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 #include "kernel.h" 16 #include "entry.h" 17 18 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) 19 { 20 struct reg_window32 *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_window32 *) regs->u_regs[UREG_FP]; 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_F31; i++) 34 gdb_regs[i] = 0; 35 36 gdb_regs[GDB_Y] = regs->y; 37 gdb_regs[GDB_PSR] = regs->psr; 38 gdb_regs[GDB_WIM] = 0; 39 gdb_regs[GDB_TBR] = (unsigned long) &trapbase; 40 gdb_regs[GDB_PC] = regs->pc; 41 gdb_regs[GDB_NPC] = regs->npc; 42 gdb_regs[GDB_FSR] = 0; 43 gdb_regs[GDB_CSR] = 0; 44 } 45 46 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) 47 { 48 struct thread_info *t = task_thread_info(p); 49 struct reg_window32 *win; 50 int i; 51 52 for (i = GDB_G0; i < GDB_G6; i++) 53 gdb_regs[i] = 0; 54 gdb_regs[GDB_G6] = (unsigned long) t; 55 gdb_regs[GDB_G7] = 0; 56 for (i = GDB_O0; i < GDB_SP; i++) 57 gdb_regs[i] = 0; 58 gdb_regs[GDB_SP] = t->ksp; 59 gdb_regs[GDB_O7] = 0; 60 61 win = (struct reg_window32 *) t->ksp; 62 for (i = 0; i < 8; i++) 63 gdb_regs[GDB_L0 + i] = win->locals[i]; 64 for (i = 0; i < 8; i++) 65 gdb_regs[GDB_I0 + i] = win->ins[i]; 66 67 for (i = GDB_F0; i <= GDB_F31; i++) 68 gdb_regs[i] = 0; 69 70 gdb_regs[GDB_Y] = 0; 71 72 gdb_regs[GDB_PSR] = t->kpsr; 73 gdb_regs[GDB_WIM] = t->kwim; 74 gdb_regs[GDB_TBR] = (unsigned long) &trapbase; 75 gdb_regs[GDB_PC] = t->kpc; 76 gdb_regs[GDB_NPC] = t->kpc + 4; 77 gdb_regs[GDB_FSR] = 0; 78 gdb_regs[GDB_CSR] = 0; 79 } 80 81 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) 82 { 83 struct reg_window32 *win; 84 int i; 85 86 for (i = 0; i < 15; i++) 87 regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i]; 88 89 /* If the PSR register is changing, we have to preserve 90 * the CWP field, otherwise window save/restore explodes. 91 */ 92 if (regs->psr != gdb_regs[GDB_PSR]) { 93 unsigned long cwp = regs->psr & PSR_CWP; 94 95 regs->psr = (gdb_regs[GDB_PSR] & ~PSR_CWP) | cwp; 96 } 97 98 regs->pc = gdb_regs[GDB_PC]; 99 regs->npc = gdb_regs[GDB_NPC]; 100 regs->y = gdb_regs[GDB_Y]; 101 102 win = (struct reg_window32 *) regs->u_regs[UREG_FP]; 103 for (i = 0; i < 8; i++) 104 win->locals[i] = gdb_regs[GDB_L0 + i]; 105 for (i = 0; i < 8; i++) 106 win->ins[i] = gdb_regs[GDB_I0 + i]; 107 } 108 109 int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, 110 char *remcomInBuffer, char *remcomOutBuffer, 111 struct pt_regs *linux_regs) 112 { 113 unsigned long addr; 114 char *ptr; 115 116 switch (remcomInBuffer[0]) { 117 case 'c': 118 /* try to read optional parameter, pc unchanged if no parm */ 119 ptr = &remcomInBuffer[1]; 120 if (kgdb_hex2long(&ptr, &addr)) { 121 linux_regs->pc = addr; 122 linux_regs->npc = addr + 4; 123 } 124 /* fallthru */ 125 126 case 'D': 127 case 'k': 128 if (linux_regs->pc == (unsigned long) arch_kgdb_breakpoint) { 129 linux_regs->pc = linux_regs->npc; 130 linux_regs->npc += 4; 131 } 132 return 0; 133 } 134 return -1; 135 } 136 137 asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs) 138 { 139 unsigned long flags; 140 141 if (user_mode(regs)) { 142 do_hw_interrupt(regs, trap_level); 143 return; 144 } 145 146 flushw_all(); 147 148 local_irq_save(flags); 149 kgdb_handle_exception(trap_level, 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