c868a8864117bbf0f3330ebd80150f263a3200ed
[linux-2.6.git] / arch / arm / kernel / kgdb.c
1 /*
2  * arch/arm/kernel/kgdb.c
3  *
4  * ARM KGDB support
5  *
6  * Copyright (c) 2002-2004 MontaVista Software, Inc
7  * Copyright (c) 2008 Wind River Systems, Inc.
8  *
9  * Authors:  George Davis <davis_g@mvista.com>
10  *           Deepak Saxena <dsaxena@plexity.net>
11  */
12 #include <linux/irq.h>
13 #include <linux/kgdb.h>
14 #include <asm/traps.h>
15
16 /* Make a local copy of the registers passed into the handler (bletch) */
17 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
18 {
19         int regno;
20
21         /* Initialize all to zero. */
22         for (regno = 0; regno < GDB_MAX_REGS; regno++)
23                 gdb_regs[regno] = 0;
24
25         gdb_regs[_R0]           = kernel_regs->ARM_r0;
26         gdb_regs[_R1]           = kernel_regs->ARM_r1;
27         gdb_regs[_R2]           = kernel_regs->ARM_r2;
28         gdb_regs[_R3]           = kernel_regs->ARM_r3;
29         gdb_regs[_R4]           = kernel_regs->ARM_r4;
30         gdb_regs[_R5]           = kernel_regs->ARM_r5;
31         gdb_regs[_R6]           = kernel_regs->ARM_r6;
32         gdb_regs[_R7]           = kernel_regs->ARM_r7;
33         gdb_regs[_R8]           = kernel_regs->ARM_r8;
34         gdb_regs[_R9]           = kernel_regs->ARM_r9;
35         gdb_regs[_R10]          = kernel_regs->ARM_r10;
36         gdb_regs[_FP]           = kernel_regs->ARM_fp;
37         gdb_regs[_IP]           = kernel_regs->ARM_ip;
38         gdb_regs[_SPT]          = kernel_regs->ARM_sp;
39         gdb_regs[_LR]           = kernel_regs->ARM_lr;
40         gdb_regs[_PC]           = kernel_regs->ARM_pc;
41         gdb_regs[_CPSR]         = kernel_regs->ARM_cpsr;
42 }
43
44 /* Copy local gdb registers back to kgdb regs, for later copy to kernel */
45 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
46 {
47         kernel_regs->ARM_r0     = gdb_regs[_R0];
48         kernel_regs->ARM_r1     = gdb_regs[_R1];
49         kernel_regs->ARM_r2     = gdb_regs[_R2];
50         kernel_regs->ARM_r3     = gdb_regs[_R3];
51         kernel_regs->ARM_r4     = gdb_regs[_R4];
52         kernel_regs->ARM_r5     = gdb_regs[_R5];
53         kernel_regs->ARM_r6     = gdb_regs[_R6];
54         kernel_regs->ARM_r7     = gdb_regs[_R7];
55         kernel_regs->ARM_r8     = gdb_regs[_R8];
56         kernel_regs->ARM_r9     = gdb_regs[_R9];
57         kernel_regs->ARM_r10    = gdb_regs[_R10];
58         kernel_regs->ARM_fp     = gdb_regs[_FP];
59         kernel_regs->ARM_ip     = gdb_regs[_IP];
60         kernel_regs->ARM_sp     = gdb_regs[_SPT];
61         kernel_regs->ARM_lr     = gdb_regs[_LR];
62         kernel_regs->ARM_pc     = gdb_regs[_PC];
63         kernel_regs->ARM_cpsr   = gdb_regs[_CPSR];
64 }
65
66 void
67 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
68 {
69         struct pt_regs *thread_regs;
70         int regno;
71
72         /* Just making sure... */
73         if (task == NULL)
74                 return;
75
76         /* Initialize to zero */
77         for (regno = 0; regno < GDB_MAX_REGS; regno++)
78                 gdb_regs[regno] = 0;
79
80         /* Otherwise, we have only some registers from switch_to() */
81         thread_regs             = task_pt_regs(task);
82         gdb_regs[_R0]           = thread_regs->ARM_r0;
83         gdb_regs[_R1]           = thread_regs->ARM_r1;
84         gdb_regs[_R2]           = thread_regs->ARM_r2;
85         gdb_regs[_R3]           = thread_regs->ARM_r3;
86         gdb_regs[_R4]           = thread_regs->ARM_r4;
87         gdb_regs[_R5]           = thread_regs->ARM_r5;
88         gdb_regs[_R6]           = thread_regs->ARM_r6;
89         gdb_regs[_R7]           = thread_regs->ARM_r7;
90         gdb_regs[_R8]           = thread_regs->ARM_r8;
91         gdb_regs[_R9]           = thread_regs->ARM_r9;
92         gdb_regs[_R10]          = thread_regs->ARM_r10;
93         gdb_regs[_FP]           = thread_regs->ARM_fp;
94         gdb_regs[_IP]           = thread_regs->ARM_ip;
95         gdb_regs[_SPT]          = thread_regs->ARM_sp;
96         gdb_regs[_LR]           = thread_regs->ARM_lr;
97         gdb_regs[_PC]           = thread_regs->ARM_pc;
98         gdb_regs[_CPSR]         = thread_regs->ARM_cpsr;
99 }
100
101 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
102 {
103         regs->ARM_pc = pc;
104 }
105
106 static int compiled_break;
107
108 int kgdb_arch_handle_exception(int exception_vector, int signo,
109                                int err_code, char *remcom_in_buffer,
110                                char *remcom_out_buffer,
111                                struct pt_regs *linux_regs)
112 {
113         unsigned long addr;
114         char *ptr;
115
116         switch (remcom_in_buffer[0]) {
117         case 'D':
118         case 'k':
119         case 'c':
120                 /*
121                  * Try to read optional parameter, pc unchanged if no parm.
122                  * If this was a compiled breakpoint, we need to move
123                  * to the next instruction or we will just breakpoint
124                  * over and over again.
125                  */
126                 ptr = &remcom_in_buffer[1];
127                 if (kgdb_hex2long(&ptr, &addr))
128                         linux_regs->ARM_pc = addr;
129                 else if (compiled_break == 1)
130                         linux_regs->ARM_pc += 4;
131
132                 compiled_break = 0;
133
134                 return 0;
135         }
136
137         return -1;
138 }
139
140 static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
141 {
142         kgdb_handle_exception(1, SIGTRAP, 0, regs);
143
144         return 0;
145 }
146
147 static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
148 {
149         compiled_break = 1;
150         kgdb_handle_exception(1, SIGTRAP, 0, regs);
151
152         return 0;
153 }
154
155 static struct undef_hook kgdb_brkpt_hook = {
156         .instr_mask             = 0xffffffff,
157         .instr_val              = KGDB_BREAKINST,
158         .fn                     = kgdb_brk_fn
159 };
160
161 static struct undef_hook kgdb_compiled_brkpt_hook = {
162         .instr_mask             = 0xffffffff,
163         .instr_val              = KGDB_COMPILED_BREAK,
164         .fn                     = kgdb_compiled_brk_fn
165 };
166
167 static void kgdb_call_nmi_hook(void *ignored)
168 {
169        kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
170 }
171
172 void kgdb_roundup_cpus(unsigned long flags)
173 {
174        local_irq_enable();
175        smp_call_function(kgdb_call_nmi_hook, NULL, 0);
176        local_irq_disable();
177 }
178
179 /**
180  *      kgdb_arch_init - Perform any architecture specific initalization.
181  *
182  *      This function will handle the initalization of any architecture
183  *      specific callbacks.
184  */
185 int kgdb_arch_init(void)
186 {
187         register_undef_hook(&kgdb_brkpt_hook);
188         register_undef_hook(&kgdb_compiled_brkpt_hook);
189
190         return 0;
191 }
192
193 /**
194  *      kgdb_arch_exit - Perform any architecture specific uninitalization.
195  *
196  *      This function will handle the uninitalization of any architecture
197  *      specific callbacks, for dynamic registration and unregistration.
198  */
199 void kgdb_arch_exit(void)
200 {
201         unregister_undef_hook(&kgdb_brkpt_hook);
202         unregister_undef_hook(&kgdb_compiled_brkpt_hook);
203 }
204
205 /*
206  * Register our undef instruction hooks with ARM undef core.
207  * We regsiter a hook specifically looking for the KGB break inst
208  * and we handle the normal undef case within the do_undefinstr
209  * handler.
210  */
211 struct kgdb_arch arch_kgdb_ops = {
212 #ifndef __ARMEB__
213         .gdb_bpt_instr          = {0xfe, 0xde, 0xff, 0xe7}
214 #else /* ! __ARMEB__ */
215         .gdb_bpt_instr          = {0xe7, 0xff, 0xde, 0xfe}
216 #endif
217 };