gdb/spu-multiarch.c

   1 /* Cell SPU GNU/Linux multi-architecture debugging support.
   2    Copyright (C) 2009-2013 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 "gdb_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   char 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       char 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       char 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       char buf[16 * SPU_NUM_GPRS], annex[32];
 185       int i;
 186
 187       xsnprintf (annex, sizeof annex, "%d/regs", spufs_fd);
 188       if (target_read (ops_beneath, TARGET_OBJECT_SPU, annex,
 189                        buf, 0, sizeof buf) == sizeof buf)
 190         for (i = 0; i < SPU_NUM_GPRS; i++)
 191           regcache_raw_supply (regcache, i, buf + i*16);
 192     }
 193 }
 194
 195 /* Override the to_store_registers routine.  */
 196 static void
 197 spu_store_registers (struct target_ops *ops,
 198                      struct regcache *regcache, int regno)
 199 {
 200   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 201   struct target_ops *ops_beneath = find_target_beneath (ops);
 202   int spufs_fd;
 203   CORE_ADDR spufs_addr;
 204
 205   /* This version applies only if we're currently in spu_run.  */
 206   if (gdbarch_bfd_arch_info (gdbarch)->arch != bfd_arch_spu)
 207     {
 208       while (ops_beneath && !ops_beneath->to_fetch_registers)
 209         ops_beneath = find_target_beneath (ops_beneath);
 210
 211       gdb_assert (ops_beneath);
 212       ops_beneath->to_store_registers (ops_beneath, regcache, regno);
 213       return;
 214     }
 215
 216   /* We must be stopped on a spu_run system call.  */
 217   if (!parse_spufs_run (inferior_ptid, &spufs_fd, &spufs_addr))
 218     return;
 219
 220   /* The NPC register is found in PPC memory at SPUFS_ADDR.  */
 221   if (regno == -1 || regno == SPU_PC_REGNUM)
 222     {
 223       char buf[4];
 224       regcache_raw_collect (regcache, SPU_PC_REGNUM, buf);
 225
 226       target_write (ops_beneath, TARGET_OBJECT_MEMORY, NULL,
 227                     buf, spufs_addr, sizeof buf);
 228     }
 229
 230   /* The GPRs are found in the "regs" spufs file.  */
 231   if (regno == -1 || (regno >= 0 && regno < SPU_NUM_GPRS))
 232     {
 233       char buf[16 * SPU_NUM_GPRS], annex[32];
 234       int i;
 235
 236       for (i = 0; i < SPU_NUM_GPRS; i++)
 237         regcache_raw_collect (regcache, i, buf + i*16);
 238
 239       xsnprintf (annex, sizeof annex, "%d/regs", spufs_fd);
 240       target_write (ops_beneath, TARGET_OBJECT_SPU, annex,
 241                     buf, 0, sizeof buf);
 242     }
 243 }
 244
 245 /* Override the to_xfer_partial routine.  */
 246 static LONGEST
 247 spu_xfer_partial (struct target_ops *ops, enum target_object object,
 248                   const char *annex, gdb_byte *readbuf,
 249                   const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
 250 {
 251   struct target_ops *ops_beneath = find_target_beneath (ops);
 252   while (ops_beneath && !ops_beneath->to_xfer_partial)
 253     ops_beneath = find_target_beneath (ops_beneath);
 254   gdb_assert (ops_beneath);
 255
 256   /* Use the "mem" spufs file to access SPU local store.  */
 257   if (object == TARGET_OBJECT_MEMORY)
 258     {
 259       int fd = SPUADDR_SPU (offset);
 260       CORE_ADDR addr = SPUADDR_ADDR (offset);
 261       char mem_annex[32], lslr_annex[32];
 262       gdb_byte buf[32];
 263       ULONGEST lslr;
 264       LONGEST ret;
 265
 266       if (fd >= 0)
 267         {
 268           xsnprintf (mem_annex, sizeof mem_annex, "%d/mem", fd);
 269           ret = ops_beneath->to_xfer_partial (ops_beneath, TARGET_OBJECT_SPU,
 270                                               mem_annex, readbuf, writebuf,
 271                                               addr, len);
 272           if (ret > 0)
 273             return ret;
 274
 275           /* SPU local store access wraps the address around at the
 276              local store limit.  We emulate this here.  To avoid needing
 277              an extra access to retrieve the LSLR, we only do that after
 278              trying the original address first, and getting end-of-file.  */
 279           xsnprintf (lslr_annex, sizeof lslr_annex, "%d/lslr", fd);
 280           memset (buf, 0, sizeof buf);
 281           if (ops_beneath->to_xfer_partial (ops_beneath, TARGET_OBJECT_SPU,
 282                                             lslr_annex, buf, NULL,
 283                                             0, sizeof buf) <= 0)
 284             return ret;
 285
 286           lslr = strtoulst (buf, NULL, 16);
 287           return ops_beneath->to_xfer_partial (ops_beneath, TARGET_OBJECT_SPU,
 288                                                mem_annex, readbuf, writebuf,
 289                                                addr & lslr, len);
 290         }
 291     }
 292
 293   return ops_beneath->to_xfer_partial (ops_beneath, object, annex,
 294                                        readbuf, writebuf, offset, len);
 295 }
 296
 297 /* Override the to_search_memory routine.  */
 298 static int
 299 spu_search_memory (struct target_ops* ops,
 300                    CORE_ADDR start_addr, ULONGEST search_space_len,
 301                    const gdb_byte *pattern, ULONGEST pattern_len,
 302                    CORE_ADDR *found_addrp)
 303 {
 304   struct target_ops *ops_beneath = find_target_beneath (ops);
 305   while (ops_beneath && !ops_beneath->to_search_memory)
 306     ops_beneath = find_target_beneath (ops_beneath);
 307
 308   /* For SPU local store, always fall back to the simple method.  Likewise
 309      if we do not have any target-specific special implementation.  */
 310   if (!ops_beneath || SPUADDR_SPU (start_addr) >= 0)
 311     return simple_search_memory (ops,
 312                                  start_addr, search_space_len,
 313                                  pattern, pattern_len, found_addrp);
 314
 315   return ops_beneath->to_search_memory (ops_beneath,
 316                                         start_addr, search_space_len,
 317                                         pattern, pattern_len, found_addrp);
 318 }
 319
 320
 321 /* Push and pop the SPU multi-architecture support target.  */
 322
 323 static void
 324 spu_multiarch_activate (void)
 325 {
 326   /* If GDB was configured without SPU architecture support,
 327      we cannot install SPU multi-architecture support either.  */
 328   if (spu_gdbarch (-1) == NULL)
 329     return;
 330
 331   push_target (&spu_ops);
 332
 333   /* Make sure the thread architecture is re-evaluated.  */
 334   registers_changed ();
 335 }
 336
 337 static void
 338 spu_multiarch_deactivate (void)
 339 {
 340   unpush_target (&spu_ops);
 341
 342   /* Make sure the thread architecture is re-evaluated.  */
 343   registers_changed ();
 344 }
 345
 346 static void
 347 spu_multiarch_inferior_created (struct target_ops *ops, int from_tty)
 348 {
 349   if (spu_standalone_p ())
 350     spu_multiarch_activate ();
 351 }
 352
 353 static void
 354 spu_multiarch_solib_loaded (struct so_list *so)
 355 {
 356   if (!spu_standalone_p ())
 357     if (so->abfd && bfd_get_arch (so->abfd) == bfd_arch_spu)
 358       if (spu_nr_solib++ == 0)
 359         spu_multiarch_activate ();
 360 }
 361
 362 static void
 363 spu_multiarch_solib_unloaded (struct so_list *so)
 364 {
 365   if (!spu_standalone_p ())
 366     if (so->abfd && bfd_get_arch (so->abfd) == bfd_arch_spu)
 367       if (--spu_nr_solib == 0)
 368         spu_multiarch_deactivate ();
 369 }
 370
 371 static void
 372 spu_mourn_inferior (struct target_ops *ops)
 373 {
 374   struct target_ops *ops_beneath = find_target_beneath (ops);
 375   while (ops_beneath && !ops_beneath->to_mourn_inferior)
 376     ops_beneath = find_target_beneath (ops_beneath);
 377
 378   gdb_assert (ops_beneath);
 379   ops_beneath->to_mourn_inferior (ops_beneath);
 380   spu_multiarch_deactivate ();
 381 }
 382
 383
 384 /* Initialize the SPU multi-architecture support target.  */
 385
 386 static void
 387 init_spu_ops (void)
 388 {
 389   spu_ops.to_shortname = "spu";
 390   spu_ops.to_longname = "SPU multi-architecture support.";
 391   spu_ops.to_doc = "SPU multi-architecture support.";
 392   spu_ops.to_mourn_inferior = spu_mourn_inferior;
 393   spu_ops.to_fetch_registers = spu_fetch_registers;
 394   spu_ops.to_store_registers = spu_store_registers;
 395   spu_ops.to_xfer_partial = spu_xfer_partial;
 396   spu_ops.to_search_memory = spu_search_memory;
 397   spu_ops.to_region_ok_for_hw_watchpoint = spu_region_ok_for_hw_watchpoint;
 398   spu_ops.to_thread_architecture = spu_thread_architecture;
 399   spu_ops.to_stratum = arch_stratum;
 400   spu_ops.to_magic = OPS_MAGIC;
 401 }
 402
 403 /* -Wmissing-prototypes */
 404 extern initialize_file_ftype _initialize_spu_multiarch;
 405
 406 void
 407 _initialize_spu_multiarch (void)
 408 {
 409   /* Install ourselves on the target stack.  */
 410   init_spu_ops ();
 411   add_target (&spu_ops);
 412
 413   /* Install observers to watch for SPU objects.  */
 414   observer_attach_inferior_created (spu_multiarch_inferior_created);
 415   observer_attach_solib_loaded (spu_multiarch_solib_loaded);
 416   observer_attach_solib_unloaded (spu_multiarch_solib_unloaded);
 417 }
 418