1 /* kgdb.c: KGDB support for 64-bit sparc. 2 * 3 * Copyright (C) 2008 David S. Miller <davem@davemloft.net> 4 */ 5 6 #include <linux/kgdb.h> 7 #include <linux/kdebug.h> 8 #include <linux/ftrace.h> 9 #include <linux/context_tracking.h> 10 11 #include <asm/cacheflush.h> 12 #include <asm/kdebug.h> 13 #include <asm/ptrace.h> 14 #include <asm/irq.h> 15 16 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) 17 { 18 struct reg_window *win; 19 int i; 20 21 gdb_regs[GDB_G0] = 0; 22 for (i = 0; i < 15; i++) 23 gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i]; 24 25 win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS); 26 for (i = 0; i < 8; i++) 27 gdb_regs[GDB_L0 + i] = win->locals[i]; 28 for (i = 0; i < 8; i++) 29 gdb_regs[GDB_I0 + i] = win->ins[i]; 30 31 for (i = GDB_F0; i <= GDB_F62; i++) 32 gdb_regs[i] = 0; 33 34 gdb_regs[GDB_PC] = regs->tpc; 35 gdb_regs[GDB_NPC] = regs->tnpc; 36 gdb_regs[GDB_STATE] = regs->tstate; 37 gdb_regs[GDB_FSR] = 0; 38 gdb_regs[GDB_FPRS] = 0; 39 gdb_regs[GDB_Y] = regs->y; 40 } 41 42 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) 43 { 44 struct thread_info *t = task_thread_info(p); 45 extern unsigned int switch_to_pc; 46 extern unsigned int ret_from_fork; 47 struct reg_window *win; 48 unsigned long pc, cwp; 49 int i; 50 51 for (i = GDB_G0; i < GDB_G6; i++) 52 gdb_regs[i] = 0; 53 gdb_regs[GDB_G6] = (unsigned long) t; 54 gdb_regs[GDB_G7] = (unsigned long) p; 55 for (i = GDB_O0; i < GDB_SP; i++) 56 gdb_regs[i] = 0; 57 gdb_regs[GDB_SP] = t->ksp; 58 gdb_regs[GDB_O7] = 0; 59 60 win = (struct reg_window *) (t->ksp + STACK_BIAS); 61 for (i = 0; i < 8; i++) 62 gdb_regs[GDB_L0 + i] = win->locals[i]; 63 for (i = 0; i < 8; i++) 64 gdb_regs[GDB_I0 + i] = win->ins[i]; 65 66 for (i = GDB_F0; i <= GDB_F62; i++) 67 gdb_regs[i] = 0; 68 69 if (t->new_child) 70 pc = (unsigned long) &ret_from_fork; 71 else 72 pc = (unsigned long) &switch_to_pc; 73 74 gdb_regs[GDB_PC] = pc; 75 gdb_regs[GDB_NPC] = pc + 4; 76 77 cwp = __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP]; 78 79 gdb_regs[GDB_STATE] = (TSTATE_PRIV | TSTATE_IE | cwp); 80 gdb_regs[GDB_FSR] = 0; 81 gdb_regs[GDB_FPRS] = 0; 82 gdb_regs[GDB_Y] = 0; 83 } 84 85 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) 86 { 87 struct reg_window *win; 88 int i; 89 90 for (i = 0; i < 15; i++) 91 regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i]; 92 93 /* If the TSTATE register is changing, we have to preserve 94 * the CWP field, otherwise window save/restore explodes. 95 */ 96 if (regs->tstate != gdb_regs[GDB_STATE]) { 97 unsigned long cwp = regs->tstate & TSTATE_CWP; 98 99 regs->tstate = (gdb_regs[GDB_STATE] & ~TSTATE_CWP) | cwp; 100 } 101 102 regs->tpc = gdb_regs[GDB_PC]; 103 regs->tnpc = gdb_regs[GDB_NPC]; 104 regs->y = gdb_regs[GDB_Y]; 105 106 win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS); 107 for (i = 0; i < 8; i++) 108 win->locals[i] = gdb_regs[GDB_L0 + i]; 109 for (i = 0; i < 8; i++) 110 win->ins[i] = gdb_regs[GDB_I0 + i]; 111 } 112 113 #ifdef CONFIG_SMP 114 void __irq_entry smp_kgdb_capture_client(int irq, struct pt_regs *regs) 115 { 116 unsigned long flags; 117 118 __asm__ __volatile__("rdpr %%pstate, %0\n\t" 119 "wrpr %0, %1, %%pstate" 120 : "=r" (flags) 121 : "i" (PSTATE_IE)); 122 123 flushw_all(); 124 125 if (atomic_read(&kgdb_active) != -1) 126 kgdb_nmicallback(raw_smp_processor_id(), regs); 127 128 __asm__ __volatile__("wrpr %0, 0, %%pstate" 129 : : "r" (flags)); 130 } 131 #endif 132 133 int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, 134 char *remcomInBuffer, char *remcomOutBuffer, 135 struct pt_regs *linux_regs) 136 { 137 unsigned long addr; 138 char *ptr; 139 140 switch (remcomInBuffer[0]) { 141 case 'c': 142 /* try to read optional parameter, pc unchanged if no parm */ 143 ptr = &remcomInBuffer[1]; 144 if (kgdb_hex2long(&ptr, &addr)) { 145 linux_regs->tpc = addr; 146 linux_regs->tnpc = addr + 4; 147 } 148 /* fallthru */ 149 150 case 'D': 151 case 'k': 152 if (linux_regs->tpc == (unsigned long) arch_kgdb_breakpoint) { 153 linux_regs->tpc = linux_regs->tnpc; 154 linux_regs->tnpc += 4; 155 } 156 return 0; 157 } 158 return -1; 159 } 160 161 asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs) 162 { 163 enum ctx_state prev_state = exception_enter(); 164 unsigned long flags; 165 166 if (user_mode(regs)) { 167 bad_trap(regs, trap_level); 168 goto out; 169 } 170 171 flushw_all(); 172 173 local_irq_save(flags); 174 kgdb_handle_exception(0x172, SIGTRAP, 0, regs); 175 local_irq_restore(flags); 176 out: 177 exception_exit(prev_state); 178 } 179 180 int kgdb_arch_init(void) 181 { 182 return 0; 183 } 184 185 void kgdb_arch_exit(void) 186 { 187 } 188 189 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) 190 { 191 regs->tpc = ip; 192 regs->tnpc = regs->tpc + 4; 193 } 194 195 struct kgdb_arch arch_kgdb_ops = { 196 /* Breakpoint instruction: ta 0x72 */ 197 .gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x72 }, 198 }; 199