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1/*
2 * This provides the callbacks and functions that KGDB needs to share between
3 * the core, I/O and arch-specific portions.
4 *
5 * Author: Amit Kale <amitkale@linsyssoft.com> and
6 * Tom Rini <trini@kernel.crashing.org>
7 *
8 * 2001-2004 (c) Amit S. Kale and 2003-2005 (c) MontaVista Software, Inc.
9 * This file is licensed under the terms of the GNU General Public License
10 * version 2. This program is licensed "as is" without any warranty of any
11 * kind, whether express or implied.
12 */
13#ifndef _KGDB_H_
14#define _KGDB_H_
15
16#include <linux/serial_8250.h>
17#include <linux/linkage.h>
18#include <linux/init.h>
19#include <asm/atomic.h>
20#ifdef CONFIG_HAVE_ARCH_KGDB
21#include <asm/kgdb.h>
22#endif
23
24#ifdef CONFIG_KGDB
25struct pt_regs;
26
27/**
28 * kgdb_skipexception - (optional) exit kgdb_handle_exception early
29 * @exception: Exception vector number
30 * @regs: Current &struct pt_regs.
31 *
32 * On some architectures it is required to skip a breakpoint
33 * exception when it occurs after a breakpoint has been removed.
34 * This can be implemented in the architecture specific portion of kgdb.
35 */
36extern int kgdb_skipexception(int exception, struct pt_regs *regs);
37
38/**
39 * kgdb_disable_hw_debug - (optional) Disable hardware debugging hook
40 * @regs: Current &struct pt_regs.
41 *
42 * This function will be called if the particular architecture must
43 * disable hardware debugging while it is processing gdb packets or
44 * handling exception.
45 */
46extern void kgdb_disable_hw_debug(struct pt_regs *regs);
47
48struct tasklet_struct;
49struct task_struct;
50struct uart_port;
51
52/**
53 * kgdb_breakpoint - compiled in breakpoint
54 *
55 * This will be implemented as a static inline per architecture. This
56 * function is called by the kgdb core to execute an architecture
57 * specific trap to cause kgdb to enter the exception processing.
58 *
59 */
60void kgdb_breakpoint(void);
61
62extern int kgdb_connected;
63extern int kgdb_io_module_registered;
64
65extern atomic_t kgdb_setting_breakpoint;
66extern atomic_t kgdb_cpu_doing_single_step;
67
68extern struct task_struct *kgdb_usethread;
69extern struct task_struct *kgdb_contthread;
70
71enum kgdb_bptype {
72 BP_BREAKPOINT = 0,
73 BP_HARDWARE_BREAKPOINT,
74 BP_WRITE_WATCHPOINT,
75 BP_READ_WATCHPOINT,
76 BP_ACCESS_WATCHPOINT
77};
78
79enum kgdb_bpstate {
80 BP_UNDEFINED = 0,
81 BP_REMOVED,
82 BP_SET,
83 BP_ACTIVE
84};
85
86struct kgdb_bkpt {
87 unsigned long bpt_addr;
88 unsigned char saved_instr[BREAK_INSTR_SIZE];
89 enum kgdb_bptype type;
90 enum kgdb_bpstate state;
91};
92
93#ifndef KGDB_MAX_BREAKPOINTS
94# define KGDB_MAX_BREAKPOINTS 1000
95#endif
96
97#define KGDB_HW_BREAKPOINT 1
98
99/*
100 * Functions each KGDB-supporting architecture must provide:
101 */
102
103/**
104 * kgdb_arch_init - Perform any architecture specific initalization.
105 *
106 * This function will handle the initalization of any architecture
107 * specific callbacks.
108 */
109extern int kgdb_arch_init(void);
110
111/**
112 * kgdb_arch_exit - Perform any architecture specific uninitalization.
113 *
114 * This function will handle the uninitalization of any architecture
115 * specific callbacks, for dynamic registration and unregistration.
116 */
117extern void kgdb_arch_exit(void);
118
119/**
120 * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
121 * @gdb_regs: A pointer to hold the registers in the order GDB wants.
122 * @regs: The &struct pt_regs of the current process.
123 *
124 * Convert the pt_regs in @regs into the format for registers that
125 * GDB expects, stored in @gdb_regs.
126 */
127extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs);
128
129/**
130 * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
131 * @gdb_regs: A pointer to hold the registers in the order GDB wants.
132 * @p: The &struct task_struct of the desired process.
133 *
134 * Convert the register values of the sleeping process in @p to
135 * the format that GDB expects.
136 * This function is called when kgdb does not have access to the
137 * &struct pt_regs and therefore it should fill the gdb registers
138 * @gdb_regs with what has been saved in &struct thread_struct
139 * thread field during switch_to.
140 */
141extern void
142sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p);
143
144/**
145 * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
146 * @gdb_regs: A pointer to hold the registers we've received from GDB.
147 * @regs: A pointer to a &struct pt_regs to hold these values in.
148 *
149 * Convert the GDB regs in @gdb_regs into the pt_regs, and store them
150 * in @regs.
151 */
152extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs);
153
154/**
155 * kgdb_arch_handle_exception - Handle architecture specific GDB packets.
156 * @vector: The error vector of the exception that happened.
157 * @signo: The signal number of the exception that happened.
158 * @err_code: The error code of the exception that happened.
159 * @remcom_in_buffer: The buffer of the packet we have read.
160 * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
161 * @regs: The &struct pt_regs of the current process.
162 *
163 * This function MUST handle the 'c' and 's' command packets,
164 * as well packets to set / remove a hardware breakpoint, if used.
165 * If there are additional packets which the hardware needs to handle,
166 * they are handled here. The code should return -1 if it wants to
167 * process more packets, and a %0 or %1 if it wants to exit from the
168 * kgdb callback.
169 */
170extern int
171kgdb_arch_handle_exception(int vector, int signo, int err_code,
172 char *remcom_in_buffer,
173 char *remcom_out_buffer,
174 struct pt_regs *regs);
175
176/**
177 * kgdb_roundup_cpus - Get other CPUs into a holding pattern
178 * @flags: Current IRQ state
179 *
180 * On SMP systems, we need to get the attention of the other CPUs
181 * and get them into a known state. This should do what is needed
182 * to get the other CPUs to call kgdb_wait(). Note that on some arches,
183 * the NMI approach is not used for rounding up all the CPUs. For example,
184 * in case of MIPS, smp_call_function() is used to roundup CPUs. In
185 * this case, we have to make sure that interrupts are enabled before
186 * calling smp_call_function(). The argument to this function is
187 * the flags that will be used when restoring the interrupts. There is
188 * local_irq_save() call before kgdb_roundup_cpus().
189 *
190 * On non-SMP systems, this is not called.
191 */
192extern void kgdb_roundup_cpus(unsigned long flags);
193
194/**
195 * kgdb_arch_set_pc - Generic call back to the program counter
196 * @regs: Current &struct pt_regs.
197 * @pc: The new value for the program counter
198 *
199 * This function handles updating the program counter and requires an
200 * architecture specific implementation.
201 */
202extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc);
203
204
205/* Optional functions. */
206extern int kgdb_validate_break_address(unsigned long addr);
207extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr);
208extern int kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle);
209
210/**
211 * kgdb_arch_late - Perform any architecture specific initalization.
212 *
213 * This function will handle the late initalization of any
214 * architecture specific callbacks. This is an optional function for
215 * handling things like late initialization of hw breakpoints. The
216 * default implementation does nothing.
217 */
218extern void kgdb_arch_late(void);
219
220
221/**
222 * struct kgdb_arch - Describe architecture specific values.
223 * @gdb_bpt_instr: The instruction to trigger a breakpoint.
224 * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT.
225 * @set_breakpoint: Allow an architecture to specify how to set a software
226 * breakpoint.
227 * @remove_breakpoint: Allow an architecture to specify how to remove a
228 * software breakpoint.
229 * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware
230 * breakpoint.
231 * @remove_hw_breakpoint: Allow an architecture to specify how to remove a
232 * hardware breakpoint.
233 * @remove_all_hw_break: Allow an architecture to specify how to remove all
234 * hardware breakpoints.
235 * @correct_hw_break: Allow an architecture to specify how to correct the
236 * hardware debug registers.
237 */
238struct kgdb_arch {
239 unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE];
240 unsigned long flags;
241
242 int (*set_breakpoint)(unsigned long, char *);
243 int (*remove_breakpoint)(unsigned long, char *);
244 int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
245 int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
246 void (*remove_all_hw_break)(void);
247 void (*correct_hw_break)(void);
248};
249
250/**
251 * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB.
252 * @name: Name of the I/O driver.
253 * @read_char: Pointer to a function that will return one char.
254 * @write_char: Pointer to a function that will write one char.
255 * @flush: Pointer to a function that will flush any pending writes.
256 * @init: Pointer to a function that will initialize the device.
257 * @pre_exception: Pointer to a function that will do any prep work for
258 * the I/O driver.
259 * @post_exception: Pointer to a function that will do any cleanup work
260 * for the I/O driver.
261 * @is_console: 1 if the end device is a console 0 if the I/O device is
262 * not a console
263 */
264struct kgdb_io {
265 const char *name;
266 int (*read_char) (void);
267 void (*write_char) (u8);
268 void (*flush) (void);
269 int (*init) (void);
270 void (*pre_exception) (void);
271 void (*post_exception) (void);
272 int is_console;
273};
274
275extern struct kgdb_arch arch_kgdb_ops;
276
277extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs);
278
279extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
280extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
281extern struct kgdb_io *dbg_io_ops;
282
283extern int kgdb_hex2long(char **ptr, unsigned long *long_val);
284extern int kgdb_mem2hex(char *mem, char *buf, int count);
285extern int kgdb_hex2mem(char *buf, char *mem, int count);
286
287extern int kgdb_isremovedbreak(unsigned long addr);
288extern void kgdb_schedule_breakpoint(void);
289
290extern int
291kgdb_handle_exception(int ex_vector, int signo, int err_code,
292 struct pt_regs *regs);
293extern int kgdb_nmicallback(int cpu, void *regs);
294
295extern int kgdb_single_step;
296extern atomic_t kgdb_active;
297#define in_dbg_master() \
298 (raw_smp_processor_id() == atomic_read(&kgdb_active))
299extern bool dbg_is_early;
300extern void __init dbg_late_init(void);
301#else /* ! CONFIG_KGDB */
302#define in_dbg_master() (0)
303#define dbg_late_init()
304#endif /* ! CONFIG_KGDB */
305#endif /* _KGDB_H_ */