack */
	addi	r1,r3,TASK_UNION_SIZE
	li	r0,0
	stdu	r0,-STACK_FRAME_OVERHEAD(r1)

	/* set up the TOC */
	LOADADDR(r2,__toc_start)
	addi    r2,r2,0x4000
	addi    r2,r2,0x4000

	li	r3,0
	bl	.do_cpu_ftr_fixups

	/* setup the systemcfg pointer                                       */
	LOADADDR(r9,systemcfg)
	SET_REG_TO_CONST(r8, KERNELBASE+0x5000)
	std	r8,0(r9)

	/* setup the naca pointer                                         */
	LOADADDR(r9,naca)
	SET_REG_TO_CONST(r8, KERNELBASE+0x4000)
	std	r8,0(r9)		/* set the value of the naca ptr  */

	LOADADDR(r4,naca)               /* Get naca ptr address           */
	ld	r4,0(r4)                /* Get the location of the naca   */
	ld	r13,PACA(r4)            /* Get the base paca pointer      */
	mtspr	SPRG3,r13

	/* ptr to current */
	LOADADDR(r4,init_task_union)
	std	r4,PACACURRENT(r13)

	std	r2,PACATOC(r13)
	li	r5,0
	std	r0,PACAKSAVE(r13)

	/* ptr to hardware interrupt stack for processor 0                */
	LOADADDR(r3, hardware_int_paca0)
	li      r5,0x1000
	sldi    r5,r5,3
	subi    r5,r5,STACK_FRAME_OVERHEAD

	add     r3,r3,r5
	std     r3,PACAHRDWINTSTACK(r13)

	li      r3,0
	stb     r3,PACAHRDWINTCOUNT(r13)

	/* Restore the parms passed in from the bootloader. */
	mr	r3,r31
	mr	r4,r30
	mr	r5,r29
	mr	r6,r28
	mr	r7,r27

	bl	.setup_system

	/* Load up the kernel context */
5:
#ifdef DO_SOFT_DISABLE
	mfspr	r4,SPRG3
	li	r5,0
	stb	r5,PACAPROCENABLED(r4)	/* Soft Disabled */
	mfmsr	r5
	ori	r5,r5,MSR_EE		/* Hard Enabled */
	mtmsrd	r5
#endif

	bl .start_kernel

_GLOBAL(__setup_cpu_power3)
	blr
_GLOBAL(__setup_cpu_power4)
	blr

_GLOBAL(hmt_init)
#ifdef CONFIG_HMT
	LOADADDR(r5, hmt_thread_data)
	mfspr	r7,PVR
	srwi	r7,r7,16
	cmpwi	r7,0x34                 /* Pulsar  */
	beq	90f
	cmpwi	r7,0x36                 /* Icestar */
	beq	91f
	cmpwi	r7,0x37                 /* SStar   */
	beq	91f
	b	101f
90:	mfspr	r6,PIR
	andi.	r6,r6,0x1f
	b	92f
91:	mfspr	r6,PIR
	andi.	r6,r6,0x3ff
92:	sldi	r4,r24,3
	stwx	r6,r5,r4
	bl	.hmt_start_secondary
	b	101f

__hmt_secondary_hold:
	LOADADDR(r5, hmt_thread_data)
	clrldi	r5,r5,4
	li	r7,0
	mfspr	r6,PIR
	mfspr	r8,PVR
	srwi	r8,r8,16
	cmpwi	r8,0x34
	bne	93f
	andi.	r6,r6,0x1f
	b	103f
93:	andi.	r6,r6,0x3f

103:	lwzx	r8,r5,r7
	cmpw	r8,r6
	beq	104f
	addi	r7,r7,8
	b	103b

104:	addi	r7,r7,4
	lwzx	r9,r5,r7
	mr      r24,r9
101:
#endif
	mr      r3,r24
	b       .pseries_secondary_smp_init

#ifdef CONFIG_HMT
_GLOBAL(hmt_start_secondary)
	LOADADDR(r4,__hmt_secondary_hold)
	clrldi	r4,r4,4
	mtspr   NIADORM, r4
	mfspr   r4, MSRDORM
	li      r5, -65
	and     r4, r4, r5
	mtspr   MSRDORM, r4
	lis	r4,0xffef
	ori	r4,r4,0x7403
	mtspr	TSC, r4
	li	r4,0x1f4
	mtspr	TST, r4
	mfspr   r4, HID0
	ori     r4, r4, 0x1
	mtspr   HID0, r4
	mfspr   r4, CTRLF
	oris    r4, r4, 0x40
	mtspr   CTRLT, r4
	blr
#endif

/*
 * We put a few things here that have to be page-aligned.
 * This stuff goes at the beginning of the data segment,
 * which is page-aligned.
 */
	.data
	.align  12
	.globl	sdata
sdata:
	.globl	empty_zero_page
empty_zero_page:
	.space	4096

	.globl	swapper_pg_dir
swapper_pg_dir:
	.space	4096

	.globl	ioremap_dir
ioremap_dir:
	.space	4096

	.globl	bolted_dir
bolted_dir:
	.space	4096

	.globl  hardware_int_paca0
hardware_int_paca0:
	.space	8*4096

/* 1 page segment table per cpu (max 48, cpu0 allocated at STAB0_PHYS_ADDR) */
	.globl	stab_array
stab_array:
        .space	4096 * (48 - 1)