Linas Vepstas | 0d71e87 | 2011-10-31 18:54:43 -0500 | [diff] [blame] | 1 | /* |
| 2 | * arch/hexagon/kernel/kgdb.c - Hexagon KGDB Support |
| 3 | * |
| 4 | * Copyright (c) 2011, Code Aurora Forum. All rights reserved. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 and |
| 8 | * only version 2 as published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 18 | * 02110-1301, USA. |
| 19 | */ |
| 20 | |
| 21 | #include <linux/kdebug.h> |
| 22 | #include <linux/kgdb.h> |
| 23 | |
| 24 | /* All registers are 4 bytes, for now */ |
| 25 | #define GDB_SIZEOF_REG 4 |
| 26 | |
| 27 | /* The register names are used during printing of the regs; |
| 28 | * Keep these at three letters to pretty-print. */ |
| 29 | struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = { |
| 30 | { " r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, r00)}, |
| 31 | { " r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, r01)}, |
| 32 | { " r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, r02)}, |
| 33 | { " r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, r03)}, |
| 34 | { " r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, r04)}, |
| 35 | { " r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, r05)}, |
| 36 | { " r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, r06)}, |
| 37 | { " r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, r07)}, |
| 38 | { " r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, r08)}, |
| 39 | { " r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, r09)}, |
| 40 | { "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, r10)}, |
| 41 | { "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, r11)}, |
| 42 | { "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, r12)}, |
| 43 | { "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, r13)}, |
| 44 | { "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, r14)}, |
| 45 | { "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, r15)}, |
| 46 | { "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, r16)}, |
| 47 | { "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, r17)}, |
| 48 | { "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, r18)}, |
| 49 | { "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, r19)}, |
| 50 | { "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, r20)}, |
| 51 | { "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, r21)}, |
| 52 | { "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, r22)}, |
| 53 | { "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, r23)}, |
| 54 | { "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, r24)}, |
| 55 | { "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, r25)}, |
| 56 | { "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, r26)}, |
| 57 | { "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, r27)}, |
| 58 | { "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, r28)}, |
| 59 | { "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, r29)}, |
| 60 | { "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, r30)}, |
| 61 | { "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, r31)}, |
| 62 | |
| 63 | { "usr", GDB_SIZEOF_REG, offsetof(struct pt_regs, usr)}, |
| 64 | { "preds", GDB_SIZEOF_REG, offsetof(struct pt_regs, preds)}, |
| 65 | { " m0", GDB_SIZEOF_REG, offsetof(struct pt_regs, m0)}, |
| 66 | { " m1", GDB_SIZEOF_REG, offsetof(struct pt_regs, m1)}, |
| 67 | { "sa0", GDB_SIZEOF_REG, offsetof(struct pt_regs, sa0)}, |
| 68 | { "sa1", GDB_SIZEOF_REG, offsetof(struct pt_regs, sa1)}, |
| 69 | { "lc0", GDB_SIZEOF_REG, offsetof(struct pt_regs, lc0)}, |
| 70 | { "lc1", GDB_SIZEOF_REG, offsetof(struct pt_regs, lc1)}, |
| 71 | { " gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, gp)}, |
| 72 | { "ugp", GDB_SIZEOF_REG, offsetof(struct pt_regs, ugp)}, |
| 73 | { "psp", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmpsp)}, |
| 74 | { "elr", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmel)}, |
| 75 | { "est", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmest)}, |
| 76 | { "badva", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmbadva)}, |
| 77 | { "restart_r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, restart_r0)}, |
| 78 | { "syscall_nr", GDB_SIZEOF_REG, offsetof(struct pt_regs, syscall_nr)}, |
| 79 | }; |
| 80 | |
| 81 | struct kgdb_arch arch_kgdb_ops = { |
| 82 | /* trap0(#0xDB) 0x0cdb0054 */ |
| 83 | .gdb_bpt_instr = {0x54, 0x00, 0xdb, 0x0c}, |
| 84 | }; |
| 85 | |
| 86 | char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs) |
| 87 | { |
| 88 | if (regno >= DBG_MAX_REG_NUM || regno < 0) |
| 89 | return NULL; |
| 90 | |
| 91 | *((unsigned long *) mem) = *((unsigned long *) ((void *)regs + |
| 92 | dbg_reg_def[regno].offset)); |
| 93 | |
| 94 | return dbg_reg_def[regno].name; |
| 95 | } |
| 96 | |
| 97 | int dbg_set_reg(int regno, void *mem, struct pt_regs *regs) |
| 98 | { |
| 99 | if (regno >= DBG_MAX_REG_NUM || regno < 0) |
| 100 | return -EINVAL; |
| 101 | |
| 102 | *((unsigned long *) ((void *)regs + dbg_reg_def[regno].offset)) = |
| 103 | *((unsigned long *) mem); |
| 104 | |
| 105 | return 0; |
| 106 | } |
| 107 | |
| 108 | void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) |
| 109 | { |
| 110 | instruction_pointer(regs) = pc; |
| 111 | } |
| 112 | |
| 113 | #ifdef CONFIG_SMP |
| 114 | |
| 115 | /** |
| 116 | * kgdb_roundup_cpus - Get other CPUs into a holding pattern |
| 117 | * @flags: Current IRQ state |
| 118 | * |
| 119 | * On SMP systems, we need to get the attention of the other CPUs |
| 120 | * and get them be in a known state. This should do what is needed |
| 121 | * to get the other CPUs to call kgdb_wait(). Note that on some arches, |
| 122 | * the NMI approach is not used for rounding up all the CPUs. For example, |
| 123 | * in case of MIPS, smp_call_function() is used to roundup CPUs. In |
| 124 | * this case, we have to make sure that interrupts are enabled before |
| 125 | * calling smp_call_function(). The argument to this function is |
| 126 | * the flags that will be used when restoring the interrupts. There is |
| 127 | * local_irq_save() call before kgdb_roundup_cpus(). |
| 128 | * |
| 129 | * On non-SMP systems, this is not called. |
| 130 | */ |
| 131 | |
| 132 | static void hexagon_kgdb_nmi_hook(void *ignored) |
| 133 | { |
| 134 | kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); |
| 135 | } |
| 136 | |
| 137 | void kgdb_roundup_cpus(unsigned long flags) |
| 138 | { |
| 139 | local_irq_enable(); |
| 140 | smp_call_function(hexagon_kgdb_nmi_hook, NULL, 0); |
| 141 | local_irq_disable(); |
| 142 | } |
| 143 | #endif |
| 144 | |
| 145 | |
| 146 | /* Not yet working */ |
| 147 | void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, |
| 148 | struct task_struct *task) |
| 149 | { |
| 150 | struct pt_regs *thread_regs; |
| 151 | |
| 152 | if (task == NULL) |
| 153 | return; |
| 154 | |
| 155 | /* Initialize to zero */ |
| 156 | memset(gdb_regs, 0, NUMREGBYTES); |
| 157 | |
| 158 | /* Otherwise, we have only some registers from switch_to() */ |
| 159 | thread_regs = task_pt_regs(task); |
| 160 | gdb_regs[0] = thread_regs->r00; |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * kgdb_arch_handle_exception - Handle architecture specific GDB packets. |
| 165 | * @vector: The error vector of the exception that happened. |
| 166 | * @signo: The signal number of the exception that happened. |
| 167 | * @err_code: The error code of the exception that happened. |
| 168 | * @remcom_in_buffer: The buffer of the packet we have read. |
| 169 | * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. |
| 170 | * @regs: The &struct pt_regs of the current process. |
| 171 | * |
| 172 | * This function MUST handle the 'c' and 's' command packets, |
| 173 | * as well packets to set / remove a hardware breakpoint, if used. |
| 174 | * If there are additional packets which the hardware needs to handle, |
| 175 | * they are handled here. The code should return -1 if it wants to |
| 176 | * process more packets, and a %0 or %1 if it wants to exit from the |
| 177 | * kgdb callback. |
| 178 | * |
| 179 | * Not yet working. |
| 180 | */ |
| 181 | int kgdb_arch_handle_exception(int vector, int signo, int err_code, |
| 182 | char *remcom_in_buffer, char *remcom_out_buffer, |
| 183 | struct pt_regs *linux_regs) |
| 184 | { |
| 185 | switch (remcom_in_buffer[0]) { |
| 186 | case 's': |
| 187 | case 'c': |
| 188 | return 0; |
| 189 | } |
| 190 | /* Stay in the debugger. */ |
| 191 | return -1; |
| 192 | } |
| 193 | |
| 194 | static int __kgdb_notify(struct die_args *args, unsigned long cmd) |
| 195 | { |
| 196 | /* cpu roundup */ |
| 197 | if (atomic_read(&kgdb_active) != -1) { |
| 198 | kgdb_nmicallback(smp_processor_id(), args->regs); |
| 199 | return NOTIFY_STOP; |
| 200 | } |
| 201 | |
| 202 | if (user_mode(args->regs)) |
| 203 | return NOTIFY_DONE; |
| 204 | |
| 205 | if (kgdb_handle_exception(args->trapnr & 0xff, args->signr, args->err, |
| 206 | args->regs)) |
| 207 | return NOTIFY_DONE; |
| 208 | |
| 209 | return NOTIFY_STOP; |
| 210 | } |
| 211 | |
| 212 | static int |
| 213 | kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr) |
| 214 | { |
| 215 | unsigned long flags; |
| 216 | int ret; |
| 217 | |
| 218 | local_irq_save(flags); |
| 219 | ret = __kgdb_notify(ptr, cmd); |
| 220 | local_irq_restore(flags); |
| 221 | |
| 222 | return ret; |
| 223 | } |
| 224 | |
| 225 | static struct notifier_block kgdb_notifier = { |
| 226 | .notifier_call = kgdb_notify, |
| 227 | |
| 228 | /* |
| 229 | * Lowest-prio notifier priority, we want to be notified last: |
| 230 | */ |
| 231 | .priority = -INT_MAX, |
| 232 | }; |
| 233 | |
| 234 | /** |
| 235 | * kgdb_arch_init - Perform any architecture specific initalization. |
| 236 | * |
| 237 | * This function will handle the initalization of any architecture |
| 238 | * specific callbacks. |
| 239 | */ |
| 240 | int kgdb_arch_init(void) |
| 241 | { |
| 242 | return register_die_notifier(&kgdb_notifier); |
| 243 | } |
| 244 | |
| 245 | /** |
| 246 | * kgdb_arch_exit - Perform any architecture specific uninitalization. |
| 247 | * |
| 248 | * This function will handle the uninitalization of any architecture |
| 249 | * specific callbacks, for dynamic registration and unregistration. |
| 250 | */ |
| 251 | void kgdb_arch_exit(void) |
| 252 | { |
| 253 | unregister_die_notifier(&kgdb_notifier); |
| 254 | } |