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