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