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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
20#include <asm/atomic.h>
21#include <asm/kgdb.h>
22
23struct pt_regs;
24
25/**
26 * kgdb_skipexception - (optional) exit kgdb_handle_exception early
27 * @exception: Exception vector number
28 * @regs: Current &struct pt_regs.
29 *
30 * On some architectures it is required to skip a breakpoint
31 * exception when it occurs after a breakpoint has been removed.
32 * This can be implemented in the architecture specific portion of kgdb.
33 */
34extern int kgdb_skipexception(int exception, struct pt_regs *regs);
35
36/**
37 * kgdb_post_primary_code - (optional) Save error vector/code numbers.
38 * @regs: Original pt_regs.
39 * @e_vector: Original error vector.
40 * @err_code: Original error code.
41 *
42 * This is usually needed on architectures which support SMP and
43 * KGDB. This function is called after all the secondary cpus have
44 * been put to a know spin state and the primary CPU has control over
45 * KGDB.
46 */
47extern void kgdb_post_primary_code(struct pt_regs *regs, int e_vector,
48 int err_code);
49
50/**
51 * kgdb_disable_hw_debug - (optional) Disable hardware debugging hook
52 * @regs: Current &struct pt_regs.
53 *
54 * This function will be called if the particular architecture must
55 * disable hardware debugging while it is processing gdb packets or
56 * handling exception.
57 */
58extern void kgdb_disable_hw_debug(struct pt_regs *regs);
59
60struct tasklet_struct;
61struct task_struct;
62struct uart_port;
63
64/**
65 * kgdb_breakpoint - compiled in breakpoint
66 *
67 * This will be implemented as a static inline per architecture. This
68 * function is called by the kgdb core to execute an architecture
69 * specific trap to cause kgdb to enter the exception processing.
70 *
71 */
72void kgdb_breakpoint(void);
73
74extern int kgdb_connected;
75
76extern atomic_t kgdb_setting_breakpoint;
77extern atomic_t kgdb_cpu_doing_single_step;
78
79extern struct task_struct *kgdb_usethread;
80extern struct task_struct *kgdb_contthread;
81
82enum kgdb_bptype {
83 BP_BREAKPOINT = 0,
84 BP_HARDWARE_BREAKPOINT,
85 BP_WRITE_WATCHPOINT,
86 BP_READ_WATCHPOINT,
87 BP_ACCESS_WATCHPOINT
88};
89
90enum kgdb_bpstate {
91 BP_UNDEFINED = 0,
92 BP_REMOVED,
93 BP_SET,
94 BP_ACTIVE
95};
96
97struct kgdb_bkpt {
98 unsigned long bpt_addr;
99 unsigned char saved_instr[BREAK_INSTR_SIZE];
100 enum kgdb_bptype type;
101 enum kgdb_bpstate state;
102};
103
104#ifndef KGDB_MAX_BREAKPOINTS
105# define KGDB_MAX_BREAKPOINTS 1000
106#endif
107
108#define KGDB_HW_BREAKPOINT 1
109
110/*
111 * Functions each KGDB-supporting architecture must provide:
112 */
113
114/**
115 * kgdb_arch_init - Perform any architecture specific initalization.
116 *
117 * This function will handle the initalization of any architecture
118 * specific callbacks.
119 */
120extern int kgdb_arch_init(void);
121
122/**
123 * kgdb_arch_exit - Perform any architecture specific uninitalization.
124 *
125 * This function will handle the uninitalization of any architecture
126 * specific callbacks, for dynamic registration and unregistration.
127 */
128extern void kgdb_arch_exit(void);
129
130/**
131 * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
132 * @gdb_regs: A pointer to hold the registers in the order GDB wants.
133 * @regs: The &struct pt_regs of the current process.
134 *
135 * Convert the pt_regs in @regs into the format for registers that
136 * GDB expects, stored in @gdb_regs.
137 */
138extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs);
139
140/**
141 * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
142 * @gdb_regs: A pointer to hold the registers in the order GDB wants.
143 * @p: The &struct task_struct of the desired process.
144 *
145 * Convert the register values of the sleeping process in @p to
146 * the format that GDB expects.
147 * This function is called when kgdb does not have access to the
148 * &struct pt_regs and therefore it should fill the gdb registers
149 * @gdb_regs with what has been saved in &struct thread_struct
150 * thread field during switch_to.
151 */
152extern void
153sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p);
154
155/**
156 * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
157 * @gdb_regs: A pointer to hold the registers we've received from GDB.
158 * @regs: A pointer to a &struct pt_regs to hold these values in.
159 *
160 * Convert the GDB regs in @gdb_regs into the pt_regs, and store them
161 * in @regs.
162 */
163extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs);
164
165/**
166 * kgdb_arch_handle_exception - Handle architecture specific GDB packets.
167 * @vector: The error vector of the exception that happened.
168 * @signo: The signal number of the exception that happened.
169 * @err_code: The error code of the exception that happened.
170 * @remcom_in_buffer: The buffer of the packet we have read.
171 * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
172 * @regs: The &struct pt_regs of the current process.
173 *
174 * This function MUST handle the 'c' and 's' command packets,
175 * as well packets to set / remove a hardware breakpoint, if used.
176 * If there are additional packets which the hardware needs to handle,
177 * they are handled here. The code should return -1 if it wants to
178 * process more packets, and a %0 or %1 if it wants to exit from the
179 * kgdb callback.
180 */
181extern int
182kgdb_arch_handle_exception(int vector, int signo, int err_code,
183 char *remcom_in_buffer,
184 char *remcom_out_buffer,
185 struct pt_regs *regs);
186
187/**
188 * kgdb_roundup_cpus - Get other CPUs into a holding pattern
189 * @flags: Current IRQ state
190 *
191 * On SMP systems, we need to get the attention of the other CPUs
192 * and get them into a known state. This should do what is needed
193 * to get the other CPUs to call kgdb_wait(). Note that on some arches,
194 * the NMI approach is not used for rounding up all the CPUs. For example,
195 * in case of MIPS, smp_call_function() is used to roundup CPUs. In
196 * this case, we have to make sure that interrupts are enabled before
197 * calling smp_call_function(). The argument to this function is
198 * the flags that will be used when restoring the interrupts. There is
199 * local_irq_save() call before kgdb_roundup_cpus().
200 *
201 * On non-SMP systems, this is not called.
202 */
203extern void kgdb_roundup_cpus(unsigned long flags);
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 * struct kgdb_arch - Describe architecture specific values.
212 * @gdb_bpt_instr: The instruction to trigger a breakpoint.
213 * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT.
214 * @set_breakpoint: Allow an architecture to specify how to set a software
215 * breakpoint.
216 * @remove_breakpoint: Allow an architecture to specify how to remove a
217 * software breakpoint.
218 * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware
219 * breakpoint.
220 * @remove_hw_breakpoint: Allow an architecture to specify how to remove a
221 * hardware breakpoint.
222 * @remove_all_hw_break: Allow an architecture to specify how to remove all
223 * hardware breakpoints.
224 * @correct_hw_break: Allow an architecture to specify how to correct the
225 * hardware debug registers.
226 */
227struct kgdb_arch {
228 unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE];
229 unsigned long flags;
230
231 int (*set_breakpoint)(unsigned long, char *);
232 int (*remove_breakpoint)(unsigned long, char *);
233 int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
234 int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
235 void (*remove_all_hw_break)(void);
236 void (*correct_hw_break)(void);
237};
238
239/**
240 * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB.
241 * @name: Name of the I/O driver.
242 * @read_char: Pointer to a function that will return one char.
243 * @write_char: Pointer to a function that will write one char.
244 * @flush: Pointer to a function that will flush any pending writes.
245 * @init: Pointer to a function that will initialize the device.
246 * @pre_exception: Pointer to a function that will do any prep work for
247 * the I/O driver.
248 * @post_exception: Pointer to a function that will do any cleanup work
249 * for the I/O driver.
250 */
251struct kgdb_io {
252 const char *name;
253 int (*read_char) (void);
254 void (*write_char) (u8);
255 void (*flush) (void);
256 int (*init) (void);
257 void (*pre_exception) (void);
258 void (*post_exception) (void);
259};
260
261extern struct kgdb_arch arch_kgdb_ops;
262
263extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs);
264
265extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
266extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
267
268extern int kgdb_hex2long(char **ptr, unsigned long *long_val);
269extern int kgdb_mem2hex(char *mem, char *buf, int count);
270extern int kgdb_hex2mem(char *buf, char *mem, int count);
271
272extern int kgdb_isremovedbreak(unsigned long addr);
273
274extern int
275kgdb_handle_exception(int ex_vector, int signo, int err_code,
276 struct pt_regs *regs);
277extern int kgdb_nmicallback(int cpu, void *regs);
278
279extern int kgdb_single_step;
280extern atomic_t kgdb_active;
281
282#endif /* _KGDB_H_ */