gdb/spu-multiarch.c

   1 /* Cell SPU GNU/Linux multi-architecture debugging support.
   2    Copyright (C) 2009-2014 Free Software Foundation, Inc.
   3
   4    Contributed by Ulrich Weigand <uweigand@de.ibm.com>.
   5
   6    This file is part of GDB.
   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 3 of the License, or
  11    (at your option) 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, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "gdbcore.h"
  23 #include "gdbcmd.h"
  24 #include <string.h>
  25 #include "gdb_assert.h"
  26 #include "arch-utils.h"
  27 #include "observer.h"
  28 #include "inferior.h"
  29 #include "regcache.h"
  30 #include "symfile.h"
  31 #include "objfiles.h"
  32 #include "solib.h"
  33 #include "solist.h"
  34
  35 #include "ppc-tdep.h"
  36 #include "ppc-linux-tdep.h"
  37 #include "spu-tdep.h"
  38
  39 /* This module's target vector.  */
  40 static struct target_ops spu_ops;
  41
  42 /* Number of SPE objects loaded into the current inferior.  */
  43 static int spu_nr_solib;
  44
  45 /* Stand-alone SPE executable?  */
  46 #define spu_standalone_p() \
  47   (symfile_objfile && symfile_objfile->obfd \
  48    && bfd_get_arch (symfile_objfile->obfd) == bfd_arch_spu)
  49
  50 /* PPU side system calls.  */
  51 #define INSTR_SC        0x44000002
  52 #define NR_spu_run      0x0116
  53
  54 /* If the PPU thread is currently stopped on a spu_run system call,
  55    return to FD and ADDR the file handle and NPC parameter address
  56    used with the system call.  Return non-zero if successful.  */
  57 static int
  58 parse_spufs_run (ptid_t ptid, int *fd, CORE_ADDR *addr)
  59 {
  60   enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
  61   struct gdbarch_tdep *tdep;
  62   struct regcache *regcache;
  63   gdb_byte buf[4];
  64   ULONGEST regval;
  65
  66   /* If we're not on PPU, there's nothing to detect.  */
  67   if (gdbarch_bfd_arch_info (target_gdbarch ())->arch != bfd_arch_powerpc)
  68     return 0;
  69
  70   /* Get PPU-side registers.  */
  71   regcache = get_thread_arch_regcache (ptid, target_gdbarch ());
  72   tdep = gdbarch_tdep (target_gdbarch ());
  73
  74   /* Fetch instruction preceding current NIP.  */
  75   if (target_read_memory (regcache_read_pc (regcache) - 4, buf, 4) != 0)
  76     return 0;
  77   /* It should be a "sc" instruction.  */
  78   if (extract_unsigned_integer (buf, 4, byte_order) != INSTR_SC)
  79     return 0;
  80   /* System call number should be NR_spu_run.  */
  81   regcache_cooked_read_unsigned (regcache, tdep->ppc_gp0_regnum, &regval);
  82   if (regval != NR_spu_run)
  83     return 0;
  84
  85   /* Register 3 contains fd, register 4 the NPC param pointer.  */
  86   regcache_cooked_read_unsigned (regcache, PPC_ORIG_R3_REGNUM, &regval);
  87   *fd = (int) regval;
  88   regcache_cooked_read_unsigned (regcache, tdep->ppc_gp0_regnum + 4, &regval);
  89   *addr = (CORE_ADDR) regval;
  90   return 1;
  91 }
  92
  93 /* Find gdbarch for SPU context SPUFS_FD.  */
  94 static struct gdbarch *
  95 spu_gdbarch (int spufs_fd)
  96 {
  97   struct gdbarch_info info;
  98   gdbarch_info_init (&info);
  99   info.bfd_arch_info = bfd_lookup_arch (bfd_arch_spu, bfd_mach_spu);
 100   info.byte_order = BFD_ENDIAN_BIG;
 101   info.osabi = GDB_OSABI_LINUX;
 102   info.tdep_info = (void *) &spufs_fd;
 103   return gdbarch_find_by_info (info);
 104 }
 105
 106 /* Override the to_thread_architecture routine.  */
 107 static struct gdbarch *
 108 spu_thread_architecture (struct target_ops *ops, ptid_t ptid)
 109 {
 110   int spufs_fd;
 111   CORE_ADDR spufs_addr;
 112
 113   if (parse_spufs_run (ptid, &spufs_fd, &spufs_addr))
 114     return spu_gdbarch (spufs_fd);
 115
 116   return target_gdbarch ();
 117 }
 118
 119 /* Override the to_region_ok_for_hw_watchpoint routine.  */
 120 static int
 121 spu_region_ok_for_hw_watchpoint (CORE_ADDR addr, int len)
 122 {
 123   struct target_ops *ops_beneath = find_target_beneath (&spu_ops);
 124   while (ops_beneath && !ops_beneath->to_region_ok_for_hw_watchpoint)
 125     ops_beneath = find_target_beneath (ops_beneath);
 126
 127   /* We cannot watch SPU local store.  */
 128   if (SPUADDR_SPU (addr) != -1)
 129     return 0;
 130
 131   if (ops_beneath)
 132     return ops_beneath->to_region_ok_for_hw_watchpoint (addr, len);
 133
 134   return 0;
 135 }
 136
 137 /* Override the to_fetch_registers routine.  */
 138 static void
 139 spu_fetch_registers (struct target_ops *ops,
 140                      struct regcache *regcache, int regno)
 141 {
 142   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 143   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 144   struct target_ops *ops_beneath = find_target_beneath (ops);
 145   int spufs_fd;
 146   CORE_ADDR spufs_addr;
 147
 148   /* This version applies only if we're currently in spu_run.  */
 149   if (gdbarch_bfd_arch_info (gdbarch)->arch != bfd_arch_spu)
 150     {
 151       while (ops_beneath && !ops_beneath->to_fetch_registers)
 152         ops_beneath = find_target_beneath (ops_beneath);
 153
 154       gdb_assert (ops_beneath);
 155       ops_beneath->to_fetch_registers (ops_beneath, regcache, regno);
 156       return;
 157     }
 158
 159   /* We must be stopped on a spu_run system call.  */
 160   if (!parse_spufs_run (inferior_ptid, &spufs_fd, &spufs_addr))
 161     return;
 162
 163   /* The ID register holds the spufs file handle.  */
 164   if (regno == -1 || regno == SPU_ID_REGNUM)
 165     {
 166       gdb_byte buf[4];
 167       store_unsigned_integer (buf, 4, byte_order, spufs_fd);
 168       regcache_raw_supply (regcache, SPU_ID_REGNUM, buf);
 169     }
 170
 171   /* The NPC register is found in PPC memory at SPUFS_ADDR.  */
 172   if (regno == -1 || regno == SPU_PC_REGNUM)
 173     {
 174       gdb_byte buf[4];
 175
 176       if (target_read (ops_beneath, TARGET_OBJECT_MEMORY, NULL,
 177                        buf, spufs_addr, sizeof buf) == sizeof buf)
 178         regcache_raw_supply (regcache, SPU_PC_REGNUM, buf);
 179     }
 180
 181   /* The GPRs are found in the "regs" spufs file.  */
 182   if (regno == -1 || (regno >= 0 && regno < SPU_NUM_GPRS))
 183     {
 184       gdb_byte buf[16 * SPU_NUM_GPRS];
 185       char annex[32];
 186       int i;
 187
 188       xsnprintf (annex, sizeof annex, "%d/regs", spufs_fd);
 189       if (target_read (ops_beneath, TARGET_OBJECT_SPU, annex,
 190                        buf, 0, sizeof buf) == sizeof buf)
 191         for (i = 0; i < SPU_NUM_GPRS; i++)
 192           regcache_raw_supply (regcache, i, buf + i*16);
 193     }
 194 }
 195
 196 /* Override the to_store_registers routine.  */
 197 static void
 198 spu_store_registers (struct target_ops *ops,
 199                      struct regcache *regcache, int regno)
 200 {
 201   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 202   struct target_ops *ops_beneath = find_target_beneath (ops);
 203   int spufs_fd;
 204   CORE_ADDR spufs_addr;
 205
 206   /* This version applies only if we're currently in spu_run.  */
 207   if (gdbarch_bfd_arch_info (gdbarch)->arch != bfd_arch_spu)
 208     {
 209       while (ops_beneath && !ops_beneath->to_fetch_registers)
 210         ops_beneath = find_target_beneath (ops_beneath);
 211
 212       gdb_assert (ops_beneath);
 213       ops_beneath->to_store_registers (ops_beneath, regcache, regno);
 214       return;
 215     }
 216
 217   /* We must be stopped on a spu_run system call.  */
 218   if (!parse_spufs_run (inferior_ptid, &spufs_fd, &spufs_addr))
 219     return;
 220
 221   /* The NPC register is found in PPC memory at SPUFS_ADDR.  */
 222   if (regno == -1 || regno == SPU_PC_REGNUM)
 223     {
 224       gdb_byte buf[4];
 225       regcache_raw_collect (regcache, SPU_PC_REGNUM, buf);
 226
 227       target_write (ops_beneath, TARGET_OBJECT_MEMORY, NULL,
 228                     buf, spufs_addr, sizeof buf);
 229     }
 230
 231   /* The GPRs are found in the "regs" spufs file.  */
 232   if (regno == -1 || (regno >= 0 && regno < SPU_NUM_GPRS))
 233     {
 234       gdb_byte buf[16 * SPU_NUM_GPRS];
 235       char annex[32];
 236       int i;
 237
 238       for (i = 0; i < SPU_NUM_GPRS; i++)
 239         regcache_raw_collect (regcache, i, buf + i*16);
 240
 241       xsnprintf (annex, sizeof annex, "%d/regs", spufs_fd);
 242       target_write (ops_beneath, TARGET_OBJECT_SPU, annex,
 243                     buf, 0, sizeof buf);
 244     }
 245 }
 246
 247 /* Override the to_xfer_partial routine.  */
 248 static LONGEST
 249 spu_xfer_partial (struct target_ops *ops, enum target_object object,
 250                   const char *annex, gdb_byte *readbuf,
 251                   const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
 252 {
 253   struct target_ops *ops_beneath = find_target_beneath (ops);
 254   while (ops_beneath && !ops_beneath->to_xfer_partial)
 255     ops_beneath = find_target_beneath (ops_beneath);
 256   gdb_assert (ops_beneath);
 257
 258   /* Use the "mem" spufs file to access SPU local store.  */
 259   if (object == TARGET_OBJECT_MEMORY)
 260     {
 261       int fd = SPUADDR_SPU (offset);
 262       CORE_ADDR addr = SPUADDR_ADDR (offset);
 263       char mem_annex[32], lslr_annex[32];
 264       gdb_byte buf[32];
 265       ULONGEST lslr;
 266       LONGEST ret;
 267
 268       if (fd >= 0)
 269         {
 270           xsnprintf (mem_annex, sizeof mem_annex, "%d/mem", fd);
 271           ret = ops_beneath->to_xfer_partial (ops_beneath, TARGET_OBJECT_SPU,
 272                                               mem_annex, readbuf, writebuf,
 273                                               addr, len);
 274           if (ret > 0)
 275             return ret;
 276
 277           /* SPU local store access wraps the address around at the
 278              local store limit.  We emulate this here.  To avoid needing
 279              an extra access to retrieve the LSLR, we only do that after
 280              trying the original address first, and getting end-of-file.  */
 281           xsnprintf (lslr_annex, sizeof lslr_annex, "%d/lslr", fd);
 282           memset (buf, 0, sizeof buf);
 283           if (ops_beneath->to_xfer_partial (ops_beneath, TARGET_OBJECT_SPU,
 284                                             lslr_annex, buf, NULL,
 285                                             0, sizeof buf) <= 0)
 286             return ret;
 287
 288           lslr = strtoulst ((char *) buf, NULL, 16);
 289           return ops_beneath->to_xfer_partial (ops_beneath, TARGET_OBJECT_SPU,
 290                                                mem_annex, readbuf, writebuf,
 291                                                addr & lslr, len);
 292         }
 293     }
 294
 295   return ops_beneath->to_xfer_partial (ops_beneath, object, annex,
 296                                        readbuf, writebuf, offset, len);
 297 }
 298
 299 /* Override the to_search_memory routine.  */
 300 static int
 301 spu_search_memory (struct target_ops* ops,
 302                    CORE_ADDR start_addr, ULONGEST search_space_len,
 303                    const gdb_byte *pattern, ULONGEST pattern_len,
 304                    CORE_ADDR *found_addrp)
 305 {
 306   struct target_ops *ops_beneath = find_target_beneath (ops);
 307   while (ops_beneath && !ops_beneath->to_search_memory)
 308     ops_beneath = find_target_beneath (ops_beneath);
 309
 310   /* For SPU local store, always fall back to the simple method.  Likewise
 311      if we do not have any target-specific special implementation.  */
 312   if (!ops_beneath || SPUADDR_SPU (start_addr) >= 0)
 313     return simple_search_memory (ops,
 314                                  start_addr, search_space_len,
 315                                  pattern, pattern_len, found_addrp);
 316
 317   return ops_beneath->to_search_memory (ops_beneath,
 318                                         start_addr, search_space_len,
 319                                         pattern, pattern_len, found_addrp);
 320 }
 321
 322
 323 /* Push and pop the SPU multi-architecture support target.  */
 324
 325 static void
 326 spu_multiarch_activate (void)
 327 {
 328   /* If GDB was configured without SPU architecture support,
 329      we cannot install SPU multi-architecture support either.  */
 330   if (spu_gdbarch (-1) == NULL)
 331     return;
 332
 333   push_target (&spu_ops);
 334
 335   /* Make sure the thread architecture is re-evaluated.  */
 336   registers_changed ();
 337 }
 338
 339 static void
 340 spu_multiarch_deactivate (void)
 341 {
 342   unpush_target (&spu_ops);
 343
 344   /* Make sure the thread architecture is re-evaluated.  */
 345   registers_changed ();
 346 }
 347
 348 static void
 349 spu_multiarch_inferior_created (struct target_ops *ops, int from_tty)
 350 {
 351   if (spu_standalone_p ())
 352     spu_multiarch_activate ();
 353 }
 354
 355 static void
 356 spu_multiarch_solib_loaded (struct so_list *so)
 357 {
 358   if (!spu_standalone_p ())
 359     if (so->abfd && bfd_get_arch (so->abfd) == bfd_arch_spu)
 360       if (spu_nr_solib++ == 0)
 361         spu_multiarch_activate ();
 362 }
 363
 364 static void
 365 spu_multiarch_solib_unloaded (struct so_list *so)
 366 {
 367   if (!spu_standalone_p ())
 368     if (so->abfd && bfd_get_arch (so->abfd) == bfd_arch_spu)
 369       if (--spu_nr_solib == 0)
 370         spu_multiarch_deactivate ();
 371 }
 372
 373 static void
 374 spu_mourn_inferior (struct target_ops *ops)
 375 {
 376   struct target_ops *ops_beneath = find_target_beneath (ops);
 377   while (ops_beneath && !ops_beneath->to_mourn_inferior)
 378     ops_beneath = find_target_beneath (ops_beneath);
 379
 380   gdb_assert (ops_beneath);
 381   ops_beneath->to_mourn_inferior (ops_beneath);
 382   spu_multiarch_deactivate ();
 383 }
 384
 385
 386 /* Initialize the SPU multi-architecture support target.  */
 387
 388 static void
 389 init_spu_ops (void)
 390 {
 391   spu_ops.to_shortname = "spu";
 392   spu_ops.to_longname = "SPU multi-architecture support.";
 393   spu_ops.to_doc = "SPU multi-architecture support.";
 394   spu_ops.to_mourn_inferior = spu_mourn_inferior;
 395   spu_ops.to_fetch_registers = spu_fetch_registers;
 396   spu_ops.to_store_registers = spu_store_registers;
 397   spu_ops.to_xfer_partial = spu_xfer_partial;
 398   spu_ops.to_search_memory = spu_search_memory;
 399   spu_ops.to_region_ok_for_hw_watchpoint = spu_region_ok_for_hw_watchpoint;
 400   spu_ops.to_thread_architecture = spu_thread_architecture;
 401   spu_ops.to_stratum = arch_stratum;
 402   spu_ops.to_magic = OPS_MAGIC;
 403 }
 404
 405 /* -Wmissing-prototypes */
 406 extern initialize_file_ftype _initialize_spu_multiarch;
 407
 408 void
 409 _initialize_spu_multiarch (void)
 410 {
 411   /* Install ourselves on the target stack.  */
 412   init_spu_ops ();
 413   complete_target_initialization (&spu_ops);
 414
 415   /* Install observers to watch for SPU objects.  */
 416   observer_attach_inferior_created (spu_multiarch_inferior_created);
 417   observer_attach_solib_loaded (spu_multiarch_solib_loaded);
 418   observer_attach_solib_unloaded (spu_multiarch_solib_unloaded);
 419 }
 420