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 */
55static tile_bundle_bits compiled_bpt = TILEGX_BPT_BUNDLE | DIE_COMPILED_BPT;
56
57enum 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 */
65static inline void arch_kgdb_breakpoint(void)
66{
67	asm volatile (".quad %0\n\t"
68		      ::""(compiled_bpt));
69}
70
71#endif /* __TILE_KGDB_H__ */
72