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/*  cpu_asm.s   1.1 - 95/12/04
 *
 *  This file contains the assembly code for the PowerPC implementation
 *  of RTEMS.
 *
 *  Author:     Andrew Bray <andy@i-cubed.co.uk>
 *
 *  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.
 *
 *  Derived from c/src/exec/cpu/no_cpu/cpu_asm.c:
 *
 *  COPYRIGHT (c) 1989-1997.
 *  On-Line Applications Research Corporation (OAR).
 *  Copyright assigned to U.S. Government, 1994.
 *
 *  The license and distribution terms for this file may in
 *  the file LICENSE in this distribution or at
 *  http://www.OARcorp.com/rtems/license.html.
 *
 *  $Id: cpu_asm.S,v 1.2 2001-09-27 11:59:29 chris Exp $
 */

#include <asm.h>

/*
 * Offsets for various Contexts
 */
        .set    GP_1, 0
        .set    GP_2, (GP_1 + 4)
        .set    GP_13, (GP_2 + 4)
        .set    GP_14, (GP_13 + 4)

        .set    GP_15, (GP_14 + 4)
        .set    GP_16, (GP_15 + 4)
        .set    GP_17, (GP_16 + 4)
        .set    GP_18, (GP_17 + 4)

        .set    GP_19, (GP_18 + 4)
        .set    GP_20, (GP_19 + 4)
        .set    GP_21, (GP_20 + 4)
        .set    GP_22, (GP_21 + 4)

        .set    GP_23, (GP_22 + 4)
        .set    GP_24, (GP_23 + 4)
        .set    GP_25, (GP_24 + 4)
        .set    GP_26, (GP_25 + 4)

        .set    GP_27, (GP_26 + 4)
        .set    GP_28, (GP_27 + 4)
        .set    GP_29, (GP_28 + 4)
        .set    GP_30, (GP_29 + 4)

        .set    GP_31, (GP_30 + 4)
        .set    GP_CR, (GP_31 + 4)
        .set    GP_PC, (GP_CR + 4)
        .set    GP_MSR, (GP_PC + 4)

        .set    FP_0, 0
        .set    FP_1, (FP_0 + 4)
        .set    FP_2, (FP_1 + 4)
        .set    FP_3, (FP_2 + 4)
        .set    FP_4, (FP_3 + 4)
        .set    FP_5, (FP_4 + 4)
        .set    FP_6, (FP_5 + 4)
        .set    FP_7, (FP_6 + 4)
        .set    FP_8, (FP_7 + 4)
        .set    FP_9, (FP_8 + 4)
        .set    FP_10, (FP_9 + 4)
        .set    FP_11, (FP_10 + 4)
        .set    FP_12, (FP_11 + 4)
        .set    FP_13, (FP_12 + 4)
        .set    FP_14, (FP_13 + 4)
        .set    FP_15, (FP_14 + 4)
        .set    FP_16, (FP_15 + 4)
        .set    FP_17, (FP_16 + 4)
        .set    FP_18, (FP_17 + 4)
        .set    FP_19, (FP_18 + 4)
        .set    FP_20, (FP_19 + 4)
        .set    FP_21, (FP_20 + 4)
        .set    FP_22, (FP_21 + 4)
        .set    FP_23, (FP_22 + 4)
        .set    FP_24, (FP_23 + 4)
        .set    FP_25, (FP_24 + 4)
        .set    FP_26, (FP_25 + 4)
        .set    FP_27, (FP_26 + 4)
        .set    FP_28, (FP_27 + 4)
        .set    FP_29, (FP_28 + 4)
        .set    FP_30, (FP_29 + 4)
        .set    FP_31, (FP_30 + 4)
        .set    FP_FPSCR, (FP_31 + 4)
        
        .set    IP_LINK, 0
        .set    IP_0, (IP_LINK + 8)
        .set    IP_2, (IP_0 + 4)

        .set    IP_3, (IP_2 + 4)
        .set    IP_4, (IP_3 + 4)
        .set    IP_5, (IP_4 + 4)
        .set    IP_6, (IP_5 + 4)
        
        .set    IP_7, (IP_6 + 4)
        .set    IP_8, (IP_7 + 4)
        .set    IP_9, (IP_8 + 4)
        .set    IP_10, (IP_9 + 4)
        
        .set    IP_11, (IP_10 + 4)
        .set    IP_12, (IP_11 + 4)
        .set    IP_13, (IP_12 + 4)
        .set    IP_28, (IP_13 + 4)

        .set    IP_29, (IP_28 + 4)
        .set    IP_30, (IP_29 + 4)
        .set    IP_31, (IP_30 + 4)
        .set    IP_CR, (IP_31 + 4)
        
        .set    IP_CTR, (IP_CR + 4)
        .set    IP_XER, (IP_CTR + 4)
        .set    IP_LR, (IP_XER + 4)
        .set    IP_PC, (IP_LR + 4)
        
        .set    IP_MSR, (IP_PC + 4)
        .set    IP_END, (IP_MSR + 16)
        
        BEGIN_CODE
/*
 *  _CPU_Context_save_fp_context
 *
 *  This routine is responsible for saving the FP context
 *  at *fp_context_ptr.  If the point to load the FP context
 *  from is changed then the pointer is modified by this routine.
 *
 *  Sometimes a macro implementation of this is in cpu.h which dereferences
 *  the ** and a similarly named routine in this file is passed something
 *  like a (Context_Control_fp *).  The general rule on making this decision
 *  is to avoid writing assembly language.
 */

        ALIGN (PPC_CACHE_ALIGNMENT, PPC_CACHE_ALIGN_POWER)
        PUBLIC_PROC (_CPU_Context_save_fp)
PROC (_CPU_Context_save_fp):
#if (PPC_HAS_FPU == 1)
        lwz     r3, 0(r3)
        stfs    f0, FP_0(r3)
        stfs    f1, FP_1(r3)
        stfs    f2, FP_2(r3)
        stfs    f3, FP_3(r3)
        stfs    f4, FP_4(r3)
        stfs    f5, FP_5(r3)
        stfs    f6, FP_6(r3)
        stfs    f7, FP_7(r3)
        stfs    f8, FP_8(r3)
        stfs    f9, FP_9(r3)
        stfs    f10, FP_10(r3)
        stfs    f11, FP_11(r3)
        stfs    f12, FP_12(r3)
        stfs    f13, FP_13(r3)
        stfs    f14, FP_14(r3)
        stfs    f15, FP_15(r3)
        stfs    f16, FP_16(r3)
        stfs    f17, FP_17(r3)
        stfs    f18, FP_18(r3)
        stfs    f19, FP_19(r3)
        stfs    f20, FP_20(r3)
        stfs    f21, FP_21(r3)
        stfs    f22, FP_22(r3)
        stfs    f23, FP_23(r3)
        stfs    f24, FP_24(r3)
        stfs    f25, FP_25(r3)
        stfs    f26, FP_26(r3)
        stfs    f27, FP_27(r3)
        stfs    f28, FP_28(r3)
        stfs    f29, FP_29(r3)
        stfs    f30, FP_30(r3)
        stfs    f31, FP_31(r3)
        mffs    f2
        stfs    f2, FP_FPSCR(r3)
#endif
        blr

/*
 *  _CPU_Context_restore_fp_context
 *
 *  This routine is responsible for restoring the FP context
 *  at *fp_context_ptr.  If the point to load the FP context
 *  from is changed then the pointer is modified by this routine.
 *
 *  Sometimes a macro implementation of this is in cpu.h which dereferences
 *  the ** and a similarly named routine in this file is passed something
 *  like a (Context_Control_fp *).  The general rule on making this decision
 *  is to avoid writing assembly language.
 */

        ALIGN (PPC_CACHE_ALIGNMENT, PPC_CACHE_ALIGN_POWER)
        PUBLIC_PROC (_CPU_Context_restore_fp)
PROC (_CPU_Context_restore_fp):
#if (PPC_HAS_FPU == 1)
        lwz     r3, 0(r3)
        lfs     f2, FP_FPSCR(r3)
        mtfsf   255, f2
        lfs     f0, FP_0(r3)
        lfs     f1, FP_1(r3)
        lfs     f2, FP_2(r3)
        lfs     f3, FP_3(r3)
        lfs     f4, FP_4(r3)
        lfs     f5, FP_5(r3)
        lfs     f6, FP_6(r3)
        lfs     f7, FP_7(r3)
        lfs     f8, FP_8(r3)
        lfs     f9, FP_9(r3)
        lfs     f10, FP_10(r3)
        lfs     f11, FP_11(r3)
        lfs     f12, FP_12(r3)
        lfs     f13, FP_13(r3)
        lfs     f14, FP_14(r3)
        lfs     f15, FP_15(r3)
        lfs     f16, FP_16(r3)
        lfs     f17, FP_17(r3)
        lfs     f18, FP_18(r3)
        lfs     f19, FP_19(r3)
        lfs     f20, FP_20(r3)
        lfs     f21, FP_21(r3)
        lfs     f22, FP_22(r3)
        lfs     f23, FP_23(r3)
        lfs     f24, FP_24(r3)
        lfs     f25, FP_25(r3)
        lfs     f26, FP_26(r3)
        lfs     f27, FP_27(r3)
        lfs     f28, FP_28(r3)
        lfs     f29, FP_29(r3)
        lfs     f30, FP_30(r3)
        lfs     f31, FP_31(r3)
#endif
        blr


/*  _CPU_Context_switch
 *
 *  This routine performs a normal non-FP context switch.
 */
        ALIGN (PPC_CACHE_ALIGNMENT, PPC_CACHE_ALIGN_POWER)
        PUBLIC_PROC (_CPU_Context_switch)
PROC (_CPU_Context_switch):
        sync
        isync
        /* This assumes that all the registers are in the given order */
        li      r5, 32
        addi    r3,r3,-4
#if ( PPC_USE_DATA_CACHE )
        dcbz    r5, r3
#endif
        stw     r1, GP_1+4(r3)
        stw     r2, GP_2+4(r3)
#if (PPC_USE_MULTIPLE == 1)
        addi    r3, r3, GP_18+4
#if ( PPC_USE_DATA_CACHE )
        dcbz    r5, r3
#endif
        stmw    r13, GP_13-GP_18(r3)
#else
        stw     r13, GP_13+4(r3)
        stw     r14, GP_14+4(r3)
        stw     r15, GP_15+4(r3)
        stw     r16, GP_16+4(r3)
        stw     r17, GP_17+4(r3)
        stwu    r18, GP_18+4(r3)
#if ( PPC_USE_DATA_CACHE )
        dcbz    r5, r3
#endif
        stw     r19, GP_19-GP_18(r3)
        stw     r20, GP_20-GP_18(r3)
        stw     r21, GP_21-GP_18(r3)
        stw     r22, GP_22-GP_18(r3)
        stw     r23, GP_23-GP_18(r3)
        stw     r24, GP_24-GP_18(r3)
        stw     r25, GP_25-GP_18(r3)
        stw     r26, GP_26-GP_18(r3)
        stw     r27, GP_27-GP_18(r3)
        stw     r28, GP_28-GP_18(r3)
        stw     r29, GP_29-GP_18(r3)
        stw     r30, GP_30-GP_18(r3)
        stw     r31, GP_31-GP_18(r3)
#endif
#if ( PPC_USE_DATA_CACHE )
        dcbt    r0, r4
#endif
        mfcr    r6
        stw     r6, GP_CR-GP_18(r3)
        mflr    r7
        stw     r7, GP_PC-GP_18(r3)
        mfmsr   r8
        stw     r8, GP_MSR-GP_18(r3)

#if ( PPC_USE_DATA_CACHE )
        dcbt    r5, r4
#endif
        lwz     r1, GP_1(r4)
        lwz     r2, GP_2(r4)
#if (PPC_USE_MULTIPLE == 1)
        addi    r4, r4, GP_19
#if ( PPC_USE_DATA_CACHE )
        dcbt    r5, r4
#endif
        lmw     r13, GP_13-GP_19(r4)
#else
        lwz     r13, GP_13(r4)
        lwz     r14, GP_14(r4)
        lwz     r15, GP_15(r4)
        lwz     r16, GP_16(r4)
        lwz     r17, GP_17(r4)
        lwz     r18, GP_18(r4)
        lwzu    r19, GP_19(r4)
#if ( PPC_USE_DATA_CACHE )
        dcbt    r5, r4
#endif
        lwz     r20, GP_20-GP_19(r4)
        lwz     r21, GP_21-GP_19(r4)
        lwz     r22, GP_22-GP_19(r4)
        lwz     r23, GP_23-GP_19(r4)
        lwz     r24, GP_24-GP_19(r4)
        lwz     r25, GP_25-GP_19(r4)
        lwz     r26, GP_26-GP_19(r4)
        lwz     r27, GP_27-GP_19(r4)
        lwz     r28, GP_28-GP_19(r4)
        lwz     r29, GP_29-GP_19(r4)
        lwz     r30, GP_30-GP_19(r4)
        lwz     r31, GP_31-GP_19(r4)
#endif
        lwz     r6, GP_CR-GP_19(r4)
        lwz     r7, GP_PC-GP_19(r4)
        lwz     r8, GP_MSR-GP_19(r4)
        mtcrf   255, r6
        mtlr    r7
        mtmsr   r8

        blr

/*
 *  _CPU_Context_restore
 *
 *  This routine is generallu used only to restart self in an
 *  efficient manner.  It may simply be a label in _CPU_Context_switch.
 *
 *  NOTE: May be unnecessary to reload some registers.
 */
/*
 * ACB: Don't worry about cache optimisation here - this is not THAT critical.
 */
        ALIGN (PPC_CACHE_ALIGNMENT, PPC_CACHE_ALIGN_POWER)
        PUBLIC_PROC (_CPU_Context_restore)
PROC (_CPU_Context_restore):
        lwz     r5, GP_CR(r3)
        lwz     r6, GP_PC(r3)
        lwz     r7, GP_MSR(r3)
        mtcrf   255, r5
        mtlr    r6
        mtmsr   r7
        lwz     r1, GP_1(r3)
        lwz     r2, GP_2(r3)
#if (PPC_USE_MULTIPLE == 1)
        lmw     r13, GP_13(r3)
#else
        lwz     r13, GP_13(r3)
        lwz     r14, GP_14(r3)
        lwz     r15, GP_15(r3)
        lwz     r16, GP_16(r3)
        lwz     r17, GP_17(r3)
        lwz     r18, GP_18(r3)
        lwz     r19, GP_19(r3)
        lwz     r20, GP_20(r3)
        lwz     r21, GP_21(r3)
        lwz     r22, GP_22(r3)
        lwz     r23, GP_23(r3)
        lwz     r24, GP_24(r3)
        lwz     r25, GP_25(r3)
        lwz     r26, GP_26(r3)
        lwz     r27, GP_27(r3)
        lwz     r28, GP_28(r3)
        lwz     r29, GP_29(r3)
        lwz     r30, GP_30(r3)
        lwz     r31, GP_31(r3)
#endif

        blr