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x86/xen: resume timer irqs early
[linux/fpc-iii.git] / arch / powerpc / kernel / kgdb.c
blobc1eef241017a1224bd424398d05b95f03cd38079
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 <linux/kdebug.h>
24 #include <asm/current.h>
25 #include <asm/processor.h>
26 #include <asm/machdep.h>
27 #include <asm/debug.h>
28 #include <linux/slab.h>
29
30 /*
31 * This table contains the mapping between PowerPC hardware trap types, and
32 * signals, which are primarily what GDB understands. GDB and the kernel
33 * don't always agree on values, so we use constants taken from gdb-6.2.
34 */
35 static struct hard_trap_info
36 {
37 unsigned int tt; /* Trap type code for powerpc */
38 unsigned char signo; /* Signal that we map this trap into */
39 } hard_trap_info[] = {
40 { 0x0100, 0x02 /* SIGINT */ }, /* system reset */
41 { 0x0200, 0x0b /* SIGSEGV */ }, /* machine check */
42 { 0x0300, 0x0b /* SIGSEGV */ }, /* data access */
43 { 0x0400, 0x0b /* SIGSEGV */ }, /* instruction access */
44 { 0x0500, 0x02 /* SIGINT */ }, /* external interrupt */
45 { 0x0600, 0x0a /* SIGBUS */ }, /* alignment */
46 { 0x0700, 0x05 /* SIGTRAP */ }, /* program check */
47 { 0x0800, 0x08 /* SIGFPE */ }, /* fp unavailable */
48 { 0x0900, 0x0e /* SIGALRM */ }, /* decrementer */
49 { 0x0c00, 0x14 /* SIGCHLD */ }, /* system call */
50 #if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
51 { 0x2002, 0x05 /* SIGTRAP */ }, /* debug */
52 #if defined(CONFIG_FSL_BOOKE)
53 { 0x2010, 0x08 /* SIGFPE */ }, /* spe unavailable */
54 { 0x2020, 0x08 /* SIGFPE */ }, /* spe unavailable */
55 { 0x2030, 0x08 /* SIGFPE */ }, /* spe fp data */
56 { 0x2040, 0x08 /* SIGFPE */ }, /* spe fp data */
57 { 0x2050, 0x08 /* SIGFPE */ }, /* spe fp round */
58 { 0x2060, 0x0e /* SIGILL */ }, /* performance monitor */
59 { 0x2900, 0x08 /* SIGFPE */ }, /* apu unavailable */
60 { 0x3100, 0x0e /* SIGALRM */ }, /* fixed interval timer */
61 { 0x3200, 0x02 /* SIGINT */ }, /* watchdog */
62 #else /* ! CONFIG_FSL_BOOKE */
63 { 0x1000, 0x0e /* SIGALRM */ }, /* prog interval timer */
64 { 0x1010, 0x0e /* SIGALRM */ }, /* fixed interval timer */
65 { 0x1020, 0x02 /* SIGINT */ }, /* watchdog */
66 { 0x2010, 0x08 /* SIGFPE */ }, /* fp unavailable */
67 { 0x2020, 0x08 /* SIGFPE */ }, /* ap unavailable */
68 #endif
69 #else /* ! (defined(CONFIG_40x) || defined(CONFIG_BOOKE)) */
70 { 0x0d00, 0x05 /* SIGTRAP */ }, /* single-step */
71 #if defined(CONFIG_8xx)
72 { 0x1000, 0x04 /* SIGILL */ }, /* software emulation */
73 #else /* ! CONFIG_8xx */
74 { 0x0f00, 0x04 /* SIGILL */ }, /* performance monitor */
75 { 0x0f20, 0x08 /* SIGFPE */ }, /* altivec unavailable */
76 { 0x1300, 0x05 /* SIGTRAP */ }, /* instruction address break */
77 #if defined(CONFIG_PPC64)
78 { 0x1200, 0x05 /* SIGILL */ }, /* system error */
79 { 0x1500, 0x04 /* SIGILL */ }, /* soft patch */
80 { 0x1600, 0x04 /* SIGILL */ }, /* maintenance */
81 { 0x1700, 0x08 /* SIGFPE */ }, /* altivec assist */
82 { 0x1800, 0x04 /* SIGILL */ }, /* thermal */
83 #else /* ! CONFIG_PPC64 */
84 { 0x1400, 0x02 /* SIGINT */ }, /* SMI */
85 { 0x1600, 0x08 /* SIGFPE */ }, /* altivec assist */
86 { 0x1700, 0x04 /* SIGILL */ }, /* TAU */
87 { 0x2000, 0x05 /* SIGTRAP */ }, /* run mode */
88 #endif
89 #endif
90 #endif
91 { 0x0000, 0x00 } /* Must be last */
92 };
93
94 static int computeSignal(unsigned int tt)
95 {
96 struct hard_trap_info *ht;
97
98 for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
99 if (ht->tt == tt)
100 return ht->signo;
101
102 return SIGHUP; /* default for things we don't know about */
103 }
104
105 /**
106 *
107 * kgdb_skipexception - Bail out of KGDB when we've been triggered.
108 * @exception: Exception vector number
109 * @regs: Current &struct pt_regs.
110 *
111 * On some architectures we need to skip a breakpoint exception when
112 * it occurs after a breakpoint has been removed.
113 *
114 */
115 int kgdb_skipexception(int exception, struct pt_regs *regs)
116 {
117 return kgdb_isremovedbreak(regs->nip);
118 }
119
120 static int kgdb_call_nmi_hook(struct pt_regs *regs)
121 {
122 kgdb_nmicallback(raw_smp_processor_id(), regs);
123 return 0;
124 }
125
126 #ifdef CONFIG_SMP
127 void kgdb_roundup_cpus(unsigned long flags)
128 {
129 smp_send_debugger_break();
130 }
131 #endif
132
133 /* KGDB functions to use existing PowerPC64 hooks. */
134 static int kgdb_debugger(struct pt_regs *regs)
135 {
136 return !kgdb_handle_exception(1, computeSignal(TRAP(regs)),
137 DIE_OOPS, regs);
138 }
139
140 static int kgdb_handle_breakpoint(struct pt_regs *regs)
141 {
142 if (user_mode(regs))
143 return 0;
144
145 if (kgdb_handle_exception(1, SIGTRAP, 0, regs) != 0)
146 return 0;
147
148 if (*(u32 *) (regs->nip) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr))
149 regs->nip += BREAK_INSTR_SIZE;
150
151 return 1;
152 }
153
154 static int kgdb_singlestep(struct pt_regs *regs)
155 {
156 struct thread_info *thread_info, *exception_thread_info;
157 struct thread_info *backup_current_thread_info;
158
159 if (user_mode(regs))
160 return 0;
161
162 backup_current_thread_info = kmalloc(sizeof(struct thread_info), GFP_KERNEL);
163 /*
164 * On Book E and perhaps other processors, singlestep is handled on
165 * the critical exception stack. This causes current_thread_info()
166 * to fail, since it it locates the thread_info by masking off
167 * the low bits of the current stack pointer. We work around
168 * this issue by copying the thread_info from the kernel stack
169 * before calling kgdb_handle_exception, and copying it back
170 * afterwards. On most processors the copy is avoided since
171 * exception_thread_info == thread_info.
172 */
173 thread_info = (struct thread_info *)(regs->gpr[1] & ~(THREAD_SIZE-1));
174 exception_thread_info = current_thread_info();
175
176 if (thread_info != exception_thread_info) {
177 /* Save the original current_thread_info. */
178 memcpy(backup_current_thread_info, exception_thread_info, sizeof *thread_info);
179 memcpy(exception_thread_info, thread_info, sizeof *thread_info);
180 }
181
182 kgdb_handle_exception(0, SIGTRAP, 0, regs);
183
184 if (thread_info != exception_thread_info)
185 /* Restore current_thread_info lastly. */
186 memcpy(exception_thread_info, backup_current_thread_info, sizeof *thread_info);
187
188 kfree(backup_current_thread_info);
189 return 1;
190 }
191
192 static int kgdb_iabr_match(struct pt_regs *regs)
193 {
194 if (user_mode(regs))
195 return 0;
196
197 if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0)
198 return 0;
199 return 1;
200 }
201
202 static int kgdb_break_match(struct pt_regs *regs)
203 {
204 if (user_mode(regs))
205 return 0;
206
207 if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0)
208 return 0;
209 return 1;
210 }
211
212 #define PACK64(ptr, src) do { *(ptr++) = (src); } while (0)
213
214 #define PACK32(ptr, src) do { \
215 u32 *ptr32; \
216 ptr32 = (u32 *)ptr; \
217 *(ptr32++) = (src); \
218 ptr = (unsigned long *)ptr32; \
219 } while (0)
220
221 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
222 {
223 struct pt_regs *regs = (struct pt_regs *)(p->thread.ksp +
224 STACK_FRAME_OVERHEAD);
225 unsigned long *ptr = gdb_regs;
226 int reg;
227
228 memset(gdb_regs, 0, NUMREGBYTES);
229
230 /* Regs GPR0-2 */
231 for (reg = 0; reg < 3; reg++)
232 PACK64(ptr, regs->gpr[reg]);
233
234 /* Regs GPR3-13 are caller saved, not in regs->gpr[] */
235 ptr += 11;
236
237 /* Regs GPR14-31 */
238 for (reg = 14; reg < 32; reg++)
239 PACK64(ptr, regs->gpr[reg]);
240
241 #ifdef CONFIG_FSL_BOOKE
242 #ifdef CONFIG_SPE
243 for (reg = 0; reg < 32; reg++)
244 PACK64(ptr, p->thread.evr[reg]);
245 #else
246 ptr += 32;
247 #endif
248 #else
249 /* fp registers not used by kernel, leave zero */
250 ptr += 32 * 8 / sizeof(long);
251 #endif
252
253 PACK64(ptr, regs->nip);
254 PACK64(ptr, regs->msr);
255 PACK32(ptr, regs->ccr);
256 PACK64(ptr, regs->link);
257 PACK64(ptr, regs->ctr);
258 PACK32(ptr, regs->xer);
259
260 BUG_ON((unsigned long)ptr >
261 (unsigned long)(((void *)gdb_regs) + NUMREGBYTES));
262 }
263
264 #define GDB_SIZEOF_REG sizeof(unsigned long)
265 #define GDB_SIZEOF_REG_U32 sizeof(u32)
266
267 #ifdef CONFIG_FSL_BOOKE
268 #define GDB_SIZEOF_FLOAT_REG sizeof(unsigned long)
269 #else
270 #define GDB_SIZEOF_FLOAT_REG sizeof(u64)
271 #endif
272
273 struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
274 {
275 { "r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[0]) },
276 { "r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[1]) },
277 { "r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[2]) },
278 { "r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[3]) },
279 { "r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[4]) },
280 { "r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[5]) },
281 { "r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[6]) },
282 { "r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[7]) },
283 { "r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[8]) },
284 { "r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[9]) },
285 { "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[10]) },
286 { "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[11]) },
287 { "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[12]) },
288 { "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[13]) },
289 { "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[14]) },
290 { "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[15]) },
291 { "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[16]) },
292 { "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[17]) },
293 { "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[18]) },
294 { "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[19]) },
295 { "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[20]) },
296 { "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[21]) },
297 { "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[22]) },
298 { "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[23]) },
299 { "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[24]) },
300 { "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[25]) },
301 { "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[26]) },
302 { "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[27]) },
303 { "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[28]) },
304 { "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[29]) },
305 { "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[30]) },
306 { "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, gpr[31]) },
307
308 { "f0", GDB_SIZEOF_FLOAT_REG, 0 },
309 { "f1", GDB_SIZEOF_FLOAT_REG, 1 },
310 { "f2", GDB_SIZEOF_FLOAT_REG, 2 },
311 { "f3", GDB_SIZEOF_FLOAT_REG, 3 },
312 { "f4", GDB_SIZEOF_FLOAT_REG, 4 },
313 { "f5", GDB_SIZEOF_FLOAT_REG, 5 },
314 { "f6", GDB_SIZEOF_FLOAT_REG, 6 },
315 { "f7", GDB_SIZEOF_FLOAT_REG, 7 },
316 { "f8", GDB_SIZEOF_FLOAT_REG, 8 },
317 { "f9", GDB_SIZEOF_FLOAT_REG, 9 },
318 { "f10", GDB_SIZEOF_FLOAT_REG, 10 },
319 { "f11", GDB_SIZEOF_FLOAT_REG, 11 },
320 { "f12", GDB_SIZEOF_FLOAT_REG, 12 },
321 { "f13", GDB_SIZEOF_FLOAT_REG, 13 },
322 { "f14", GDB_SIZEOF_FLOAT_REG, 14 },
323 { "f15", GDB_SIZEOF_FLOAT_REG, 15 },
324 { "f16", GDB_SIZEOF_FLOAT_REG, 16 },
325 { "f17", GDB_SIZEOF_FLOAT_REG, 17 },
326 { "f18", GDB_SIZEOF_FLOAT_REG, 18 },
327 { "f19", GDB_SIZEOF_FLOAT_REG, 19 },
328 { "f20", GDB_SIZEOF_FLOAT_REG, 20 },
329 { "f21", GDB_SIZEOF_FLOAT_REG, 21 },
330 { "f22", GDB_SIZEOF_FLOAT_REG, 22 },
331 { "f23", GDB_SIZEOF_FLOAT_REG, 23 },
332 { "f24", GDB_SIZEOF_FLOAT_REG, 24 },
333 { "f25", GDB_SIZEOF_FLOAT_REG, 25 },
334 { "f26", GDB_SIZEOF_FLOAT_REG, 26 },
335 { "f27", GDB_SIZEOF_FLOAT_REG, 27 },
336 { "f28", GDB_SIZEOF_FLOAT_REG, 28 },
337 { "f29", GDB_SIZEOF_FLOAT_REG, 29 },
338 { "f30", GDB_SIZEOF_FLOAT_REG, 30 },
339 { "f31", GDB_SIZEOF_FLOAT_REG, 31 },
340
341 { "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, nip) },
342 { "msr", GDB_SIZEOF_REG, offsetof(struct pt_regs, msr) },
343 { "cr", GDB_SIZEOF_REG_U32, offsetof(struct pt_regs, ccr) },
344 { "lr", GDB_SIZEOF_REG, offsetof(struct pt_regs, link) },
345 { "ctr", GDB_SIZEOF_REG_U32, offsetof(struct pt_regs, ctr) },
346 { "xer", GDB_SIZEOF_REG, offsetof(struct pt_regs, xer) },
347 };
348
349 char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
350 {
351 if (regno >= DBG_MAX_REG_NUM || regno < 0)
352 return NULL;
353
354 if (regno < 32 || regno >= 64)
355 /* First 0 -> 31 gpr registers*/
356 /* pc, msr, ls... registers 64 -> 69 */
357 memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
358 dbg_reg_def[regno].size);
359
360 if (regno >= 32 && regno < 64) {
361 /* FP registers 32 -> 63 */
362 #if defined(CONFIG_FSL_BOOKE) && defined(CONFIG_SPE)
363 if (current)
364 memcpy(mem, &current->thread.evr[regno-32],
365 dbg_reg_def[regno].size);
366 #else
367 /* fp registers not used by kernel, leave zero */
368 memset(mem, 0, dbg_reg_def[regno].size);
369 #endif
370 }
371
372 return dbg_reg_def[regno].name;
373 }
374
375 int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
376 {
377 if (regno >= DBG_MAX_REG_NUM || regno < 0)
378 return -EINVAL;
379
380 if (regno < 32 || regno >= 64)
381 /* First 0 -> 31 gpr registers*/
382 /* pc, msr, ls... registers 64 -> 69 */
383 memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
384 dbg_reg_def[regno].size);
385
386 if (regno >= 32 && regno < 64) {
387 /* FP registers 32 -> 63 */
388 #if defined(CONFIG_FSL_BOOKE) && defined(CONFIG_SPE)
389 memcpy(&current->thread.evr[regno-32], mem,
390 dbg_reg_def[regno].size);
391 #else
392 /* fp registers not used by kernel, leave zero */
393 return 0;
394 #endif
395 }
396
397 return 0;
398 }
399
400 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
401 {
402 regs->nip = pc;
403 }
404
405 /*
406 * This function does PowerPC specific procesing for interfacing to gdb.
407 */
408 int kgdb_arch_handle_exception(int vector, int signo, int err_code,
409 char *remcom_in_buffer, char *remcom_out_buffer,
410 struct pt_regs *linux_regs)
411 {
412 char *ptr = &remcom_in_buffer[1];
413 unsigned long addr;
414
415 switch (remcom_in_buffer[0]) {
416 /*
417 * sAA..AA Step one instruction from AA..AA
418 * This will return an error to gdb ..
419 */
420 case 's':
421 case 'c':
422 /* handle the optional parameter */
423 if (kgdb_hex2long(&ptr, &addr))
424 linux_regs->nip = addr;
425
426 atomic_set(&kgdb_cpu_doing_single_step, -1);
427 /* set the trace bit if we're stepping */
428 if (remcom_in_buffer[0] == 's') {
429 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
430 mtspr(SPRN_DBCR0,
431 mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
432 linux_regs->msr |= MSR_DE;
433 #else
434 linux_regs->msr |= MSR_SE;
435 #endif
436 atomic_set(&kgdb_cpu_doing_single_step,
437 raw_smp_processor_id());
438 }
439 return 0;
440 }
441
442 return -1;
443 }
444
445 /*
446 * Global data
447 */
448 struct kgdb_arch arch_kgdb_ops = {
449 .gdb_bpt_instr = {0x7d, 0x82, 0x10, 0x08},
450 };
451
452 static int kgdb_not_implemented(struct pt_regs *regs)
453 {
454 return 0;
455 }
456
457 static void *old__debugger_ipi;
458 static void *old__debugger;
459 static void *old__debugger_bpt;
460 static void *old__debugger_sstep;
461 static void *old__debugger_iabr_match;
462 static void *old__debugger_break_match;
463 static void *old__debugger_fault_handler;
464
465 int kgdb_arch_init(void)
466 {
467 old__debugger_ipi = __debugger_ipi;
468 old__debugger = __debugger;
469 old__debugger_bpt = __debugger_bpt;
470 old__debugger_sstep = __debugger_sstep;
471 old__debugger_iabr_match = __debugger_iabr_match;
472 old__debugger_break_match = __debugger_break_match;
473 old__debugger_fault_handler = __debugger_fault_handler;
474
475 __debugger_ipi = kgdb_call_nmi_hook;
476 __debugger = kgdb_debugger;
477 __debugger_bpt = kgdb_handle_breakpoint;
478 __debugger_sstep = kgdb_singlestep;
479 __debugger_iabr_match = kgdb_iabr_match;
480 __debugger_break_match = kgdb_break_match;
481 __debugger_fault_handler = kgdb_not_implemented;
482
483 return 0;
484 }
485
486 void kgdb_arch_exit(void)
487 {
488 __debugger_ipi = old__debugger_ipi;
489 __debugger = old__debugger;
490 __debugger_bpt = old__debugger_bpt;
491 __debugger_sstep = old__debugger_sstep;
492 __debugger_iabr_match = old__debugger_iabr_match;
493 __debugger_break_match = old__debugger_break_match;
494 __debugger_fault_handler = old__debugger_fault_handler;
495 }
Linux with added FPC-III support