arch/tile/include/asm/kgdb.h

   1 /*
   2  * Copyright 2013 Tilera Corporation. All Rights Reserved.
   3  *
   4  *   This program is free software; you can redistribute it and/or
   5  *   modify it under the terms of the GNU General Public License
   6  *   as published by the Free Software Foundation, version 2.
   7  *
   8  *   This program is distributed in the hope that it will be useful, but
   9  *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11  *   NON INFRINGEMENT.  See the GNU General Public License for
  12  *   more details.
  13  *
  14  * TILE-Gx KGDB support.
  15  */
  16
  17 #ifndef __TILE_KGDB_H__
  18 #define __TILE_KGDB_H__
  19
  20 #include <linux/kdebug.h>
  21 #include <arch/opcode.h>
  22
  23 #define GDB_SIZEOF_REG          sizeof(unsigned long)
  24
  25 /*
  26  * TILE-Gx gdb is expecting the following register layout:
  27  * 56 GPRs(R0 - R52, TP, SP, LR), 8 special GPRs(networks and ZERO),
  28  * plus the PC and the faultnum.
  29  *
  30  * Even though kernel not use the 8 special GPRs, they need to be present
  31  * in the registers sent for correct processing in the host-side gdb.
  32  *
  33  */
  34 #define DBG_MAX_REG_NUM         (56+8+2)
  35 #define NUMREGBYTES             (DBG_MAX_REG_NUM * GDB_SIZEOF_REG)
  36
  37 /*
  38  * BUFMAX defines the maximum number of characters in inbound/outbound
  39  * buffers at least NUMREGBYTES*2 are needed for register packets,
  40  * Longer buffer is needed to list all threads.
  41  */
  42 #define BUFMAX                  2048
  43
  44 #define BREAK_INSTR_SIZE        TILEGX_BUNDLE_SIZE_IN_BYTES
  45
  46 /*
  47  * Require cache flush for set/clear a software breakpoint or write memory.
  48  */
  49 #define CACHE_FLUSH_IS_SAFE     1
  50
  51 /*
  52  * The compiled-in breakpoint instruction can be used to "break" into
  53  * the debugger via magic system request key (sysrq-G).
  54  */
  55 static tile_bundle_bits compiled_bpt = TILEGX_BPT_BUNDLE | DIE_COMPILED_BPT;
  56
  57 enum tilegx_regnum {
  58         TILEGX_PC_REGNUM = TREG_LAST_GPR + 9,
  59         TILEGX_FAULTNUM_REGNUM,
  60 };
  61
  62 /*
  63  * Generate a breakpoint exception to "break" into the debugger.
  64  */
  65 static inline void arch_kgdb_breakpoint(void)
  66 {
  67         asm volatile (".quad %0\n\t"
  68                       ::""(compiled_bpt));
  69 }
  70
  71 #endif /* __TILE_KGDB_H__ */