1200 lines
		
	
	
	
		
			33 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			1200 lines
		
	
	
	
		
			33 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
/*
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 * Exception handling for Microblaze
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 *
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 * Rewriten interrupt handling
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 *
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 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
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 * Copyright (C) 2008-2009 PetaLogix
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 *
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 * uClinux customisation (C) 2005 John Williams
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 *
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 * MMU code derived from arch/ppc/kernel/head_4xx.S:
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 *	Copyright (C) 1995-1996 Gary Thomas <gdt@linuxppc.org>
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 *		Initial PowerPC version.
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 *	Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
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 *		Rewritten for PReP
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 *	Copyright (C) 1996 Paul Mackerras <paulus@cs.anu.edu.au>
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 *		Low-level exception handers, MMU support, and rewrite.
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 *	Copyright (C) 1997 Dan Malek <dmalek@jlc.net>
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 *		PowerPC 8xx modifications.
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 *	Copyright (C) 1998-1999 TiVo, Inc.
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 *		PowerPC 403GCX modifications.
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 *	Copyright (C) 1999 Grant Erickson <grant@lcse.umn.edu>
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 *		PowerPC 403GCX/405GP modifications.
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 *	Copyright 2000 MontaVista Software Inc.
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 *		PPC405 modifications
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 *	PowerPC 403GCX/405GP modifications.
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 *		Author: MontaVista Software, Inc.
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 *		frank_rowand@mvista.com or source@mvista.com
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 *		debbie_chu@mvista.com
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 *
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 * Original code
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 * Copyright (C) 2004 Xilinx, Inc.
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 *
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 * This program is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 as published
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 * by the Free Software Foundation.
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 */
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/*
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 * Here are the handlers which don't require enabling translation
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 * and calling other kernel code thus we can keep their design very simple
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 * and do all processing in real mode. All what they need is a valid current
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 * (that is an issue for the CONFIG_REGISTER_TASK_PTR case)
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 * This handlers use r3,r4,r5,r6 and optionally r[current] to work therefore
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 * these registers are saved/restored
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 * The handlers which require translation are in entry.S --KAA
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 *
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 * Microblaze HW Exception Handler
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 * - Non self-modifying exception handler for the following exception conditions
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 *   - Unalignment
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 *   - Instruction bus error
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 *   - Data bus error
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 *   - Illegal instruction opcode
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 *   - Divide-by-zero
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 *
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 *   - Privileged instruction exception (MMU)
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 *   - Data storage exception (MMU)
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 *   - Instruction storage exception (MMU)
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 *   - Data TLB miss exception (MMU)
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 *   - Instruction TLB miss exception (MMU)
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 *
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 * Note we disable interrupts during exception handling, otherwise we will
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 * possibly get multiple re-entrancy if interrupt handles themselves cause
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 * exceptions. JW
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 */
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#include <asm/exceptions.h>
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#include <asm/unistd.h>
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#include <asm/page.h>
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#include <asm/entry.h>
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#include <asm/current.h>
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#include <linux/linkage.h>
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#include <asm/mmu.h>
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#include <asm/pgtable.h>
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#include <asm/signal.h>
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#include <asm/registers.h>
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#include <asm/asm-offsets.h>
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#undef DEBUG
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/* Helpful Macros */
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#define NUM_TO_REG(num)		r ## num
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#ifdef CONFIG_MMU
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	#define RESTORE_STATE			\
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		lwi	r5, r1, 0;		\
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		mts	rmsr, r5;		\
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		nop;				\
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		lwi	r3, r1, PT_R3;		\
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		lwi	r4, r1, PT_R4;		\
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		lwi	r5, r1, PT_R5;		\
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		lwi	r6, r1, PT_R6;		\
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		lwi	r11, r1, PT_R11;	\
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		lwi	r31, r1, PT_R31;	\
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		lwi	r1, r1, PT_R1;
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#endif /* CONFIG_MMU */
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#define LWREG_NOP			\
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	bri	ex_handler_unhandled;	\
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	nop;
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#define SWREG_NOP			\
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	bri	ex_handler_unhandled;	\
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	nop;
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/* FIXME this is weird - for noMMU kernel is not possible to use brid
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 * instruction which can shorten executed time
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 */
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/* r3 is the source */
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#define R3_TO_LWREG_V(regnum)				\
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	swi	r3, r1, 4 * regnum;				\
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	bri	ex_handler_done;
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/* r3 is the source */
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#define R3_TO_LWREG(regnum)				\
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	or	NUM_TO_REG (regnum), r0, r3;		\
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	bri	ex_handler_done;
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/* r3 is the target */
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#define SWREG_TO_R3_V(regnum)				\
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	lwi	r3, r1, 4 * regnum;				\
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	bri	ex_sw_tail;
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/* r3 is the target */
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#define SWREG_TO_R3(regnum)				\
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	or	r3, r0, NUM_TO_REG (regnum);		\
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	bri	ex_sw_tail;
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#ifdef CONFIG_MMU
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	#define R3_TO_LWREG_VM_V(regnum)		\
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		brid	ex_lw_end_vm;			\
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		swi	r3, r7, 4 * regnum;
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	#define R3_TO_LWREG_VM(regnum)			\
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		brid	ex_lw_end_vm;			\
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		or	NUM_TO_REG (regnum), r0, r3;
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	#define SWREG_TO_R3_VM_V(regnum)		\
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		brid	ex_sw_tail_vm;			\
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		lwi	r3, r7, 4 * regnum;
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	#define SWREG_TO_R3_VM(regnum)			\
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		brid	ex_sw_tail_vm;			\
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		or	r3, r0, NUM_TO_REG (regnum);
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	/* Shift right instruction depending on available configuration */
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	#if CONFIG_XILINX_MICROBLAZE0_USE_BARREL > 0
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	#define BSRLI(rD, rA, imm)	\
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		bsrli rD, rA, imm
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	#else
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	#define BSRLI(rD, rA, imm) BSRLI ## imm (rD, rA)
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	/* Only the used shift constants defined here - add more if needed */
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	#define BSRLI2(rD, rA)				\
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		srl rD, rA;		/* << 1 */	\
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		srl rD, rD;		/* << 2 */
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	#define BSRLI10(rD, rA)				\
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		srl rD, rA;		/* << 1 */	\
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		srl rD, rD;		/* << 2 */	\
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		srl rD, rD;		/* << 3 */	\
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		srl rD, rD;		/* << 4 */	\
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		srl rD, rD;		/* << 5 */	\
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		srl rD, rD;		/* << 6 */	\
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		srl rD, rD;		/* << 7 */	\
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		srl rD, rD;		/* << 8 */	\
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		srl rD, rD;		/* << 9 */	\
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		srl rD, rD		/* << 10 */
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	#define BSRLI20(rD, rA)		\
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		BSRLI10(rD, rA);	\
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		BSRLI10(rD, rD)
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	#endif
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#endif /* CONFIG_MMU */
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.extern other_exception_handler /* Defined in exception.c */
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/*
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 * hw_exception_handler - Handler for exceptions
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 *
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 * Exception handler notes:
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 * - Handles all exceptions
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 * - Does not handle unaligned exceptions during load into r17, r1, r0.
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 * - Does not handle unaligned exceptions during store from r17 (cannot be
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 *   done) and r1 (slows down common case)
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 *
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 *  Relevant register structures
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 *
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 *  EAR - |----|----|----|----|----|----|----|----|
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 *      - <  ##   32 bit faulting address     ##  >
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 *
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 *  ESR - |----|----|----|----|----| - | - |-----|-----|
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 *      -                            W   S   REG   EXC
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 *
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 *
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 * STACK FRAME STRUCTURE (for NO_MMU)
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 * ---------------------------------
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 *
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 *      +-------------+         + 0
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 *      |     MSR     |
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 *      +-------------+         + 4
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 *      |     r1      |
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 *      |      .      |
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 *      |      .      |
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 *      |      .      |
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 *      |      .      |
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 *      |     r18     |
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 *      +-------------+         + 76
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 *      |      .      |
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 *      |      .      |
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 *
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 * MMU kernel uses the same 'pt_pool_space' pointed space
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 * which is used for storing register values - noMMu style was, that values were
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 * stored in stack but in case of failure you lost information about register.
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 * Currently you can see register value in memory in specific place.
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 * In compare to with previous solution the speed should be the same.
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 *
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 * MMU exception handler has different handling compare to no MMU kernel.
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 * Exception handler use jump table for directing of what happen. For MMU kernel
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 * is this approach better because MMU relate exception are handled by asm code
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 * in this file. In compare to with MMU expect of unaligned exception
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 * is everything handled by C code.
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 */
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/*
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 * every of these handlers is entered having R3/4/5/6/11/current saved on stack
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 * and clobbered so care should be taken to restore them if someone is going to
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 * return from exception
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 */
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/* wrappers to restore state before coming to entry.S */
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#ifdef CONFIG_MMU
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.section .data
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.align 4
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pt_pool_space:
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	.space	PT_SIZE
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#ifdef DEBUG
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/* Create space for exception counting. */
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.section .data
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.global exception_debug_table
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.align 4
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exception_debug_table:
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	/* Look at exception vector table. There is 32 exceptions * word size */
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	.space	(32 * 4)
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#endif /* DEBUG */
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.section .rodata
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.align 4
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_MB_HW_ExceptionVectorTable:
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/*  0 - Undefined */
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	.long	TOPHYS(ex_handler_unhandled)
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/*  1 - Unaligned data access exception */
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	.long	TOPHYS(handle_unaligned_ex)
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/*  2 - Illegal op-code exception */
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	.long	TOPHYS(full_exception_trapw)
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/*  3 - Instruction bus error exception */
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	.long	TOPHYS(full_exception_trapw)
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/*  4 - Data bus error exception */
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	.long	TOPHYS(full_exception_trapw)
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/*  5 - Divide by zero exception */
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	.long	TOPHYS(full_exception_trapw)
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/*  6 - Floating point unit exception */
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	.long	TOPHYS(full_exception_trapw)
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/*  7 - Privileged instruction exception */
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	.long	TOPHYS(full_exception_trapw)
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/*  8 - 15 - Undefined */
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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/* 16 - Data storage exception */
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	.long	TOPHYS(handle_data_storage_exception)
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/* 17 - Instruction storage exception */
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	.long	TOPHYS(handle_instruction_storage_exception)
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/* 18 - Data TLB miss exception */
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	.long	TOPHYS(handle_data_tlb_miss_exception)
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/* 19 - Instruction TLB miss exception */
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	.long	TOPHYS(handle_instruction_tlb_miss_exception)
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/* 20 - 31 - Undefined */
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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	.long	TOPHYS(ex_handler_unhandled)
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#endif
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.global _hw_exception_handler
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.section .text
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.align 4
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.ent _hw_exception_handler
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_hw_exception_handler:
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#ifndef CONFIG_MMU
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	addik	r1, r1, -(EX_HANDLER_STACK_SIZ); /* Create stack frame */
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#else
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	swi	r1, r0, TOPHYS(pt_pool_space + PT_R1); /* GET_SP */
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	/* Save date to kernel memory. Here is the problem
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	 * when you came from user space */
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	ori	r1, r0, TOPHYS(pt_pool_space);
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#endif
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	swi	r3, r1, PT_R3
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	swi	r4, r1, PT_R4
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	swi	r5, r1, PT_R5
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	swi	r6, r1, PT_R6
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#ifdef CONFIG_MMU
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	swi	r11, r1, PT_R11
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	swi	r31, r1, PT_R31
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	lwi	r31, r0, TOPHYS(PER_CPU(CURRENT_SAVE)) /* get saved current */
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#endif
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	mfs	r5, rmsr;
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	nop
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	swi	r5, r1, 0;
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	mfs	r4, resr
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	nop
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	mfs	r3, rear;
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	nop
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#ifndef CONFIG_MMU
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	andi	r5, r4, 0x1000;		/* Check ESR[DS] */
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	beqi	r5, not_in_delay_slot;	/* Branch if ESR[DS] not set */
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	mfs	r17, rbtr;	/* ESR[DS] set - return address in BTR */
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	nop
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not_in_delay_slot:
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	swi	r17, r1, PT_R17
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#endif
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	andi	r5, r4, 0x1F;		/* Extract ESR[EXC] */
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#ifdef CONFIG_MMU
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	/* Calculate exception vector offset = r5 << 2 */
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	addk	r6, r5, r5; /* << 1 */
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	addk	r6, r6, r6; /* << 2 */
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#ifdef DEBUG
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/* counting which exception happen */
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	lwi	r5, r0, TOPHYS(exception_debug_table)
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	addi	r5, r5, 1
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	swi	r5, r0, TOPHYS(exception_debug_table)
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	lwi	r5, r6, TOPHYS(exception_debug_table)
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	addi	r5, r5, 1
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	swi	r5, r6, TOPHYS(exception_debug_table)
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#endif
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/* end */
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	/* Load the HW Exception vector */
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	lwi	r6, r6, TOPHYS(_MB_HW_ExceptionVectorTable)
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	bra	r6
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full_exception_trapw:
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	RESTORE_STATE
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	bri	full_exception_trap
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#else
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	/* Exceptions enabled here. This will allow nested exceptions */
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	mfs	r6, rmsr;
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	nop
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	swi	r6, r1, 0; /* RMSR_OFFSET */
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	ori	r6, r6, 0x100; /* Turn ON the EE bit */
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	andi	r6, r6, ~2; /* Disable interrupts */
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	mts	rmsr, r6;
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	nop
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	xori	r6, r5, 1; /* 00001 = Unaligned Exception */
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	/* Jump to unalignment exception handler */
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	beqi	r6, handle_unaligned_ex;
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handle_other_ex: /* Handle Other exceptions here */
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	/* Save other volatiles before we make procedure calls below */
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	swi	r7, r1, PT_R7
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	swi	r8, r1, PT_R8
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	swi	r9, r1, PT_R9
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	swi	r10, r1, PT_R10
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	swi	r11, r1, PT_R11
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	swi	r12, r1, PT_R12
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	swi	r14, r1, PT_R14
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	swi	r15, r1, PT_R15
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	swi	r18, r1, PT_R18
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	or	r5, r1, r0
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	andi	r6, r4, 0x1F; /* Load ESR[EC] */
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	lwi	r7, r0, PER_CPU(KM) /* MS: saving current kernel mode to regs */
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	swi	r7, r1, PT_MODE
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	mfs	r7, rfsr
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	nop
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	addk	r8, r17, r0; /* Load exception address */
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	bralid	r15, full_exception; /* Branch to the handler */
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	nop;
 | 
						|
	mts	rfsr, r0;	/* Clear sticky fsr */
 | 
						|
	nop
 | 
						|
 | 
						|
	/*
 | 
						|
	 * Trigger execution of the signal handler by enabling
 | 
						|
	 * interrupts and calling an invalid syscall.
 | 
						|
	 */
 | 
						|
	mfs	r5, rmsr;
 | 
						|
	nop
 | 
						|
	ori	r5, r5, 2;
 | 
						|
	mts	rmsr, r5; /* enable interrupt */
 | 
						|
	nop
 | 
						|
	addi	r12, r0, __NR_syscalls;
 | 
						|
	brki	r14, 0x08;
 | 
						|
	mfs	r5, rmsr; /* disable interrupt */
 | 
						|
	nop
 | 
						|
	andi	r5, r5, ~2;
 | 
						|
	mts	rmsr, r5;
 | 
						|
	nop
 | 
						|
 | 
						|
	lwi	r7, r1, PT_R7
 | 
						|
	lwi	r8, r1, PT_R8
 | 
						|
	lwi	r9, r1, PT_R9
 | 
						|
	lwi	r10, r1, PT_R10
 | 
						|
	lwi	r11, r1, PT_R11
 | 
						|
	lwi	r12, r1, PT_R12
 | 
						|
	lwi	r14, r1, PT_R14
 | 
						|
	lwi	r15, r1, PT_R15
 | 
						|
	lwi	r18, r1, PT_R18
 | 
						|
 | 
						|
	bri	ex_handler_done; /* Complete exception handling */
 | 
						|
#endif
 | 
						|
 | 
						|
/* 0x01 - Unaligned data access exception
 | 
						|
 * This occurs when a word access is not aligned on a word boundary,
 | 
						|
 * or when a 16-bit access is not aligned on a 16-bit boundary.
 | 
						|
 * This handler perform the access, and returns, except for MMU when
 | 
						|
 * the unaligned address is last on a 4k page or the physical address is
 | 
						|
 * not found in the page table, in which case unaligned_data_trap is called.
 | 
						|
 */
 | 
						|
handle_unaligned_ex:
 | 
						|
	/* Working registers already saved: R3, R4, R5, R6
 | 
						|
	 *  R4 = ESR
 | 
						|
	 *  R3 = EAR
 | 
						|
	 */
 | 
						|
#ifdef CONFIG_MMU
 | 
						|
	andi	r6, r4, 0x1000			/* Check ESR[DS] */
 | 
						|
	beqi	r6, _no_delayslot		/* Branch if ESR[DS] not set */
 | 
						|
	mfs	r17, rbtr;	/* ESR[DS] set - return address in BTR */
 | 
						|
	nop
 | 
						|
_no_delayslot:
 | 
						|
	/* jump to high level unaligned handler */
 | 
						|
	RESTORE_STATE;
 | 
						|
	bri	unaligned_data_trap
 | 
						|
#endif
 | 
						|
	andi	r6, r4, 0x3E0; /* Mask and extract the register operand */
 | 
						|
	srl	r6, r6; /* r6 >> 5 */
 | 
						|
	srl	r6, r6;
 | 
						|
	srl	r6, r6;
 | 
						|
	srl	r6, r6;
 | 
						|
	srl	r6, r6;
 | 
						|
	/* Store the register operand in a temporary location */
 | 
						|
	sbi	r6, r0, TOPHYS(ex_reg_op);
 | 
						|
 | 
						|
	andi	r6, r4, 0x400; /* Extract ESR[S] */
 | 
						|
	bnei	r6, ex_sw;
 | 
						|
ex_lw:
 | 
						|
	andi	r6, r4, 0x800; /* Extract ESR[W] */
 | 
						|
	beqi	r6, ex_lhw;
 | 
						|
	lbui	r5, r3, 0; /* Exception address in r3 */
 | 
						|
	/* Load a word, byte-by-byte from destination address
 | 
						|
		and save it in tmp space */
 | 
						|
	sbi	r5, r0, TOPHYS(ex_tmp_data_loc_0);
 | 
						|
	lbui	r5, r3, 1;
 | 
						|
	sbi	r5, r0, TOPHYS(ex_tmp_data_loc_1);
 | 
						|
	lbui	r5, r3, 2;
 | 
						|
	sbi	r5, r0, TOPHYS(ex_tmp_data_loc_2);
 | 
						|
	lbui	r5, r3, 3;
 | 
						|
	sbi	r5, r0, TOPHYS(ex_tmp_data_loc_3);
 | 
						|
	/* Get the destination register value into r4 */
 | 
						|
	lwi	r4, r0, TOPHYS(ex_tmp_data_loc_0);
 | 
						|
	bri	ex_lw_tail;
 | 
						|
ex_lhw:
 | 
						|
	lbui	r5, r3, 0; /* Exception address in r3 */
 | 
						|
	/* Load a half-word, byte-by-byte from destination
 | 
						|
		address and save it in tmp space */
 | 
						|
	sbi	r5, r0, TOPHYS(ex_tmp_data_loc_0);
 | 
						|
	lbui	r5, r3, 1;
 | 
						|
	sbi	r5, r0, TOPHYS(ex_tmp_data_loc_1);
 | 
						|
	/* Get the destination register value into r4 */
 | 
						|
	lhui	r4, r0, TOPHYS(ex_tmp_data_loc_0);
 | 
						|
ex_lw_tail:
 | 
						|
	/* Get the destination register number into r5 */
 | 
						|
	lbui	r5, r0, TOPHYS(ex_reg_op);
 | 
						|
	/* Form load_word jump table offset (lw_table + (8 * regnum)) */
 | 
						|
	addik	r6, r0, TOPHYS(lw_table);
 | 
						|
	addk	r5, r5, r5;
 | 
						|
	addk	r5, r5, r5;
 | 
						|
	addk	r5, r5, r5;
 | 
						|
	addk	r5, r5, r6;
 | 
						|
	bra	r5;
 | 
						|
ex_lw_end: /* Exception handling of load word, ends */
 | 
						|
ex_sw:
 | 
						|
	/* Get the destination register number into r5 */
 | 
						|
	lbui	r5, r0, TOPHYS(ex_reg_op);
 | 
						|
	/* Form store_word jump table offset (sw_table + (8 * regnum)) */
 | 
						|
	addik	r6, r0, TOPHYS(sw_table);
 | 
						|
	add	r5, r5, r5;
 | 
						|
	add	r5, r5, r5;
 | 
						|
	add	r5, r5, r5;
 | 
						|
	add	r5, r5, r6;
 | 
						|
	bra	r5;
 | 
						|
ex_sw_tail:
 | 
						|
	mfs	r6, resr;
 | 
						|
	nop
 | 
						|
	andi	r6, r6, 0x800; /* Extract ESR[W] */
 | 
						|
	beqi	r6, ex_shw;
 | 
						|
	/* Get the word - delay slot */
 | 
						|
	swi	r4, r0, TOPHYS(ex_tmp_data_loc_0);
 | 
						|
	/* Store the word, byte-by-byte into destination address */
 | 
						|
	lbui	r4, r0, TOPHYS(ex_tmp_data_loc_0);
 | 
						|
	sbi	r4, r3, 0;
 | 
						|
	lbui	r4, r0, TOPHYS(ex_tmp_data_loc_1);
 | 
						|
	sbi	r4, r3, 1;
 | 
						|
	lbui	r4, r0, TOPHYS(ex_tmp_data_loc_2);
 | 
						|
	sbi	r4, r3, 2;
 | 
						|
	lbui	r4, r0, TOPHYS(ex_tmp_data_loc_3);
 | 
						|
	sbi	r4, r3, 3;
 | 
						|
	bri	ex_handler_done;
 | 
						|
 | 
						|
ex_shw:
 | 
						|
	/* Store the lower half-word, byte-by-byte into destination address */
 | 
						|
	swi	r4, r0, TOPHYS(ex_tmp_data_loc_0);
 | 
						|
	lbui	r4, r0, TOPHYS(ex_tmp_data_loc_2);
 | 
						|
	sbi	r4, r3, 0;
 | 
						|
	lbui	r4, r0, TOPHYS(ex_tmp_data_loc_3);
 | 
						|
	sbi	r4, r3, 1;
 | 
						|
ex_sw_end: /* Exception handling of store word, ends. */
 | 
						|
 | 
						|
ex_handler_done:
 | 
						|
#ifndef CONFIG_MMU
 | 
						|
	lwi	r5, r1, 0 /* RMSR */
 | 
						|
	mts	rmsr, r5
 | 
						|
	nop
 | 
						|
	lwi	r3, r1, PT_R3
 | 
						|
	lwi	r4, r1, PT_R4
 | 
						|
	lwi	r5, r1, PT_R5
 | 
						|
	lwi	r6, r1, PT_R6
 | 
						|
	lwi	r17, r1, PT_R17
 | 
						|
 | 
						|
	rted	r17, 0
 | 
						|
	addik	r1, r1, (EX_HANDLER_STACK_SIZ); /* Restore stack frame */
 | 
						|
#else
 | 
						|
	RESTORE_STATE;
 | 
						|
	rted	r17, 0
 | 
						|
	nop
 | 
						|
#endif
 | 
						|
 | 
						|
#ifdef CONFIG_MMU
 | 
						|
	/* Exception vector entry code. This code runs with address translation
 | 
						|
	 * turned off (i.e. using physical addresses). */
 | 
						|
 | 
						|
	/* Exception vectors. */
 | 
						|
 | 
						|
	/* 0x10 - Data Storage Exception
 | 
						|
	 * This happens for just a few reasons. U0 set (but we don't do that),
 | 
						|
	 * or zone protection fault (user violation, write to protected page).
 | 
						|
	 * If this is just an update of modified status, we do that quickly
 | 
						|
	 * and exit. Otherwise, we call heavyweight functions to do the work.
 | 
						|
	 */
 | 
						|
	handle_data_storage_exception:
 | 
						|
		/* Working registers already saved: R3, R4, R5, R6
 | 
						|
		 * R3 = ESR
 | 
						|
		 */
 | 
						|
		mfs	r11, rpid
 | 
						|
		nop
 | 
						|
		/* If we are faulting a kernel address, we have to use the
 | 
						|
		 * kernel page tables.
 | 
						|
		 */
 | 
						|
		ori	r5, r0, CONFIG_KERNEL_START
 | 
						|
		cmpu	r5, r3, r5
 | 
						|
		bgti	r5, ex3
 | 
						|
		/* First, check if it was a zone fault (which means a user
 | 
						|
		 * tried to access a kernel or read-protected page - always
 | 
						|
		 * a SEGV). All other faults here must be stores, so no
 | 
						|
		 * need to check ESR_S as well. */
 | 
						|
		andi	r4, r4, ESR_DIZ		/* ESR_Z - zone protection */
 | 
						|
		bnei	r4, ex2
 | 
						|
 | 
						|
		ori	r4, r0, swapper_pg_dir
 | 
						|
		mts	rpid, r0		/* TLB will have 0 TID */
 | 
						|
		nop
 | 
						|
		bri	ex4
 | 
						|
 | 
						|
		/* Get the PGD for the current thread. */
 | 
						|
	ex3:
 | 
						|
		/* First, check if it was a zone fault (which means a user
 | 
						|
		 * tried to access a kernel or read-protected page - always
 | 
						|
		 * a SEGV). All other faults here must be stores, so no
 | 
						|
		 * need to check ESR_S as well. */
 | 
						|
		andi	r4, r4, ESR_DIZ		/* ESR_Z */
 | 
						|
		bnei	r4, ex2
 | 
						|
		/* get current task address */
 | 
						|
		addi	r4 ,CURRENT_TASK, TOPHYS(0);
 | 
						|
		lwi	r4, r4, TASK_THREAD+PGDIR
 | 
						|
	ex4:
 | 
						|
		tophys(r4,r4)
 | 
						|
		/* Create L1 (pgdir/pmd) address */
 | 
						|
		BSRLI(r5,r3, PGDIR_SHIFT - 2)
 | 
						|
		andi	r5, r5, PAGE_SIZE - 4
 | 
						|
/* Assume pgdir aligned on 4K boundary, no need for "andi r4,r4,0xfffff003" */
 | 
						|
		or	r4, r4, r5
 | 
						|
		lwi	r4, r4, 0		/* Get L1 entry */
 | 
						|
		andi	r5, r4, PAGE_MASK /* Extract L2 (pte) base address */
 | 
						|
		beqi	r5, ex2			/* Bail if no table */
 | 
						|
 | 
						|
		tophys(r5,r5)
 | 
						|
		BSRLI(r6,r3,PTE_SHIFT) /* Compute PTE address */
 | 
						|
		andi	r6, r6, PAGE_SIZE - 4
 | 
						|
		or	r5, r5, r6
 | 
						|
		lwi	r4, r5, 0		/* Get Linux PTE */
 | 
						|
 | 
						|
		andi	r6, r4, _PAGE_RW	/* Is it writeable? */
 | 
						|
		beqi	r6, ex2			/* Bail if not */
 | 
						|
 | 
						|
		/* Update 'changed' */
 | 
						|
		ori	r4, r4, _PAGE_DIRTY|_PAGE_ACCESSED|_PAGE_HWWRITE
 | 
						|
		swi	r4, r5, 0		/* Update Linux page table */
 | 
						|
 | 
						|
		/* Most of the Linux PTE is ready to load into the TLB LO.
 | 
						|
		 * We set ZSEL, where only the LS-bit determines user access.
 | 
						|
		 * We set execute, because we don't have the granularity to
 | 
						|
		 * properly set this at the page level (Linux problem).
 | 
						|
		 * If shared is set, we cause a zero PID->TID load.
 | 
						|
		 * Many of these bits are software only. Bits we don't set
 | 
						|
		 * here we (properly should) assume have the appropriate value.
 | 
						|
		 */
 | 
						|
/* Ignore memory coherent, just LSB on ZSEL is used + EX/WR */
 | 
						|
		andi	r4, r4, PAGE_MASK | TLB_EX | TLB_WR | \
 | 
						|
						TLB_ZSEL(1) | TLB_ATTR_MASK
 | 
						|
		ori	r4, r4, _PAGE_HWEXEC	/* make it executable */
 | 
						|
 | 
						|
		/* find the TLB index that caused the fault. It has to be here*/
 | 
						|
		mts	rtlbsx, r3
 | 
						|
		nop
 | 
						|
		mfs	r5, rtlbx		/* DEBUG: TBD */
 | 
						|
		nop
 | 
						|
		mts	rtlblo, r4		/* Load TLB LO */
 | 
						|
		nop
 | 
						|
						/* Will sync shadow TLBs */
 | 
						|
 | 
						|
		/* Done...restore registers and get out of here. */
 | 
						|
		mts	rpid, r11
 | 
						|
		nop
 | 
						|
		bri 4
 | 
						|
 | 
						|
		RESTORE_STATE;
 | 
						|
		rted	r17, 0
 | 
						|
		nop
 | 
						|
	ex2:
 | 
						|
		/* The bailout. Restore registers to pre-exception conditions
 | 
						|
		 * and call the heavyweights to help us out. */
 | 
						|
		mts	rpid, r11
 | 
						|
		nop
 | 
						|
		bri 4
 | 
						|
		RESTORE_STATE;
 | 
						|
		bri	page_fault_data_trap
 | 
						|
 | 
						|
 | 
						|
	/* 0x11 - Instruction Storage Exception
 | 
						|
	 * This is caused by a fetch from non-execute or guarded pages. */
 | 
						|
	handle_instruction_storage_exception:
 | 
						|
		/* Working registers already saved: R3, R4, R5, R6
 | 
						|
		 * R3 = ESR
 | 
						|
		 */
 | 
						|
 | 
						|
		RESTORE_STATE;
 | 
						|
		bri	page_fault_instr_trap
 | 
						|
 | 
						|
	/* 0x12 - Data TLB Miss Exception
 | 
						|
	 * As the name implies, translation is not in the MMU, so search the
 | 
						|
	 * page tables and fix it. The only purpose of this function is to
 | 
						|
	 * load TLB entries from the page table if they exist.
 | 
						|
	 */
 | 
						|
	handle_data_tlb_miss_exception:
 | 
						|
		/* Working registers already saved: R3, R4, R5, R6
 | 
						|
		 * R3 = EAR, R4 = ESR
 | 
						|
		 */
 | 
						|
		mfs	r11, rpid
 | 
						|
		nop
 | 
						|
 | 
						|
		/* If we are faulting a kernel address, we have to use the
 | 
						|
		 * kernel page tables. */
 | 
						|
		ori	r6, r0, CONFIG_KERNEL_START
 | 
						|
		cmpu	r4, r3, r6
 | 
						|
		bgti	r4, ex5
 | 
						|
		ori	r4, r0, swapper_pg_dir
 | 
						|
		mts	rpid, r0		/* TLB will have 0 TID */
 | 
						|
		nop
 | 
						|
		bri	ex6
 | 
						|
 | 
						|
		/* Get the PGD for the current thread. */
 | 
						|
	ex5:
 | 
						|
		/* get current task address */
 | 
						|
		addi	r4 ,CURRENT_TASK, TOPHYS(0);
 | 
						|
		lwi	r4, r4, TASK_THREAD+PGDIR
 | 
						|
	ex6:
 | 
						|
		tophys(r4,r4)
 | 
						|
		/* Create L1 (pgdir/pmd) address */
 | 
						|
		BSRLI(r5,r3, PGDIR_SHIFT - 2)
 | 
						|
		andi	r5, r5, PAGE_SIZE - 4
 | 
						|
/* Assume pgdir aligned on 4K boundary, no need for "andi r4,r4,0xfffff003" */
 | 
						|
		or	r4, r4, r5
 | 
						|
		lwi	r4, r4, 0		/* Get L1 entry */
 | 
						|
		andi	r5, r4, PAGE_MASK /* Extract L2 (pte) base address */
 | 
						|
		beqi	r5, ex7			/* Bail if no table */
 | 
						|
 | 
						|
		tophys(r5,r5)
 | 
						|
		BSRLI(r6,r3,PTE_SHIFT) /* Compute PTE address */
 | 
						|
		andi	r6, r6, PAGE_SIZE - 4
 | 
						|
		or	r5, r5, r6
 | 
						|
		lwi	r4, r5, 0		/* Get Linux PTE */
 | 
						|
 | 
						|
		andi	r6, r4, _PAGE_PRESENT
 | 
						|
		beqi	r6, ex7
 | 
						|
 | 
						|
		ori	r4, r4, _PAGE_ACCESSED
 | 
						|
		swi	r4, r5, 0
 | 
						|
 | 
						|
		/* Most of the Linux PTE is ready to load into the TLB LO.
 | 
						|
		 * We set ZSEL, where only the LS-bit determines user access.
 | 
						|
		 * We set execute, because we don't have the granularity to
 | 
						|
		 * properly set this at the page level (Linux problem).
 | 
						|
		 * If shared is set, we cause a zero PID->TID load.
 | 
						|
		 * Many of these bits are software only. Bits we don't set
 | 
						|
		 * here we (properly should) assume have the appropriate value.
 | 
						|
		 */
 | 
						|
		brid	finish_tlb_load
 | 
						|
		andi	r4, r4, PAGE_MASK | TLB_EX | TLB_WR | \
 | 
						|
						TLB_ZSEL(1) | TLB_ATTR_MASK
 | 
						|
	ex7:
 | 
						|
		/* The bailout. Restore registers to pre-exception conditions
 | 
						|
		 * and call the heavyweights to help us out.
 | 
						|
		 */
 | 
						|
		mts	rpid, r11
 | 
						|
		nop
 | 
						|
		bri	4
 | 
						|
		RESTORE_STATE;
 | 
						|
		bri	page_fault_data_trap
 | 
						|
 | 
						|
	/* 0x13 - Instruction TLB Miss Exception
 | 
						|
	 * Nearly the same as above, except we get our information from
 | 
						|
	 * different registers and bailout to a different point.
 | 
						|
	 */
 | 
						|
	handle_instruction_tlb_miss_exception:
 | 
						|
		/* Working registers already saved: R3, R4, R5, R6
 | 
						|
		 *  R3 = ESR
 | 
						|
		 */
 | 
						|
		mfs	r11, rpid
 | 
						|
		nop
 | 
						|
 | 
						|
		/* If we are faulting a kernel address, we have to use the
 | 
						|
		 * kernel page tables.
 | 
						|
		 */
 | 
						|
		ori	r4, r0, CONFIG_KERNEL_START
 | 
						|
		cmpu	r4, r3, r4
 | 
						|
		bgti	r4, ex8
 | 
						|
		ori	r4, r0, swapper_pg_dir
 | 
						|
		mts	rpid, r0		/* TLB will have 0 TID */
 | 
						|
		nop
 | 
						|
		bri	ex9
 | 
						|
 | 
						|
		/* Get the PGD for the current thread. */
 | 
						|
	ex8:
 | 
						|
		/* get current task address */
 | 
						|
		addi	r4 ,CURRENT_TASK, TOPHYS(0);
 | 
						|
		lwi	r4, r4, TASK_THREAD+PGDIR
 | 
						|
	ex9:
 | 
						|
		tophys(r4,r4)
 | 
						|
		/* Create L1 (pgdir/pmd) address */
 | 
						|
		BSRLI(r5,r3, PGDIR_SHIFT - 2)
 | 
						|
		andi	r5, r5, PAGE_SIZE - 4
 | 
						|
/* Assume pgdir aligned on 4K boundary, no need for "andi r4,r4,0xfffff003" */
 | 
						|
		or	r4, r4, r5
 | 
						|
		lwi	r4, r4, 0		/* Get L1 entry */
 | 
						|
		andi	r5, r4, PAGE_MASK /* Extract L2 (pte) base address */
 | 
						|
		beqi	r5, ex10		/* Bail if no table */
 | 
						|
 | 
						|
		tophys(r5,r5)
 | 
						|
		BSRLI(r6,r3,PTE_SHIFT) /* Compute PTE address */
 | 
						|
		andi	r6, r6, PAGE_SIZE - 4
 | 
						|
		or	r5, r5, r6
 | 
						|
		lwi	r4, r5, 0		/* Get Linux PTE */
 | 
						|
 | 
						|
		andi	r6, r4, _PAGE_PRESENT
 | 
						|
		beqi	r6, ex10
 | 
						|
 | 
						|
		ori	r4, r4, _PAGE_ACCESSED
 | 
						|
		swi	r4, r5, 0
 | 
						|
 | 
						|
		/* Most of the Linux PTE is ready to load into the TLB LO.
 | 
						|
		 * We set ZSEL, where only the LS-bit determines user access.
 | 
						|
		 * We set execute, because we don't have the granularity to
 | 
						|
		 * properly set this at the page level (Linux problem).
 | 
						|
		 * If shared is set, we cause a zero PID->TID load.
 | 
						|
		 * Many of these bits are software only. Bits we don't set
 | 
						|
		 * here we (properly should) assume have the appropriate value.
 | 
						|
		 */
 | 
						|
		brid	finish_tlb_load
 | 
						|
		andi	r4, r4, PAGE_MASK | TLB_EX | TLB_WR | \
 | 
						|
						TLB_ZSEL(1) | TLB_ATTR_MASK
 | 
						|
	ex10:
 | 
						|
		/* The bailout. Restore registers to pre-exception conditions
 | 
						|
		 * and call the heavyweights to help us out.
 | 
						|
		 */
 | 
						|
		mts	rpid, r11
 | 
						|
		nop
 | 
						|
		bri 4
 | 
						|
		RESTORE_STATE;
 | 
						|
		bri	page_fault_instr_trap
 | 
						|
 | 
						|
/* Both the instruction and data TLB miss get to this point to load the TLB.
 | 
						|
 *	r3 - EA of fault
 | 
						|
 *	r4 - TLB LO (info from Linux PTE)
 | 
						|
 *	r5, r6 - available to use
 | 
						|
 *	PID - loaded with proper value when we get here
 | 
						|
 *	Upon exit, we reload everything and RFI.
 | 
						|
 * A common place to load the TLB.
 | 
						|
 */
 | 
						|
.section .data
 | 
						|
.align 4
 | 
						|
.global tlb_skip
 | 
						|
	tlb_skip:
 | 
						|
		.long	MICROBLAZE_TLB_SKIP
 | 
						|
	tlb_index:
 | 
						|
		/* MS: storing last used tlb index */
 | 
						|
		.long	MICROBLAZE_TLB_SIZE/2
 | 
						|
.previous
 | 
						|
	finish_tlb_load:
 | 
						|
		/* MS: load the last used TLB index. */
 | 
						|
		lwi	r5, r0, TOPHYS(tlb_index)
 | 
						|
		addik	r5, r5, 1 /* MS: inc tlb_index -> use next one */
 | 
						|
 | 
						|
/* MS: FIXME this is potential fault, because this is mask not count */
 | 
						|
		andi	r5, r5, MICROBLAZE_TLB_SIZE - 1
 | 
						|
		ori	r6, r0, 1
 | 
						|
		cmp	r31, r5, r6
 | 
						|
		blti	r31, ex12
 | 
						|
		lwi	r5, r0, TOPHYS(tlb_skip)
 | 
						|
	ex12:
 | 
						|
		/* MS: save back current TLB index */
 | 
						|
		swi	r5, r0, TOPHYS(tlb_index)
 | 
						|
 | 
						|
		ori	r4, r4, _PAGE_HWEXEC	/* make it executable */
 | 
						|
		mts	rtlbx, r5		/* MS: save current TLB */
 | 
						|
		nop
 | 
						|
		mts	rtlblo,	r4		/* MS: save to TLB LO */
 | 
						|
		nop
 | 
						|
 | 
						|
		/* Create EPN. This is the faulting address plus a static
 | 
						|
		 * set of bits. These are size, valid, E, U0, and ensure
 | 
						|
		 * bits 20 and 21 are zero.
 | 
						|
		 */
 | 
						|
		andi	r3, r3, PAGE_MASK
 | 
						|
#ifdef CONFIG_MICROBLAZE_64K_PAGES
 | 
						|
		ori	r3, r3, TLB_VALID | TLB_PAGESZ(PAGESZ_64K)
 | 
						|
#elif CONFIG_MICROBLAZE_16K_PAGES
 | 
						|
		ori	r3, r3, TLB_VALID | TLB_PAGESZ(PAGESZ_16K)
 | 
						|
#else
 | 
						|
		ori	r3, r3, TLB_VALID | TLB_PAGESZ(PAGESZ_4K)
 | 
						|
#endif
 | 
						|
		mts	rtlbhi,	r3		/* Load TLB HI */
 | 
						|
		nop
 | 
						|
 | 
						|
		/* Done...restore registers and get out of here. */
 | 
						|
		mts	rpid, r11
 | 
						|
		nop
 | 
						|
		bri 4
 | 
						|
		RESTORE_STATE;
 | 
						|
		rted	r17, 0
 | 
						|
		nop
 | 
						|
 | 
						|
	/* extern void giveup_fpu(struct task_struct *prev)
 | 
						|
	 *
 | 
						|
	 * The MicroBlaze processor may have an FPU, so this should not just
 | 
						|
	 * return: TBD.
 | 
						|
	 */
 | 
						|
	.globl giveup_fpu;
 | 
						|
	.align 4;
 | 
						|
	giveup_fpu:
 | 
						|
		bralid	r15,0			/* TBD */
 | 
						|
		nop
 | 
						|
 | 
						|
	/* At present, this routine just hangs. - extern void abort(void) */
 | 
						|
	.globl abort;
 | 
						|
	.align 4;
 | 
						|
	abort:
 | 
						|
		br	r0
 | 
						|
 | 
						|
	.globl set_context;
 | 
						|
	.align 4;
 | 
						|
	set_context:
 | 
						|
		mts	rpid, r5	/* Shadow TLBs are automatically */
 | 
						|
		nop
 | 
						|
		bri	4		/* flushed by changing PID */
 | 
						|
		rtsd	r15,8
 | 
						|
		nop
 | 
						|
 | 
						|
#endif
 | 
						|
.end _hw_exception_handler
 | 
						|
 | 
						|
#ifdef CONFIG_MMU
 | 
						|
/* Unaligned data access exception last on a 4k page for MMU.
 | 
						|
 * When this is called, we are in virtual mode with exceptions enabled
 | 
						|
 * and registers 1-13,15,17,18 saved.
 | 
						|
 *
 | 
						|
 * R3 = ESR
 | 
						|
 * R4 = EAR
 | 
						|
 * R7 = pointer to saved registers (struct pt_regs *regs)
 | 
						|
 *
 | 
						|
 * This handler perform the access, and returns via ret_from_exc.
 | 
						|
 */
 | 
						|
.global _unaligned_data_exception
 | 
						|
.ent _unaligned_data_exception
 | 
						|
_unaligned_data_exception:
 | 
						|
	andi	r8, r3, 0x3E0;	/* Mask and extract the register operand */
 | 
						|
	BSRLI(r8,r8,2);		/* r8 >> 2 = register operand * 8 */
 | 
						|
	andi	r6, r3, 0x400;	/* Extract ESR[S] */
 | 
						|
	bneid	r6, ex_sw_vm;
 | 
						|
	andi	r6, r3, 0x800;	/* Extract ESR[W] - delay slot */
 | 
						|
ex_lw_vm:
 | 
						|
	beqid	r6, ex_lhw_vm;
 | 
						|
load1:	lbui	r5, r4, 0;	/* Exception address in r4 - delay slot */
 | 
						|
/* Load a word, byte-by-byte from destination address and save it in tmp space*/
 | 
						|
	addik	r6, r0, ex_tmp_data_loc_0;
 | 
						|
	sbi	r5, r6, 0;
 | 
						|
load2:	lbui	r5, r4, 1;
 | 
						|
	sbi	r5, r6, 1;
 | 
						|
load3:	lbui	r5, r4, 2;
 | 
						|
	sbi	r5, r6, 2;
 | 
						|
load4:	lbui	r5, r4, 3;
 | 
						|
	sbi	r5, r6, 3;
 | 
						|
	brid	ex_lw_tail_vm;
 | 
						|
/* Get the destination register value into r3 - delay slot */
 | 
						|
	lwi	r3, r6, 0;
 | 
						|
ex_lhw_vm:
 | 
						|
	/* Load a half-word, byte-by-byte from destination address and
 | 
						|
	 * save it in tmp space */
 | 
						|
	addik	r6, r0, ex_tmp_data_loc_0;
 | 
						|
	sbi	r5, r6, 0;
 | 
						|
load5:	lbui	r5, r4, 1;
 | 
						|
	sbi	r5, r6, 1;
 | 
						|
	lhui	r3, r6, 0;	/* Get the destination register value into r3 */
 | 
						|
ex_lw_tail_vm:
 | 
						|
	/* Form load_word jump table offset (lw_table_vm + (8 * regnum)) */
 | 
						|
	addik	r5, r8, lw_table_vm;
 | 
						|
	bra	r5;
 | 
						|
ex_lw_end_vm:			/* Exception handling of load word, ends */
 | 
						|
	brai	ret_from_exc;
 | 
						|
ex_sw_vm:
 | 
						|
/* Form store_word jump table offset (sw_table_vm + (8 * regnum)) */
 | 
						|
	addik	r5, r8, sw_table_vm;
 | 
						|
	bra	r5;
 | 
						|
ex_sw_tail_vm:
 | 
						|
	addik	r5, r0, ex_tmp_data_loc_0;
 | 
						|
	beqid	r6, ex_shw_vm;
 | 
						|
	swi	r3, r5, 0;	/* Get the word - delay slot */
 | 
						|
	/* Store the word, byte-by-byte into destination address */
 | 
						|
	lbui	r3, r5, 0;
 | 
						|
store1:	sbi	r3, r4, 0;
 | 
						|
	lbui	r3, r5, 1;
 | 
						|
store2:	sbi	r3, r4, 1;
 | 
						|
	lbui	r3, r5, 2;
 | 
						|
store3:	sbi	r3, r4, 2;
 | 
						|
	lbui	r3, r5, 3;
 | 
						|
	brid	ret_from_exc;
 | 
						|
store4:	sbi	r3, r4, 3;	/* Delay slot */
 | 
						|
ex_shw_vm:
 | 
						|
	/* Store the lower half-word, byte-by-byte into destination address */
 | 
						|
#ifdef __MICROBLAZEEL__
 | 
						|
	lbui	r3, r5, 0;
 | 
						|
store5:	sbi	r3, r4, 0;
 | 
						|
	lbui	r3, r5, 1;
 | 
						|
	brid	ret_from_exc;
 | 
						|
store6:	sbi	r3, r4, 1;	/* Delay slot */
 | 
						|
#else
 | 
						|
	lbui	r3, r5, 2;
 | 
						|
store5:	sbi	r3, r4, 0;
 | 
						|
	lbui	r3, r5, 3;
 | 
						|
	brid	ret_from_exc;
 | 
						|
store6:	sbi	r3, r4, 1;	/* Delay slot */
 | 
						|
#endif
 | 
						|
 | 
						|
ex_sw_end_vm:			/* Exception handling of store word, ends. */
 | 
						|
 | 
						|
/* We have to prevent cases that get/put_user macros get unaligned pointer
 | 
						|
 * to bad page area. We have to find out which origin instruction caused it
 | 
						|
 * and called fixup for that origin instruction not instruction in unaligned
 | 
						|
 * handler */
 | 
						|
ex_unaligned_fixup:
 | 
						|
	ori	r5, r7, 0 /* setup pointer to pt_regs */
 | 
						|
	lwi	r6, r7, PT_PC; /* faulting address is one instruction above */
 | 
						|
	addik	r6, r6, -4 /* for finding proper fixup */
 | 
						|
	swi	r6, r7, PT_PC; /* a save back it to PT_PC */
 | 
						|
	addik	r7, r0, SIGSEGV
 | 
						|
	/* call bad_page_fault for finding aligned fixup, fixup address is saved
 | 
						|
	 * in PT_PC which is used as return address from exception */
 | 
						|
	addik	r15, r0, ret_from_exc-8 /* setup return address */
 | 
						|
	brid	bad_page_fault
 | 
						|
	nop
 | 
						|
 | 
						|
/* We prevent all load/store because it could failed any attempt to access */
 | 
						|
.section __ex_table,"a";
 | 
						|
	.word	load1,ex_unaligned_fixup;
 | 
						|
	.word	load2,ex_unaligned_fixup;
 | 
						|
	.word	load3,ex_unaligned_fixup;
 | 
						|
	.word	load4,ex_unaligned_fixup;
 | 
						|
	.word	load5,ex_unaligned_fixup;
 | 
						|
	.word	store1,ex_unaligned_fixup;
 | 
						|
	.word	store2,ex_unaligned_fixup;
 | 
						|
	.word	store3,ex_unaligned_fixup;
 | 
						|
	.word	store4,ex_unaligned_fixup;
 | 
						|
	.word	store5,ex_unaligned_fixup;
 | 
						|
	.word	store6,ex_unaligned_fixup;
 | 
						|
.previous;
 | 
						|
.end _unaligned_data_exception
 | 
						|
#endif /* CONFIG_MMU */
 | 
						|
 | 
						|
.global ex_handler_unhandled
 | 
						|
ex_handler_unhandled:
 | 
						|
/* FIXME add handle function for unhandled exception - dump register */
 | 
						|
	bri 0
 | 
						|
 | 
						|
/*
 | 
						|
 * hw_exception_handler Jump Table
 | 
						|
 * - Contains code snippets for each register that caused the unalign exception
 | 
						|
 * - Hence exception handler is NOT self-modifying
 | 
						|
 * - Separate table for load exceptions and store exceptions.
 | 
						|
 * - Each table is of size: (8 * 32) = 256 bytes
 | 
						|
 */
 | 
						|
 | 
						|
.section .text
 | 
						|
.align 4
 | 
						|
lw_table:
 | 
						|
lw_r0:		R3_TO_LWREG	(0);
 | 
						|
lw_r1:		LWREG_NOP;
 | 
						|
lw_r2:		R3_TO_LWREG	(2);
 | 
						|
lw_r3:		R3_TO_LWREG_V	(3);
 | 
						|
lw_r4:		R3_TO_LWREG_V	(4);
 | 
						|
lw_r5:		R3_TO_LWREG_V	(5);
 | 
						|
lw_r6:		R3_TO_LWREG_V	(6);
 | 
						|
lw_r7:		R3_TO_LWREG	(7);
 | 
						|
lw_r8:		R3_TO_LWREG	(8);
 | 
						|
lw_r9:		R3_TO_LWREG	(9);
 | 
						|
lw_r10:		R3_TO_LWREG	(10);
 | 
						|
lw_r11:		R3_TO_LWREG	(11);
 | 
						|
lw_r12:		R3_TO_LWREG	(12);
 | 
						|
lw_r13:		R3_TO_LWREG	(13);
 | 
						|
lw_r14:		R3_TO_LWREG	(14);
 | 
						|
lw_r15:		R3_TO_LWREG	(15);
 | 
						|
lw_r16:		R3_TO_LWREG	(16);
 | 
						|
lw_r17:		LWREG_NOP;
 | 
						|
lw_r18:		R3_TO_LWREG	(18);
 | 
						|
lw_r19:		R3_TO_LWREG	(19);
 | 
						|
lw_r20:		R3_TO_LWREG	(20);
 | 
						|
lw_r21:		R3_TO_LWREG	(21);
 | 
						|
lw_r22:		R3_TO_LWREG	(22);
 | 
						|
lw_r23:		R3_TO_LWREG	(23);
 | 
						|
lw_r24:		R3_TO_LWREG	(24);
 | 
						|
lw_r25:		R3_TO_LWREG	(25);
 | 
						|
lw_r26:		R3_TO_LWREG	(26);
 | 
						|
lw_r27:		R3_TO_LWREG	(27);
 | 
						|
lw_r28:		R3_TO_LWREG	(28);
 | 
						|
lw_r29:		R3_TO_LWREG	(29);
 | 
						|
lw_r30:		R3_TO_LWREG	(30);
 | 
						|
#ifdef CONFIG_MMU
 | 
						|
lw_r31: 	R3_TO_LWREG_V	(31);
 | 
						|
#else
 | 
						|
lw_r31:		R3_TO_LWREG	(31);
 | 
						|
#endif
 | 
						|
 | 
						|
sw_table:
 | 
						|
sw_r0:		SWREG_TO_R3	(0);
 | 
						|
sw_r1:		SWREG_NOP;
 | 
						|
sw_r2:		SWREG_TO_R3	(2);
 | 
						|
sw_r3:		SWREG_TO_R3_V	(3);
 | 
						|
sw_r4:		SWREG_TO_R3_V	(4);
 | 
						|
sw_r5:		SWREG_TO_R3_V	(5);
 | 
						|
sw_r6:		SWREG_TO_R3_V	(6);
 | 
						|
sw_r7:		SWREG_TO_R3	(7);
 | 
						|
sw_r8:		SWREG_TO_R3	(8);
 | 
						|
sw_r9:		SWREG_TO_R3	(9);
 | 
						|
sw_r10:		SWREG_TO_R3	(10);
 | 
						|
sw_r11:		SWREG_TO_R3	(11);
 | 
						|
sw_r12:		SWREG_TO_R3	(12);
 | 
						|
sw_r13:		SWREG_TO_R3	(13);
 | 
						|
sw_r14:		SWREG_TO_R3	(14);
 | 
						|
sw_r15:		SWREG_TO_R3	(15);
 | 
						|
sw_r16:		SWREG_TO_R3	(16);
 | 
						|
sw_r17:		SWREG_NOP;
 | 
						|
sw_r18:		SWREG_TO_R3	(18);
 | 
						|
sw_r19:		SWREG_TO_R3	(19);
 | 
						|
sw_r20:		SWREG_TO_R3	(20);
 | 
						|
sw_r21:		SWREG_TO_R3	(21);
 | 
						|
sw_r22:		SWREG_TO_R3	(22);
 | 
						|
sw_r23:		SWREG_TO_R3	(23);
 | 
						|
sw_r24:		SWREG_TO_R3	(24);
 | 
						|
sw_r25:		SWREG_TO_R3	(25);
 | 
						|
sw_r26:		SWREG_TO_R3	(26);
 | 
						|
sw_r27:		SWREG_TO_R3	(27);
 | 
						|
sw_r28:		SWREG_TO_R3	(28);
 | 
						|
sw_r29:		SWREG_TO_R3	(29);
 | 
						|
sw_r30:		SWREG_TO_R3	(30);
 | 
						|
#ifdef CONFIG_MMU
 | 
						|
sw_r31:		SWREG_TO_R3_V	(31);
 | 
						|
#else
 | 
						|
sw_r31:		SWREG_TO_R3	(31);
 | 
						|
#endif
 | 
						|
 | 
						|
#ifdef CONFIG_MMU
 | 
						|
lw_table_vm:
 | 
						|
lw_r0_vm:	R3_TO_LWREG_VM		(0);
 | 
						|
lw_r1_vm:	R3_TO_LWREG_VM_V	(1);
 | 
						|
lw_r2_vm:	R3_TO_LWREG_VM_V	(2);
 | 
						|
lw_r3_vm:	R3_TO_LWREG_VM_V	(3);
 | 
						|
lw_r4_vm:	R3_TO_LWREG_VM_V	(4);
 | 
						|
lw_r5_vm:	R3_TO_LWREG_VM_V	(5);
 | 
						|
lw_r6_vm:	R3_TO_LWREG_VM_V	(6);
 | 
						|
lw_r7_vm:	R3_TO_LWREG_VM_V	(7);
 | 
						|
lw_r8_vm:	R3_TO_LWREG_VM_V	(8);
 | 
						|
lw_r9_vm:	R3_TO_LWREG_VM_V	(9);
 | 
						|
lw_r10_vm:	R3_TO_LWREG_VM_V	(10);
 | 
						|
lw_r11_vm:	R3_TO_LWREG_VM_V	(11);
 | 
						|
lw_r12_vm:	R3_TO_LWREG_VM_V	(12);
 | 
						|
lw_r13_vm:	R3_TO_LWREG_VM_V	(13);
 | 
						|
lw_r14_vm:	R3_TO_LWREG_VM_V	(14);
 | 
						|
lw_r15_vm:	R3_TO_LWREG_VM_V	(15);
 | 
						|
lw_r16_vm:	R3_TO_LWREG_VM_V	(16);
 | 
						|
lw_r17_vm:	R3_TO_LWREG_VM_V	(17);
 | 
						|
lw_r18_vm:	R3_TO_LWREG_VM_V	(18);
 | 
						|
lw_r19_vm:	R3_TO_LWREG_VM_V	(19);
 | 
						|
lw_r20_vm:	R3_TO_LWREG_VM_V	(20);
 | 
						|
lw_r21_vm:	R3_TO_LWREG_VM_V	(21);
 | 
						|
lw_r22_vm:	R3_TO_LWREG_VM_V	(22);
 | 
						|
lw_r23_vm:	R3_TO_LWREG_VM_V	(23);
 | 
						|
lw_r24_vm:	R3_TO_LWREG_VM_V	(24);
 | 
						|
lw_r25_vm:	R3_TO_LWREG_VM_V	(25);
 | 
						|
lw_r26_vm:	R3_TO_LWREG_VM_V	(26);
 | 
						|
lw_r27_vm:	R3_TO_LWREG_VM_V	(27);
 | 
						|
lw_r28_vm:	R3_TO_LWREG_VM_V	(28);
 | 
						|
lw_r29_vm:	R3_TO_LWREG_VM_V	(29);
 | 
						|
lw_r30_vm:	R3_TO_LWREG_VM_V	(30);
 | 
						|
lw_r31_vm:	R3_TO_LWREG_VM_V	(31);
 | 
						|
 | 
						|
sw_table_vm:
 | 
						|
sw_r0_vm:	SWREG_TO_R3_VM		(0);
 | 
						|
sw_r1_vm:	SWREG_TO_R3_VM_V	(1);
 | 
						|
sw_r2_vm:	SWREG_TO_R3_VM_V	(2);
 | 
						|
sw_r3_vm:	SWREG_TO_R3_VM_V	(3);
 | 
						|
sw_r4_vm:	SWREG_TO_R3_VM_V	(4);
 | 
						|
sw_r5_vm:	SWREG_TO_R3_VM_V	(5);
 | 
						|
sw_r6_vm:	SWREG_TO_R3_VM_V	(6);
 | 
						|
sw_r7_vm:	SWREG_TO_R3_VM_V	(7);
 | 
						|
sw_r8_vm:	SWREG_TO_R3_VM_V	(8);
 | 
						|
sw_r9_vm:	SWREG_TO_R3_VM_V	(9);
 | 
						|
sw_r10_vm:	SWREG_TO_R3_VM_V	(10);
 | 
						|
sw_r11_vm:	SWREG_TO_R3_VM_V	(11);
 | 
						|
sw_r12_vm:	SWREG_TO_R3_VM_V	(12);
 | 
						|
sw_r13_vm:	SWREG_TO_R3_VM_V	(13);
 | 
						|
sw_r14_vm:	SWREG_TO_R3_VM_V	(14);
 | 
						|
sw_r15_vm:	SWREG_TO_R3_VM_V	(15);
 | 
						|
sw_r16_vm:	SWREG_TO_R3_VM_V	(16);
 | 
						|
sw_r17_vm:	SWREG_TO_R3_VM_V	(17);
 | 
						|
sw_r18_vm:	SWREG_TO_R3_VM_V	(18);
 | 
						|
sw_r19_vm:	SWREG_TO_R3_VM_V	(19);
 | 
						|
sw_r20_vm:	SWREG_TO_R3_VM_V	(20);
 | 
						|
sw_r21_vm:	SWREG_TO_R3_VM_V	(21);
 | 
						|
sw_r22_vm:	SWREG_TO_R3_VM_V	(22);
 | 
						|
sw_r23_vm:	SWREG_TO_R3_VM_V	(23);
 | 
						|
sw_r24_vm:	SWREG_TO_R3_VM_V	(24);
 | 
						|
sw_r25_vm:	SWREG_TO_R3_VM_V	(25);
 | 
						|
sw_r26_vm:	SWREG_TO_R3_VM_V	(26);
 | 
						|
sw_r27_vm:	SWREG_TO_R3_VM_V	(27);
 | 
						|
sw_r28_vm:	SWREG_TO_R3_VM_V	(28);
 | 
						|
sw_r29_vm:	SWREG_TO_R3_VM_V	(29);
 | 
						|
sw_r30_vm:	SWREG_TO_R3_VM_V	(30);
 | 
						|
sw_r31_vm:	SWREG_TO_R3_VM_V	(31);
 | 
						|
#endif /* CONFIG_MMU */
 | 
						|
 | 
						|
/* Temporary data structures used in the handler */
 | 
						|
.section .data
 | 
						|
.align 4
 | 
						|
ex_tmp_data_loc_0:
 | 
						|
	.byte 0
 | 
						|
ex_tmp_data_loc_1:
 | 
						|
	.byte 0
 | 
						|
ex_tmp_data_loc_2:
 | 
						|
	.byte 0
 | 
						|
ex_tmp_data_loc_3:
 | 
						|
	.byte 0
 | 
						|
ex_reg_op:
 | 
						|
	.byte 0
 |