2 * This provides the callbacks and functions that KGDB needs to share between
3 * the core, I/O and arch-specific portions.
5 * Author: Amit Kale <amitkale@linsyssoft.com> and
6 * Tom Rini <trini@kernel.crashing.org>
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.
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
28 * kgdb_skipexception - (optional) exit kgdb_handle_exception early
29 * @exception: Exception vector number
30 * @regs: Current &struct pt_regs.
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.
36 extern int kgdb_skipexception(int exception, struct pt_regs *regs);
39 * kgdb_disable_hw_debug - (optional) Disable hardware debugging hook
40 * @regs: Current &struct pt_regs.
42 * This function will be called if the particular architecture must
43 * disable hardware debugging while it is processing gdb packets or
46 extern void kgdb_disable_hw_debug(struct pt_regs *regs);
48 struct tasklet_struct;
53 * kgdb_breakpoint - compiled in breakpoint
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.
60 void kgdb_breakpoint(void);
62 extern int kgdb_connected;
64 extern atomic_t kgdb_setting_breakpoint;
65 extern atomic_t kgdb_cpu_doing_single_step;
67 extern struct task_struct *kgdb_usethread;
68 extern struct task_struct *kgdb_contthread;
72 BP_HARDWARE_BREAKPOINT,
86 unsigned long bpt_addr;
87 unsigned char saved_instr[BREAK_INSTR_SIZE];
88 enum kgdb_bptype type;
89 enum kgdb_bpstate state;
92 #ifndef KGDB_MAX_BREAKPOINTS
93 # define KGDB_MAX_BREAKPOINTS 1000
96 #define KGDB_HW_BREAKPOINT 1
99 * Functions each KGDB-supporting architecture must provide:
103 * kgdb_arch_init - Perform any architecture specific initalization.
105 * This function will handle the initalization of any architecture
106 * specific callbacks.
108 extern int kgdb_arch_init(void);
111 * kgdb_arch_exit - Perform any architecture specific uninitalization.
113 * This function will handle the uninitalization of any architecture
114 * specific callbacks, for dynamic registration and unregistration.
116 extern void kgdb_arch_exit(void);
119 * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
120 * @gdb_regs: A pointer to hold the registers in the order GDB wants.
121 * @regs: The &struct pt_regs of the current process.
123 * Convert the pt_regs in @regs into the format for registers that
124 * GDB expects, stored in @gdb_regs.
126 extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs);
129 * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
130 * @gdb_regs: A pointer to hold the registers in the order GDB wants.
131 * @p: The &struct task_struct of the desired process.
133 * Convert the register values of the sleeping process in @p to
134 * the format that GDB expects.
135 * This function is called when kgdb does not have access to the
136 * &struct pt_regs and therefore it should fill the gdb registers
137 * @gdb_regs with what has been saved in &struct thread_struct
138 * thread field during switch_to.
141 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p);
144 * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
145 * @gdb_regs: A pointer to hold the registers we've received from GDB.
146 * @regs: A pointer to a &struct pt_regs to hold these values in.
148 * Convert the GDB regs in @gdb_regs into the pt_regs, and store them
151 extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs);
154 * kgdb_arch_handle_exception - Handle architecture specific GDB packets.
155 * @vector: The error vector of the exception that happened.
156 * @signo: The signal number of the exception that happened.
157 * @err_code: The error code of the exception that happened.
158 * @remcom_in_buffer: The buffer of the packet we have read.
159 * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
160 * @regs: The &struct pt_regs of the current process.
162 * This function MUST handle the 'c' and 's' command packets,
163 * as well packets to set / remove a hardware breakpoint, if used.
164 * If there are additional packets which the hardware needs to handle,
165 * they are handled here. The code should return -1 if it wants to
166 * process more packets, and a %0 or %1 if it wants to exit from the
170 kgdb_arch_handle_exception(int vector, int signo, int err_code,
171 char *remcom_in_buffer,
172 char *remcom_out_buffer,
173 struct pt_regs *regs);
176 * kgdb_roundup_cpus - Get other CPUs into a holding pattern
177 * @flags: Current IRQ state
179 * On SMP systems, we need to get the attention of the other CPUs
180 * and get them into a known state. This should do what is needed
181 * to get the other CPUs to call kgdb_wait(). Note that on some arches,
182 * the NMI approach is not used for rounding up all the CPUs. For example,
183 * in case of MIPS, smp_call_function() is used to roundup CPUs. In
184 * this case, we have to make sure that interrupts are enabled before
185 * calling smp_call_function(). The argument to this function is
186 * the flags that will be used when restoring the interrupts. There is
187 * local_irq_save() call before kgdb_roundup_cpus().
189 * On non-SMP systems, this is not called.
191 extern void kgdb_roundup_cpus(unsigned long flags);
194 * kgdb_arch_set_pc - Generic call back to the program counter
195 * @regs: Current &struct pt_regs.
196 * @pc: The new value for the program counter
198 * This function handles updating the program counter and requires an
199 * architecture specific implementation.
201 extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc);
204 /* Optional functions. */
205 extern int kgdb_validate_break_address(unsigned long addr);
206 extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr);
207 extern int kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle);
210 * struct kgdb_arch - Describe architecture specific values.
211 * @gdb_bpt_instr: The instruction to trigger a breakpoint.
212 * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT.
213 * @set_breakpoint: Allow an architecture to specify how to set a software
215 * @remove_breakpoint: Allow an architecture to specify how to remove a
216 * software breakpoint.
217 * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware
219 * @remove_hw_breakpoint: Allow an architecture to specify how to remove a
220 * hardware breakpoint.
221 * @remove_all_hw_break: Allow an architecture to specify how to remove all
222 * hardware breakpoints.
223 * @correct_hw_break: Allow an architecture to specify how to correct the
224 * hardware debug registers.
227 unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE];
230 int (*set_breakpoint)(unsigned long, char *);
231 int (*remove_breakpoint)(unsigned long, char *);
232 int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
233 int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype);
234 void (*remove_all_hw_break)(void);
235 void (*correct_hw_break)(void);
239 * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB.
240 * @name: Name of the I/O driver.
241 * @read_char: Pointer to a function that will return one char.
242 * @write_char: Pointer to a function that will write one char.
243 * @flush: Pointer to a function that will flush any pending writes.
244 * @init: Pointer to a function that will initialize the device.
245 * @pre_exception: Pointer to a function that will do any prep work for
247 * @post_exception: Pointer to a function that will do any cleanup work
248 * for the I/O driver.
252 int (*read_char) (void);
253 void (*write_char) (u8);
254 void (*flush) (void);
256 void (*pre_exception) (void);
257 void (*post_exception) (void);
260 extern struct kgdb_arch arch_kgdb_ops;
262 extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs);
264 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops);
265 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops);
266 extern struct kgdb_io *dbg_io_ops;
268 extern int kgdb_hex2long(char **ptr, unsigned long *long_val);
269 extern int kgdb_mem2hex(char *mem, char *buf, int count);
270 extern int kgdb_hex2mem(char *buf, char *mem, int count);
272 extern int kgdb_isremovedbreak(unsigned long addr);
275 kgdb_handle_exception(int ex_vector, int signo, int err_code,
276 struct pt_regs *regs);
277 extern int kgdb_nmicallback(int cpu, void *regs);
279 extern int kgdb_single_step;
280 extern atomic_t kgdb_active;
281 #define in_dbg_master() \
282 (raw_smp_processor_id() == atomic_read(&kgdb_active))
283 #else /* ! CONFIG_KGDB */
284 #define in_dbg_master() (0)
285 #endif /* ! CONFIG_KGDB */
286 #endif /* _KGDB_H_ */