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 20 #include <asm/atomic.h> 21 #include <asm/kgdb.h> 22 23 struct 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 */ 34 extern 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 */ 47 extern 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 */ 58 extern void kgdb_disable_hw_debug(struct pt_regs *regs); 59 60 struct tasklet_struct; 61 struct task_struct; 62 struct 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 */ 72 void kgdb_breakpoint(void); 73 74 extern int kgdb_connected; 75 76 extern atomic_t kgdb_setting_breakpoint; 77 extern atomic_t kgdb_cpu_doing_single_step; 78 79 extern struct task_struct *kgdb_usethread; 80 extern struct task_struct *kgdb_contthread; 81 82 enum kgdb_bptype { 83 BP_BREAKPOINT = 0, 84 BP_HARDWARE_BREAKPOINT, 85 BP_WRITE_WATCHPOINT, 86 BP_READ_WATCHPOINT, 87 BP_ACCESS_WATCHPOINT 88 }; 89 90 enum kgdb_bpstate { 91 BP_UNDEFINED = 0, 92 BP_REMOVED, 93 BP_SET, 94 BP_ACTIVE 95 }; 96 97 struct 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 */ 120 extern 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 */ 128 extern 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 */ 138 extern 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 */ 152 extern void 153 sleeping_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 */ 163 extern 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 */ 181 extern int 182 kgdb_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 */ 203 extern void kgdb_roundup_cpus(unsigned long flags); 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 * 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 */ 227 struct 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 */ 251 struct 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 }; 260 261 extern struct kgdb_arch arch_kgdb_ops; 262 263 extern unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs); 264 265 extern int kgdb_register_io_module(struct kgdb_io *local_kgdb_io_ops); 266 extern void kgdb_unregister_io_module(struct kgdb_io *local_kgdb_io_ops); 267 268 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); 271 272 extern int kgdb_isremovedbreak(unsigned long addr); 273 274 extern int 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); 278 279 extern int kgdb_single_step; 280 extern atomic_t kgdb_active; 281 282 #endif /* _KGDB_H_ */ 283