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 <[email protected]> and 6 * Tom Rini <[email protected]> 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 #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 */ 109 extern 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 */ 117 extern 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 */ 127 extern 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 */ 141 extern void 142 sleeping_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 */ 152 extern 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 */ 170 extern int 171 kgdb_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 */ 192 extern 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 */ 202 extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); 203 204 205 /* Optional functions. */ 206 extern int kgdb_validate_break_address(unsigned long addr); 207 extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr); 208 extern 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 */ 218 extern 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 */ 238 struct 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 */ 264 struct 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 }; 274 275 extern struct kgdb_arch arch_kgdb_ops; 276 277 extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs); 278 279 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); 280 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); 281 extern struct kgdb_io *dbg_io_ops; 282 283 extern int kgdb_hex2long(char **ptr, unsigned long *long_val); 284 extern int kgdb_mem2hex(char *mem, char *buf, int count); 285 extern int kgdb_hex2mem(char *buf, char *mem, int count); 286 287 extern int kgdb_isremovedbreak(unsigned long addr); 288 extern void kgdb_schedule_breakpoint(void); 289 290 extern int 291 kgdb_handle_exception(int ex_vector, int signo, int err_code, 292 struct pt_regs *regs); 293 extern int kgdb_nmicallback(int cpu, void *regs); 294 295 extern int kgdb_single_step; 296 extern atomic_t kgdb_active; 297 #define in_dbg_master() \ 298 (raw_smp_processor_id() == atomic_read(&kgdb_active)) 299 extern bool dbg_is_early; 300 extern 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_ */ 306