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[net-next-2.6.git] / arch / powerpc / kernel / kgdb.c
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17ce452f
JW		 1/*
2 * PowerPC backend to the KGDB stub.
3 *
4 * 1998 (c) Michael AK Tesch (tesch@cs.wisc.edu)
5 * Copyright (C) 2003 Timesys Corporation.
6 * Copyright (C) 2004-2006 MontaVista Software, Inc.
7 * PPC64 Mods (C) 2005 Frank Rowand (frowand@mvista.com)
8 * PPC32 support restored by Vitaly Wool <vwool@ru.mvista.com> and
9 * Sergei Shtylyov <sshtylyov@ru.mvista.com>
10 * Copyright (C) 2007-2008 Wind River Systems, Inc.
11 *
12 * This file is licensed under the terms of the GNU General Public License
13 * version 2. This program as licensed "as is" without any warranty of any
14 * kind, whether express or implied.
15 */
16
17#include <linux/kernel.h>
18#include <linux/init.h>
19#include <linux/kgdb.h>
20#include <linux/smp.h>
21#include <linux/signal.h>
22#include <linux/ptrace.h>
23#include <asm/current.h>
24#include <asm/processor.h>
25#include <asm/machdep.h>
26
27/*
28 * This table contains the mapping between PowerPC hardware trap types, and
29 * signals, which are primarily what GDB understands. GDB and the kernel
30 * don't always agree on values, so we use constants taken from gdb-6.2.
31 */
32static struct hard_trap_info
33{
34 unsigned int tt; /* Trap type code for powerpc */
35 unsigned char signo; /* Signal that we map this trap into */
36} hard_trap_info[] = {
37 { 0x0100, 0x02 /* SIGINT */ }, /* system reset */
38 { 0x0200, 0x0b /* SIGSEGV */ }, /* machine check */
39 { 0x0300, 0x0b /* SIGSEGV */ }, /* data access */
40 { 0x0400, 0x0b /* SIGSEGV */ }, /* instruction access */
41 { 0x0500, 0x02 /* SIGINT */ }, /* external interrupt */
42 { 0x0600, 0x0a /* SIGBUS */ }, /* alignment */
43 { 0x0700, 0x05 /* SIGTRAP */ }, /* program check */
44 { 0x0800, 0x08 /* SIGFPE */ }, /* fp unavailable */
45 { 0x0900, 0x0e /* SIGALRM */ }, /* decrementer */
46 { 0x0c00, 0x14 /* SIGCHLD */ }, /* system call */
47#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
48 { 0x2002, 0x05 /* SIGTRAP */ }, /* debug */
49#if defined(CONFIG_FSL_BOOKE)
50 { 0x2010, 0x08 /* SIGFPE */ }, /* spe unavailable */
51 { 0x2020, 0x08 /* SIGFPE */ }, /* spe unavailable */
52 { 0x2030, 0x08 /* SIGFPE */ }, /* spe fp data */
53 { 0x2040, 0x08 /* SIGFPE */ }, /* spe fp data */
54 { 0x2050, 0x08 /* SIGFPE */ }, /* spe fp round */
55 { 0x2060, 0x0e /* SIGILL */ }, /* performace monitor */
56 { 0x2900, 0x08 /* SIGFPE */ }, /* apu unavailable */
57 { 0x3100, 0x0e /* SIGALRM */ }, /* fixed interval timer */
58 { 0x3200, 0x02 /* SIGINT */ }, /* watchdog */
59#else /* ! CONFIG_FSL_BOOKE */
60 { 0x1000, 0x0e /* SIGALRM */ }, /* prog interval timer */
61 { 0x1010, 0x0e /* SIGALRM */ }, /* fixed interval timer */
62 { 0x1020, 0x02 /* SIGINT */ }, /* watchdog */
63 { 0x2010, 0x08 /* SIGFPE */ }, /* fp unavailable */
64 { 0x2020, 0x08 /* SIGFPE */ }, /* ap unavailable */
65#endif
66#else /* ! (defined(CONFIG_40x) || defined(CONFIG_BOOKE)) */
67 { 0x0d00, 0x05 /* SIGTRAP */ }, /* single-step */
68#if defined(CONFIG_8xx)
69 { 0x1000, 0x04 /* SIGILL */ }, /* software emulation */
70#else /* ! CONFIG_8xx */
71 { 0x0f00, 0x04 /* SIGILL */ }, /* performance monitor */
72 { 0x0f20, 0x08 /* SIGFPE */ }, /* altivec unavailable */
73 { 0x1300, 0x05 /* SIGTRAP */ }, /* instruction address break */
74#if defined(CONFIG_PPC64)
75 { 0x1200, 0x05 /* SIGILL */ }, /* system error */
76 { 0x1500, 0x04 /* SIGILL */ }, /* soft patch */
77 { 0x1600, 0x04 /* SIGILL */ }, /* maintenance */
78 { 0x1700, 0x08 /* SIGFPE */ }, /* altivec assist */
79 { 0x1800, 0x04 /* SIGILL */ }, /* thermal */
80#else /* ! CONFIG_PPC64 */
81 { 0x1400, 0x02 /* SIGINT */ }, /* SMI */
82 { 0x1600, 0x08 /* SIGFPE */ }, /* altivec assist */
83 { 0x1700, 0x04 /* SIGILL */ }, /* TAU */
84 { 0x2000, 0x05 /* SIGTRAP */ }, /* run mode */
85#endif
86#endif
87#endif
88 { 0x0000, 0x00 } /* Must be last */
89};
90
91static int computeSignal(unsigned int tt)
92{
93 struct hard_trap_info *ht;
94
95 for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
96 if (ht->tt == tt)
97 return ht->signo;
98
99 return SIGHUP; /* default for things we don't know about */
100}
101
102static int kgdb_call_nmi_hook(struct pt_regs *regs)
103{
104 kgdb_nmicallback(raw_smp_processor_id(), regs);
105 return 0;
106}
107
108#ifdef CONFIG_SMP
109void kgdb_roundup_cpus(unsigned long flags)
110{
111 smp_send_debugger_break(MSG_ALL_BUT_SELF);
112}
113#endif
114
115/* KGDB functions to use existing PowerPC64 hooks. */
116static int kgdb_debugger(struct pt_regs *regs)
117{
118 return kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs);
119}
120
121static int kgdb_handle_breakpoint(struct pt_regs *regs)
122{
123 if (user_mode(regs))
124 return 0;
125
126 if (kgdb_handle_exception(0, SIGTRAP, 0, regs) != 0)
127 return 0;
128
129 if (*(u32 *) (regs->nip) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr))
130 regs->nip += 4;
131
132 return 1;
133}
134
135static int kgdb_singlestep(struct pt_regs *regs)
136{
137 struct thread_info *thread_info, *exception_thread_info;
138
139 if (user_mode(regs))
140 return 0;
141
142 /*
143 * On Book E and perhaps other processsors, singlestep is handled on
144 * the critical exception stack. This causes current_thread_info()
145 * to fail, since it it locates the thread_info by masking off
146 * the low bits of the current stack pointer. We work around
147 * this issue by copying the thread_info from the kernel stack
148 * before calling kgdb_handle_exception, and copying it back
149 * afterwards. On most processors the copy is avoided since
150 * exception_thread_info == thread_info.
151 */
152 thread_info = (struct thread_info *)(regs->gpr[1] & ~(THREAD_SIZE-1));
153 exception_thread_info = current_thread_info();
154
155 if (thread_info != exception_thread_info)
156 memcpy(exception_thread_info, thread_info, sizeof *thread_info);
157
158 kgdb_handle_exception(0, SIGTRAP, 0, regs);
159
160 if (thread_info != exception_thread_info)
161 memcpy(thread_info, exception_thread_info, sizeof *thread_info);
162
163 return 1;
164}
165
166static int kgdb_iabr_match(struct pt_regs *regs)
167{
168 if (user_mode(regs))
169 return 0;
170
171 if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0)
172 return 0;
173 return 1;
174}
175
176static int kgdb_dabr_match(struct pt_regs *regs)
177{
178 if (user_mode(regs))
179 return 0;
180
181 if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0)
182 return 0;
183 return 1;
184}
185
186#define PACK64(ptr, src) do { *(ptr++) = (src); } while (0)
187
188#define PACK32(ptr, src) do { \
189 u32 *ptr32; \
190 ptr32 = (u32 *)ptr; \
191 *(ptr32++) = (src); \
192 ptr = (unsigned long *)ptr32; \
193 } while (0)
194
195
196void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
197{
198 unsigned long *ptr = gdb_regs;
199 int reg;
200
201 memset(gdb_regs, 0, NUMREGBYTES);
202
203 for (reg = 0; reg < 32; reg++)
204 PACK64(ptr, regs->gpr[reg]);
205
206#ifdef CONFIG_FSL_BOOKE
207#ifdef CONFIG_SPE
208 for (reg = 0; reg < 32; reg++)
209 PACK64(ptr, current->thread.evr[reg]);
210#else
211 ptr += 32;
212#endif
213#else
214 /* fp registers not used by kernel, leave zero */
215 ptr += 32 * 8 / sizeof(long);
216#endif
217
218 PACK64(ptr, regs->nip);
219 PACK64(ptr, regs->msr);
220 PACK32(ptr, regs->ccr);
221 PACK64(ptr, regs->link);
222 PACK64(ptr, regs->ctr);
223 PACK32(ptr, regs->xer);
224
225 BUG_ON((unsigned long)ptr >
226 (unsigned long)(((void *)gdb_regs) + NUMREGBYTES));
227}
228
229void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
230{
231 struct pt_regs *regs = (struct pt_regs *)(p->thread.ksp +
232 STACK_FRAME_OVERHEAD);
233 unsigned long *ptr = gdb_regs;
234 int reg;
235
236 memset(gdb_regs, 0, NUMREGBYTES);
237
238 /* Regs GPR0-2 */
239 for (reg = 0; reg < 3; reg++)
240 PACK64(ptr, regs->gpr[reg]);
241
242 /* Regs GPR3-13 are caller saved, not in regs->gpr[] */
243 ptr += 11;
244
245 /* Regs GPR14-31 */
246 for (reg = 14; reg < 32; reg++)
247 PACK64(ptr, regs->gpr[reg]);
248
249#ifdef CONFIG_FSL_BOOKE
250#ifdef CONFIG_SPE
251 for (reg = 0; reg < 32; reg++)
252 PACK64(ptr, p->thread.evr[reg]);
253#else
254 ptr += 32;
255#endif
256#else
257 /* fp registers not used by kernel, leave zero */
258 ptr += 32 * 8 / sizeof(long);
259#endif
260
261 PACK64(ptr, regs->nip);
262 PACK64(ptr, regs->msr);
263 PACK32(ptr, regs->ccr);
264 PACK64(ptr, regs->link);
265 PACK64(ptr, regs->ctr);
266 PACK32(ptr, regs->xer);
267
268 BUG_ON((unsigned long)ptr >
269 (unsigned long)(((void *)gdb_regs) + NUMREGBYTES));
270}
271
272#define UNPACK64(dest, ptr) do { dest = *(ptr++); } while (0)
273
274#define UNPACK32(dest, ptr) do { \
275 u32 *ptr32; \
276 ptr32 = (u32 *)ptr; \
277 dest = *(ptr32++); \
278 ptr = (unsigned long *)ptr32; \
279 } while (0)
280
281void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
282{
283 unsigned long *ptr = gdb_regs;
284 int reg;
285#ifdef CONFIG_SPE
286 union {
287 u32 v32[2];
288 u64 v64;
289 } acc;
290#endif
291
292 for (reg = 0; reg < 32; reg++)
293 UNPACK64(regs->gpr[reg], ptr);
294
295#ifdef CONFIG_FSL_BOOKE
296#ifdef CONFIG_SPE
297 for (reg = 0; reg < 32; reg++)
298 UNPACK64(current->thread.evr[reg], ptr);
299#else
300 ptr += 32;
301#endif
302#else
303 /* fp registers not used by kernel, leave zero */
304 ptr += 32 * 8 / sizeof(int);
305#endif
306
307 UNPACK64(regs->nip, ptr);
308 UNPACK64(regs->msr, ptr);
309 UNPACK32(regs->ccr, ptr);
310 UNPACK64(regs->link, ptr);
311 UNPACK64(regs->ctr, ptr);
312 UNPACK32(regs->xer, ptr);
313
314 BUG_ON((unsigned long)ptr >
315 (unsigned long)(((void *)gdb_regs) + NUMREGBYTES));
316}
317
318/*
319 * This function does PowerPC specific procesing for interfacing to gdb.
320 */
321int kgdb_arch_handle_exception(int vector, int signo, int err_code,
322 char *remcom_in_buffer, char *remcom_out_buffer,
323 struct pt_regs *linux_regs)
324{
325 char *ptr = &remcom_in_buffer[1];
326 unsigned long addr;
327
328 switch (remcom_in_buffer[0]) {
329 /*
330 * sAA..AA Step one instruction from AA..AA
331 * This will return an error to gdb ..
332 */
333 case 's':
334 case 'c':
335 /* handle the optional parameter */
336 if (kgdb_hex2long(&ptr, &addr))
337 linux_regs->nip = addr;
338
339 atomic_set(&kgdb_cpu_doing_single_step, -1);
340 /* set the trace bit if we're stepping */
341 if (remcom_in_buffer[0] == 's') {
342#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
343 mtspr(SPRN_DBCR0,
344 mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
345 linux_regs->msr |= MSR_DE;
346#else
347 linux_regs->msr |= MSR_SE;
348#endif
349 kgdb_single_step = 1;
350 if (kgdb_contthread)
351 atomic_set(&kgdb_cpu_doing_single_step,
352 raw_smp_processor_id());
353 }
354 return 0;
355 }
356
357 return -1;
358}
359
360/*
361 * Global data
362 */
363struct kgdb_arch arch_kgdb_ops = {
364 .gdb_bpt_instr = {0x7d, 0x82, 0x10, 0x08},
365};
366
367static int kgdb_not_implemented(struct pt_regs *regs)
368{
369 return 0;
370}
371
372static void *old__debugger_ipi;
373static void *old__debugger;
374static void *old__debugger_bpt;
375static void *old__debugger_sstep;
376static void *old__debugger_iabr_match;
377static void *old__debugger_dabr_match;
378static void *old__debugger_fault_handler;
379
380int kgdb_arch_init(void)
381{
382 old__debugger_ipi = __debugger_ipi;
383 old__debugger = __debugger;
384 old__debugger_bpt = __debugger_bpt;
385 old__debugger_sstep = __debugger_sstep;
386 old__debugger_iabr_match = __debugger_iabr_match;
387 old__debugger_dabr_match = __debugger_dabr_match;
388 old__debugger_fault_handler = __debugger_fault_handler;
389
390 __debugger_ipi = kgdb_call_nmi_hook;
391 __debugger = kgdb_debugger;
392 __debugger_bpt = kgdb_handle_breakpoint;
393 __debugger_sstep = kgdb_singlestep;
394 __debugger_iabr_match = kgdb_iabr_match;
395 __debugger_dabr_match = kgdb_dabr_match;
396 __debugger_fault_handler = kgdb_not_implemented;
397
398 return 0;
399}
400
401void kgdb_arch_exit(void)
402{
403 __debugger_ipi = old__debugger_ipi;
404 __debugger = old__debugger;
405 __debugger_bpt = old__debugger_bpt;
406 __debugger_sstep = old__debugger_sstep;
407 __debugger_iabr_match = old__debugger_iabr_match;
408 __debugger_dabr_match = old__debugger_dabr_match;
409 __debugger_fault_handler = old__debugger_fault_handler;
410}
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