1 /* kgdb.c: KGDB support for 32-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/sched.h> 9 10 #include <asm/kdebug.h> 11 #include <asm/ptrace.h> 12 #include <asm/irq.h> 13 #include <asm/cacheflush.h> 14 15 extern unsigned long trapbase; 16 17 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) 18 { 19 struct reg_window32 *win; 20 int i; 21 22 gdb_regs[GDB_G0] = 0; 23 for (i = 0; i < 15; i++) 24 gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i]; 25 26 win = (struct reg_window32 *) regs->u_regs[UREG_FP]; 27 for (i = 0; i < 8; i++) 28 gdb_regs[GDB_L0 + i] = win->locals[i]; 29 for (i = 0; i < 8; i++) 30 gdb_regs[GDB_I0 + i] = win->ins[i]; 31 32 for (i = GDB_F0; i <= GDB_F31; i++) 33 gdb_regs[i] = 0; 34 35 gdb_regs[GDB_Y] = regs->y; 36 gdb_regs[GDB_PSR] = regs->psr; 37 gdb_regs[GDB_WIM] = 0; 38 gdb_regs[GDB_TBR] = (unsigned long) &trapbase; 39 gdb_regs[GDB_PC] = regs->pc; 40 gdb_regs[GDB_NPC] = regs->npc; 41 gdb_regs[GDB_FSR] = 0; 42 gdb_regs[GDB_CSR] = 0; 43 } 44 45 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) 46 { 47 struct thread_info *t = task_thread_info(p); 48 struct reg_window32 *win; 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] = 0; 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_window32 *) t->ksp; 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_F31; i++) 67 gdb_regs[i] = 0; 68 69 gdb_regs[GDB_Y] = 0; 70 71 gdb_regs[GDB_PSR] = t->kpsr; 72 gdb_regs[GDB_WIM] = t->kwim; 73 gdb_regs[GDB_TBR] = (unsigned long) &trapbase; 74 gdb_regs[GDB_PC] = t->kpc; 75 gdb_regs[GDB_NPC] = t->kpc + 4; 76 gdb_regs[GDB_FSR] = 0; 77 gdb_regs[GDB_CSR] = 0; 78 } 79 80 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) 81 { 82 struct reg_window32 *win; 83 int i; 84 85 for (i = 0; i < 15; i++) 86 regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i]; 87 88 /* If the PSR register is changing, we have to preserve 89 * the CWP field, otherwise window save/restore explodes. 90 */ 91 if (regs->psr != gdb_regs[GDB_PSR]) { 92 unsigned long cwp = regs->psr & PSR_CWP; 93 94 regs->psr = (gdb_regs[GDB_PSR] & ~PSR_CWP) | cwp; 95 } 96 97 regs->pc = gdb_regs[GDB_PC]; 98 regs->npc = gdb_regs[GDB_NPC]; 99 regs->y = gdb_regs[GDB_Y]; 100 101 win = (struct reg_window32 *) regs->u_regs[UREG_FP]; 102 for (i = 0; i < 8; i++) 103 win->locals[i] = gdb_regs[GDB_L0 + i]; 104 for (i = 0; i < 8; i++) 105 win->ins[i] = gdb_regs[GDB_I0 + i]; 106 } 107 108 int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, 109 char *remcomInBuffer, char *remcomOutBuffer, 110 struct pt_regs *linux_regs) 111 { 112 unsigned long addr; 113 char *ptr; 114 115 switch (remcomInBuffer[0]) { 116 case 'c': 117 /* try to read optional parameter, pc unchanged if no parm */ 118 ptr = &remcomInBuffer[1]; 119 if (kgdb_hex2long(&ptr, &addr)) { 120 linux_regs->pc = addr; 121 linux_regs->npc = addr + 4; 122 } 123 /* fallthru */ 124 125 case 'D': 126 case 'k': 127 if (linux_regs->pc == (unsigned long) arch_kgdb_breakpoint) { 128 linux_regs->pc = linux_regs->npc; 129 linux_regs->npc += 4; 130 } 131 return 0; 132 } 133 return -1; 134 } 135 136 extern void do_hw_interrupt(struct pt_regs *regs, unsigned long type); 137 138 asmlinkage void kgdb_trap(struct pt_regs *regs) 139 { 140 unsigned long flags; 141 142 if (user_mode(regs)) { 143 do_hw_interrupt(regs, 0xfd); 144 return; 145 } 146 147 flushw_all(); 148 149 local_irq_save(flags); 150 kgdb_handle_exception(0x172, SIGTRAP, 0, regs); 151 local_irq_restore(flags); 152 } 153 154 int kgdb_arch_init(void) 155 { 156 return 0; 157 } 158 159 void kgdb_arch_exit(void) 160 { 161 } 162 163 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) 164 { 165 regs->pc = ip; 166 regs->npc = regs->pc + 4; 167 } 168 169 struct kgdb_arch arch_kgdb_ops = { 170 /* Breakpoint instruction: ta 0x7d */ 171 .gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x7d }, 172 }; 173