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 #include "kernel.h" 17 18 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) 19 { 20 struct reg_window *win; 21 int i; 22 23 gdb_regs[GDB_G0] = 0; 24 for (i = 0; i < 15; i++) 25 gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i]; 26 27 win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS); 28 for (i = 0; i < 8; i++) 29 gdb_regs[GDB_L0 + i] = win->locals[i]; 30 for (i = 0; i < 8; i++) 31 gdb_regs[GDB_I0 + i] = win->ins[i]; 32 33 for (i = GDB_F0; i <= GDB_F62; i++) 34 gdb_regs[i] = 0; 35 36 gdb_regs[GDB_PC] = regs->tpc; 37 gdb_regs[GDB_NPC] = regs->tnpc; 38 gdb_regs[GDB_STATE] = regs->tstate; 39 gdb_regs[GDB_FSR] = 0; 40 gdb_regs[GDB_FPRS] = 0; 41 gdb_regs[GDB_Y] = regs->y; 42 } 43 44 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) 45 { 46 struct thread_info *t = task_thread_info(p); 47 extern unsigned int switch_to_pc; 48 extern unsigned int ret_from_fork; 49 struct reg_window *win; 50 unsigned long pc, cwp; 51 int i; 52 53 for (i = GDB_G0; i < GDB_G6; i++) 54 gdb_regs[i] = 0; 55 gdb_regs[GDB_G6] = (unsigned long) t; 56 gdb_regs[GDB_G7] = (unsigned long) p; 57 for (i = GDB_O0; i < GDB_SP; i++) 58 gdb_regs[i] = 0; 59 gdb_regs[GDB_SP] = t->ksp; 60 gdb_regs[GDB_O7] = 0; 61 62 win = (struct reg_window *) (t->ksp + STACK_BIAS); 63 for (i = 0; i < 8; i++) 64 gdb_regs[GDB_L0 + i] = win->locals[i]; 65 for (i = 0; i < 8; i++) 66 gdb_regs[GDB_I0 + i] = win->ins[i]; 67 68 for (i = GDB_F0; i <= GDB_F62; i++) 69 gdb_regs[i] = 0; 70 71 if (t->new_child) 72 pc = (unsigned long) &ret_from_fork; 73 else 74 pc = (unsigned long) &switch_to_pc; 75 76 gdb_regs[GDB_PC] = pc; 77 gdb_regs[GDB_NPC] = pc + 4; 78 79 cwp = __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP]; 80 81 gdb_regs[GDB_STATE] = (TSTATE_PRIV | TSTATE_IE | cwp); 82 gdb_regs[GDB_FSR] = 0; 83 gdb_regs[GDB_FPRS] = 0; 84 gdb_regs[GDB_Y] = 0; 85 } 86 87 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) 88 { 89 struct reg_window *win; 90 int i; 91 92 for (i = 0; i < 15; i++) 93 regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i]; 94 95 /* If the TSTATE register is changing, we have to preserve 96 * the CWP field, otherwise window save/restore explodes. 97 */ 98 if (regs->tstate != gdb_regs[GDB_STATE]) { 99 unsigned long cwp = regs->tstate & TSTATE_CWP; 100 101 regs->tstate = (gdb_regs[GDB_STATE] & ~TSTATE_CWP) | cwp; 102 } 103 104 regs->tpc = gdb_regs[GDB_PC]; 105 regs->tnpc = gdb_regs[GDB_NPC]; 106 regs->y = gdb_regs[GDB_Y]; 107 108 win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS); 109 for (i = 0; i < 8; i++) 110 win->locals[i] = gdb_regs[GDB_L0 + i]; 111 for (i = 0; i < 8; i++) 112 win->ins[i] = gdb_regs[GDB_I0 + i]; 113 } 114 115 #ifdef CONFIG_SMP 116 void __irq_entry smp_kgdb_capture_client(int irq, struct pt_regs *regs) 117 { 118 unsigned long flags; 119 120 __asm__ __volatile__("rdpr %%pstate, %0\n\t" 121 "wrpr %0, %1, %%pstate" 122 : "=r" (flags) 123 : "i" (PSTATE_IE)); 124 125 flushw_all(); 126 127 if (atomic_read(&kgdb_active) != -1) 128 kgdb_nmicallback(raw_smp_processor_id(), regs); 129 130 __asm__ __volatile__("wrpr %0, 0, %%pstate" 131 : : "r" (flags)); 132 } 133 #endif 134 135 int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, 136 char *remcomInBuffer, char *remcomOutBuffer, 137 struct pt_regs *linux_regs) 138 { 139 unsigned long addr; 140 char *ptr; 141 142 switch (remcomInBuffer[0]) { 143 case 'c': 144 /* try to read optional parameter, pc unchanged if no parm */ 145 ptr = &remcomInBuffer[1]; 146 if (kgdb_hex2long(&ptr, &addr)) { 147 linux_regs->tpc = addr; 148 linux_regs->tnpc = addr + 4; 149 } 150 /* fallthru */ 151 152 case 'D': 153 case 'k': 154 if (linux_regs->tpc == (unsigned long) arch_kgdb_breakpoint) { 155 linux_regs->tpc = linux_regs->tnpc; 156 linux_regs->tnpc += 4; 157 } 158 return 0; 159 } 160 return -1; 161 } 162 163 asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs) 164 { 165 enum ctx_state prev_state = exception_enter(); 166 unsigned long flags; 167 168 if (user_mode(regs)) { 169 bad_trap(regs, trap_level); 170 goto out; 171 } 172 173 flushw_all(); 174 175 local_irq_save(flags); 176 kgdb_handle_exception(0x172, SIGTRAP, 0, regs); 177 local_irq_restore(flags); 178 out: 179 exception_exit(prev_state); 180 } 181 182 int kgdb_arch_init(void) 183 { 184 return 0; 185 } 186 187 void kgdb_arch_exit(void) 188 { 189 } 190 191 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) 192 { 193 regs->tpc = ip; 194 regs->tnpc = regs->tpc + 4; 195 } 196 197 struct kgdb_arch arch_kgdb_ops = { 198 /* Breakpoint instruction: ta 0x72 */ 199 .gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x72 }, 200 }; 201