uboot/arch/blackfin/cpu/traps.c
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   1/*
   2 * U-Boot - traps.c Routines related to interrupts and exceptions
   3 *
   4 * Copyright (c) 2005-2008 Analog Devices Inc.
   5 *
   6 * This file is based on
   7 * No original Copyright holder listed,
   8 * Probabily original (C) Roman Zippel (assigned DJD, 1999)
   9 *
  10 * Copyright 2003 Metrowerks - for Blackfin
  11 * Copyright 2000-2001 Lineo, Inc. D. Jeff Dionne <jeff@lineo.ca>
  12 * Copyright 1999-2000 D. Jeff Dionne, <jeff@uclinux.org>
  13 *
  14 * (C) Copyright 2000-2004
  15 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  16 *
  17 * Licensed under the GPL-2 or later.
  18 */
  19
  20#include <common.h>
  21#include <kgdb.h>
  22#include <linux/types.h>
  23#include <asm/traps.h>
  24#include <asm/cplb.h>
  25#include <asm/io.h>
  26#include <asm/mach-common/bits/core.h>
  27#include <asm/mach-common/bits/mpu.h>
  28#include <asm/mach-common/bits/trace.h>
  29#include <asm/deferred.h>
  30#include "cpu.h"
  31
  32#ifdef CONFIG_DEBUG_DUMP
  33# define ENABLE_DUMP 1
  34#else
  35# define ENABLE_DUMP 0
  36#endif
  37
  38#define trace_buffer_save(x) \
  39        do { \
  40                if (!ENABLE_DUMP) \
  41                        break; \
  42                (x) = bfin_read_TBUFCTL(); \
  43                bfin_write_TBUFCTL((x) & ~TBUFEN); \
  44        } while (0)
  45
  46#define trace_buffer_restore(x) \
  47        do { \
  48                if (!ENABLE_DUMP) \
  49                        break; \
  50                bfin_write_TBUFCTL((x)); \
  51        } while (0);
  52
  53/* The purpose of this map is to provide a mapping of address<->cplb settings
  54 * rather than an exact map of what is actually addressable on the part.  This
  55 * map covers all current Blackfin parts.  If you try to access an address that
  56 * is in this map but not actually on the part, you won't get an exception and
  57 * reboot, you'll get an external hardware addressing error and reboot.  Since
  58 * only the ends matter (you did something wrong and the board reset), the means
  59 * are largely irrelevant.
  60 */
  61struct memory_map {
  62        uint32_t start, end;
  63        uint32_t data_flags, inst_flags;
  64};
  65const struct memory_map const bfin_memory_map[] = {
  66        {       /* external memory */
  67                .start = 0x00000000,
  68                .end   = 0x20000000,
  69                .data_flags = SDRAM_DGENERIC,
  70                .inst_flags = SDRAM_IGENERIC,
  71        },
  72        {       /* async banks */
  73                .start = 0x20000000,
  74                .end   = 0x30000000,
  75                .data_flags = SDRAM_EBIU,
  76                .inst_flags = SDRAM_INON_CHBL,
  77        },
  78        {       /* everything on chip */
  79                .start = 0xE0000000,
  80                .end   = 0xFFFFFFFF,
  81                .data_flags = L1_DMEMORY,
  82                .inst_flags = L1_IMEMORY,
  83        }
  84};
  85
  86#ifdef CONFIG_EXCEPTION_DEFER
  87unsigned int deferred_regs[deferred_regs_last];
  88#endif
  89
  90/*
  91 * Handle all exceptions while running in EVT3 or EVT5
  92 */
  93int trap_c(struct pt_regs *regs, uint32_t level)
  94{
  95        uint32_t ret = 0;
  96        uint32_t trapnr = (regs->seqstat & EXCAUSE);
  97        unsigned long tflags;
  98        bool data = false;
  99
 100        /*
 101         * Keep the trace buffer so that a miss here points people
 102         * to the right place (their code).  Crashes here rarely
 103         * happen.  If they do, only the Blackfin maintainer cares.
 104         */
 105        trace_buffer_save(tflags);
 106
 107        switch (trapnr) {
 108        /* 0x26 - Data CPLB Miss */
 109        case VEC_CPLB_M:
 110
 111                if (ANOMALY_05000261) {
 112                        static uint32_t last_cplb_fault_retx;
 113                        /*
 114                         * Work around an anomaly: if we see a new DCPLB fault,
 115                         * return without doing anything. Then,
 116                         * if we get the same fault again, handle it.
 117                         */
 118                        if (last_cplb_fault_retx != regs->retx) {
 119                                last_cplb_fault_retx = regs->retx;
 120                                break;
 121                        }
 122                }
 123
 124                data = true;
 125                /* fall through */
 126
 127        /* 0x27 - Instruction CPLB Miss */
 128        case VEC_CPLB_I_M: {
 129                volatile uint32_t *CPLB_ADDR_BASE, *CPLB_DATA_BASE, *CPLB_ADDR, *CPLB_DATA;
 130                uint32_t new_cplb_addr = 0, new_cplb_data = 0;
 131                static size_t last_evicted;
 132                size_t i;
 133
 134#ifdef CONFIG_EXCEPTION_DEFER
 135                /* This should never happen */
 136                if (level == 5)
 137                        bfin_panic(regs);
 138#endif
 139
 140                new_cplb_addr = (data ? bfin_read_DCPLB_FAULT_ADDR() : bfin_read_ICPLB_FAULT_ADDR()) & ~(4 * 1024 * 1024 - 1);
 141
 142                for (i = 0; i < ARRAY_SIZE(bfin_memory_map); ++i) {
 143                        /* if the exception is inside this range, lets use it */
 144                        if (new_cplb_addr >= bfin_memory_map[i].start &&
 145                            new_cplb_addr < bfin_memory_map[i].end)
 146                                break;
 147                }
 148                if (i == ARRAY_SIZE(bfin_memory_map)) {
 149                        printf("%cCPLB exception outside of memory map at 0x%p\n",
 150                                (data ? 'D' : 'I'), (void *)new_cplb_addr);
 151                        bfin_panic(regs);
 152                } else
 153                        debug("CPLB addr %p matches map 0x%p - 0x%p\n",
 154                                (void *)new_cplb_addr,
 155                                (void *)bfin_memory_map[i].start,
 156                                (void *)bfin_memory_map[i].end);
 157                new_cplb_data = (data ? bfin_memory_map[i].data_flags : bfin_memory_map[i].inst_flags);
 158
 159                if (data) {
 160                        CPLB_ADDR_BASE = (uint32_t *)DCPLB_ADDR0;
 161                        CPLB_DATA_BASE = (uint32_t *)DCPLB_DATA0;
 162                } else {
 163                        CPLB_ADDR_BASE = (uint32_t *)ICPLB_ADDR0;
 164                        CPLB_DATA_BASE = (uint32_t *)ICPLB_DATA0;
 165                }
 166
 167                /* find the next unlocked entry and evict it */
 168                i = last_evicted & 0xF;
 169                debug("last evicted = %zu\n", i);
 170                CPLB_DATA = CPLB_DATA_BASE + i;
 171                while (*CPLB_DATA & CPLB_LOCK) {
 172                        debug("skipping %zu %p - %08X\n", i, CPLB_DATA, *CPLB_DATA);
 173                        i = (i + 1) & 0xF;      /* wrap around */
 174                        CPLB_DATA = CPLB_DATA_BASE + i;
 175                }
 176                CPLB_ADDR = CPLB_ADDR_BASE + i;
 177
 178                debug("evicting entry %zu: 0x%p 0x%08X\n", i,
 179                        (void *)*CPLB_ADDR, *CPLB_DATA);
 180                last_evicted = i + 1;
 181
 182                /* need to turn off cplbs whenever we muck with the cplb table */
 183#if ENDCPLB != ENICPLB
 184# error cplb enable bit violates my sanity
 185#endif
 186                uint32_t mem_control = (data ? DMEM_CONTROL : IMEM_CONTROL);
 187                bfin_write32(mem_control, bfin_read32(mem_control) & ~ENDCPLB);
 188                *CPLB_ADDR = new_cplb_addr;
 189                *CPLB_DATA = new_cplb_data;
 190                bfin_write32(mem_control, bfin_read32(mem_control) | ENDCPLB);
 191                SSYNC();
 192
 193                /* dump current table for debugging purposes */
 194                CPLB_ADDR = CPLB_ADDR_BASE;
 195                CPLB_DATA = CPLB_DATA_BASE;
 196                for (i = 0; i < 16; ++i)
 197                        debug("%2zu 0x%p 0x%08X\n", i,
 198                                (void *)*CPLB_ADDR++, *CPLB_DATA++);
 199
 200                break;
 201        }
 202#ifdef CONFIG_CMD_KGDB
 203        /* Single step
 204         * if we are in IRQ5, just ignore, otherwise defer, and handle it in kgdb
 205         */
 206        case VEC_STEP:
 207                if (level == 3) {
 208                        /* If we just returned from an interrupt, the single step
 209                         * event is for the RTI instruction.
 210                         */
 211                        if (regs->retx == regs->pc)
 212                                break;
 213                        /* we just return if we are single stepping through IRQ5 */
 214                        if (regs->ipend & 0x20)
 215                                break;
 216                        /* Otherwise, turn single stepping off & fall through,
 217                         * which defers to IRQ5
 218                         */
 219                        regs->syscfg &= ~1;
 220                }
 221                /* fall through */
 222#endif
 223        default:
 224#ifdef CONFIG_CMD_KGDB
 225                if (level == 3) {
 226                        /* We need to handle this at EVT5, so try again */
 227                        bfin_dump(regs);
 228                        ret = 1;
 229                        break;
 230                }
 231                if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 232                        break;
 233#endif
 234                bfin_panic(regs);
 235        }
 236
 237        trace_buffer_restore(tflags);
 238
 239        return ret;
 240}
 241
 242#ifndef CONFIG_KALLSYMS
 243const char *symbol_lookup(unsigned long addr, unsigned long *caddr)
 244{
 245        *caddr = addr;
 246        return "N/A";
 247}
 248#endif
 249
 250static void decode_address(char *buf, unsigned long address)
 251{
 252        unsigned long sym_addr;
 253        void *paddr = (void *)address;
 254        const char *sym = symbol_lookup(address, &sym_addr);
 255
 256        if (sym) {
 257                sprintf(buf, "<0x%p> { %s + 0x%lx }", paddr, sym, address - sym_addr);
 258                return;
 259        }
 260
 261        if (!address)
 262                sprintf(buf, "<0x%p> /* Maybe null pointer? */", paddr);
 263        else if (address >= CONFIG_SYS_MONITOR_BASE &&
 264                 address < CONFIG_SYS_MONITOR_BASE + CONFIG_SYS_MONITOR_LEN)
 265                sprintf(buf, "<0x%p> /* somewhere in u-boot */", paddr);
 266        else
 267                sprintf(buf, "<0x%p> /* unknown address */", paddr);
 268}
 269
 270static char *strhwerrcause(uint16_t hwerrcause)
 271{
 272        switch (hwerrcause) {
 273                case 0x02: return "system mmr error";
 274                case 0x03: return "external memory addressing error";
 275                case 0x12: return "performance monitor overflow";
 276                case 0x18: return "raise 5 instruction";
 277                default:   return "undef";
 278        }
 279}
 280
 281static char *strexcause(uint16_t excause)
 282{
 283        switch (excause) {
 284                case 0x00 ... 0xf: return "custom exception";
 285                case 0x10: return "single step";
 286                case 0x11: return "trace buffer full";
 287                case 0x21: return "undef inst";
 288                case 0x22: return "illegal inst";
 289                case 0x23: return "dcplb prot violation";
 290                case 0x24: return "misaligned data";
 291                case 0x25: return "unrecoverable event";
 292                case 0x26: return "dcplb miss";
 293                case 0x27: return "multiple dcplb hit";
 294                case 0x28: return "emulation watchpoint";
 295                case 0x2a: return "misaligned inst";
 296                case 0x2b: return "icplb prot violation";
 297                case 0x2c: return "icplb miss";
 298                case 0x2d: return "multiple icplb hit";
 299                case 0x2e: return "illegal use of supervisor resource";
 300                default:   return "undef";
 301        }
 302}
 303
 304void dump(struct pt_regs *fp)
 305{
 306        char buf[150];
 307        int i;
 308        uint16_t hwerrcause, excause;
 309
 310        if (!ENABLE_DUMP)
 311                return;
 312
 313#ifndef CONFIG_CMD_KGDB
 314        /* fp->ipend is normally garbage, so load it ourself */
 315        fp->ipend = bfin_read_IPEND();
 316#endif
 317
 318        hwerrcause = (fp->seqstat & HWERRCAUSE) >> HWERRCAUSE_P;
 319        excause = (fp->seqstat & EXCAUSE) >> EXCAUSE_P;
 320
 321        printf("SEQUENCER STATUS:\n");
 322        printf(" SEQSTAT: %08lx  IPEND: %04lx  SYSCFG: %04lx\n",
 323                fp->seqstat, fp->ipend, fp->syscfg);
 324        printf("  HWERRCAUSE: 0x%x: %s\n", hwerrcause, strhwerrcause(hwerrcause));
 325        printf("  EXCAUSE   : 0x%x: %s\n", excause, strexcause(excause));
 326        for (i = 6; i <= 15; ++i) {
 327                if (fp->ipend & (1 << i)) {
 328                        decode_address(buf, bfin_read32(EVT0 + 4*i));
 329                        printf("  physical IVG%i asserted : %s\n", i, buf);
 330                }
 331        }
 332        decode_address(buf, fp->rete);
 333        printf(" RETE: %s\n", buf);
 334        decode_address(buf, fp->retn);
 335        printf(" RETN: %s\n", buf);
 336        decode_address(buf, fp->retx);
 337        printf(" RETX: %s\n", buf);
 338        decode_address(buf, fp->rets);
 339        printf(" RETS: %s\n", buf);
 340        /* we lie and store RETI in "pc" */
 341        decode_address(buf, fp->pc);
 342        printf(" RETI: %s\n", buf);
 343
 344        if (fp->seqstat & EXCAUSE) {
 345                decode_address(buf, bfin_read_DCPLB_FAULT_ADDR());
 346                printf("DCPLB_FAULT_ADDR: %s\n", buf);
 347                decode_address(buf, bfin_read_ICPLB_FAULT_ADDR());
 348                printf("ICPLB_FAULT_ADDR: %s\n", buf);
 349        }
 350
 351        printf("\nPROCESSOR STATE:\n");
 352        printf(" R0 : %08lx    R1 : %08lx    R2 : %08lx    R3 : %08lx\n",
 353                fp->r0, fp->r1, fp->r2, fp->r3);
 354        printf(" R4 : %08lx    R5 : %08lx    R6 : %08lx    R7 : %08lx\n",
 355                fp->r4, fp->r5, fp->r6, fp->r7);
 356        printf(" P0 : %08lx    P1 : %08lx    P2 : %08lx    P3 : %08lx\n",
 357                fp->p0, fp->p1, fp->p2, fp->p3);
 358        printf(" P4 : %08lx    P5 : %08lx    FP : %08lx    SP : %08lx\n",
 359                fp->p4, fp->p5, fp->fp, (unsigned long)fp);
 360        printf(" LB0: %08lx    LT0: %08lx    LC0: %08lx\n",
 361                fp->lb0, fp->lt0, fp->lc0);
 362        printf(" LB1: %08lx    LT1: %08lx    LC1: %08lx\n",
 363                fp->lb1, fp->lt1, fp->lc1);
 364        printf(" B0 : %08lx    L0 : %08lx    M0 : %08lx    I0 : %08lx\n",
 365                fp->b0, fp->l0, fp->m0, fp->i0);
 366        printf(" B1 : %08lx    L1 : %08lx    M1 : %08lx    I1 : %08lx\n",
 367                fp->b1, fp->l1, fp->m1, fp->i1);
 368        printf(" B2 : %08lx    L2 : %08lx    M2 : %08lx    I2 : %08lx\n",
 369                fp->b2, fp->l2, fp->m2, fp->i2);
 370        printf(" B3 : %08lx    L3 : %08lx    M3 : %08lx    I3 : %08lx\n",
 371                fp->b3, fp->l3, fp->m3, fp->i3);
 372        printf("A0.w: %08lx   A0.x: %08lx   A1.w: %08lx   A1.x: %08lx\n",
 373                fp->a0w, fp->a0x, fp->a1w, fp->a1x);
 374
 375        printf("USP : %08lx  ASTAT: %08lx\n",
 376                fp->usp, fp->astat);
 377
 378        printf("\n");
 379}
 380
 381static void _dump_bfin_trace_buffer(void)
 382{
 383        char buf[150];
 384        int i = 0;
 385
 386        if (!ENABLE_DUMP)
 387                return;
 388
 389        printf("Hardware Trace:\n");
 390
 391        if (bfin_read_TBUFSTAT() & TBUFCNT) {
 392                for (; bfin_read_TBUFSTAT() & TBUFCNT; i++) {
 393                        decode_address(buf, bfin_read_TBUF());
 394                        printf("%4i Target : %s\n", i, buf);
 395                        decode_address(buf, bfin_read_TBUF());
 396                        printf("     Source : %s\n", buf);
 397                }
 398        }
 399}
 400
 401void dump_bfin_trace_buffer(void)
 402{
 403        unsigned long tflags;
 404        trace_buffer_save(tflags);
 405        _dump_bfin_trace_buffer();
 406        trace_buffer_restore(tflags);
 407}
 408
 409void bfin_dump(struct pt_regs *regs)
 410{
 411        unsigned long tflags;
 412
 413        trace_buffer_save(tflags);
 414
 415        puts(
 416                "\n"
 417                "\n"
 418                "\n"
 419                "Ack! Something bad happened to the Blackfin!\n"
 420                "\n"
 421        );
 422        dump(regs);
 423        _dump_bfin_trace_buffer();
 424        puts("\n");
 425
 426        trace_buffer_restore(tflags);
 427}
 428
 429void bfin_panic(struct pt_regs *regs)
 430{
 431        unsigned long tflags;
 432        trace_buffer_save(tflags);
 433        bfin_dump(regs);
 434        panic("PANIC: Blackfin internal error");
 435}
 436