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 9 #include <asm/kdebug.h> 10 #include <asm/ptrace.h> 11 #include <asm/irq.h> 12 #include <asm/cacheflush.h> 13 14 extern unsigned long trapbase; 15 16 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) 17 { 18 struct reg_window32 *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_window32 *) regs->u_regs[UREG_FP]; 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_F31; i++) 32 gdb_regs[i] = 0; 33 34 gdb_regs[GDB_Y] = regs->y; 35 gdb_regs[GDB_PSR] = regs->psr; 36 gdb_regs[GDB_WIM] = 0; 37 gdb_regs[GDB_TBR] = (unsigned long) &trapbase; 38 gdb_regs[GDB_PC] = regs->pc; 39 gdb_regs[GDB_NPC] = regs->npc; 40 gdb_regs[GDB_FSR] = 0; 41 gdb_regs[GDB_CSR] = 0; 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 struct reg_window32 *win; 48 int i; 49 50 for (i = GDB_G0; i < GDB_G6; i++) 51 gdb_regs[i] = 0; 52 gdb_regs[GDB_G6] = (unsigned long) t; 53 gdb_regs[GDB_G7] = 0; 54 for (i = GDB_O0; i < GDB_SP; i++) 55 gdb_regs[i] = 0; 56 gdb_regs[GDB_SP] = t->ksp; 57 gdb_regs[GDB_O7] = 0; 58 59 win = (struct reg_window32 *) t->ksp; 60 for (i = 0; i < 8; i++) 61 gdb_regs[GDB_L0 + i] = win->locals[i]; 62 for (i = 0; i < 8; i++) 63 gdb_regs[GDB_I0 + i] = win->ins[i]; 64 65 for (i = GDB_F0; i <= GDB_F31; i++) 66 gdb_regs[i] = 0; 67 68 gdb_regs[GDB_Y] = 0; 69 70 gdb_regs[GDB_PSR] = t->kpsr; 71 gdb_regs[GDB_WIM] = t->kwim; 72 gdb_regs[GDB_TBR] = (unsigned long) &trapbase; 73 gdb_regs[GDB_PC] = t->kpc; 74 gdb_regs[GDB_NPC] = t->kpc + 4; 75 gdb_regs[GDB_FSR] = 0; 76 gdb_regs[GDB_CSR] = 0; 77 } 78 79 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) 80 { 81 struct reg_window32 *win; 82 int i; 83 84 for (i = 0; i < 15; i++) 85 regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i]; 86 87 /* If the PSR register is changing, we have to preserve 88 * the CWP field, otherwise window save/restore explodes. 89 */ 90 if (regs->psr != gdb_regs[GDB_PSR]) { 91 unsigned long cwp = regs->psr & PSR_CWP; 92 93 regs->psr = (gdb_regs[GDB_PSR] & ~PSR_CWP) | cwp; 94 } 95 96 regs->pc = gdb_regs[GDB_PC]; 97 regs->npc = gdb_regs[GDB_NPC]; 98 regs->y = gdb_regs[GDB_Y]; 99 100 win = (struct reg_window32 *) regs->u_regs[UREG_FP]; 101 for (i = 0; i < 8; i++) 102 win->locals[i] = gdb_regs[GDB_L0 + i]; 103 for (i = 0; i < 8; i++) 104 win->ins[i] = gdb_regs[GDB_I0 + i]; 105 } 106 107 int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, 108 char *remcomInBuffer, char *remcomOutBuffer, 109 struct pt_regs *linux_regs) 110 { 111 unsigned long addr; 112 char *ptr; 113 114 switch (remcomInBuffer[0]) { 115 case 'c': 116 /* try to read optional parameter, pc unchanged if no parm */ 117 ptr = &remcomInBuffer[1]; 118 if (kgdb_hex2long(&ptr, &addr)) { 119 linux_regs->pc = addr; 120 linux_regs->npc = addr + 4; 121 } 122 /* fallthru */ 123 124 case 'D': 125 case 'k': 126 if (linux_regs->pc == (unsigned long) arch_kgdb_breakpoint) { 127 linux_regs->pc = linux_regs->npc; 128 linux_regs->npc += 4; 129 } 130 return 0; 131 } 132 return -1; 133 } 134 135 extern void do_hw_interrupt(struct pt_regs *regs, unsigned long type); 136 137 asmlinkage void kgdb_trap(struct pt_regs *regs) 138 { 139 unsigned long flags; 140 141 if (user_mode(regs)) { 142 do_hw_interrupt(regs, 0xfd); 143 return; 144 } 145 146 flushw_all(); 147 148 local_irq_save(flags); 149 kgdb_handle_exception(0x172, SIGTRAP, 0, regs); 150 local_irq_restore(flags); 151 } 152 153 int kgdb_arch_init(void) 154 { 155 return 0; 156 } 157 158 void kgdb_arch_exit(void) 159 { 160 } 161 162 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) 163 { 164 regs->pc = ip; 165 regs->npc = regs->pc + 4; 166 } 167 168 struct kgdb_arch arch_kgdb_ops = { 169 /* Breakpoint instruction: ta 0x7d */ 170 .gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x7d }, 171 }; 172