1 | /* align_h.s 1.1 - 95/12/04 |
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2 | * |
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3 | * This file contains the assembly code for the PowerPC 403 |
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4 | * alignment exception handler for RTEMS. |
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5 | * |
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6 | * Based upon IBM provided code with the following release: |
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7 | * |
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8 | * This source code has been made available to you by IBM on an AS-IS |
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9 | * basis. Anyone receiving this source is licensed under IBM |
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10 | * copyrights to use it in any way he or she deems fit, including |
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11 | * copying it, modifying it, compiling it, and redistributing it either |
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12 | * with or without modifications. No license under IBM patents or |
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13 | * patent applications is to be implied by the copyright license. |
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14 | * |
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15 | * Any user of this software should understand that IBM cannot provide |
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16 | * technical support for this software and will not be responsible for |
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17 | * any consequences resulting from the use of this software. |
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18 | * |
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19 | * Any person who transfers this source code or any derivative work |
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20 | * must include the IBM copyright notice, this paragraph, and the |
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21 | * preceding two paragraphs in the transferred software. |
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22 | * |
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23 | * COPYRIGHT I B M CORPORATION 1995 |
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24 | * LICENSED MATERIAL - PROGRAM PROPERTY OF I B M |
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25 | * |
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26 | * Modifications: |
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27 | * |
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28 | * Author: Andrew Bray <andy@i-cubed.co.uk> |
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29 | * |
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30 | * COPYRIGHT (c) 1995 by i-cubed ltd. |
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31 | * |
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32 | * To anyone who acknowledges that this file is provided "AS IS" |
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33 | * without any express or implied warranty: |
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34 | * permission to use, copy, modify, and distribute this file |
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35 | * for any purpose is hereby granted without fee, provided that |
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36 | * the above copyright notice and this notice appears in all |
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37 | * copies, and that the name of i-cubed limited not be used in |
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38 | * advertising or publicity pertaining to distribution of the |
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39 | * software without specific, written prior permission. |
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40 | * i-cubed limited makes no representations about the suitability |
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41 | * of this software for any purpose. |
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42 | */ |
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43 | |
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44 | #include <rtems/asm.h> |
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45 | #include <bsp.h> |
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46 | |
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47 | .set CACHE_SIZE,16 # cache line size of 32 bytes |
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48 | .set CACHE_SIZE_L2,4 # cache line size, log 2 |
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49 | |
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50 | .set Open_gpr0,0 |
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51 | .set Open_gpr1,4 |
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52 | .set Open_gpr2,8 |
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53 | .set Open_gpr3,12 |
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54 | .set Open_gpr4,16 |
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55 | .set Open_gpr5,20 |
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56 | .set Open_gpr6,24 |
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57 | .set Open_gpr7,28 |
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58 | .set Open_gpr8,32 |
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59 | .set Open_gpr9,36 |
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60 | .set Open_gpr10,40 |
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61 | .set Open_gpr11,44 |
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62 | .set Open_gpr12,48 |
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63 | .set Open_gpr13,52 |
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64 | .set Open_gpr14,56 |
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65 | .set Open_gpr15,60 |
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66 | .set Open_gpr16,64 |
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67 | .set Open_gpr17,68 |
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68 | .set Open_gpr18,72 |
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69 | .set Open_gpr19,76 |
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70 | .set Open_gpr20,80 |
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71 | .set Open_gpr21,84 |
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72 | .set Open_gpr22,88 |
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73 | .set Open_gpr23,92 |
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74 | .set Open_gpr24,96 |
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75 | .set Open_gpr25,100 |
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76 | .set Open_gpr26,104 |
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77 | .set Open_gpr27,108 |
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78 | .set Open_gpr28,112 |
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79 | .set Open_gpr29,116 |
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80 | .set Open_gpr30,120 |
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81 | .set Open_gpr31,124 |
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82 | .set Open_xer,128 |
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83 | .set Open_lr,132 |
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84 | .set Open_ctr,136 |
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85 | .set Open_cr,140 |
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86 | .set Open_srr2,144 |
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87 | .set Open_srr3,148 |
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88 | .set Open_srr0,152 |
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89 | .set Open_srr1,156 |
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90 | |
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91 | /* |
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92 | * This code makes several assumptions for processing efficiency |
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93 | * * General purpose registers are continuous in the image, beginning with |
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94 | * Open_gpr0 |
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95 | * * Hash table is highly dependent on opcodes - opcode changes *will* |
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96 | * require rework of the instruction decode mechanism. |
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97 | */ |
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98 | |
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99 | .text |
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100 | .globl align_h |
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101 | |
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102 | .align CACHE_SIZE_L2 |
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103 | align_h: |
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104 | /*----------------------------------------------------------------------- |
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105 | * Store GPRs in Open Reg save area |
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106 | * Set up r2 as base reg, r1 pointing to Open Reg save area |
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107 | *----------------------------------------------------------------------*/ |
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108 | stmw r0,ALIGN_REGS(r0) |
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109 | li r1,ALIGN_REGS |
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110 | /*----------------------------------------------------------------------- |
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111 | * Store special purpose registers in reg save area |
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112 | *----------------------------------------------------------------------*/ |
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113 | mfxer r7 |
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114 | mflr r8 |
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115 | mfcr r9 |
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116 | mfctr r10 |
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117 | stw r7,Open_xer(r1) |
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118 | stw r8,Open_lr(r1) |
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119 | stw r9,Open_cr(r1) |
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120 | stw r10,Open_ctr(r1) |
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121 | #if defined(ppc403) || defined(ppc405) |
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122 | mfspr r7, srr2 /* SRR 2 */ |
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123 | mfspr r8, srr3 /* SRR 3 */ |
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124 | #endif |
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125 | mfspr r9, srr0 /* SRR 0 */ |
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126 | mfspr r10, srr1 /* SRR 1 */ |
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127 | #if defined(ppc403) || defined(ppc405) |
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128 | stw r7,Open_srr2(r1) |
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129 | stw r8,Open_srr3(r1) |
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130 | #endif |
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131 | stw r9,Open_srr0(r1) |
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132 | stw r10,Open_srr1(r1) |
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133 | |
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134 | /* Set up common registers */ |
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135 | #if defined(ppc403) || defined(ppc405) |
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136 | mfspr r5, dear /* DEAR: R5 is data exception address */ |
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137 | #endif |
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138 | lwz r9,Open_srr0(r1) /* get faulting instruction */ |
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139 | addi r7,r9,4 /* bump instruction */ |
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140 | stw r7,Open_srr0(r1) /* restore to image */ |
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141 | lwz r9, 0(r9) /* retrieve actual instruction */ |
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142 | rlwinm r6,r9,18,25,29 /* r6 is RA * 4 field from instruction */ |
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143 | rlwinm r7,r9,6,26,31 /* r7 is primary opcode */ |
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144 | bl ref_point /* establish addressibility */ |
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145 | ref_point: |
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146 | mflr r11 /* r11 is the anchor point for ref_point */ |
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147 | addi r10, r7, -31 /* r10 = r7 - 31 */ |
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148 | rlwinm r10,r10,2,2,31 /* r10 *= 4 */ |
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149 | add r10, r10, r11 /* r10 += anchor point */ |
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150 | lwz r10, primary_jt-ref_point(r10) |
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151 | mtlr r10 |
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152 | rlwinm r8,r9,13,25,29 /* r8 is RD * 4 */ |
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153 | la r7,Open_gpr0(r1) /* r7 is address of GPR 0 in list */ |
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154 | blr |
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155 | primary_jt: |
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156 | .long xform |
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157 | .long lwz |
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158 | .long lwzu |
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159 | .long 0 |
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160 | .long 0 |
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161 | .long stw |
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162 | .long stwu |
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163 | .long 0 |
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164 | .long 0 |
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165 | .long lhz |
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166 | .long lhzu |
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167 | .long lha |
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168 | .long lhau |
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169 | .long sth |
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170 | .long sthu |
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171 | .long lmw |
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172 | .long stmw |
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173 | /* |
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174 | * handlers |
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175 | */ |
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176 | /* |
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177 | * xform instructions require an additional decode. Fortunately, a relatively |
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178 | * simple hash step breaks the instructions out with no collisions |
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179 | */ |
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180 | xform: |
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181 | rlwinm r7,r9,31,22,31 /* r7 is secondary opcode */ |
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182 | rlwinm r10,r7,27,5,31 /* r10 = r7 >> 5 */ |
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183 | add r10,r7,r10 /* r10 = r7 + r10 */ |
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184 | rlwinm r10,r10,2,25,29 /* r10 = (r10 & 0x1F) * 4 */ |
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185 | add r10,r10,r11 /* r10 += anchor point */ |
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186 | lwz r10, secondary_ht-ref_point(r10) |
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187 | mtlr r10 |
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188 | la r7,Open_gpr0(r1) /* r7 is address of GPR 0 in list */ |
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189 | rlwinm r8,r9,13,25,29 /* r8 is RD * 4 */ |
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190 | blrl |
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191 | |
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192 | secondary_ht: |
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193 | .long lhzux /* b 0 0x137 */ |
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194 | .long lhax /* b 1 0x157 */ |
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195 | .long lhaux /* b 2 0x177 */ |
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196 | .long sthx /* b 3 0x197 */ |
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197 | .long sthux /* b 4 0x1b7 */ |
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198 | .long 0 /* b 5 */ |
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199 | .long lwbrx /* b 6 0x216 */ |
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200 | .long 0 /* b 7 */ |
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201 | .long 0 /* b 8 */ |
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202 | .long 0 /* b 9 */ |
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203 | .long stwbrx /* b A 0x296 */ |
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204 | .long 0 /* b B */ |
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205 | .long 0 /* b C */ |
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206 | .long 0 /* b D */ |
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207 | .long lhbrx /* b E 0x316 */ |
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208 | .long 0 /* b F */ |
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209 | .long 0 /* b 10 */ |
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210 | .long 0 /* b 11 */ |
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211 | .long sthbrx /* b 12 0x396 */ |
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212 | .long 0 /* b 13 */ |
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213 | .long lwarx /* b 14 0x014 */ |
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214 | .long dcbz /* b 15 0x3f6 */ |
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215 | .long 0 /* b 16 */ |
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216 | .long lwzx /* b 17 0x017 */ |
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217 | .long lwzux /* b 18 0x037 */ |
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218 | .long 0 /* b 19 */ |
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219 | .long stwcx /* b 1A 0x096 */ |
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220 | .long stwx /* b 1B 0x097 */ |
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221 | .long stwux /* b 1C 0x0B7 */ |
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222 | .long 0 /* b 1D */ |
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223 | .long 0 /* b 1E */ |
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224 | .long lhzx /* b 1F 0x117 */ |
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225 | |
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226 | /* |
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227 | * for all handlers |
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228 | * r4 - Addressability to interrupt context |
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229 | * r5 - DEAR address (faulting data address) |
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230 | * r6 - RA field * 4 |
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231 | * r7 - Address of GPR 0 in image |
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232 | * r8 - RD field * 4 |
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233 | * r9 - Failing instruction |
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234 | */ |
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235 | |
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236 | /* Load halfword algebraic with update */ |
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237 | lhau: |
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238 | /* Load halfword algebraic with update indexed */ |
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239 | lhaux: |
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240 | stwx r5,r7,r6 /* update RA with effective addr */ |
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241 | |
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242 | /* Load halfword algebraic */ |
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243 | lha: |
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244 | /* Load halfword algebraic indexed */ |
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245 | lhax: |
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246 | lswi r10,r5,2 /* load two bytes into r10 */ |
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247 | srawi r10,r10,16 /* shift right 2 bytes, extending sign */ |
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248 | stwx r10,r7,r8 /* update reg image */ |
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249 | b align_complete /* return */ |
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250 | |
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251 | /* Load Half Word Byte-Reversed Indexed */ |
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252 | lhbrx: |
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253 | lswi r10,r5,2 /* load two bytes from DEAR into r10 */ |
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254 | rlwinm r10,r10,0,0,15 /* mask off lower 2 bytes */ |
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255 | stwbrx r10,r7,r8 /* store reversed in reg image */ |
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256 | b align_complete /* return */ |
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257 | |
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258 | /* Load Half Word and Zero with Update */ |
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259 | lhzu: |
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260 | /* Load Half Word and Zero with Update Indexed */ |
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261 | lhzux: |
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262 | stwx r5,r7,r6 /* update RA with effective addr */ |
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263 | |
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264 | /* Load Half Word and Zero */ |
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265 | lhz: |
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266 | /* Load Half Word and Zero Indexed */ |
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267 | lhzx: |
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268 | lswi r10,r5,2 /* load two bytes from DEAR into r10 */ |
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269 | rlwinm r10,r10,16,16,31 /* shift right 2 bytes, with zero fill */ |
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270 | stwx r10,r7,r8 /* update reg image */ |
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271 | b align_complete /* return */ |
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272 | |
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273 | /* |
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274 | * Load Multiple Word |
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275 | */ |
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276 | lmw: |
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277 | lwzx r9,r6,r7 /* R9 contains saved value of RA */ |
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278 | addi r10,r7,32*4 /* r10 points to r31 in image + 4 */ |
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279 | rlwinm r8,r8,30,2,31 /* r8 >>= 2 (recovers RT) */ |
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280 | subfic r8,r8,32 /* r8 is reg count to load */ |
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281 | mtctr r8 /* load counter */ |
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282 | addi r8,r8,-1 /* r8-- */ |
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283 | rlwinm r8,r8,2,2,31 /* r8 *= 4 */ |
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284 | add r5,r5,r8 /* update DEAR to point to last reg */ |
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285 | lwmloop: |
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286 | lswi r11,r5,4 /* load r11 with 4 bytes from DEAR */ |
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287 | stwu r11,-4(r10) /* load image and decrement pointer */ |
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288 | addi r5,r5,-4 /* decrement effective address */ |
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289 | bdnz lwmloop |
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290 | stwx r9,r6,r7 /* restore RA (in case it was trashed) */ |
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291 | b align_complete /* return */ |
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292 | |
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293 | /* |
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294 | * Load Word and Reserve Indexed |
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295 | */ |
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296 | lwarx: |
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297 | lswi r10,r5,4 /* load four bytes from DEAR into r10 */ |
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298 | stwx r10,r7,r8 /* update reg image */ |
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299 | rlwinm r5,r5,0,0,29 /* Word align address */ |
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300 | lwarx r10,0,r5 /* Set reservation */ |
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301 | b align_complete /* return */ |
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302 | |
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303 | /* |
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304 | * Load Word Byte-Reversed Indexed |
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305 | */ |
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306 | lwbrx: |
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307 | lswi r10,r5,4 /* load four bytes from DEAR into r10 */ |
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308 | stwbrx r10,r7,r8 /* store reversed in reg image */ |
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309 | b align_complete /* return */ |
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310 | |
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311 | /* Load Word and Zero with Update */ |
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312 | lwzu: |
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313 | /* Load Word and Zero with Update Indexed */ |
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314 | lwzux: |
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315 | stwx r5,r7,r6 /* update RA with effective addr */ |
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316 | |
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317 | /* Load Word and Zero */ |
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318 | lwz: |
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319 | /* Load Word and Zero Indexed */ |
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320 | lwzx: |
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321 | lswi r10,r5,4 /* load four bytes from DEAR into r10 */ |
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322 | stwx r10,r7,r8 /* update reg image */ |
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323 | b align_complete /* return */ |
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324 | |
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325 | /* Store instructions */ |
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326 | |
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327 | /* */ |
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328 | /* Store Half Word and Update */ |
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329 | sthu: |
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330 | /* Store Half Word and Update Indexed */ |
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331 | sthux: |
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332 | stwx r5,r7,r6 /* Update RA with effective address */ |
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333 | |
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334 | /* Store Half Word */ |
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335 | sth: |
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336 | /* Store Half Word Indexed */ |
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337 | sthx: |
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338 | lwzx r10,r8,r7 /* retrieve source register value */ |
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339 | rlwinm r10,r10,16,0,15 /* move two bytes to high end of reg */ |
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340 | stswi r10,r5,2 /* store bytes to DEAR address */ |
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341 | b align_complete /* return */ |
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342 | |
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343 | /* */ |
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344 | /* Store Half Word Byte-Reversed Indexed */ |
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345 | sthbrx: |
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346 | lwbrx r10,r8,r7 /* retrieve src reg value byte reversed */ |
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347 | stswi r10,r5,2 /* move two bytes to DEAR address */ |
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348 | b align_complete /* return */ |
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349 | |
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350 | /* */ |
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351 | /* Store Multiple Word */ |
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352 | stmw: |
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353 | addi r10,r7,32*4 /* r10 points to r31 in image + 4 */ |
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354 | rlwinm r8,r8,30,2,31 /* r8 >>= 2 (recovers RT) */ |
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355 | subfic r8,r8,32 /* r8 is reg count to load */ |
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356 | mtctr r8 /* load counter */ |
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357 | addi r8,r8,-1 /* r8-- */ |
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358 | rlwinm r8,r8,2,2,31 /* r8 *= 4 */ |
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359 | add r5,r5,r8 /* update DEAR to point to last reg */ |
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360 | stmloop: |
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361 | lwzu r11,-4(r10) /* get register value */ |
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362 | stswi r11,r5,4 /* output to DEAR address */ |
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363 | addi r5,r5,-4 /* decrement effective address */ |
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364 | bdnz stmloop |
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365 | b align_complete /* return */ |
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366 | |
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367 | /* */ |
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368 | /* Store Word and Update */ |
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369 | stwu: |
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370 | /* Store Word and Update Indexed */ |
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371 | stwux: |
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372 | stwx r5,r7,r6 /* Update RA with effective address */ |
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373 | |
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374 | /* Store Word */ |
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375 | stw: |
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376 | /* Store Word Indexed */ |
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377 | stwx: |
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378 | lwzx r10,r8,r7 /* retrieve source register value */ |
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379 | stswi r10,r5,4 /* store bytes to DEAR address */ |
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380 | b align_complete /* return */ |
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381 | |
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382 | /* */ |
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383 | /* Store Word Byte-Reversed Indexed */ |
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384 | stwbrx: |
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385 | lwbrx r10,r8,r7 /* retrieve src reg value byte reversed */ |
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386 | stswi r10,r5,4 /* move two bytes to DEAR address */ |
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387 | b align_complete /* return */ |
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388 | |
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389 | /* */ |
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390 | /* Store Word Conditional Indexed */ |
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391 | stwcx: |
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392 | rlwinm r10,r5,0,0,29 /* r10 = word aligned DEAR */ |
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393 | lwz r11,0(r10) /* save original value of store */ |
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394 | stwcx. r11,r0,r10 /* attempt store to address */ |
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395 | bne stwcx_moveon /* store failed, move on */ |
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396 | stw r11,0(r10) /* repair damage */ |
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397 | lwzx r9,r7,r8 /* get register value */ |
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398 | stswi r10,r5,4 /* store bytes to DEAR address */ |
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399 | stwcx_moveon: |
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400 | mfcr r11 /* get condition reg */ |
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401 | lwz r9,Open_cr(r1) /* get condition reg image */ |
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402 | rlwimi r9,r11,0,0,2 /* insert 3 CR bits into cr image */ |
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403 | lwz r11,Open_xer(r1) /* get XER reg */ |
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404 | rlwimi r9,r11,29,2,2 /* insert XER SO bit into cr image */ |
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405 | stw r9,Open_cr(r1) /* store cr image */ |
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406 | b align_complete /* return */ |
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407 | |
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408 | /* */ |
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409 | /* Data Cache Block Zero */ |
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410 | dcbz: |
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411 | rlwinm r5,r5,0,0,31-CACHE_SIZE_L2 |
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412 | /* get address to nearest Cache line */ |
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413 | addi r5,r5,-4 /* adjust by a word */ |
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414 | addi r10,r0,CACHE_SIZE/4 /* set counter value */ |
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415 | mtctr r10 |
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416 | addi r11,r0,0 /* r11 = 0 */ |
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417 | dcbz_loop: |
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418 | stwu r11,4(r5) /* store a word and update EA */ |
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419 | bdnz dcbz_loop |
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420 | b align_complete /* return */ |
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421 | |
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422 | align_complete: |
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423 | /*----------------------------------------------------------------------- |
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424 | * Restore regs and return from the interrupt |
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425 | *----------------------------------------------------------------------*/ |
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426 | lmw r24,Open_xer+ALIGN_REGS(r0) |
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427 | mtxer r24 |
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428 | mtlr r25 |
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429 | mtctr r26 |
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430 | mtcrf 0xFF, r27 |
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431 | #if defined(ppc403) || defined(ppc405) |
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432 | mtspr srr2, r28 /* SRR 2 */ |
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433 | mtspr srr3, r29 /* SRR 3 */ |
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434 | #endif |
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435 | mtspr srr0, r30 /* SRR 0 */ |
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436 | mtspr srr1, r31 /* SRR 1 */ |
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437 | lmw r1,Open_gpr1+ALIGN_REGS(r0) |
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438 | lwz r0,Open_gpr0+ALIGN_REGS(r0) |
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439 | rfi |
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