powerpc: Remaining 64-bit Book3E support

This contains all the bits that didn't fit in previous patches :-) This
includes the actual exception handlers assembly, the changes to the
kernel entry, other misc bits and wiring it all up in Kconfig.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
new file mode 100644
index 0000000..695d484
--- /dev/null
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -0,0 +1,784 @@
+/*
+ *  Boot code and exception vectors for Book3E processors
+ *
+ *  Copyright (C) 2007 Ben. Herrenschmidt (benh@kernel.crashing.org), IBM Corp.
+ *
+ *  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/threads.h>
+#include <asm/reg.h>
+#include <asm/page.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/cputable.h>
+#include <asm/setup.h>
+#include <asm/thread_info.h>
+#include <asm/reg.h>
+#include <asm/exception-64e.h>
+#include <asm/bug.h>
+#include <asm/irqflags.h>
+#include <asm/ptrace.h>
+#include <asm/ppc-opcode.h>
+#include <asm/mmu.h>
+
+/* XXX This will ultimately add space for a special exception save
+ *     structure used to save things like SRR0/SRR1, SPRGs, MAS, etc...
+ *     when taking special interrupts. For now we don't support that,
+ *     special interrupts from within a non-standard level will probably
+ *     blow you up
+ */
+#define	SPECIAL_EXC_FRAME_SIZE	INT_FRAME_SIZE
+
+/* Exception prolog code for all exceptions */
+#define EXCEPTION_PROLOG(n, type, addition)				    \
+	mtspr	SPRN_SPRG_##type##_SCRATCH,r13;	/* get spare registers */   \
+	mfspr	r13,SPRN_SPRG_PACA;	/* get PACA */			    \
+	std	r10,PACA_EX##type+EX_R10(r13);				    \
+	std	r11,PACA_EX##type+EX_R11(r13);				    \
+	mfcr	r10;			/* save CR */			    \
+	addition;			/* additional code for that exc. */ \
+	std	r1,PACA_EX##type+EX_R1(r13); /* save old r1 in the PACA */  \
+	stw	r10,PACA_EX##type+EX_CR(r13); /* save old CR in the PACA */ \
+	mfspr	r11,SPRN_##type##_SRR1;/* what are we coming from */	    \
+	type##_SET_KSTACK;		/* get special stack if necessary */\
+	andi.	r10,r11,MSR_PR;		/* save stack pointer */	    \
+	beq	1f;			/* branch around if supervisor */   \
+	ld	r1,PACAKSAVE(r13);	/* get kernel stack coming from usr */\
+1:	cmpdi	cr1,r1,0;		/* check if SP makes sense */	    \
+	bge-	cr1,exc_##n##_bad_stack;/* bad stack (TODO: out of line) */ \
+	mfspr	r10,SPRN_##type##_SRR0;	/* read SRR0 before touching stack */
+
+/* Exception type-specific macros */
+#define	GEN_SET_KSTACK							    \
+	subi	r1,r1,INT_FRAME_SIZE;	/* alloc frame on kernel stack */
+#define SPRN_GEN_SRR0	SPRN_SRR0
+#define SPRN_GEN_SRR1	SPRN_SRR1
+
+#define CRIT_SET_KSTACK						            \
+	ld	r1,PACA_CRIT_STACK(r13);				    \
+	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
+#define SPRN_CRIT_SRR0	SPRN_CSRR0
+#define SPRN_CRIT_SRR1	SPRN_CSRR1
+
+#define DBG_SET_KSTACK						            \
+	ld	r1,PACA_DBG_STACK(r13);					    \
+	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
+#define SPRN_DBG_SRR0	SPRN_DSRR0
+#define SPRN_DBG_SRR1	SPRN_DSRR1
+
+#define MC_SET_KSTACK						            \
+	ld	r1,PACA_MC_STACK(r13);					    \
+	subi	r1,r1,SPECIAL_EXC_FRAME_SIZE;
+#define SPRN_MC_SRR0	SPRN_MCSRR0
+#define SPRN_MC_SRR1	SPRN_MCSRR1
+
+#define NORMAL_EXCEPTION_PROLOG(n, addition)				    \
+	EXCEPTION_PROLOG(n, GEN, addition##_GEN)
+
+#define CRIT_EXCEPTION_PROLOG(n, addition)				    \
+	EXCEPTION_PROLOG(n, CRIT, addition##_CRIT)
+
+#define DBG_EXCEPTION_PROLOG(n, addition)				    \
+	EXCEPTION_PROLOG(n, DBG, addition##_DBG)
+
+#define MC_EXCEPTION_PROLOG(n, addition)				    \
+	EXCEPTION_PROLOG(n, MC, addition##_MC)
+
+
+/* Variants of the "addition" argument for the prolog
+ */
+#define PROLOG_ADDITION_NONE_GEN
+#define PROLOG_ADDITION_NONE_CRIT
+#define PROLOG_ADDITION_NONE_DBG
+#define PROLOG_ADDITION_NONE_MC
+
+#define PROLOG_ADDITION_MASKABLE_GEN					    \
+	lbz	r11,PACASOFTIRQEN(r13); /* are irqs soft-disabled ? */	    \
+	cmpwi	cr0,r11,0;		/* yes -> go out of line */	    \
+	beq	masked_interrupt_book3e;
+
+#define PROLOG_ADDITION_2REGS_GEN					    \
+	std	r14,PACA_EXGEN+EX_R14(r13);				    \
+	std	r15,PACA_EXGEN+EX_R15(r13)
+
+#define PROLOG_ADDITION_1REG_GEN					    \
+	std	r14,PACA_EXGEN+EX_R14(r13);
+
+#define PROLOG_ADDITION_2REGS_CRIT					    \
+	std	r14,PACA_EXCRIT+EX_R14(r13);				    \
+	std	r15,PACA_EXCRIT+EX_R15(r13)
+
+#define PROLOG_ADDITION_2REGS_DBG					    \
+	std	r14,PACA_EXDBG+EX_R14(r13);				    \
+	std	r15,PACA_EXDBG+EX_R15(r13)
+
+#define PROLOG_ADDITION_2REGS_MC					    \
+	std	r14,PACA_EXMC+EX_R14(r13);				    \
+	std	r15,PACA_EXMC+EX_R15(r13)
+
+/* Core exception code for all exceptions except TLB misses.
+ * XXX: Needs to make SPRN_SPRG_GEN depend on exception type
+ */
+#define EXCEPTION_COMMON(n, excf, ints)					    \
+	std	r0,GPR0(r1);		/* save r0 in stackframe */	    \
+	std	r2,GPR2(r1);		/* save r2 in stackframe */	    \
+	SAVE_4GPRS(3, r1);		/* save r3 - r6 in stackframe */    \
+	SAVE_2GPRS(7, r1);		/* save r7, r8 in stackframe */	    \
+	std	r9,GPR9(r1);		/* save r9 in stackframe */	    \
+	std	r10,_NIP(r1);		/* save SRR0 to stackframe */	    \
+	std	r11,_MSR(r1);		/* save SRR1 to stackframe */	    \
+	ACCOUNT_CPU_USER_ENTRY(r10,r11);/* accounting (uses cr0+eq) */	    \
+	ld	r3,excf+EX_R10(r13);	/* get back r10 */		    \
+	ld	r4,excf+EX_R11(r13);	/* get back r11 */		    \
+	mfspr	r5,SPRN_SPRG_GEN_SCRATCH;/* get back r13 */		    \
+	std	r12,GPR12(r1);		/* save r12 in stackframe */	    \
+	ld	r2,PACATOC(r13);	/* get kernel TOC into r2 */	    \
+	mflr	r6;			/* save LR in stackframe */	    \
+	mfctr	r7;			/* save CTR in stackframe */	    \
+	mfspr	r8,SPRN_XER;		/* save XER in stackframe */	    \
+	ld	r9,excf+EX_R1(r13);	/* load orig r1 back from PACA */   \
+	lwz	r10,excf+EX_CR(r13);	/* load orig CR back from PACA	*/  \
+	lbz	r11,PACASOFTIRQEN(r13);	/* get current IRQ softe */	    \
+	ld	r12,exception_marker@toc(r2);				    \
+	li	r0,0;							    \
+	std	r3,GPR10(r1);		/* save r10 to stackframe */	    \
+	std	r4,GPR11(r1);		/* save r11 to stackframe */	    \
+	std	r5,GPR13(r1);		/* save it to stackframe */	    \
+	std	r6,_LINK(r1);						    \
+	std	r7,_CTR(r1);						    \
+	std	r8,_XER(r1);						    \
+	li	r3,(n)+1;		/* indicate partial regs in trap */ \
+	std	r9,0(r1);		/* store stack frame back link */   \
+	std	r10,_CCR(r1);		/* store orig CR in stackframe */   \
+	std	r9,GPR1(r1);		/* store stack frame back link */   \
+	std	r11,SOFTE(r1);		/* and save it to stackframe */     \
+	std	r12,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame */	    \
+	std	r3,_TRAP(r1);		/* set trap number		*/  \
+	std	r0,RESULT(r1);		/* clear regs->result */	    \
+	ints;
+
+/* Variants for the "ints" argument */
+#define INTS_KEEP
+#define INTS_DISABLE_SOFT						    \
+	stb	r0,PACASOFTIRQEN(r13);	/* mark interrupts soft-disabled */ \
+	TRACE_DISABLE_INTS;
+#define INTS_DISABLE_HARD						    \
+	stb	r0,PACAHARDIRQEN(r13); /* and hard disabled */
+#define INTS_DISABLE_ALL						    \
+	INTS_DISABLE_SOFT						    \
+	INTS_DISABLE_HARD
+
+/* This is called by exceptions that used INTS_KEEP (that is did not clear
+ * neither soft nor hard IRQ indicators in the PACA. This will restore MSR:EE
+ * to it's previous value
+ *
+ * XXX In the long run, we may want to open-code it in order to separate the
+ *     load from the wrtee, thus limiting the latency caused by the dependency
+ *     but at this point, I'll favor code clarity until we have a near to final
+ *     implementation
+ */
+#define INTS_RESTORE_HARD						    \
+	ld	r11,_MSR(r1);						    \
+	wrtee	r11;
+
+/* XXX FIXME: Restore r14/r15 when necessary */
+#define BAD_STACK_TRAMPOLINE(n)						    \
+exc_##n##_bad_stack:							    \
+	li	r1,(n);			/* get exception number */	    \
+	sth	r1,PACA_TRAP_SAVE(r13);	/* store trap */		    \
+	b	bad_stack_book3e;	/* bad stack error */
+
+#define	EXCEPTION_STUB(loc, label)					\
+	. = interrupt_base_book3e + loc;				\
+	nop;	/* To make debug interrupts happy */			\
+	b	exc_##label##_book3e;
+
+#define ACK_NONE(r)
+#define ACK_DEC(r)							\
+	lis	r,TSR_DIS@h;						\
+	mtspr	SPRN_TSR,r
+#define ACK_FIT(r)							\
+	lis	r,TSR_FIS@h;						\
+	mtspr	SPRN_TSR,r
+
+#define MASKABLE_EXCEPTION(trapnum, label, hdlr, ack)			\
+	START_EXCEPTION(label);						\
+	NORMAL_EXCEPTION_PROLOG(trapnum, PROLOG_ADDITION_MASKABLE)	\
+	EXCEPTION_COMMON(trapnum, PACA_EXGEN, INTS_DISABLE_ALL)		\
+	ack(r8);							\
+	addi	r3,r1,STACK_FRAME_OVERHEAD;				\
+	bl	hdlr;							\
+	b	.ret_from_except_lite;
+
+/* This value is used to mark exception frames on the stack. */
+	.section	".toc","aw"
+exception_marker:
+	.tc	ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER
+
+
+/*
+ * And here we have the exception vectors !
+ */
+
+	.text
+	.balign	0x1000
+	.globl interrupt_base_book3e
+interrupt_base_book3e:					/* fake trap */
+	/* Note: If real debug exceptions are supported by the HW, the vector
+	 * below will have to be patched up to point to an appropriate handler
+	 */
+	EXCEPTION_STUB(0x000, machine_check)		/* 0x0200 */
+	EXCEPTION_STUB(0x020, critical_input)		/* 0x0580 */
+	EXCEPTION_STUB(0x040, debug_crit)		/* 0x0d00 */
+	EXCEPTION_STUB(0x060, data_storage)		/* 0x0300 */
+	EXCEPTION_STUB(0x080, instruction_storage)	/* 0x0400 */
+	EXCEPTION_STUB(0x0a0, external_input)		/* 0x0500 */
+	EXCEPTION_STUB(0x0c0, alignment)		/* 0x0600 */
+	EXCEPTION_STUB(0x0e0, program)			/* 0x0700 */
+	EXCEPTION_STUB(0x100, fp_unavailable)		/* 0x0800 */
+	EXCEPTION_STUB(0x120, system_call)		/* 0x0c00 */
+	EXCEPTION_STUB(0x140, ap_unavailable)		/* 0x0f20 */
+	EXCEPTION_STUB(0x160, decrementer)		/* 0x0900 */
+	EXCEPTION_STUB(0x180, fixed_interval)		/* 0x0980 */
+	EXCEPTION_STUB(0x1a0, watchdog)			/* 0x09f0 */
+	EXCEPTION_STUB(0x1c0, data_tlb_miss)
+	EXCEPTION_STUB(0x1e0, instruction_tlb_miss)
+
+#if 0
+	EXCEPTION_STUB(0x280, processor_doorbell)
+	EXCEPTION_STUB(0x220, processor_doorbell_crit)
+#endif
+	.globl interrupt_end_book3e
+interrupt_end_book3e:
+
+/* Critical Input Interrupt */
+	START_EXCEPTION(critical_input);
+	CRIT_EXCEPTION_PROLOG(0x100, PROLOG_ADDITION_NONE)
+//	EXCEPTION_COMMON(0x100, PACA_EXCRIT, INTS_DISABLE_ALL)
+//	bl	special_reg_save_crit
+//	addi	r3,r1,STACK_FRAME_OVERHEAD
+//	bl	.critical_exception
+//	b	ret_from_crit_except
+	b	.
+
+/* Machine Check Interrupt */
+	START_EXCEPTION(machine_check);
+	CRIT_EXCEPTION_PROLOG(0x200, PROLOG_ADDITION_NONE)
+//	EXCEPTION_COMMON(0x200, PACA_EXMC, INTS_DISABLE_ALL)
+//	bl	special_reg_save_mc
+//	addi	r3,r1,STACK_FRAME_OVERHEAD
+//	bl	.machine_check_exception
+//	b	ret_from_mc_except
+	b	.
+
+/* Data Storage Interrupt */
+	START_EXCEPTION(data_storage)
+	NORMAL_EXCEPTION_PROLOG(0x300, PROLOG_ADDITION_2REGS)
+	mfspr	r14,SPRN_DEAR
+	mfspr	r15,SPRN_ESR
+	EXCEPTION_COMMON(0x300, PACA_EXGEN, INTS_KEEP)
+	b	storage_fault_common
+
+/* Instruction Storage Interrupt */
+	START_EXCEPTION(instruction_storage);
+	NORMAL_EXCEPTION_PROLOG(0x400, PROLOG_ADDITION_2REGS)
+	li	r15,0
+	mr	r14,r10
+	EXCEPTION_COMMON(0x400, PACA_EXGEN, INTS_KEEP)
+	b	storage_fault_common
+
+/* External Input Interrupt */
+	MASKABLE_EXCEPTION(0x500, external_input, .do_IRQ, ACK_NONE)
+
+/* Alignment */
+	START_EXCEPTION(alignment);
+	NORMAL_EXCEPTION_PROLOG(0x600, PROLOG_ADDITION_2REGS)
+	mfspr	r14,SPRN_DEAR
+	mfspr	r15,SPRN_ESR
+	EXCEPTION_COMMON(0x600, PACA_EXGEN, INTS_KEEP)
+	b	alignment_more	/* no room, go out of line */
+
+/* Program Interrupt */
+	START_EXCEPTION(program);
+	NORMAL_EXCEPTION_PROLOG(0x700, PROLOG_ADDITION_1REG)
+	mfspr	r14,SPRN_ESR
+	EXCEPTION_COMMON(0x700, PACA_EXGEN, INTS_DISABLE_SOFT)
+	std	r14,_DSISR(r1)
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	ld	r14,PACA_EXGEN+EX_R14(r13)
+	bl	.save_nvgprs
+	INTS_RESTORE_HARD
+	bl	.program_check_exception
+	b	.ret_from_except
+
+/* Floating Point Unavailable Interrupt */
+	START_EXCEPTION(fp_unavailable);
+	NORMAL_EXCEPTION_PROLOG(0x800, PROLOG_ADDITION_NONE)
+	/* we can probably do a shorter exception entry for that one... */
+	EXCEPTION_COMMON(0x800, PACA_EXGEN, INTS_KEEP)
+	bne	1f			/* if from user, just load it up */
+	bl	.save_nvgprs
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	INTS_RESTORE_HARD
+	bl	.kernel_fp_unavailable_exception
+	BUG_OPCODE
+1:	ld	r12,_MSR(r1)
+	bl	.load_up_fpu
+	b	fast_exception_return
+
+/* Decrementer Interrupt */
+	MASKABLE_EXCEPTION(0x900, decrementer, .timer_interrupt, ACK_DEC)
+
+/* Fixed Interval Timer Interrupt */
+	MASKABLE_EXCEPTION(0x980, fixed_interval, .unknown_exception, ACK_FIT)
+
+/* Watchdog Timer Interrupt */
+	START_EXCEPTION(watchdog);
+	CRIT_EXCEPTION_PROLOG(0x9f0, PROLOG_ADDITION_NONE)
+//	EXCEPTION_COMMON(0x9f0, PACA_EXCRIT, INTS_DISABLE_ALL)
+//	bl	special_reg_save_crit
+//	addi	r3,r1,STACK_FRAME_OVERHEAD
+//	bl	.unknown_exception
+//	b	ret_from_crit_except
+	b	.
+
+/* System Call Interrupt */
+	START_EXCEPTION(system_call)
+	mr	r9,r13			/* keep a copy of userland r13 */
+	mfspr	r11,SPRN_SRR0		/* get return address */
+	mfspr	r12,SPRN_SRR1		/* get previous MSR */
+	mfspr	r13,SPRN_SPRG_PACA	/* get our PACA */
+	b	system_call_common
+
+/* Auxillary Processor Unavailable Interrupt */
+	START_EXCEPTION(ap_unavailable);
+	NORMAL_EXCEPTION_PROLOG(0xf20, PROLOG_ADDITION_NONE)
+	EXCEPTION_COMMON(0xf20, PACA_EXGEN, INTS_KEEP)
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	.save_nvgprs
+	INTS_RESTORE_HARD
+	bl	.unknown_exception
+	b	.ret_from_except
+
+/* Debug exception as a critical interrupt*/
+	START_EXCEPTION(debug_crit);
+	CRIT_EXCEPTION_PROLOG(0xd00, PROLOG_ADDITION_2REGS)
+
+	/*
+	 * If there is a single step or branch-taken exception in an
+	 * exception entry sequence, it was probably meant to apply to
+	 * the code where the exception occurred (since exception entry
+	 * doesn't turn off DE automatically).  We simulate the effect
+	 * of turning off DE on entry to an exception handler by turning
+	 * off DE in the CSRR1 value and clearing the debug status.
+	 */
+
+	mfspr	r14,SPRN_DBSR		/* check single-step/branch taken */
+	andis.	r15,r14,DBSR_IC@h
+	beq+	1f
+
+	LOAD_REG_IMMEDIATE(r14,interrupt_base_book3e)
+	LOAD_REG_IMMEDIATE(r15,interrupt_end_book3e)
+	cmpld	cr0,r10,r14
+	cmpld	cr1,r10,r15
+	blt+	cr0,1f
+	bge+	cr1,1f
+
+	/* here it looks like we got an inappropriate debug exception. */
+	lis	r14,DBSR_IC@h		/* clear the IC event */
+	rlwinm	r11,r11,0,~MSR_DE	/* clear DE in the CSRR1 value */
+	mtspr	SPRN_DBSR,r14
+	mtspr	SPRN_CSRR1,r11
+	lwz	r10,PACA_EXCRIT+EX_CR(r13)	/* restore registers */
+	ld	r1,PACA_EXCRIT+EX_R1(r13)
+	ld	r14,PACA_EXCRIT+EX_R14(r13)
+	ld	r15,PACA_EXCRIT+EX_R15(r13)
+	mtcr	r10
+	ld	r10,PACA_EXCRIT+EX_R10(r13)	/* restore registers */
+	ld	r11,PACA_EXCRIT+EX_R11(r13)
+	mfspr	r13,SPRN_SPRG_CRIT_SCRATCH
+	rfci
+
+	/* Normal debug exception */
+	/* XXX We only handle coming from userspace for now since we can't
+	 *     quite save properly an interrupted kernel state yet
+	 */
+1:	andi.	r14,r11,MSR_PR;		/* check for userspace again */
+	beq	kernel_dbg_exc;		/* if from kernel mode */
+
+	/* Now we mash up things to make it look like we are coming on a
+	 * normal exception
+	 */
+	mfspr	r15,SPRN_SPRG_CRIT_SCRATCH
+	mtspr	SPRN_SPRG_GEN_SCRATCH,r15
+	mfspr	r14,SPRN_DBSR
+	EXCEPTION_COMMON(0xd00, PACA_EXCRIT, INTS_DISABLE_ALL)
+	std	r14,_DSISR(r1)
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	mr	r4,r14
+	ld	r14,PACA_EXCRIT+EX_R14(r13)
+	ld	r15,PACA_EXCRIT+EX_R15(r13)
+	bl	.save_nvgprs
+	bl	.DebugException
+	b	.ret_from_except
+
+kernel_dbg_exc:
+	b	.	/* NYI */
+
+
+/*
+ * An interrupt came in while soft-disabled; clear EE in SRR1,
+ * clear paca->hard_enabled and return.
+ */
+masked_interrupt_book3e:
+	mtcr	r10
+	stb	r11,PACAHARDIRQEN(r13)
+	mfspr	r10,SPRN_SRR1
+	rldicl	r11,r10,48,1		/* clear MSR_EE */
+	rotldi	r10,r11,16
+	mtspr	SPRN_SRR1,r10
+	ld	r10,PACA_EXGEN+EX_R10(r13);	/* restore registers */
+	ld	r11,PACA_EXGEN+EX_R11(r13);
+	mfspr	r13,SPRN_SPRG_GEN_SCRATCH;
+	rfi
+	b	.
+
+/*
+ * This is called from 0x300 and 0x400 handlers after the prologs with
+ * r14 and r15 containing the fault address and error code, with the
+ * original values stashed away in the PACA
+ */
+storage_fault_common:
+	std	r14,_DAR(r1)
+	std	r15,_DSISR(r1)
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	mr	r4,r14
+	mr	r5,r15
+	ld	r14,PACA_EXGEN+EX_R14(r13)
+	ld	r15,PACA_EXGEN+EX_R15(r13)
+	INTS_RESTORE_HARD
+	bl	.do_page_fault
+	cmpdi	r3,0
+	bne-	1f
+	b	.ret_from_except_lite
+1:	bl	.save_nvgprs
+	mr	r5,r3
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	ld	r4,_DAR(r1)
+	bl	.bad_page_fault
+	b	.ret_from_except
+
+/*
+ * Alignment exception doesn't fit entirely in the 0x100 bytes so it
+ * continues here.
+ */
+alignment_more:
+	std	r14,_DAR(r1)
+	std	r15,_DSISR(r1)
+	addi	r3,r1,STACK_FRAME_OVERHEAD
+	ld	r14,PACA_EXGEN+EX_R14(r13)
+	ld	r15,PACA_EXGEN+EX_R15(r13)
+	bl	.save_nvgprs
+	INTS_RESTORE_HARD
+	bl	.alignment_exception
+	b	.ret_from_except
+
+/*
+ * We branch here from entry_64.S for the last stage of the exception
+ * return code path. MSR:EE is expected to be off at that point
+ */
+_GLOBAL(exception_return_book3e)
+	b	1f
+
+/* This is the return from load_up_fpu fast path which could do with
+ * less GPR restores in fact, but for now we have a single return path
+ */
+	.globl fast_exception_return
+fast_exception_return:
+	wrteei	0
+1:	mr	r0,r13
+	ld	r10,_MSR(r1)
+	REST_4GPRS(2, r1)
+	andi.	r6,r10,MSR_PR
+	REST_2GPRS(6, r1)
+	beq	1f
+	ACCOUNT_CPU_USER_EXIT(r10, r11)
+	ld	r0,GPR13(r1)
+
+1:	stdcx.	r0,0,r1		/* to clear the reservation */
+
+	ld	r8,_CCR(r1)
+	ld	r9,_LINK(r1)
+	ld	r10,_CTR(r1)
+	ld	r11,_XER(r1)
+	mtcr	r8
+	mtlr	r9
+	mtctr	r10
+	mtxer	r11
+	REST_2GPRS(8, r1)
+	ld	r10,GPR10(r1)
+	ld	r11,GPR11(r1)
+	ld	r12,GPR12(r1)
+	mtspr	SPRN_SPRG_GEN_SCRATCH,r0
+
+	std	r10,PACA_EXGEN+EX_R10(r13);
+	std	r11,PACA_EXGEN+EX_R11(r13);
+	ld	r10,_NIP(r1)
+	ld	r11,_MSR(r1)
+	ld	r0,GPR0(r1)
+	ld	r1,GPR1(r1)
+	mtspr	SPRN_SRR0,r10
+	mtspr	SPRN_SRR1,r11
+	ld	r10,PACA_EXGEN+EX_R10(r13)
+	ld	r11,PACA_EXGEN+EX_R11(r13)
+	mfspr	r13,SPRN_SPRG_GEN_SCRATCH
+	rfi
+
+/*
+ * Trampolines used when spotting a bad kernel stack pointer in
+ * the exception entry code.
+ *
+ * TODO: move some bits like SRR0 read to trampoline, pass PACA
+ * index around, etc... to handle crit & mcheck
+ */
+BAD_STACK_TRAMPOLINE(0x000)
+BAD_STACK_TRAMPOLINE(0x100)
+BAD_STACK_TRAMPOLINE(0x200)
+BAD_STACK_TRAMPOLINE(0x300)
+BAD_STACK_TRAMPOLINE(0x400)
+BAD_STACK_TRAMPOLINE(0x500)
+BAD_STACK_TRAMPOLINE(0x600)
+BAD_STACK_TRAMPOLINE(0x700)
+BAD_STACK_TRAMPOLINE(0x800)
+BAD_STACK_TRAMPOLINE(0x900)
+BAD_STACK_TRAMPOLINE(0x980)
+BAD_STACK_TRAMPOLINE(0x9f0)
+BAD_STACK_TRAMPOLINE(0xa00)
+BAD_STACK_TRAMPOLINE(0xb00)
+BAD_STACK_TRAMPOLINE(0xc00)
+BAD_STACK_TRAMPOLINE(0xd00)
+BAD_STACK_TRAMPOLINE(0xe00)
+BAD_STACK_TRAMPOLINE(0xf00)
+BAD_STACK_TRAMPOLINE(0xf20)
+
+	.globl	bad_stack_book3e
+bad_stack_book3e:
+	/* XXX: Needs to make SPRN_SPRG_GEN depend on exception type */
+	mfspr	r10,SPRN_SRR0;		  /* read SRR0 before touching stack */
+	ld	r1,PACAEMERGSP(r13)
+	subi	r1,r1,64+INT_FRAME_SIZE
+	std	r10,_NIP(r1)
+	std	r11,_MSR(r1)
+	ld	r10,PACA_EXGEN+EX_R1(r13) /* FIXME for crit & mcheck */
+	lwz	r11,PACA_EXGEN+EX_CR(r13) /* FIXME for crit & mcheck */
+	std	r10,GPR1(r1)
+	std	r11,_CCR(r1)
+	mfspr	r10,SPRN_DEAR
+	mfspr	r11,SPRN_ESR
+	std	r10,_DAR(r1)
+	std	r11,_DSISR(r1)
+	std	r0,GPR0(r1);		/* save r0 in stackframe */	    \
+	std	r2,GPR2(r1);		/* save r2 in stackframe */	    \
+	SAVE_4GPRS(3, r1);		/* save r3 - r6 in stackframe */    \
+	SAVE_2GPRS(7, r1);		/* save r7, r8 in stackframe */	    \
+	std	r9,GPR9(r1);		/* save r9 in stackframe */	    \
+	ld	r3,PACA_EXGEN+EX_R10(r13);/* get back r10 */		    \
+	ld	r4,PACA_EXGEN+EX_R11(r13);/* get back r11 */		    \
+	mfspr	r5,SPRN_SPRG_GEN_SCRATCH;/* get back r13 XXX can be wrong */ \
+	std	r3,GPR10(r1);		/* save r10 to stackframe */	    \
+	std	r4,GPR11(r1);		/* save r11 to stackframe */	    \
+	std	r12,GPR12(r1);		/* save r12 in stackframe */	    \
+	std	r5,GPR13(r1);		/* save it to stackframe */	    \
+	mflr	r10
+	mfctr	r11
+	mfxer	r12
+	std	r10,_LINK(r1)
+	std	r11,_CTR(r1)
+	std	r12,_XER(r1)
+	SAVE_10GPRS(14,r1)
+	SAVE_8GPRS(24,r1)
+	lhz	r12,PACA_TRAP_SAVE(r13)
+	std	r12,_TRAP(r1)
+	addi	r11,r1,INT_FRAME_SIZE
+	std	r11,0(r1)
+	li	r12,0
+	std	r12,0(r11)
+	ld	r2,PACATOC(r13)
+1:	addi	r3,r1,STACK_FRAME_OVERHEAD
+	bl	.kernel_bad_stack
+	b	1b
+
+/*
+ * Setup the initial TLB for a core. This current implementation
+ * assume that whatever we are running off will not conflict with
+ * the new mapping at PAGE_OFFSET.
+ * We also make various assumptions about the processor we run on,
+ * this might have to be made more flexible based on the content
+ * of MMUCFG and friends.
+ */
+_GLOBAL(initial_tlb_book3e)
+
+	/* Setup MAS 0,1,2,3 and 7 for tlbwe of a 1G entry that maps the
+	 * kernel linear mapping. We also set MAS8 once for all here though
+	 * that will have to be made dependent on whether we are running under
+	 * a hypervisor I suppose.
+	 */
+	li	r3,MAS0_HES | MAS0_WQ_ALLWAYS
+	mtspr	SPRN_MAS0,r3
+	lis	r3,(MAS1_VALID | MAS1_IPROT)@h
+	ori	r3,r3,BOOK3E_PAGESZ_1GB << MAS1_TSIZE_SHIFT
+	mtspr	SPRN_MAS1,r3
+	LOAD_REG_IMMEDIATE(r3, PAGE_OFFSET | MAS2_M)
+	mtspr	SPRN_MAS2,r3
+	li	r3,MAS3_SR | MAS3_SW | MAS3_SX
+	mtspr	SPRN_MAS7_MAS3,r3
+	li	r3,0
+	mtspr	SPRN_MAS8,r3
+
+	/* Write the TLB entry */
+	tlbwe
+
+	/* Now we branch the new virtual address mapped by this entry */
+	LOAD_REG_IMMEDIATE(r3,1f)
+	mtctr	r3
+	bctr
+
+1:	/* We are now running at PAGE_OFFSET, clean the TLB of everything
+	 * else (XXX we should scan for bolted crap from the firmware too)
+	 */
+	PPC_TLBILX(0,0,0)
+	sync
+	isync
+
+	/* We translate LR and return */
+	mflr	r3
+	tovirt(r3,r3)
+	mtlr	r3
+	blr
+
+/*
+ * Main entry (boot CPU, thread 0)
+ *
+ * We enter here from head_64.S, possibly after the prom_init trampoline
+ * with r3 and r4 already saved to r31 and 30 respectively and in 64 bits
+ * mode. Anything else is as it was left by the bootloader
+ *
+ * Initial requirements of this port:
+ *
+ * - Kernel loaded at 0 physical
+ * - A good lump of memory mapped 0:0 by UTLB entry 0
+ * - MSR:IS & MSR:DS set to 0
+ *
+ * Note that some of the above requirements will be relaxed in the future
+ * as the kernel becomes smarter at dealing with different initial conditions
+ * but for now you have to be careful
+ */
+_GLOBAL(start_initialization_book3e)
+	mflr	r28
+
+	/* First, we need to setup some initial TLBs to map the kernel
+	 * text, data and bss at PAGE_OFFSET. We don't have a real mode
+	 * and always use AS 0, so we just set it up to match our link
+	 * address and never use 0 based addresses.
+	 */
+	bl	.initial_tlb_book3e
+
+	/* Init global core bits */
+	bl	.init_core_book3e
+
+	/* Init per-thread bits */
+	bl	.init_thread_book3e
+
+	/* Return to common init code */
+	tovirt(r28,r28)
+	mtlr	r28
+	blr
+
+
+/*
+ * Secondary core/processor entry
+ *
+ * This is entered for thread 0 of a secondary core, all other threads
+ * are expected to be stopped. It's similar to start_initialization_book3e
+ * except that it's generally entered from the holding loop in head_64.S
+ * after CPUs have been gathered by Open Firmware.
+ *
+ * We assume we are in 32 bits mode running with whatever TLB entry was
+ * set for us by the firmware or POR engine.
+ */
+_GLOBAL(book3e_secondary_core_init_tlb_set)
+	li	r4,1
+	b	.generic_secondary_smp_init
+
+_GLOBAL(book3e_secondary_core_init)
+	mflr	r28
+
+	/* Do we need to setup initial TLB entry ? */
+	cmplwi	r4,0
+	bne	2f
+
+	/* Setup TLB for this core */
+	bl	.initial_tlb_book3e
+
+	/* We can return from the above running at a different
+	 * address, so recalculate r2 (TOC)
+	 */
+	bl	.relative_toc
+
+	/* Init global core bits */
+2:	bl	.init_core_book3e
+
+	/* Init per-thread bits */
+3:	bl	.init_thread_book3e
+
+	/* Return to common init code at proper virtual address.
+	 *
+	 * Due to various previous assumptions, we know we entered this
+	 * function at either the final PAGE_OFFSET mapping or using a
+	 * 1:1 mapping at 0, so we don't bother doing a complicated check
+	 * here, we just ensure the return address has the right top bits.
+	 *
+	 * Note that if we ever want to be smarter about where we can be
+	 * started from, we have to be careful that by the time we reach
+	 * the code below we may already be running at a different location
+	 * than the one we were called from since initial_tlb_book3e can
+	 * have moved us already.
+	 */
+	cmpdi	cr0,r28,0
+	blt	1f
+	lis	r3,PAGE_OFFSET@highest
+	sldi	r3,r3,32
+	or	r28,r28,r3
+1:	mtlr	r28
+	blr
+
+_GLOBAL(book3e_secondary_thread_init)
+	mflr	r28
+	b	3b
+
+_STATIC(init_core_book3e)
+	/* Establish the interrupt vector base */
+	LOAD_REG_IMMEDIATE(r3, interrupt_base_book3e)
+	mtspr	SPRN_IVPR,r3
+	sync
+	blr
+
+_STATIC(init_thread_book3e)
+	lis	r3,(SPRN_EPCR_ICM | SPRN_EPCR_GICM)@h
+	mtspr	SPRN_EPCR,r3
+
+	/* Make sure interrupts are off */
+	wrteei	0
+
+	/* disable watchdog and FIT and enable DEC interrupts */
+	lis	r3,TCR_DIE@h
+	mtspr	SPRN_TCR,r3
+
+	blr
+
+
+