summaryrefslogtreecommitdiff
path: root/arch/ppc/lib/kgdb.c
blob: d3eb1f35a9fd90191268cf0336522aa280c05795 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
#include <common.h>
#include <command.h>
#include <kgdb.h>
#include <asm/signal.h>
#include <asm/processor.h>

#define PC_REGNUM 64
#define SP_REGNUM 1

void breakinst(void);

int
kgdb_setjmp(long *buf)
{
	asm ("mflr 0; stw 0,0(%0);"
	     "stw 1,4(%0); stw 2,8(%0);"
	     "mfcr 0; stw 0,12(%0);"
	     "stmw 13,16(%0)"
	     : : "r" (buf));
	/* XXX should save fp regs as well */
	return 0;
}

void
kgdb_longjmp(long *buf, int val)
{
	if (val == 0)
		val = 1;
	asm ("lmw 13,16(%0);"
	     "lwz 0,12(%0); mtcrf 0x38,0;"
	     "lwz 0,0(%0); lwz 1,4(%0); lwz 2,8(%0);"
	     "mtlr 0; mr 3,%1"
	     : : "r" (buf), "r" (val));
}

static inline unsigned long
get_msr(void)
{
	unsigned long msr;
	asm volatile("mfmsr %0" : "=r" (msr):);
	return msr;
}

static inline void
set_msr(unsigned long msr)
{
	asm volatile("mtmsr %0" : : "r" (msr));
}

/* Convert the SPARC hardware trap type code to a unix signal number. */
/*
 * This table contains the mapping between PowerPC hardware trap types, and
 * signals, which are primarily what GDB understands.
 */
static struct hard_trap_info
{
	unsigned int tt;		/* Trap type code for powerpc */
	unsigned char signo;		/* Signal that we map this trap into */
} hard_trap_info[] = {
	{ 0x200, SIGSEGV },			/* machine check */
	{ 0x300, SIGSEGV },			/* address error (store) */
	{ 0x400, SIGBUS },			/* instruction bus error */
	{ 0x500, SIGINT },			/* interrupt */
	{ 0x600, SIGBUS },			/* alingment */
	{ 0x700, SIGTRAP },			/* breakpoint trap */
	{ 0x800, SIGFPE },			/* fpu unavail */
	{ 0x900, SIGALRM },			/* decrementer */
	{ 0xa00, SIGILL },			/* reserved */
	{ 0xb00, SIGILL },			/* reserved */
	{ 0xc00, SIGCHLD },			/* syscall */
	{ 0xd00, SIGTRAP },			/* single-step/watch */
	{ 0xe00, SIGFPE },			/* fp assist */
	{ 0, 0}				/* Must be last */
};

static int
computeSignal(unsigned int tt)
{
	struct hard_trap_info *ht;

	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
		if (ht->tt == tt)
			return ht->signo;

	return SIGHUP;         /* default for things we don't know about */
}

void
kgdb_enter(struct pt_regs *regs, kgdb_data *kdp)
{
	unsigned long msr;

	kdp->private[0] = msr = get_msr();
	set_msr(msr & ~MSR_EE);	/* disable interrupts */

	if (regs->nip == (unsigned long)breakinst) {
		/* Skip over breakpoint trap insn */
		regs->nip += 4;
	}
	regs->msr &= ~MSR_SE;

	/* reply to host that an exception has occurred */
	kdp->sigval = computeSignal(regs->trap);

	kdp->nregs = 2;

	kdp->regs[0].num = PC_REGNUM;
	kdp->regs[0].val = regs->nip;

	kdp->regs[1].num = SP_REGNUM;
	kdp->regs[1].val = regs->gpr[SP_REGNUM];
}

void
kgdb_exit(struct pt_regs *regs, kgdb_data *kdp)
{
	unsigned long msr = kdp->private[0];

	if (kdp->extype & KGDBEXIT_WITHADDR)
		regs->nip = kdp->exaddr;

	switch (kdp->extype & KGDBEXIT_TYPEMASK) {

	case KGDBEXIT_KILL:
	case KGDBEXIT_CONTINUE:
		set_msr(msr);
		break;

	case KGDBEXIT_SINGLE:
		regs->msr |= MSR_SE;
#if 0
		set_msr(msr | MSR_SE);
#endif
		break;
	}
}

int
kgdb_trap(struct pt_regs *regs)
{
	return (regs->trap);
}

/* return the value of the CPU registers.
 * some of them are non-PowerPC names :(
 * they are stored in gdb like:
 * struct {
 *     u32 gpr[32];
 *     f64 fpr[32];
 *     u32 pc, ps, cnd, lr; (ps=msr)
 *     u32 cnt, xer, mq;
 * }
 */

#define SPACE_REQUIRED	((32*4)+(32*8)+(6*4))

#ifdef CONFIG_8260
/* store floating double indexed */
#define STFDI(n,p)	__asm__ __volatile__ ("stfd " #n ",%0" : "=o"(p[2*n]))
/* store floating double multiple */
#define STFDM(p)	{ STFDI( 0,p); STFDI( 1,p); STFDI( 2,p); STFDI( 3,p); \
			  STFDI( 4,p); STFDI( 5,p); STFDI( 6,p); STFDI( 7,p); \
			  STFDI( 8,p); STFDI( 9,p); STFDI(10,p); STFDI(11,p); \
			  STFDI(12,p); STFDI(13,p); STFDI(14,p); STFDI(15,p); \
			  STFDI(16,p); STFDI(17,p); STFDI(18,p); STFDI(19,p); \
			  STFDI(20,p); STFDI(21,p); STFDI(22,p); STFDI(23,p); \
			  STFDI(24,p); STFDI(25,p); STFDI(26,p); STFDI(27,p); \
			  STFDI(28,p); STFDI(29,p); STFDI(30,p); STFDI(31,p); }
#endif

int
kgdb_getregs(struct pt_regs *regs, char *buf, int max)
{
	int i;
	unsigned long *ptr = (unsigned long *)buf;

	if (max < SPACE_REQUIRED)
		kgdb_error(KGDBERR_NOSPACE);

	if ((unsigned long)ptr & 3)
		kgdb_error(KGDBERR_ALIGNFAULT);

	/* General Purpose Regs */
	for (i = 0; i < 32; i++)
		*ptr++ = regs->gpr[i];

	/* Floating Point Regs */
#ifdef CONFIG_8260
	STFDM(ptr);
	ptr += 32*2;
#else
	for (i = 0; i < 32; i++) {
		*ptr++ = 0;
		*ptr++ = 0;
	}
#endif

	/* pc, msr, cr, lr, ctr, xer, (mq is unused) */
	*ptr++ = regs->nip;
	*ptr++ = regs->msr;
	*ptr++ = regs->ccr;
	*ptr++ = regs->link;
	*ptr++ = regs->ctr;
	*ptr++ = regs->xer;

	return (SPACE_REQUIRED);
}

/* set the value of the CPU registers */

#ifdef CONFIG_8260
/* load floating double */
#define LFD(n,v)	__asm__ __volatile__ ("lfd " #n ",%0" :: "o"(v))
/* load floating double indexed */
#define LFDI(n,p)	__asm__ __volatile__ ("lfd " #n ",%0" :: "o"((p)[2*n]))
/* load floating double multiple */
#define LFDM(p)		{ LFDI( 0,p); LFDI( 1,p); LFDI( 2,p); LFDI( 3,p); \
			  LFDI( 4,p); LFDI( 5,p); LFDI( 6,p); LFDI( 7,p); \
			  LFDI( 8,p); LFDI( 9,p); LFDI(10,p); LFDI(11,p); \
			  LFDI(12,p); LFDI(13,p); LFDI(14,p); LFDI(15,p); \
			  LFDI(16,p); LFDI(17,p); LFDI(18,p); LFDI(19,p); \
			  LFDI(20,p); LFDI(21,p); LFDI(22,p); LFDI(23,p); \
			  LFDI(24,p); LFDI(25,p); LFDI(26,p); LFDI(27,p); \
			  LFDI(28,p); LFDI(29,p); LFDI(30,p); LFDI(31,p); }
#endif

void
kgdb_putreg(struct pt_regs *regs, int regno, char *buf, int length)
{
	unsigned long *ptr = (unsigned long *)buf;

	if (regno < 0 || regno >= 70)
		kgdb_error(KGDBERR_BADPARAMS);
	else if (regno >= 32 && regno < 64) {
		if (length < 8)
			kgdb_error(KGDBERR_NOSPACE);
	}
	else {
		if (length < 4)
			kgdb_error(KGDBERR_NOSPACE);
	}

	if ((unsigned long)ptr & 3)
		kgdb_error(KGDBERR_ALIGNFAULT);

	if (regno >= 0 && regno < 32)
		regs->gpr[regno] = *ptr;
	else switch (regno) {

#ifdef CONFIG_8260
#define caseF(n) \
	case (n) + 32:	LFD(n, *ptr);		break;

caseF( 0) caseF( 1) caseF( 2) caseF( 3) caseF( 4) caseF( 5) caseF( 6) caseF( 7)
caseF( 8) caseF( 9) caseF(10) caseF(11) caseF(12) caseF(13) caseF(14) caseF(15)
caseF(16) caseF(17) caseF(18) caseF(19) caseF(20) caseF(21) caseF(22) caseF(23)
caseF(24) caseF(25) caseF(26) caseF(27) caseF(28) caseF(29) caseF(30) caseF(31)

#undef caseF
#endif

	case 64:	regs->nip = *ptr;	break;
	case 65:	regs->msr = *ptr;	break;
	case 66:	regs->ccr = *ptr;	break;
	case 67:	regs->link = *ptr;	break;
	case 68:	regs->ctr = *ptr;	break;
	case 69:	regs->ctr = *ptr;	break;

	default:
		kgdb_error(KGDBERR_BADPARAMS);
	}
}

void
kgdb_putregs(struct pt_regs *regs, char *buf, int length)
{
	int i;
	unsigned long *ptr = (unsigned long *)buf;

	if (length < SPACE_REQUIRED)
		kgdb_error(KGDBERR_NOSPACE);

	if ((unsigned long)ptr & 3)
		kgdb_error(KGDBERR_ALIGNFAULT);

	/*
	 * If the stack pointer has moved, you should pray.
	 * (cause only god can help you).
	 */

	/* General Purpose Regs */
	for (i = 0; i < 32; i++)
		regs->gpr[i] = *ptr++;

	/* Floating Point Regs */
#ifdef CONFIG_8260
	LFDM(ptr);
#endif
	ptr += 32*2;

	/* pc, msr, cr, lr, ctr, xer, (mq is unused) */
	regs->nip = *ptr++;
	regs->msr = *ptr++;
	regs->ccr = *ptr++;
	regs->link = *ptr++;
	regs->ctr = *ptr++;
	regs->xer = *ptr++;
}

/* This function will generate a breakpoint exception.  It is used at the
   beginning of a program to sync up with a debugger and can be used
   otherwise as a quick means to stop program execution and "break" into
   the debugger. */

void
kgdb_breakpoint(int argc, char *argv[])
{
	asm("	.globl breakinst\n\
	     breakinst: .long 0x7d821008\n\
	    ");
}