align_h.s

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

/*  align_h.s	1.1 - 95/12/04
 *
 *  This file contains the assembly code for the PowerPC 403
 *  alignment exception handler for RTEMS.
 *
 *  Based upon IBM provided code with the following release:
 *
 *  This source code has been made available to you by IBM on an AS-IS
 *  basis.  Anyone receiving this source is licensed under IBM
 *  copyrights to use it in any way he or she deems fit, including
 *  copying it, modifying it, compiling it, and redistributing it either
 *  with or without modifications.  No license under IBM patents or
 *  patent applications is to be implied by the copyright license.
 *
 *  Any user of this software should understand that IBM cannot provide
 *  technical support for this software and will not be responsible for
 *  any consequences resulting from the use of this software.
 *
 *  Any person who transfers this source code or any derivative work
 *  must include the IBM copyright notice, this paragraph, and the
 *  preceding two paragraphs in the transferred software.
 *
 *      COPYRIGHT   I B M   CORPORATION 1995
 *      LICENSED MATERIAL  -  PROGRAM PROPERTY OF I B M
 *
 * Modifications:
 *
 *  Author:	Andrew Bray <[e-mail]>
 *
 *  COPYRIGHT (c) 1995 by i-cubed ltd.
 *
 *  To anyone who acknowledges that this file is provided "AS IS"
 *  without any express or implied warranty:
 *      permission to use, copy, modify, and distribute this file
 *      for any purpose is hereby granted without fee, provided that
 *      the above copyright notice and this notice appears in all
 *      copies, and that the name of i-cubed limited not be used in
 *      advertising or publicity pertaining to distribution of the
 *      software without specific, written prior permission.
 *      i-cubed limited makes no representations about the suitability
 *      of this software for any purpose.
 *
 *  $Id: align_h.S,v 1.3 1999/11/09 03:37:40 joel Exp $
 */

#include "asm.h"
#define ALIGN_REGS 0x0140


.set    CACHE_SIZE,16           # cache line size of 32 bytes
.set    CACHE_SIZE_L2,4         # cache line size, log 2

.set	Open_gpr0,0
.set	Open_gpr1,4
.set	Open_gpr2,8
.set	Open_gpr3,12
.set	Open_gpr4,16
.set	Open_gpr5,20
.set	Open_gpr6,24
.set	Open_gpr7,28
.set	Open_gpr8,32
.set	Open_gpr9,36
.set	Open_gpr10,40
.set	Open_gpr11,44
.set	Open_gpr12,48
.set	Open_gpr13,52
.set	Open_gpr14,56
.set	Open_gpr15,60
.set	Open_gpr16,64
.set	Open_gpr17,68
.set	Open_gpr18,72
.set	Open_gpr19,76
.set	Open_gpr20,80
.set	Open_gpr21,84
.set	Open_gpr22,88
.set	Open_gpr23,92
.set	Open_gpr24,96
.set	Open_gpr25,100
.set	Open_gpr26,104
.set	Open_gpr27,108
.set	Open_gpr28,112
.set	Open_gpr29,116
.set	Open_gpr30,120
.set	Open_gpr31,124
.set	Open_xer,128
.set	Open_lr,132
.set	Open_ctr,136
.set	Open_cr,140
.set	Open_srr2,144
.set	Open_srr3,148
.set	Open_srr0,152
.set	Open_srr1,156


/*
 *  This code makes several assumptions for processing efficiency
 *  *  General purpose registers are continuous in the image, beginning with
 *     Open_gpr0
 *  *  Hash table is highly dependent on opcodes - opcode changes *will*
 *     require rework of the instruction decode mechanism.
 */

        .text
        .globl  align_h

	.align	CACHE_SIZE_L2
align_h:
        /*-----------------------------------------------------------------------
         * Store GPRs in Open Reg save area
         * Set up r2 as base reg, r1 pointing to Open Reg save area
         *----------------------------------------------------------------------*/
        stmw    r0,ALIGN_REGS(r0)
	li	r1,ALIGN_REGS
        /*-----------------------------------------------------------------------
         * Store special purpose registers in reg save area
         *----------------------------------------------------------------------*/
        mfxer   r7
        mflr    r8
        mfcr    r9
        mfctr   r10
        stw     r7,Open_xer(r1)
        stw     r8,Open_lr(r1)
        stw     r9,Open_cr(r1)
        stw     r10,Open_ctr(r1)
        mfspr	r7, srr2		/* SRR 2 */
        mfspr	r8, srr3		/* SRR 3 */
        mfspr	r9, srr0		/* SRR 0 */
        mfspr	r10, srr1		/* SRR 1 */
        stw     r7,Open_srr2(r1)
        stw     r8,Open_srr3(r1)
        stw     r9,Open_srr0(r1)
        stw     r10,Open_srr1(r1)

/*      Set up common registers */
        mfspr	r5, dear		/* DEAR: R5 is data exception address */
        lwz     r9,Open_srr0(r1)        /* get faulting instruction */
        addi    r7,r9,4                 /* bump instruction */
        stw     r7,Open_srr0(r1)        /* restore to image */
        lwz     r9, 0(r9)               /* retrieve actual instruction */
        rlwinm  r6,r9,18,25,29          /* r6 is RA * 4 field from instruction */
        rlwinm  r7,r9,6,26,31           /* r7 is primary opcode */
        bl      ref_point               /* establish addressibility */
ref_point:
        mflr    r11                     /* r11 is the anchor point for ref_point */
        addi    r10, r7, -31            /* r10 = r7 - 31 */
        rlwinm  r10,r10,2,2,31          /* r10 *= 4 */
        add     r10, r10, r11           /* r10 += anchor point */
        lwz     r10, primary_jt-ref_point(r10)
        mtlr    r10
        rlwinm  r8,r9,13,25,29          /* r8 is RD * 4 */
        la      r7,Open_gpr0(r1)        /* r7 is address of GPR 0 in list */
        blr
primary_jt:
        .long   xform
        .long   lwz
        .long   lwzu
        .long   0
        .long   0
        .long   stw
        .long   stwu
        .long   0
        .long   0
        .long   lhz
        .long   lhzu
        .long   lha
        .long   lhau
        .long   sth
        .long   sthu
        .long   lmw
        .long   stmw
/*
 *   handlers
 */
/*
 * xform instructions require an additional decode.  Fortunately, a relatively
 * simple hash step breaks the instructions out with no collisions
 */
xform:
        rlwinm  r7,r9,31,22,31          /* r7 is secondary opcode */
        rlwinm  r10,r7,27,5,31          /* r10 = r7 >> 5 */
        add     r10,r7,r10              /* r10 = r7 + r10 */
        rlwinm  r10,r10,2,25,29         /* r10 = (r10 & 0x1F) * 4 */
        add     r10,r10,r11             /* r10 += anchor point */
        lwz     r10, secondary_ht-ref_point(r10)
        mtlr    r10
        la      r7,Open_gpr0(r1)        /* r7 is address of GPR 0 in list */
        rlwinm  r8,r9,13,25,29          /* r8 is RD * 4 */
        blrl

secondary_ht:
        .long   lhzux                   /* b 0  0x137 */
        .long   lhax                    /* b 1  0x157 */
        .long   lhaux                   /* b 2  0x177 */
        .long   sthx                    /* b 3  0x197 */
        .long   sthux                   /* b 4  0x1b7 */
        .long   0                       /* b 5 */
        .long   lwbrx                   /* b 6  0x216 */
        .long   0                       /* b 7 */
        .long   0                       /* b 8 */
        .long   0                       /* b 9 */
        .long   stwbrx                  /* b A  0x296 */
        .long   0                       /* b B */
        .long   0                       /* b C */
        .long   0                       /* b D */
        .long   lhbrx                   /* b E   0x316 */
        .long   0                       /* b F */
        .long   0                       /* b 10 */
        .long   0                       /* b 11 */
        .long   sthbrx                  /* b 12  0x396 */
        .long   0                       /* b 13 */
        .long   lwarx                   /* b 14  0x014 */
        .long   dcbz                    /* b 15  0x3f6 */
        .long   0                       /* b 16 */
        .long   lwzx                    /* b 17  0x017 */
        .long   lwzux                   /* b 18  0x037 */
        .long   0                       /* b 19 */
        .long   stwcx                   /* b 1A  0x096 */
        .long   stwx                    /* b 1B  0x097 */