powerpc: Introduce entry_{32,64}.S, misc_{32,64}.S, systbl.S

The system call table has been consolidated into systbl.S.  We have
separate 32-bit and 64-bit versions of entry.S and misc.S since the
code is mostly sufficiently different to be not worth merging.
There are some common bits that will be extracted in future.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 898 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
new file mode 100644
index 0000000..8fe2956
--- /dev/null
+++ b/arch/powerpc/kernel/misc_64.S
@@ -0,0 +1,898 @@
+/*
+ *  arch/powerpc/kernel/misc64.S
+ *
+ * This file contains miscellaneous low-level functions.
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
+ * and Paul Mackerras.
+ * Adapted for iSeries by Mike Corrigan (mikejc@us.ibm.com)
+ * PPC64 updates by Dave Engebretsen (engebret@us.ibm.com) 
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/sys.h>
+#include <asm/unistd.h>
+#include <asm/errno.h>
+#include <asm/processor.h>
+#include <asm/page.h>
+#include <asm/cache.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/cputable.h>
+
+	.text
+
+/*
+ * Returns (address we are running at) - (address we were linked at)
+ * for use before the text and data are mapped to KERNELBASE.
+ */
+
+_GLOBAL(reloc_offset)
+	mflr	r0
+	bl	1f
+1:	mflr	r3
+	LOADADDR(r4,1b)
+	subf	r3,r4,r3
+	mtlr	r0
+	blr
+
+/*
+ * add_reloc_offset(x) returns x + reloc_offset().
+ */
+_GLOBAL(add_reloc_offset)
+	mflr	r0
+	bl	1f
+1:	mflr	r5
+	LOADADDR(r4,1b)
+	subf	r5,r4,r5
+	add	r3,r3,r5
+	mtlr	r0
+	blr
+
+_GLOBAL(get_msr)
+	mfmsr	r3
+	blr
+
+_GLOBAL(get_dar)
+	mfdar	r3
+	blr
+
+_GLOBAL(get_srr0)
+	mfsrr0  r3
+	blr
+
+_GLOBAL(get_srr1)
+	mfsrr1  r3
+	blr
+	
+_GLOBAL(get_sp)
+	mr	r3,r1
+	blr
+
+#ifdef CONFIG_IRQSTACKS
+_GLOBAL(call_do_softirq)
+	mflr	r0
+	std	r0,16(r1)
+	stdu	r1,THREAD_SIZE-112(r3)
+	mr	r1,r3
+	bl	.__do_softirq
+	ld	r1,0(r1)
+	ld	r0,16(r1)
+	mtlr	r0
+	blr
+
+_GLOBAL(call_handle_IRQ_event)
+	mflr	r0
+	std	r0,16(r1)
+	stdu	r1,THREAD_SIZE-112(r6)
+	mr	r1,r6
+	bl	.handle_IRQ_event
+	ld	r1,0(r1)
+	ld	r0,16(r1)
+	mtlr	r0
+	blr
+#endif /* CONFIG_IRQSTACKS */
+
+	/*
+ * To be called by C code which needs to do some operations with MMU
+ * disabled. Note that interrupts have to be disabled by the caller
+ * prior to calling us. The code called _MUST_ be in the RMO of course
+ * and part of the linear mapping as we don't attempt to translate the
+ * stack pointer at all. The function is called with the stack switched
+ * to this CPU emergency stack
+ *
+ * prototype is void *call_with_mmu_off(void *func, void *data);
+ *
+ * the called function is expected to be of the form
+ *
+ * void *called(void *data); 
+ */
+_GLOBAL(call_with_mmu_off)
+	mflr	r0			/* get link, save it on stackframe */
+	std	r0,16(r1)
+	mr	r1,r5			/* save old stack ptr */
+	ld	r1,PACAEMERGSP(r13)	/* get emerg. stack */
+	subi	r1,r1,STACK_FRAME_OVERHEAD
+	std	r0,16(r1)		/* save link on emerg. stack */
+	std	r5,0(r1)		/* save old stack ptr in backchain */
+	ld	r3,0(r3)		/* get to real function ptr (assume same TOC) */
+	bl	2f			/* we need LR to return, continue at label 2 */
+
+	ld	r0,16(r1)		/* we return here from the call, get LR and */
+	ld	r1,0(r1)		/* .. old stack ptr */
+	mtspr	SPRN_SRR0,r0		/* and get back to virtual mode with these */
+	mfmsr	r4
+	ori	r4,r4,MSR_IR|MSR_DR
+	mtspr	SPRN_SRR1,r4
+	rfid
+
+2:	mtspr	SPRN_SRR0,r3		/* coming from above, enter real mode */
+	mr	r3,r4			/* get parameter */
+	mfmsr	r0
+	ori	r0,r0,MSR_IR|MSR_DR
+	xori	r0,r0,MSR_IR|MSR_DR
+	mtspr	SPRN_SRR1,r0
+	rfid
+
+
+	.section	".toc","aw"
+PPC64_CACHES:
+	.tc		ppc64_caches[TC],ppc64_caches
+	.section	".text"
+
+/*
+ * Write any modified data cache blocks out to memory
+ * and invalidate the corresponding instruction cache blocks.
+ *
+ * flush_icache_range(unsigned long start, unsigned long stop)
+ *
+ *   flush all bytes from start through stop-1 inclusive
+ */
+
+_KPROBE(__flush_icache_range)
+
+/*
+ * Flush the data cache to memory 
+ * 
+ * Different systems have different cache line sizes
+ * and in some cases i-cache and d-cache line sizes differ from
+ * each other.
+ */
+ 	ld	r10,PPC64_CACHES@toc(r2)
+	lwz	r7,DCACHEL1LINESIZE(r10)/* Get cache line size */
+	addi	r5,r7,-1
+	andc	r6,r3,r5		/* round low to line bdy */
+	subf	r8,r6,r4		/* compute length */
+	add	r8,r8,r5		/* ensure we get enough */
+	lwz	r9,DCACHEL1LOGLINESIZE(r10)	/* Get log-2 of cache line size */
+	srw.	r8,r8,r9		/* compute line count */
+	beqlr				/* nothing to do? */
+	mtctr	r8
+1:	dcbst	0,r6
+	add	r6,r6,r7
+	bdnz	1b
+	sync
+
+/* Now invalidate the instruction cache */
+	
+	lwz	r7,ICACHEL1LINESIZE(r10)	/* Get Icache line size */
+	addi	r5,r7,-1
+	andc	r6,r3,r5		/* round low to line bdy */
+	subf	r8,r6,r4		/* compute length */
+	add	r8,r8,r5
+	lwz	r9,ICACHEL1LOGLINESIZE(r10)	/* Get log-2 of Icache line size */
+	srw.	r8,r8,r9		/* compute line count */
+	beqlr				/* nothing to do? */
+	mtctr	r8
+2:	icbi	0,r6
+	add	r6,r6,r7
+	bdnz	2b
+	isync
+	blr
+	.previous .text
+/*
+ * Like above, but only do the D-cache.
+ *
+ * flush_dcache_range(unsigned long start, unsigned long stop)
+ *
+ *    flush all bytes from start to stop-1 inclusive
+ */
+_GLOBAL(flush_dcache_range)
+
+/*
+ * Flush the data cache to memory 
+ * 
+ * Different systems have different cache line sizes
+ */
+ 	ld	r10,PPC64_CACHES@toc(r2)
+	lwz	r7,DCACHEL1LINESIZE(r10)	/* Get dcache line size */
+	addi	r5,r7,-1
+	andc	r6,r3,r5		/* round low to line bdy */
+	subf	r8,r6,r4		/* compute length */
+	add	r8,r8,r5		/* ensure we get enough */
+	lwz	r9,DCACHEL1LOGLINESIZE(r10)	/* Get log-2 of dcache line size */
+	srw.	r8,r8,r9		/* compute line count */
+	beqlr				/* nothing to do? */
+	mtctr	r8
+0:	dcbst	0,r6
+	add	r6,r6,r7
+	bdnz	0b
+	sync
+	blr
+
+/*
+ * Like above, but works on non-mapped physical addresses.
+ * Use only for non-LPAR setups ! It also assumes real mode
+ * is cacheable. Used for flushing out the DART before using
+ * it as uncacheable memory 
+ *
+ * flush_dcache_phys_range(unsigned long start, unsigned long stop)
+ *
+ *    flush all bytes from start to stop-1 inclusive
+ */
+_GLOBAL(flush_dcache_phys_range)
+ 	ld	r10,PPC64_CACHES@toc(r2)
+	lwz	r7,DCACHEL1LINESIZE(r10)	/* Get dcache line size */
+	addi	r5,r7,-1
+	andc	r6,r3,r5		/* round low to line bdy */
+	subf	r8,r6,r4		/* compute length */
+	add	r8,r8,r5		/* ensure we get enough */
+	lwz	r9,DCACHEL1LOGLINESIZE(r10)	/* Get log-2 of dcache line size */
+	srw.	r8,r8,r9		/* compute line count */
+	beqlr				/* nothing to do? */
+	mfmsr	r5			/* Disable MMU Data Relocation */
+	ori	r0,r5,MSR_DR
+	xori	r0,r0,MSR_DR
+	sync
+	mtmsr	r0
+	sync
+	isync
+	mtctr	r8
+0:	dcbst	0,r6
+	add	r6,r6,r7
+	bdnz	0b
+	sync
+	isync
+	mtmsr	r5			/* Re-enable MMU Data Relocation */
+	sync
+	isync
+	blr
+
+_GLOBAL(flush_inval_dcache_range)
+ 	ld	r10,PPC64_CACHES@toc(r2)
+	lwz	r7,DCACHEL1LINESIZE(r10)	/* Get dcache line size */
+	addi	r5,r7,-1
+	andc	r6,r3,r5		/* round low to line bdy */
+	subf	r8,r6,r4		/* compute length */
+	add	r8,r8,r5		/* ensure we get enough */
+	lwz	r9,DCACHEL1LOGLINESIZE(r10)/* Get log-2 of dcache line size */
+	srw.	r8,r8,r9		/* compute line count */
+	beqlr				/* nothing to do? */
+	sync
+	isync
+	mtctr	r8
+0:	dcbf	0,r6
+	add	r6,r6,r7
+	bdnz	0b
+	sync
+	isync
+	blr
+
+
+/*
+ * Flush a particular page from the data cache to RAM.
+ * Note: this is necessary because the instruction cache does *not*
+ * snoop from the data cache.
+ *
+ *	void __flush_dcache_icache(void *page)
+ */
+_GLOBAL(__flush_dcache_icache)
+/*
+ * Flush the data cache to memory 
+ * 
+ * Different systems have different cache line sizes
+ */
+
+/* Flush the dcache */
+ 	ld	r7,PPC64_CACHES@toc(r2)
+	clrrdi	r3,r3,PAGE_SHIFT           	    /* Page align */
+	lwz	r4,DCACHEL1LINESPERPAGE(r7)	/* Get # dcache lines per page */
+	lwz	r5,DCACHEL1LINESIZE(r7)		/* Get dcache line size */
+	mr	r6,r3
+	mtctr	r4
+0:	dcbst	0,r6
+	add	r6,r6,r5
+	bdnz	0b
+	sync
+
+/* Now invalidate the icache */	
+
+	lwz	r4,ICACHEL1LINESPERPAGE(r7)	/* Get # icache lines per page */
+	lwz	r5,ICACHEL1LINESIZE(r7)		/* Get icache line size */
+	mtctr	r4
+1:	icbi	0,r3
+	add	r3,r3,r5
+	bdnz	1b
+	isync
+	blr
+	
+/*
+ * I/O string operations
+ *
+ * insb(port, buf, len)
+ * outsb(port, buf, len)
+ * insw(port, buf, len)
+ * outsw(port, buf, len)
+ * insl(port, buf, len)
+ * outsl(port, buf, len)
+ * insw_ns(port, buf, len)
+ * outsw_ns(port, buf, len)
+ * insl_ns(port, buf, len)
+ * outsl_ns(port, buf, len)
+ *
+ * The *_ns versions don't do byte-swapping.
+ */
+_GLOBAL(_insb)
+	cmpwi	0,r5,0
+	mtctr	r5
+	subi	r4,r4,1
+	blelr-
+00:	lbz	r5,0(r3)
+	eieio
+	stbu	r5,1(r4)
+	bdnz	00b
+	twi	0,r5,0
+	isync
+	blr
+
+_GLOBAL(_outsb)
+	cmpwi	0,r5,0
+	mtctr	r5
+	subi	r4,r4,1
+	blelr-
+00:	lbzu	r5,1(r4)
+	stb	r5,0(r3)
+	bdnz	00b
+	sync
+	blr	
+
+_GLOBAL(_insw)
+	cmpwi	0,r5,0
+	mtctr	r5
+	subi	r4,r4,2
+	blelr-
+00:	lhbrx	r5,0,r3
+	eieio
+	sthu	r5,2(r4)
+	bdnz	00b
+	twi	0,r5,0
+	isync
+	blr
+
+_GLOBAL(_outsw)
+	cmpwi	0,r5,0
+	mtctr	r5
+	subi	r4,r4,2
+	blelr-
+00:	lhzu	r5,2(r4)
+	sthbrx	r5,0,r3	
+	bdnz	00b
+	sync
+	blr	
+
+_GLOBAL(_insl)
+	cmpwi	0,r5,0
+	mtctr	r5
+	subi	r4,r4,4
+	blelr-
+00:	lwbrx	r5,0,r3
+	eieio
+	stwu	r5,4(r4)
+	bdnz	00b
+	twi	0,r5,0
+	isync
+	blr
+
+_GLOBAL(_outsl)
+	cmpwi	0,r5,0
+	mtctr	r5
+	subi	r4,r4,4
+	blelr-
+00:	lwzu	r5,4(r4)
+	stwbrx	r5,0,r3
+	bdnz	00b
+	sync
+	blr	
+
+/* _GLOBAL(ide_insw) now in drivers/ide/ide-iops.c */
+_GLOBAL(_insw_ns)
+	cmpwi	0,r5,0
+	mtctr	r5
+	subi	r4,r4,2
+	blelr-
+00:	lhz	r5,0(r3)
+	eieio
+	sthu	r5,2(r4)
+	bdnz	00b
+	twi	0,r5,0
+	isync
+	blr
+
+/* _GLOBAL(ide_outsw) now in drivers/ide/ide-iops.c */
+_GLOBAL(_outsw_ns)
+	cmpwi	0,r5,0
+	mtctr	r5
+	subi	r4,r4,2
+	blelr-
+00:	lhzu	r5,2(r4)
+	sth	r5,0(r3)
+	bdnz	00b
+	sync
+	blr	
+
+_GLOBAL(_insl_ns)
+	cmpwi	0,r5,0
+	mtctr	r5
+	subi	r4,r4,4
+	blelr-
+00:	lwz	r5,0(r3)
+	eieio
+	stwu	r5,4(r4)
+	bdnz	00b
+	twi	0,r5,0
+	isync
+	blr
+
+_GLOBAL(_outsl_ns)
+	cmpwi	0,r5,0
+	mtctr	r5
+	subi	r4,r4,4
+	blelr-
+00:	lwzu	r5,4(r4)
+	stw	r5,0(r3)
+	bdnz	00b
+	sync
+	blr	
+
+
+_GLOBAL(cvt_fd)
+	lfd	0,0(r5)		/* load up fpscr value */
+	mtfsf	0xff,0
+	lfs	0,0(r3)
+	stfd	0,0(r4)
+	mffs	0		/* save new fpscr value */
+	stfd	0,0(r5)
+	blr
+
+_GLOBAL(cvt_df)
+	lfd	0,0(r5)		/* load up fpscr value */
+	mtfsf	0xff,0
+	lfd	0,0(r3)
+	stfs	0,0(r4)
+	mffs	0		/* save new fpscr value */
+	stfd	0,0(r5)
+	blr
+
+/*
+ * identify_cpu and calls setup_cpu
+ * In:	r3 = base of the cpu_specs array
+ *	r4 = address of cur_cpu_spec
+ *	r5 = relocation offset
+ */
+_GLOBAL(identify_cpu)
+	mfpvr	r7
+1:
+	lwz	r8,CPU_SPEC_PVR_MASK(r3)
+	and	r8,r8,r7
+	lwz	r9,CPU_SPEC_PVR_VALUE(r3)
+	cmplw	0,r9,r8
+	beq	1f
+	addi	r3,r3,CPU_SPEC_ENTRY_SIZE
+	b	1b
+1:
+	sub	r0,r3,r5
+	std	r0,0(r4)
+	ld	r4,CPU_SPEC_SETUP(r3)
+	add	r4,r4,r5
+	ld	r4,0(r4)
+	add	r4,r4,r5
+	mtctr	r4
+	/* Calling convention for cpu setup is r3=offset, r4=cur_cpu_spec */
+	mr	r4,r3
+	mr	r3,r5
+	bctr
+
+/*
+ * do_cpu_ftr_fixups - goes through the list of CPU feature fixups
+ * and writes nop's over sections of code that don't apply for this cpu.
+ * r3 = data offset (not changed)
+ */
+_GLOBAL(do_cpu_ftr_fixups)
+	/* Get CPU 0 features */
+	LOADADDR(r6,cur_cpu_spec)
+	sub	r6,r6,r3
+	ld	r4,0(r6)
+	sub	r4,r4,r3
+	ld	r4,CPU_SPEC_FEATURES(r4)
+	/* Get the fixup table */
+	LOADADDR(r6,__start___ftr_fixup)
+	sub	r6,r6,r3
+	LOADADDR(r7,__stop___ftr_fixup)
+	sub	r7,r7,r3
+	/* Do the fixup */
+1:	cmpld	r6,r7
+	bgelr
+	addi	r6,r6,32
+	ld	r8,-32(r6)	/* mask */
+	and	r8,r8,r4
+	ld	r9,-24(r6)	/* value */
+	cmpld	r8,r9
+	beq	1b
+	ld	r8,-16(r6)	/* section begin */
+	ld	r9,-8(r6)	/* section end */
+	subf.	r9,r8,r9
+	beq	1b
+	/* write nops over the section of code */
+	/* todo: if large section, add a branch at the start of it */
+	srwi	r9,r9,2
+	mtctr	r9
+	sub	r8,r8,r3
+	lis	r0,0x60000000@h	/* nop */
+3:	stw	r0,0(r8)
+	andi.	r10,r4,CPU_FTR_SPLIT_ID_CACHE@l
+	beq	2f
+	dcbst	0,r8		/* suboptimal, but simpler */
+	sync
+	icbi	0,r8
+2:	addi	r8,r8,4
+	bdnz	3b
+	sync			/* additional sync needed on g4 */
+	isync
+	b	1b
+
+#if defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE)
+/*
+ * Do an IO access in real mode
+ */
+_GLOBAL(real_readb)
+	mfmsr	r7
+	ori	r0,r7,MSR_DR
+	xori	r0,r0,MSR_DR
+	sync
+	mtmsrd	r0
+	sync
+	isync
+	mfspr	r6,SPRN_HID4
+	rldicl	r5,r6,32,0
+	ori	r5,r5,0x100
+	rldicl	r5,r5,32,0
+	sync
+	mtspr	SPRN_HID4,r5
+	isync
+	slbia
+	isync
+	lbz	r3,0(r3)
+	sync
+	mtspr	SPRN_HID4,r6
+	isync
+	slbia
+	isync
+	mtmsrd	r7
+	sync
+	isync
+	blr
+
+	/*
+ * Do an IO access in real mode
+ */
+_GLOBAL(real_writeb)
+	mfmsr	r7
+	ori	r0,r7,MSR_DR
+	xori	r0,r0,MSR_DR
+	sync
+	mtmsrd	r0
+	sync
+	isync
+	mfspr	r6,SPRN_HID4
+	rldicl	r5,r6,32,0
+	ori	r5,r5,0x100
+	rldicl	r5,r5,32,0
+	sync
+	mtspr	SPRN_HID4,r5
+	isync
+	slbia
+	isync
+	stb	r3,0(r4)
+	sync
+	mtspr	SPRN_HID4,r6
+	isync
+	slbia
+	isync
+	mtmsrd	r7
+	sync
+	isync
+	blr
+#endif /* defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE) */
+
+/*
+ * Create a kernel thread
+ *   kernel_thread(fn, arg, flags)
+ */
+_GLOBAL(kernel_thread)
+	std	r29,-24(r1)
+	std	r30,-16(r1)
+	stdu	r1,-STACK_FRAME_OVERHEAD(r1)
+	mr	r29,r3
+	mr	r30,r4
+	ori	r3,r5,CLONE_VM	/* flags */
+	oris	r3,r3,(CLONE_UNTRACED>>16)
+	li	r4,0		/* new sp (unused) */
+	li	r0,__NR_clone
+	sc
+	cmpdi	0,r3,0		/* parent or child? */
+	bne	1f		/* return if parent */
+	li	r0,0
+	stdu	r0,-STACK_FRAME_OVERHEAD(r1)
+	ld	r2,8(r29)
+	ld	r29,0(r29)
+	mtlr	r29              /* fn addr in lr */
+	mr	r3,r30	        /* load arg and call fn */
+	blrl
+	li	r0,__NR_exit	/* exit after child exits */
+        li	r3,0
+	sc
+1:	addi	r1,r1,STACK_FRAME_OVERHEAD	
+	ld	r29,-24(r1)
+	ld	r30,-16(r1)
+	blr
+
+/*
+ * disable_kernel_fp()
+ * Disable the FPU.
+ */
+_GLOBAL(disable_kernel_fp)
+	mfmsr	r3
+	rldicl	r0,r3,(63-MSR_FP_LG),1
+	rldicl	r3,r0,(MSR_FP_LG+1),0
+	mtmsrd	r3			/* disable use of fpu now */
+	isync
+	blr
+
+#ifdef CONFIG_ALTIVEC
+
+#if 0 /* this has no callers for now */
+/*
+ * disable_kernel_altivec()
+ * Disable the VMX.
+ */
+_GLOBAL(disable_kernel_altivec)
+	mfmsr	r3
+	rldicl	r0,r3,(63-MSR_VEC_LG),1
+	rldicl	r3,r0,(MSR_VEC_LG+1),0
+	mtmsrd	r3			/* disable use of VMX now */
+	isync
+	blr
+#endif /* 0 */
+
+/*
+ * giveup_altivec(tsk)
+ * Disable VMX for the task given as the argument,
+ * and save the vector registers in its thread_struct.
+ * Enables the VMX for use in the kernel on return.
+ */
+_GLOBAL(giveup_altivec)
+	mfmsr	r5
+	oris	r5,r5,MSR_VEC@h
+	mtmsrd	r5			/* enable use of VMX now */
+	isync
+	cmpdi	0,r3,0
+	beqlr-				/* if no previous owner, done */
+	addi	r3,r3,THREAD		/* want THREAD of task */
+	ld	r5,PT_REGS(r3)
+	cmpdi	0,r5,0
+	SAVE_32VRS(0,r4,r3)
+	mfvscr	vr0
+	li	r4,THREAD_VSCR
+	stvx	vr0,r4,r3
+	beq	1f
+	ld	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+	lis	r3,MSR_VEC@h
+	andc	r4,r4,r3		/* disable FP for previous task */
+	std	r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+1:
+#ifndef CONFIG_SMP
+	li	r5,0
+	ld	r4,last_task_used_altivec@got(r2)
+	std	r5,0(r4)
+#endif /* CONFIG_SMP */
+	blr
+
+#endif /* CONFIG_ALTIVEC */
+
+_GLOBAL(__setup_cpu_power3)
+	blr
+
+_GLOBAL(execve)
+	li	r0,__NR_execve
+	sc
+	bnslr
+	neg	r3,r3
+	blr
+
+/* kexec_wait(phys_cpu)
+ *
+ * wait for the flag to change, indicating this kernel is going away but
+ * the slave code for the next one is at addresses 0 to 100.
+ *
+ * This is used by all slaves.
+ *
+ * Physical (hardware) cpu id should be in r3.
+ */
+_GLOBAL(kexec_wait)
+	bl	1f
+1:	mflr	r5
+	addi	r5,r5,kexec_flag-1b
+
+99:	HMT_LOW
+#ifdef CONFIG_KEXEC		/* use no memory without kexec */
+	lwz	r4,0(r5)
+	cmpwi	0,r4,0
+	bnea	0x60
+#endif
+	b	99b
+
+/* this can be in text because we won't change it until we are
+ * running in real anyways
+ */
+kexec_flag:
+	.long	0
+
+
+#ifdef CONFIG_KEXEC
+
+/* kexec_smp_wait(void)
+ *
+ * call with interrupts off
+ * note: this is a terminal routine, it does not save lr
+ *
+ * get phys id from paca
+ * set paca id to -1 to say we got here
+ * switch to real mode
+ * join other cpus in kexec_wait(phys_id)
+ */
+_GLOBAL(kexec_smp_wait)
+	lhz	r3,PACAHWCPUID(r13)
+	li	r4,-1
+	sth	r4,PACAHWCPUID(r13)	/* let others know we left */
+	bl	real_mode
+	b	.kexec_wait
+
+/*
+ * switch to real mode (turn mmu off)
+ * we use the early kernel trick that the hardware ignores bits
+ * 0 and 1 (big endian) of the effective address in real mode
+ *
+ * don't overwrite r3 here, it is live for kexec_wait above.
+ */
+real_mode:	/* assume normal blr return */
+1:	li	r9,MSR_RI
+	li	r10,MSR_DR|MSR_IR
+	mflr	r11		/* return address to SRR0 */
+	mfmsr	r12
+	andc	r9,r12,r9
+	andc	r10,r12,r10
+
+	mtmsrd	r9,1
+	mtspr	SPRN_SRR1,r10
+	mtspr	SPRN_SRR0,r11
+	rfid
+
+
+/*
+ * kexec_sequence(newstack, start, image, control, clear_all())
+ *
+ * does the grungy work with stack switching and real mode switches
+ * also does simple calls to other code
+ */
+
+_GLOBAL(kexec_sequence)
+	mflr	r0
+	std	r0,16(r1)
+
+	/* switch stacks to newstack -- &kexec_stack.stack */
+	stdu	r1,THREAD_SIZE-112(r3)
+	mr	r1,r3
+
+	li	r0,0
+	std	r0,16(r1)
+
+	/* save regs for local vars on new stack.
+	 * yes, we won't go back, but ...
+	 */
+	std	r31,-8(r1)
+	std	r30,-16(r1)
+	std	r29,-24(r1)
+	std	r28,-32(r1)
+	std	r27,-40(r1)
+	std	r26,-48(r1)
+	std	r25,-56(r1)
+
+	stdu	r1,-112-64(r1)
+
+	/* save args into preserved regs */
+	mr	r31,r3			/* newstack (both) */
+	mr	r30,r4			/* start (real) */
+	mr	r29,r5			/* image (virt) */
+	mr	r28,r6			/* control, unused */
+	mr	r27,r7			/* clear_all() fn desc */
+	mr	r26,r8			/* spare */
+	lhz	r25,PACAHWCPUID(r13)	/* get our phys cpu from paca */
+
+	/* disable interrupts, we are overwriting kernel data next */
+	mfmsr	r3
+	rlwinm	r3,r3,0,17,15
+	mtmsrd	r3,1
+
+	/* copy dest pages, flush whole dest image */
+	mr	r3,r29
+	bl	.kexec_copy_flush	/* (image) */
+
+	/* turn off mmu */
+	bl	real_mode
+
+	/* clear out hardware hash page table and tlb */
+	ld	r5,0(r27)		/* deref function descriptor */
+	mtctr	r5
+	bctrl				/* ppc_md.hash_clear_all(void); */
+
+/*
+ *   kexec image calling is:
+ *      the first 0x100 bytes of the entry point are copied to 0
+ *
+ *      all slaves branch to slave = 0x60 (absolute)
+ *              slave(phys_cpu_id);
+ *
+ *      master goes to start = entry point
+ *              start(phys_cpu_id, start, 0);
+ *
+ *
+ *   a wrapper is needed to call existing kernels, here is an approximate
+ *   description of one method:
+ *
+ * v2: (2.6.10)
+ *   start will be near the boot_block (maybe 0x100 bytes before it?)
+ *   it will have a 0x60, which will b to boot_block, where it will wait
+ *   and 0 will store phys into struct boot-block and load r3 from there,
+ *   copy kernel 0-0x100 and tell slaves to back down to 0x60 again
+ *
+ * v1: (2.6.9)
+ *    boot block will have all cpus scanning device tree to see if they
+ *    are the boot cpu ?????
+ *    other device tree differences (prop sizes, va vs pa, etc)...
+ */
+
+	/* copy  0x100 bytes starting at start to 0 */
+	li	r3,0
+	mr	r4,r30
+	li	r5,0x100
+	li	r6,0
+	bl	.copy_and_flush	/* (dest, src, copy limit, start offset) */
+1:	/* assume normal blr return */
+
+	/* release other cpus to the new kernel secondary start at 0x60 */
+	mflr	r5
+	li	r6,1
+	stw	r6,kexec_flag-1b(5)
+	mr	r3,r25	# my phys cpu
+	mr	r4,r30	# start, aka phys mem offset
+	mtlr	4
+	li	r5,0
+	blr	/* image->start(physid, image->start, 0); */
+#endif /* CONFIG_KEXEC */