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 25 struct 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 */ 36 extern 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 */ 46 extern void kgdb_disable_hw_debug(struct pt_regs *regs); 47 48 struct tasklet_struct; 49 struct task_struct; 50 struct 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 */ 60 void kgdb_breakpoint(void); 61 62 extern int kgdb_connected; 63 extern int kgdb_io_module_registered; 64 65 extern atomic_t kgdb_setting_breakpoint; 66 extern atomic_t kgdb_cpu_doing_single_step; 67 68 extern struct task_struct *kgdb_usethread; 69 extern struct task_struct *kgdb_contthread; 70 71 enum kgdb_bptype { 72 BP_BREAKPOINT = 0, 73 BP_HARDWARE_BREAKPOINT, 74 BP_WRITE_WATCHPOINT, 75 BP_READ_WATCHPOINT, 76 BP_ACCESS_WATCHPOINT 77 }; 78 79 enum kgdb_bpstate { 80 BP_UNDEFINED = 0, 81 BP_REMOVED, 82 BP_SET, 83 BP_ACTIVE 84 }; 85 86 struct 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 struct dbg_reg_def_t { 94 char *name; 95 int size; 96 int offset; 97 }; 98 99 #ifndef DBG_MAX_REG_NUM 100 #define DBG_MAX_REG_NUM 0 101 #else 102 extern struct dbg_reg_def_t dbg_reg_def[]; 103 extern char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs); 104 extern int dbg_set_reg(int regno, void *mem, struct pt_regs *regs); 105 #endif 106 #ifndef KGDB_MAX_BREAKPOINTS 107 # define KGDB_MAX_BREAKPOINTS 1000 108 #endif 109 110 #define KGDB_HW_BREAKPOINT 1 111 112 /* 113 * Functions each KGDB-supporting architecture must provide: 114 */ 115 116 /** 117 * kgdb_arch_init - Perform any architecture specific initalization. 118 * 119 * This function will handle the initalization of any architecture 120 * specific callbacks. 121 */ 122 extern int kgdb_arch_init(void); 123 124 /** 125 * kgdb_arch_exit - Perform any architecture specific uninitalization. 126 * 127 * This function will handle the uninitalization of any architecture 128 * specific callbacks, for dynamic registration and unregistration. 129 */ 130 extern void kgdb_arch_exit(void); 131 132 /** 133 * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs 134 * @gdb_regs: A pointer to hold the registers in the order GDB wants. 135 * @regs: The &struct pt_regs of the current process. 136 * 137 * Convert the pt_regs in @regs into the format for registers that 138 * GDB expects, stored in @gdb_regs. 139 */ 140 extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs); 141 142 /** 143 * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs 144 * @gdb_regs: A pointer to hold the registers in the order GDB wants. 145 * @p: The &struct task_struct of the desired process. 146 * 147 * Convert the register values of the sleeping process in @p to 148 * the format that GDB expects. 149 * This function is called when kgdb does not have access to the 150 * &struct pt_regs and therefore it should fill the gdb registers 151 * @gdb_regs with what has been saved in &struct thread_struct 152 * thread field during switch_to. 153 */ 154 extern void 155 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p); 156 157 /** 158 * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs. 159 * @gdb_regs: A pointer to hold the registers we've received from GDB. 160 * @regs: A pointer to a &struct pt_regs to hold these values in. 161 * 162 * Convert the GDB regs in @gdb_regs into the pt_regs, and store them 163 * in @regs. 164 */ 165 extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs); 166 167 /** 168 * kgdb_arch_handle_exception - Handle architecture specific GDB packets. 169 * @vector: The error vector of the exception that happened. 170 * @signo: The signal number of the exception that happened. 171 * @err_code: The error code of the exception that happened. 172 * @remcom_in_buffer: The buffer of the packet we have read. 173 * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. 174 * @regs: The &struct pt_regs of the current process. 175 * 176 * This function MUST handle the 'c' and 's' command packets, 177 * as well packets to set / remove a hardware breakpoint, if used. 178 * If there are additional packets which the hardware needs to handle, 179 * they are handled here. The code should return -1 if it wants to 180 * process more packets, and a %0 or %1 if it wants to exit from the 181 * kgdb callback. 182 */ 183 extern int 184 kgdb_arch_handle_exception(int vector, int signo, int err_code, 185 char *remcom_in_buffer, 186 char *remcom_out_buffer, 187 struct pt_regs *regs); 188 189 /** 190 * kgdb_roundup_cpus - Get other CPUs into a holding pattern 191 * @flags: Current IRQ state 192 * 193 * On SMP systems, we need to get the attention of the other CPUs 194 * and get them into a known state. This should do what is needed 195 * to get the other CPUs to call kgdb_wait(). Note that on some arches, 196 * the NMI approach is not used for rounding up all the CPUs. For example, 197 * in case of MIPS, smp_call_function() is used to roundup CPUs. In 198 * this case, we have to make sure that interrupts are enabled before 199 * calling smp_call_function(). The argument to this function is 200 * the flags that will be used when restoring the interrupts. There is 201 * local_irq_save() call before kgdb_roundup_cpus(). 202 * 203 * On non-SMP systems, this is not called. 204 */ 205 extern void kgdb_roundup_cpus(unsigned long flags); 206 207 /** 208 * kgdb_arch_set_pc - Generic call back to the program counter 209 * @regs: Current &struct pt_regs. 210 * @pc: The new value for the program counter 211 * 212 * This function handles updating the program counter and requires an 213 * architecture specific implementation. 214 */ 215 extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); 216 217 218 /* Optional functions. */ 219 extern int kgdb_validate_break_address(unsigned long addr); 220 extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr); 221 extern int kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle); 222 223 /** 224 * kgdb_arch_late - Perform any architecture specific initalization. 225 * 226 * This function will handle the late initalization of any 227 * architecture specific callbacks. This is an optional function for 228 * handling things like late initialization of hw breakpoints. The 229 * default implementation does nothing. 230 */ 231 extern void kgdb_arch_late(void); 232 233 234 /** 235 * struct kgdb_arch - Describe architecture specific values. 236 * @gdb_bpt_instr: The instruction to trigger a breakpoint. 237 * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT. 238 * @set_breakpoint: Allow an architecture to specify how to set a software 239 * breakpoint. 240 * @remove_breakpoint: Allow an architecture to specify how to remove a 241 * software breakpoint. 242 * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware 243 * breakpoint. 244 * @remove_hw_breakpoint: Allow an architecture to specify how to remove a 245 * hardware breakpoint. 246 * @remove_all_hw_break: Allow an architecture to specify how to remove all 247 * hardware breakpoints. 248 * @correct_hw_break: Allow an architecture to specify how to correct the 249 * hardware debug registers. 250 */ 251 struct kgdb_arch { 252 unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE]; 253 unsigned long flags; 254 255 int (*set_breakpoint)(unsigned long, char *); 256 int (*remove_breakpoint)(unsigned long, char *); 257 int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); 258 int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); 259 void (*remove_all_hw_break)(void); 260 void (*correct_hw_break)(void); 261 }; 262 263 /** 264 * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB. 265 * @name: Name of the I/O driver. 266 * @read_char: Pointer to a function that will return one char. 267 * @write_char: Pointer to a function that will write one char. 268 * @flush: Pointer to a function that will flush any pending writes. 269 * @init: Pointer to a function that will initialize the device. 270 * @pre_exception: Pointer to a function that will do any prep work for 271 * the I/O driver. 272 * @post_exception: Pointer to a function that will do any cleanup work 273 * for the I/O driver. 274 * @is_console: 1 if the end device is a console 0 if the I/O device is 275 * not a console 276 */ 277 struct kgdb_io { 278 const char *name; 279 int (*read_char) (void); 280 void (*write_char) (u8); 281 void (*flush) (void); 282 int (*init) (void); 283 void (*pre_exception) (void); 284 void (*post_exception) (void); 285 int is_console; 286 }; 287 288 extern struct kgdb_arch arch_kgdb_ops; 289 290 extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs); 291 292 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); 293 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); 294 extern struct kgdb_io *dbg_io_ops; 295 296 extern int kgdb_hex2long(char **ptr, unsigned long *long_val); 297 extern char *kgdb_mem2hex(char *mem, char *buf, int count); 298 extern int kgdb_hex2mem(char *buf, char *mem, int count); 299 300 extern int kgdb_isremovedbreak(unsigned long addr); 301 extern void kgdb_schedule_breakpoint(void); 302 303 extern int 304 kgdb_handle_exception(int ex_vector, int signo, int err_code, 305 struct pt_regs *regs); 306 extern int kgdb_nmicallback(int cpu, void *regs); 307 308 extern int kgdb_single_step; 309 extern atomic_t kgdb_active; 310 #define in_dbg_master() \ 311 (raw_smp_processor_id() == atomic_read(&kgdb_active)) 312 extern bool dbg_is_early; 313 extern void __init dbg_late_init(void); 314 #else /* ! CONFIG_KGDB */ 315 #define in_dbg_master() (0) 316 #define dbg_late_init() 317 #endif /* ! CONFIG_KGDB */ 318 #endif /* _KGDB_H_ */ 319