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 45#include <asm/assembly.h> 46#include <asm/pdc.h> 47 48#include <linux/linkage.h> 49#include <linux/init.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 __PAGE_ALIGNED_BSS 59 .align 4096 60hpmc_stack: 61 .block 16384 62 63#define HPMC_IODC_BUF_SIZE 0x8000 64 65 __PAGE_ALIGNED_BSS 66 .align 4096 67hpmc_iodc_buf: 68 .block HPMC_IODC_BUF_SIZE 69 70 .section .bss 71 .align 8 72hpmc_raddr: 73 .block 128 74 75#define HPMC_PIM_DATA_SIZE 896 /* Enough to hold all architected 2.0 state */ 76 77 .section .bss 78 .align 8 79ENTRY(hpmc_pim_data) 80 .block HPMC_PIM_DATA_SIZE 81END(hpmc_pim_data) 82 83 .text 84 85 .import intr_save, code 86ENTRY_CFI(os_hpmc) 87.os_hpmc: 88 89 /* 90 * registers modified: 91 * 92 * Using callee saves registers without saving them. The 93 * original values are in the pim dump if we need them. 94 * 95 * r2 (rp) return pointer 96 * r3 address of PDCE_PROC 97 * r4 scratch 98 * r5 scratch 99 * r23 (arg3) procedure arg 100 * r24 (arg2) procedure arg 101 * r25 (arg1) procedure arg 102 * r26 (arg0) procedure arg 103 * r30 (sp) stack pointer 104 * 105 * registers read: 106 * 107 * r26 contains address of PDCE_PROC on entry 108 * r28 (ret0) return value from procedure 109 */ 110 111 copy arg0, %r3 /* save address of PDCE_PROC */ 112 113 /* 114 * disable nested HPMCs 115 * 116 * Increment os_hpmc checksum to invalidate it. 117 * Do this before turning the PSW M bit off. 118 */ 119 120 mfctl %cr14, %r4 121 ldw 52(%r4),%r5 122 addi 1,%r5,%r5 123 stw %r5,52(%r4) 124 125 /* MP_FIXME: synchronize all processors. */ 126 127 /* Setup stack pointer. */ 128 129 load32 PA(hpmc_stack),sp 130 131 ldo 128(sp),sp /* leave room for arguments */ 132 133 /* 134 * Most PDC routines require that the M bit be off. 135 * So turn on the Q bit and turn off the M bit. 136 */ 137 138 ldo 8(%r0),%r4 /* PSW Q on, PSW M off */ 139 mtctl %r4,ipsw 140 mtctl %r0,pcsq 141 mtctl %r0,pcsq 142 load32 PA(os_hpmc_1),%r4 143 mtctl %r4,pcoq 144 ldo 4(%r4),%r4 145 mtctl %r4,pcoq 146 rfi 147 nop 148 149os_hpmc_1: 150 151 /* Call PDC_PIM to get HPMC pim info */ 152 153 /* 154 * Note that on some newer boxes, PDC_PIM must be called 155 * before PDC_IO if you want IO to be reset. PDC_PIM sets 156 * a flag that PDC_IO examines. 157 */ 158 159 ldo PDC_PIM(%r0), arg0 160 ldo PDC_PIM_HPMC(%r0),arg1 /* Transfer HPMC data */ 161 load32 PA(hpmc_raddr),arg2 162 load32 PA(hpmc_pim_data),arg3 163 load32 HPMC_PIM_DATA_SIZE,%r4 164 stw %r4,-52(sp) 165 166 ldil L%PA(os_hpmc_2), rp 167 bv (r3) /* call pdce_proc */ 168 ldo R%PA(os_hpmc_2)(rp), rp 169 170os_hpmc_2: 171 comib,<> 0,ret0, os_hpmc_fail 172 173 /* Reset IO by calling the hversion dependent PDC_IO routine */ 174 175 ldo PDC_IO(%r0),arg0 176 ldo 0(%r0),arg1 /* log IO errors */ 177 ldo 0(%r0),arg2 /* reserved */ 178 ldo 0(%r0),arg3 /* reserved */ 179 stw %r0,-52(sp) /* reserved */ 180 181 ldil L%PA(os_hpmc_3),rp 182 bv (%r3) /* call pdce_proc */ 183 ldo R%PA(os_hpmc_3)(rp),rp 184 185os_hpmc_3: 186 187 /* FIXME? Check for errors from PDC_IO (-1 might be OK) */ 188 189 /* 190 * Initialize the IODC console device (HPA,SPA, path etc. 191 * are stored on page 0. 192 */ 193 194 /* 195 * Load IODC into hpmc_iodc_buf by calling PDC_IODC. 196 * Note that PDC_IODC handles flushing the appropriate 197 * data and instruction cache lines. 198 */ 199 200 ldo PDC_IODC(%r0),arg0 201 ldo PDC_IODC_READ(%r0),arg1 202 load32 PA(hpmc_raddr),arg2 203 ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg3 /* console hpa */ 204 ldo PDC_IODC_RI_INIT(%r0),%r4 205 stw %r4,-52(sp) 206 load32 PA(hpmc_iodc_buf),%r4 207 stw %r4,-56(sp) 208 load32 HPMC_IODC_BUF_SIZE,%r4 209 stw %r4,-60(sp) 210 211 ldil L%PA(os_hpmc_4),rp 212 bv (%r3) /* call pdce_proc */ 213 ldo R%PA(os_hpmc_4)(rp),rp 214 215os_hpmc_4: 216 comib,<> 0,ret0,os_hpmc_fail 217 218 /* Call the entry init (just loaded by PDC_IODC) */ 219 220 ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg0 /* console hpa */ 221 ldo ENTRY_INIT_MOD_DEV(%r0), arg1 222 ldw BOOT_CONSOLE_SPA_OFFSET(%r0),arg2 /* console spa */ 223 depi 0,31,11,arg2 /* clear bits 21-31 */ 224 ldo BOOT_CONSOLE_PATH_OFFSET(%r0),arg3 /* console path */ 225 load32 PA(hpmc_raddr),%r4 226 stw %r4, -52(sp) 227 stw %r0, -56(sp) /* HV */ 228 stw %r0, -60(sp) /* HV */ 229 stw %r0, -64(sp) /* HV */ 230 stw %r0, -68(sp) /* lang, must be zero */ 231 232 load32 PA(hpmc_iodc_buf),%r5 233 ldil L%PA(os_hpmc_5),rp 234 bv (%r5) 235 ldo R%PA(os_hpmc_5)(rp),rp 236 237os_hpmc_5: 238 comib,<> 0,ret0,os_hpmc_fail 239 240 /* Prepare to call intr_save */ 241 242 /* 243 * Load kernel page directory (load into user also, since 244 * we don't intend to ever return to user land anyway) 245 */ 246 247 load32 PA(swapper_pg_dir),%r4 248 mtctl %r4,%cr24 /* Initialize kernel root pointer */ 249 mtctl %r4,%cr25 /* Initialize user root pointer */ 250 251 /* Clear sr4-sr7 */ 252 253 mtsp %r0, %sr4 254 mtsp %r0, %sr5 255 mtsp %r0, %sr6 256 mtsp %r0, %sr7 257 258 tovirt_r1 %r30 /* make sp virtual */ 259 260 rsm 8,%r0 /* Clear Q bit */ 261 ldi 1,%r8 /* Set trap code to "1" for HPMC */ 262 load32 PA(intr_save),%r1 263 be 0(%sr7,%r1) 264 nop 265 266os_hpmc_fail: 267 268 /* 269 * Reset the system 270 * 271 * Some systems may lockup from a broadcast reset, so try the 272 * hversion PDC_BROADCAST_RESET() first. 273 * MP_FIXME: reset all processors if more than one central bus. 274 */ 275 276 /* PDC_BROADCAST_RESET() */ 277 278 ldo PDC_BROADCAST_RESET(%r0),arg0 279 ldo 0(%r0),arg1 /* do reset */ 280 281 ldil L%PA(os_hpmc_6),rp 282 bv (%r3) /* call pdce_proc */ 283 ldo R%PA(os_hpmc_6)(rp),rp 284 285os_hpmc_6: 286 287 /* 288 * possible return values: 289 * -1 non-existent procedure 290 * -2 non-existent option 291 * -16 unaligned stack 292 * 293 * If call returned, do a broadcast reset. 294 */ 295 296 ldil L%0xfffc0000,%r4 /* IO_BROADCAST */ 297 ldo 5(%r0),%r5 298 stw %r5,48(%r4) /* CMD_RESET to IO_COMMAND offset */ 299 300 b . 301 nop 302ENDPROC_CFI(os_hpmc) 303.os_hpmc_end: 304 305 306 __INITRODATA 307 .export os_hpmc_size 308os_hpmc_size: 309 .word .os_hpmc_end-.os_hpmc 310