1/* 2 * HPMC (High Priority Machine Check) handler. 3 * 4 * Copyright (C) 1999 Philipp Rumpf <prumpf@tux.org> 5 * Copyright (C) 1999 Hewlett-Packard (Frank Rowand) 6 * Copyright (C) 2000 Hewlett-Packard (John Marvin) 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2, or (at your option) 11 * any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 */ 22 23 24/* 25 * This HPMC handler retrieves the HPMC pim data, resets IO and 26 * returns to the default trap handler with code set to 1 (HPMC). 27 * The default trap handler calls handle interruption, which 28 * does a stack and register dump. This at least allows kernel 29 * developers to get back to C code in virtual mode, where they 30 * have the option to examine and print values from memory that 31 * would help in debugging an HPMC caused by a software bug. 32 * 33 * There is more to do here: 34 * 35 * 1) On MP systems we need to synchronize processors 36 * before calling pdc/iodc. 37 * 2) We should be checking the system state and not 38 * returning to the fault handler if things are really 39 * bad. 40 * 41 */ 42 43 .level 1.1 44 .data 45 46#include <asm/assembly.h> 47#include <asm/pdc.h> 48 49#include <linux/linkage.h> 50 51 /* 52 * stack for os_hpmc, the HPMC handler. 53 * buffer for IODC procedures (for the HPMC handler). 54 * 55 * IODC requires 7K byte stack. That leaves 1K byte for os_hpmc. 56 */ 57 58 .align PAGE_SIZE 59hpmc_stack: 60 .block 16384 61 62#define HPMC_IODC_BUF_SIZE 0x8000 63 64 .align PAGE_SIZE 65hpmc_iodc_buf: 66 .block HPMC_IODC_BUF_SIZE 67 68 .align 8 69hpmc_raddr: 70 .block 128 71 72#define HPMC_PIM_DATA_SIZE 896 /* Enough to hold all architected 2.0 state */ 73 74 .align 8 75ENTRY(hpmc_pim_data) 76 .block HPMC_PIM_DATA_SIZE 77END(hpmc_pim_data) 78 79 .text 80 81 .import intr_save, code 82ENTRY(os_hpmc) 83.os_hpmc: 84 85 /* 86 * registers modified: 87 * 88 * Using callee saves registers without saving them. The 89 * original values are in the pim dump if we need them. 90 * 91 * r2 (rp) return pointer 92 * r3 address of PDCE_PROC 93 * r4 scratch 94 * r5 scratch 95 * r23 (arg3) procedure arg 96 * r24 (arg2) procedure arg 97 * r25 (arg1) procedure arg 98 * r26 (arg0) procedure arg 99 * r30 (sp) stack pointer 100 * 101 * registers read: 102 * 103 * r26 contains address of PDCE_PROC on entry 104 * r28 (ret0) return value from procedure 105 */ 106 107 copy arg0, %r3 /* save address of PDCE_PROC */ 108 109 /* 110 * disable nested HPMCs 111 * 112 * Increment os_hpmc checksum to invalidate it. 113 * Do this before turning the PSW M bit off. 114 */ 115 116 mfctl %cr14, %r4 117 ldw 52(%r4),%r5 118 addi 1,%r5,%r5 119 stw %r5,52(%r4) 120 121 /* MP_FIXME: synchronize all processors. */ 122 123 /* Setup stack pointer. */ 124 125 load32 PA(hpmc_stack),sp 126 127 ldo 128(sp),sp /* leave room for arguments */ 128 129 /* 130 * Most PDC routines require that the M bit be off. 131 * So turn on the Q bit and turn off the M bit. 132 */ 133 134 ldo 8(%r0),%r4 /* PSW Q on, PSW M off */ 135 mtctl %r4,ipsw 136 mtctl %r0,pcsq 137 mtctl %r0,pcsq 138 load32 PA(os_hpmc_1),%r4 139 mtctl %r4,pcoq 140 ldo 4(%r4),%r4 141 mtctl %r4,pcoq 142 rfi 143 nop 144 145os_hpmc_1: 146 147 /* Call PDC_PIM to get HPMC pim info */ 148 149 /* 150 * Note that on some newer boxes, PDC_PIM must be called 151 * before PDC_IO if you want IO to be reset. PDC_PIM sets 152 * a flag that PDC_IO examines. 153 */ 154 155 ldo PDC_PIM(%r0), arg0 156 ldo PDC_PIM_HPMC(%r0),arg1 /* Transfer HPMC data */ 157 load32 PA(hpmc_raddr),arg2 158 load32 PA(hpmc_pim_data),arg3 159 load32 HPMC_PIM_DATA_SIZE,%r4 160 stw %r4,-52(sp) 161 162 ldil L%PA(os_hpmc_2), rp 163 bv (r3) /* call pdce_proc */ 164 ldo R%PA(os_hpmc_2)(rp), rp 165 166os_hpmc_2: 167 comib,<> 0,ret0, os_hpmc_fail 168 169 /* Reset IO by calling the hversion dependent PDC_IO routine */ 170 171 ldo PDC_IO(%r0),arg0 172 ldo 0(%r0),arg1 /* log IO errors */ 173 ldo 0(%r0),arg2 /* reserved */ 174 ldo 0(%r0),arg3 /* reserved */ 175 stw %r0,-52(sp) /* reserved */ 176 177 ldil L%PA(os_hpmc_3),rp 178 bv (%r3) /* call pdce_proc */ 179 ldo R%PA(os_hpmc_3)(rp),rp 180 181os_hpmc_3: 182 183 /* FIXME? Check for errors from PDC_IO (-1 might be OK) */ 184 185 /* 186 * Initialize the IODC console device (HPA,SPA, path etc. 187 * are stored on page 0. 188 */ 189 190 /* 191 * Load IODC into hpmc_iodc_buf by calling PDC_IODC. 192 * Note that PDC_IODC handles flushing the appropriate 193 * data and instruction cache lines. 194 */ 195 196 ldo PDC_IODC(%r0),arg0 197 ldo PDC_IODC_READ(%r0),arg1 198 load32 PA(hpmc_raddr),arg2 199 ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg3 /* console hpa */ 200 ldo PDC_IODC_RI_INIT(%r0),%r4 201 stw %r4,-52(sp) 202 load32 PA(hpmc_iodc_buf),%r4 203 stw %r4,-56(sp) 204 load32 HPMC_IODC_BUF_SIZE,%r4 205 stw %r4,-60(sp) 206 207 ldil L%PA(os_hpmc_4),rp 208 bv (%r3) /* call pdce_proc */ 209 ldo R%PA(os_hpmc_4)(rp),rp 210 211os_hpmc_4: 212 comib,<> 0,ret0,os_hpmc_fail 213 214 /* Call the entry init (just loaded by PDC_IODC) */ 215 216 ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg0 /* console hpa */ 217 ldo ENTRY_INIT_MOD_DEV(%r0), arg1 218 ldw BOOT_CONSOLE_SPA_OFFSET(%r0),arg2 /* console spa */ 219 depi 0,31,11,arg2 /* clear bits 21-31 */ 220 ldo BOOT_CONSOLE_PATH_OFFSET(%r0),arg3 /* console path */ 221 load32 PA(hpmc_raddr),%r4 222 stw %r4, -52(sp) 223 stw %r0, -56(sp) /* HV */ 224 stw %r0, -60(sp) /* HV */ 225 stw %r0, -64(sp) /* HV */ 226 stw %r0, -68(sp) /* lang, must be zero */ 227 228 load32 PA(hpmc_iodc_buf),%r5 229 ldil L%PA(os_hpmc_5),rp 230 bv (%r5) 231 ldo R%PA(os_hpmc_5)(rp),rp 232 233os_hpmc_5: 234 comib,<> 0,ret0,os_hpmc_fail 235 236 /* Prepare to call intr_save */ 237 238 /* 239 * Load kernel page directory (load into user also, since 240 * we don't intend to ever return to user land anyway) 241 */ 242 243 load32 PA(swapper_pg_dir),%r4 244 mtctl %r4,%cr24 /* Initialize kernel root pointer */ 245 mtctl %r4,%cr25 /* Initialize user root pointer */ 246 247 /* Clear sr4-sr7 */ 248 249 mtsp %r0, %sr4 250 mtsp %r0, %sr5 251 mtsp %r0, %sr6 252 mtsp %r0, %sr7 253 254 tovirt_r1 %r30 /* make sp virtual */ 255 256 rsm 8,%r0 /* Clear Q bit */ 257 ldi 1,%r8 /* Set trap code to "1" for HPMC */ 258 load32 PA(intr_save),%r1 259 be 0(%sr7,%r1) 260 nop 261 262os_hpmc_fail: 263 264 /* 265 * Reset the system 266 * 267 * Some systems may lockup from a broadcast reset, so try the 268 * hversion PDC_BROADCAST_RESET() first. 269 * MP_FIXME: reset all processors if more than one central bus. 270 */ 271 272 /* PDC_BROADCAST_RESET() */ 273 274 ldo PDC_BROADCAST_RESET(%r0),arg0 275 ldo 0(%r0),arg1 /* do reset */ 276 277 ldil L%PA(os_hpmc_6),rp 278 bv (%r3) /* call pdce_proc */ 279 ldo R%PA(os_hpmc_6)(rp),rp 280 281os_hpmc_6: 282 283 /* 284 * possible return values: 285 * -1 non-existent procedure 286 * -2 non-existent option 287 * -16 unaligned stack 288 * 289 * If call returned, do a broadcast reset. 290 */ 291 292 ldil L%0xfffc0000,%r4 /* IO_BROADCAST */ 293 ldo 5(%r0),%r5 294 stw %r5,48(%r4) /* CMD_RESET to IO_COMMAND offset */ 295 296 b . 297 nop 298ENDPROC(os_hpmc) 299.os_hpmc_end: 300 nop 301.data 302.align 4 303 .export os_hpmc_size 304os_hpmc_size: 305 .word .os_hpmc_end-.os_hpmc 306