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 38struct tasklet_struct; 39struct task_struct; 40struct uart_port; 41 42/** 43 * kgdb_breakpoint - compiled in breakpoint 44 * 45 * This will be implemented as a static inline per architecture. This 46 * function is called by the kgdb core to execute an architecture 47 * specific trap to cause kgdb to enter the exception processing. 48 * 49 */ 50void kgdb_breakpoint(void); 51 52extern int kgdb_connected; 53extern int kgdb_io_module_registered; 54 55extern atomic_t kgdb_setting_breakpoint; 56extern atomic_t kgdb_cpu_doing_single_step; 57 58extern struct task_struct *kgdb_usethread; 59extern struct task_struct *kgdb_contthread; 60 61enum kgdb_bptype { 62 BP_BREAKPOINT = 0, 63 BP_HARDWARE_BREAKPOINT, 64 BP_WRITE_WATCHPOINT, 65 BP_READ_WATCHPOINT, 66 BP_ACCESS_WATCHPOINT 67}; 68 69enum kgdb_bpstate { 70 BP_UNDEFINED = 0, 71 BP_REMOVED, 72 BP_SET, 73 BP_ACTIVE 74}; 75 76struct kgdb_bkpt { 77 unsigned long bpt_addr; 78 unsigned char saved_instr[BREAK_INSTR_SIZE]; 79 enum kgdb_bptype type; 80 enum kgdb_bpstate state; 81}; 82 83struct dbg_reg_def_t { 84 char *name; 85 int size; 86 int offset; 87}; 88 89#ifndef DBG_MAX_REG_NUM 90#define DBG_MAX_REG_NUM 0 91#else 92extern struct dbg_reg_def_t dbg_reg_def[]; 93extern char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs); 94extern int dbg_set_reg(int regno, void *mem, struct pt_regs *regs); 95#endif 96#ifndef KGDB_MAX_BREAKPOINTS 97# define KGDB_MAX_BREAKPOINTS 1000 98#endif 99 100#define KGDB_HW_BREAKPOINT 1 101 102/* 103 * Functions each KGDB-supporting architecture must provide: 104 */ 105 106/** 107 * kgdb_arch_init - Perform any architecture specific initalization. 108 * 109 * This function will handle the initalization of any architecture 110 * specific callbacks. 111 */ 112extern int kgdb_arch_init(void); 113 114/** 115 * kgdb_arch_exit - Perform any architecture specific uninitalization. 116 * 117 * This function will handle the uninitalization of any architecture 118 * specific callbacks, for dynamic registration and unregistration. 119 */ 120extern void kgdb_arch_exit(void); 121 122/** 123 * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs 124 * @gdb_regs: A pointer to hold the registers in the order GDB wants. 125 * @regs: The &struct pt_regs of the current process. 126 * 127 * Convert the pt_regs in @regs into the format for registers that 128 * GDB expects, stored in @gdb_regs. 129 */ 130extern void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs); 131 132/** 133 * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs 134 * @gdb_regs: A pointer to hold the registers in the order GDB wants. 135 * @p: The &struct task_struct of the desired process. 136 * 137 * Convert the register values of the sleeping process in @p to 138 * the format that GDB expects. 139 * This function is called when kgdb does not have access to the 140 * &struct pt_regs and therefore it should fill the gdb registers 141 * @gdb_regs with what has been saved in &struct thread_struct 142 * thread field during switch_to. 143 */ 144extern void 145sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p); 146 147/** 148 * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs. 149 * @gdb_regs: A pointer to hold the registers we've received from GDB. 150 * @regs: A pointer to a &struct pt_regs to hold these values in. 151 * 152 * Convert the GDB regs in @gdb_regs into the pt_regs, and store them 153 * in @regs. 154 */ 155extern void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs); 156 157/** 158 * kgdb_arch_handle_exception - Handle architecture specific GDB packets. 159 * @vector: The error vector of the exception that happened. 160 * @signo: The signal number of the exception that happened. 161 * @err_code: The error code of the exception that happened. 162 * @remcom_in_buffer: The buffer of the packet we have read. 163 * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. 164 * @regs: The &struct pt_regs of the current process. 165 * 166 * This function MUST handle the 'c' and 's' command packets, 167 * as well packets to set / remove a hardware breakpoint, if used. 168 * If there are additional packets which the hardware needs to handle, 169 * they are handled here. The code should return -1 if it wants to 170 * process more packets, and a %0 or %1 if it wants to exit from the 171 * kgdb callback. 172 */ 173extern int 174kgdb_arch_handle_exception(int vector, int signo, int err_code, 175 char *remcom_in_buffer, 176 char *remcom_out_buffer, 177 struct pt_regs *regs); 178 179/** 180 * kgdb_roundup_cpus - Get other CPUs into a holding pattern 181 * @flags: Current IRQ state 182 * 183 * On SMP systems, we need to get the attention of the other CPUs 184 * and get them into a known state. This should do what is needed 185 * to get the other CPUs to call kgdb_wait(). Note that on some arches, 186 * the NMI approach is not used for rounding up all the CPUs. For example, 187 * in case of MIPS, smp_call_function() is used to roundup CPUs. In 188 * this case, we have to make sure that interrupts are enabled before 189 * calling smp_call_function(). The argument to this function is 190 * the flags that will be used when restoring the interrupts. There is 191 * local_irq_save() call before kgdb_roundup_cpus(). 192 * 193 * On non-SMP systems, this is not called. 194 */ 195extern void kgdb_roundup_cpus(unsigned long flags); 196 197/** 198 * kgdb_arch_set_pc - Generic call back to the program counter 199 * @regs: Current &struct pt_regs. 200 * @pc: The new value for the program counter 201 * 202 * This function handles updating the program counter and requires an 203 * architecture specific implementation. 204 */ 205extern void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc); 206 207 208/* Optional functions. */ 209extern int kgdb_validate_break_address(unsigned long addr); 210extern int kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr); 211extern int kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle); 212 213/** 214 * kgdb_arch_late - Perform any architecture specific initalization. 215 * 216 * This function will handle the late initalization of any 217 * architecture specific callbacks. This is an optional function for 218 * handling things like late initialization of hw breakpoints. The 219 * default implementation does nothing. 220 */ 221extern void kgdb_arch_late(void); 222 223 224/** 225 * struct kgdb_arch - Describe architecture specific values. 226 * @gdb_bpt_instr: The instruction to trigger a breakpoint. 227 * @flags: Flags for the breakpoint, currently just %KGDB_HW_BREAKPOINT. 228 * @set_breakpoint: Allow an architecture to specify how to set a software 229 * breakpoint. 230 * @remove_breakpoint: Allow an architecture to specify how to remove a 231 * software breakpoint. 232 * @set_hw_breakpoint: Allow an architecture to specify how to set a hardware 233 * breakpoint. 234 * @remove_hw_breakpoint: Allow an architecture to specify how to remove a 235 * hardware breakpoint. 236 * @disable_hw_break: Allow an architecture to specify how to disable 237 * hardware breakpoints for a single cpu. 238 * @remove_all_hw_break: Allow an architecture to specify how to remove all 239 * hardware breakpoints. 240 * @correct_hw_break: Allow an architecture to specify how to correct the 241 * hardware debug registers. 242 */ 243struct kgdb_arch { 244 unsigned char gdb_bpt_instr[BREAK_INSTR_SIZE]; 245 unsigned long flags; 246 247 int (*set_breakpoint)(unsigned long, char *); 248 int (*remove_breakpoint)(unsigned long, char *); 249 int (*set_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); 250 int (*remove_hw_breakpoint)(unsigned long, int, enum kgdb_bptype); 251 void (*disable_hw_break)(struct pt_regs *regs); 252 void (*remove_all_hw_break)(void); 253 void (*correct_hw_break)(void); 254}; 255 256/** 257 * struct kgdb_io - Describe the interface for an I/O driver to talk with KGDB. 258 * @name: Name of the I/O driver. 259 * @read_char: Pointer to a function that will return one char. 260 * @write_char: Pointer to a function that will write one char. 261 * @flush: Pointer to a function that will flush any pending writes. 262 * @init: Pointer to a function that will initialize the device. 263 * @pre_exception: Pointer to a function that will do any prep work for 264 * the I/O driver. 265 * @post_exception: Pointer to a function that will do any cleanup work 266 * for the I/O driver. 267 * @is_console: 1 if the end device is a console 0 if the I/O device is 268 * not a console 269 */ 270struct kgdb_io { 271 const char *name; 272 int (*read_char) (void); 273 void (*write_char) (u8); 274 void (*flush) (void); 275 int (*init) (void); 276 void (*pre_exception) (void); 277 void (*post_exception) (void); 278 int is_console; 279}; 280 281extern struct kgdb_arch arch_kgdb_ops; 282 283extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs); 284 285extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); 286extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); 287extern struct kgdb_io *dbg_io_ops; 288 289extern int kgdb_hex2long(char **ptr, unsigned long *long_val); 290extern char *kgdb_mem2hex(char *mem, char *buf, int count); 291extern int kgdb_hex2mem(char *buf, char *mem, int count); 292 293extern int kgdb_isremovedbreak(unsigned long addr); 294extern void kgdb_schedule_breakpoint(void); 295 296extern int 297kgdb_handle_exception(int ex_vector, int signo, int err_code, 298 struct pt_regs *regs); 299extern int kgdb_nmicallback(int cpu, void *regs); 300 301extern int kgdb_single_step; 302extern atomic_t kgdb_active; 303#define in_dbg_master() \ 304 (raw_smp_processor_id() == atomic_read(&kgdb_active)) 305extern bool dbg_is_early; 306extern void __init dbg_late_init(void); 307#else /* ! CONFIG_KGDB */ 308#define in_dbg_master() (0) 309#define dbg_late_init() 310#endif /* ! CONFIG_KGDB */ 311#endif /* _KGDB_H_ */ 312