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