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#include <asm/psw.h> 48 49#include <linux/linkage.h> 50#include <linux/init.h> 51 52 /* 53 * stack for os_hpmc, the HPMC handler. 54 * buffer for IODC procedures (for the HPMC handler). 55 * 56 * IODC requires 7K byte stack. That leaves 1K byte for os_hpmc. 57 */ 58 59 __PAGE_ALIGNED_BSS 60 .align 4096 61hpmc_stack: 62 .block 16384 63 64#define HPMC_IODC_BUF_SIZE 0x8000 65 66 __PAGE_ALIGNED_BSS 67 .align 4096 68hpmc_iodc_buf: 69 .block HPMC_IODC_BUF_SIZE 70 71 .section .bss 72 .align 8 73hpmc_raddr: 74 .block 128 75 76#define HPMC_PIM_DATA_SIZE 896 /* Enough to hold all architected 2.0 state */ 77 78 .section .bss 79 .align 8 80ENTRY(hpmc_pim_data) 81 .block HPMC_PIM_DATA_SIZE 82END(hpmc_pim_data) 83 84 .text 85 86 .import intr_save, code 87ENTRY_CFI(os_hpmc) 88.os_hpmc: 89 90 /* 91 * registers modified: 92 * 93 * Using callee saves registers without saving them. The 94 * original values are in the pim dump if we need them. 95 * 96 * r2 (rp) return pointer 97 * r3 address of PDCE_PROC 98 * r4 scratch 99 * r5 scratch 100 * r23 (arg3) procedure arg 101 * r24 (arg2) procedure arg 102 * r25 (arg1) procedure arg 103 * r26 (arg0) procedure arg 104 * r30 (sp) stack pointer 105 * 106 * registers read: 107 * 108 * r26 contains address of PDCE_PROC on entry 109 * r28 (ret0) return value from procedure 110 */ 111 112 copy arg0, %r3 /* save address of PDCE_PROC */ 113 114 /* 115 * disable nested HPMCs 116 * 117 * Increment os_hpmc checksum to invalidate it. 118 * Do this before turning the PSW M bit off. 119 */ 120 121 mfctl %cr14, %r4 122 ldw 52(%r4),%r5 123 addi 1,%r5,%r5 124 stw %r5,52(%r4) 125 126 /* MP_FIXME: synchronize all processors. */ 127 128 /* Setup stack pointer. */ 129 130 load32 PA(hpmc_stack),sp 131 132 ldo 128(sp),sp /* leave room for arguments */ 133 134 /* 135 * Most PDC routines require that the M bit be off. 136 * So turn on the Q bit and turn off the M bit. 137 */ 138 139 ldi PSW_SM_Q,%r4 /* PSW Q on, PSW M off */ 140 mtctl %r4,ipsw 141 mtctl %r0,pcsq 142 mtctl %r0,pcsq 143 load32 PA(os_hpmc_1),%r4 144 mtctl %r4,pcoq 145 ldo 4(%r4),%r4 146 mtctl %r4,pcoq 147 rfi 148 nop 149 150os_hpmc_1: 151 152 /* Call PDC_PIM to get HPMC pim info */ 153 154 /* 155 * Note that on some newer boxes, PDC_PIM must be called 156 * before PDC_IO if you want IO to be reset. PDC_PIM sets 157 * a flag that PDC_IO examines. 158 */ 159 160 ldo PDC_PIM(%r0), arg0 161 ldo PDC_PIM_HPMC(%r0),arg1 /* Transfer HPMC data */ 162 load32 PA(hpmc_raddr),arg2 163 load32 PA(hpmc_pim_data),arg3 164 load32 HPMC_PIM_DATA_SIZE,%r4 165 stw %r4,-52(sp) 166 167 ldil L%PA(os_hpmc_2), rp 168 bv (r3) /* call pdce_proc */ 169 ldo R%PA(os_hpmc_2)(rp), rp 170 171os_hpmc_2: 172 comib,<> 0,ret0, os_hpmc_fail 173 174 /* Reset IO by calling the hversion dependent PDC_IO routine */ 175 176 ldo PDC_IO(%r0),arg0 177 ldo 0(%r0),arg1 /* log IO errors */ 178 ldo 0(%r0),arg2 /* reserved */ 179 ldo 0(%r0),arg3 /* reserved */ 180 stw %r0,-52(sp) /* reserved */ 181 182 ldil L%PA(os_hpmc_3),rp 183 bv (%r3) /* call pdce_proc */ 184 ldo R%PA(os_hpmc_3)(rp),rp 185 186os_hpmc_3: 187 188 /* FIXME? Check for errors from PDC_IO (-1 might be OK) */ 189 190 /* 191 * Initialize the IODC console device (HPA,SPA, path etc. 192 * are stored on page 0. 193 */ 194 195 /* 196 * Load IODC into hpmc_iodc_buf by calling PDC_IODC. 197 * Note that PDC_IODC handles flushing the appropriate 198 * data and instruction cache lines. 199 */ 200 201 ldo PDC_IODC(%r0),arg0 202 ldo PDC_IODC_READ(%r0),arg1 203 load32 PA(hpmc_raddr),arg2 204 ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg3 /* console hpa */ 205 ldo PDC_IODC_RI_INIT(%r0),%r4 206 stw %r4,-52(sp) 207 load32 PA(hpmc_iodc_buf),%r4 208 stw %r4,-56(sp) 209 load32 HPMC_IODC_BUF_SIZE,%r4 210 stw %r4,-60(sp) 211 212 ldil L%PA(os_hpmc_4),rp 213 bv (%r3) /* call pdce_proc */ 214 ldo R%PA(os_hpmc_4)(rp),rp 215 216os_hpmc_4: 217 comib,<> 0,ret0,os_hpmc_fail 218 219 /* Call the entry init (just loaded by PDC_IODC) */ 220 221 ldw BOOT_CONSOLE_HPA_OFFSET(%r0),arg0 /* console hpa */ 222 ldo ENTRY_INIT_MOD_DEV(%r0), arg1 223 ldw BOOT_CONSOLE_SPA_OFFSET(%r0),arg2 /* console spa */ 224 depi 0,31,11,arg2 /* clear bits 21-31 */ 225 ldo BOOT_CONSOLE_PATH_OFFSET(%r0),arg3 /* console path */ 226 load32 PA(hpmc_raddr),%r4 227 stw %r4, -52(sp) 228 stw %r0, -56(sp) /* HV */ 229 stw %r0, -60(sp) /* HV */ 230 stw %r0, -64(sp) /* HV */ 231 stw %r0, -68(sp) /* lang, must be zero */ 232 233 load32 PA(hpmc_iodc_buf),%r5 234 ldil L%PA(os_hpmc_5),rp 235 bv (%r5) 236 ldo R%PA(os_hpmc_5)(rp),rp 237 238os_hpmc_5: 239 comib,<> 0,ret0,os_hpmc_fail 240 241 /* Prepare to call intr_save */ 242 243 /* 244 * Load kernel page directory (load into user also, since 245 * we don't intend to ever return to user land anyway) 246 */ 247 248 load32 PA(swapper_pg_dir),%r4 249 mtctl %r4,%cr24 /* Initialize kernel root pointer */ 250 mtctl %r4,%cr25 /* Initialize user root pointer */ 251 252 /* Clear sr4-sr7 */ 253 254 mtsp %r0, %sr4 255 mtsp %r0, %sr5 256 mtsp %r0, %sr6 257 mtsp %r0, %sr7 258 259 tovirt_r1 %r30 /* make sp virtual */ 260 261 rsm PSW_SM_Q,%r0 /* Clear Q bit */ 262 ldi 1,%r8 /* Set trap code to "1" for HPMC */ 263 load32 PA(intr_save),%r1 264 be 0(%sr7,%r1) 265 nop 266 267os_hpmc_fail: 268 269 /* 270 * Reset the system 271 * 272 * Some systems may lockup from a broadcast reset, so try the 273 * hversion PDC_BROADCAST_RESET() first. 274 * MP_FIXME: reset all processors if more than one central bus. 275 */ 276 277 /* PDC_BROADCAST_RESET() */ 278 279 ldo PDC_BROADCAST_RESET(%r0),arg0 280 ldo 0(%r0),arg1 /* do reset */ 281 282 ldil L%PA(os_hpmc_6),rp 283 bv (%r3) /* call pdce_proc */ 284 ldo R%PA(os_hpmc_6)(rp),rp 285 286os_hpmc_6: 287 288 /* 289 * possible return values: 290 * -1 non-existent procedure 291 * -2 non-existent option 292 * -16 unaligned stack 293 * 294 * If call returned, do a broadcast reset. 295 */ 296 297 ldil L%0xfffc0000,%r4 /* IO_BROADCAST */ 298 ldo 5(%r0),%r5 299 stw %r5,48(%r4) /* CMD_RESET to IO_COMMAND offset */ 300 301 b . 302 nop 303ENDPROC_CFI(os_hpmc) 304.os_hpmc_end: 305 306 307 __INITRODATA 308 .export os_hpmc_size 309os_hpmc_size: 310 .word .os_hpmc_end-.os_hpmc 311