2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
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.
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
15 #ifndef _TILE_BACKTRACE_H
16 #define _TILE_BACKTRACE_H
20 #include <linux/types.h>
22 #include <arch/chip.h>
25 typedef unsigned long VirtualAddress;
26 #elif CHIP_VA_WIDTH() > 32
27 typedef unsigned long long VirtualAddress;
29 typedef unsigned int VirtualAddress;
33 /** Reads 'size' bytes from 'address' and writes the data to 'result'.
34 * Returns true if successful, else false (e.g. memory not readable).
36 typedef bool (*BacktraceMemoryReader)(void *result,
37 VirtualAddress address,
45 /** Current stack pointer value. */
48 /** Current frame pointer value (i.e. caller's stack pointer) */
51 /** Internal use only: caller's PC for first frame. */
52 VirtualAddress initial_frame_caller_pc;
54 /** Internal use only: callback to read memory. */
55 BacktraceMemoryReader read_memory_func;
57 /** Internal use only: arbitrary argument to read_memory_func. */
58 void *read_memory_func_extra;
63 /** Initializes a backtracer to start from the given location.
65 * If the frame pointer cannot be determined it is set to -1.
67 * @param state The state to be filled in.
68 * @param read_memory_func A callback that reads memory. If NULL, a default
70 * @param read_memory_func_extra An arbitrary argument to read_memory_func.
71 * @param pc The current PC.
72 * @param lr The current value of the 'lr' register.
73 * @param sp The current value of the 'sp' register.
74 * @param r52 The current value of the 'r52' register.
76 extern void backtrace_init(BacktraceIterator *state,
77 BacktraceMemoryReader read_memory_func,
78 void *read_memory_func_extra,
79 VirtualAddress pc, VirtualAddress lr,
80 VirtualAddress sp, VirtualAddress r52);
83 /** Advances the backtracing state to the calling frame, returning
84 * true iff successful.
86 extern bool backtrace_next(BacktraceIterator *state);
91 /* We have no idea what the caller's pc is. */
94 /* The caller's pc is currently in lr. */
97 /* The caller's pc can be found by dereferencing the caller's sp. */
105 /* We have no idea what the caller's sp is. */
108 /* The caller's sp is currently in r52. */
111 /* The caller's sp can be found by adding a certain constant
112 * to the current value of sp.
119 /* Bit values ORed into CALLER_* values for info ops. */
121 /* Setting the low bit on any of these values means the info op
122 * applies only to one bundle ago.
124 ONE_BUNDLE_AGO_FLAG = 1,
126 /* Setting this bit on a CALLER_SP_* value means the PC is in LR.
127 * If not set, PC is on the stack.
131 /* This many of the low bits of a CALLER_SP_* value are for the
134 NUM_INFO_OP_FLAGS = 2,
136 /* We cannot have one in the memory pipe so this is the maximum. */
137 MAX_INFO_OPS_PER_BUNDLE = 2
141 /** Internal constants used to define 'info' operands. */
143 /* 0 and 1 are reserved, as are all negative numbers. */
145 CALLER_UNKNOWN_BASE = 2,
147 CALLER_SP_IN_R52_BASE = 4,
149 CALLER_SP_OFFSET_BASE = 8,
151 /* Marks the entry point of certain functions. */
152 ENTRY_POINT_INFO_OP = 16
156 /** Current backtracer state describing where it thinks the caller is. */
162 /* How do we find the caller's PC? */
163 CallerPCLocation pc_location : 8;
165 /* How do we find the caller's SP? */
166 CallerSPLocation sp_location : 8;
168 /* If sp_location == SP_LOC_OFFSET, then caller_sp == sp +
169 * loc->sp_offset. Else this field is undefined.
173 /* In the most recently visited bundle a terminating bundle? */
174 bool at_terminating_bundle;
180 /* Will the forward scanner see someone clobbering sp
181 * (i.e. changing it with something other than addi sp, sp, N?)
183 bool sp_clobber_follows;
185 /* Operand to next "visible" info op (no more than one bundle past
186 * the next terminating bundle), or -32768 if none.
188 int16_t next_info_operand;
190 /* Is the info of in next_info_op in the very next bundle? */
191 bool is_next_info_operand_adjacent;
198 #endif /* _TILE_BACKTRACE_H */