1/*
2 * arch/blackfin/kernel/kgdb.c - Blackfin kgdb pieces
3 *
4 * Copyright 2005-2008 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2 or later.
7 */
8
9#include <linux/ptrace.h>		/* for linux pt_regs struct */
10#include <linux/kgdb.h>
11#include <linux/uaccess.h>
12#include <asm/irq_regs.h>
13
14void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
15{
16	gdb_regs[BFIN_R0] = regs->r0;
17	gdb_regs[BFIN_R1] = regs->r1;
18	gdb_regs[BFIN_R2] = regs->r2;
19	gdb_regs[BFIN_R3] = regs->r3;
20	gdb_regs[BFIN_R4] = regs->r4;
21	gdb_regs[BFIN_R5] = regs->r5;
22	gdb_regs[BFIN_R6] = regs->r6;
23	gdb_regs[BFIN_R7] = regs->r7;
24	gdb_regs[BFIN_P0] = regs->p0;
25	gdb_regs[BFIN_P1] = regs->p1;
26	gdb_regs[BFIN_P2] = regs->p2;
27	gdb_regs[BFIN_P3] = regs->p3;
28	gdb_regs[BFIN_P4] = regs->p4;
29	gdb_regs[BFIN_P5] = regs->p5;
30	gdb_regs[BFIN_SP] = regs->reserved;
31	gdb_regs[BFIN_FP] = regs->fp;
32	gdb_regs[BFIN_I0] = regs->i0;
33	gdb_regs[BFIN_I1] = regs->i1;
34	gdb_regs[BFIN_I2] = regs->i2;
35	gdb_regs[BFIN_I3] = regs->i3;
36	gdb_regs[BFIN_M0] = regs->m0;
37	gdb_regs[BFIN_M1] = regs->m1;
38	gdb_regs[BFIN_M2] = regs->m2;
39	gdb_regs[BFIN_M3] = regs->m3;
40	gdb_regs[BFIN_B0] = regs->b0;
41	gdb_regs[BFIN_B1] = regs->b1;
42	gdb_regs[BFIN_B2] = regs->b2;
43	gdb_regs[BFIN_B3] = regs->b3;
44	gdb_regs[BFIN_L0] = regs->l0;
45	gdb_regs[BFIN_L1] = regs->l1;
46	gdb_regs[BFIN_L2] = regs->l2;
47	gdb_regs[BFIN_L3] = regs->l3;
48	gdb_regs[BFIN_A0_DOT_X] = regs->a0x;
49	gdb_regs[BFIN_A0_DOT_W] = regs->a0w;
50	gdb_regs[BFIN_A1_DOT_X] = regs->a1x;
51	gdb_regs[BFIN_A1_DOT_W] = regs->a1w;
52	gdb_regs[BFIN_ASTAT] = regs->astat;
53	gdb_regs[BFIN_RETS] = regs->rets;
54	gdb_regs[BFIN_LC0] = regs->lc0;
55	gdb_regs[BFIN_LT0] = regs->lt0;
56	gdb_regs[BFIN_LB0] = regs->lb0;
57	gdb_regs[BFIN_LC1] = regs->lc1;
58	gdb_regs[BFIN_LT1] = regs->lt1;
59	gdb_regs[BFIN_LB1] = regs->lb1;
60	gdb_regs[BFIN_CYCLES] = 0;
61	gdb_regs[BFIN_CYCLES2] = 0;
62	gdb_regs[BFIN_USP] = regs->usp;
63	gdb_regs[BFIN_SEQSTAT] = regs->seqstat;
64	gdb_regs[BFIN_SYSCFG] = regs->syscfg;
65	gdb_regs[BFIN_RETI] = regs->pc;
66	gdb_regs[BFIN_RETX] = regs->retx;
67	gdb_regs[BFIN_RETN] = regs->retn;
68	gdb_regs[BFIN_RETE] = regs->rete;
69	gdb_regs[BFIN_PC] = regs->pc;
70	gdb_regs[BFIN_CC] = (regs->astat >> 5) & 1;
71	gdb_regs[BFIN_EXTRA1] = 0;
72	gdb_regs[BFIN_EXTRA2] = 0;
73	gdb_regs[BFIN_EXTRA3] = 0;
74	gdb_regs[BFIN_IPEND] = regs->ipend;
75}
76
77/*
78 * Extracts ebp, esp and eip values understandable by gdb from the values
79 * saved by switch_to.
80 * thread.esp points to ebp. flags and ebp are pushed in switch_to hence esp
81 * prior to entering switch_to is 8 greater than the value that is saved.
82 * If switch_to changes, change following code appropriately.
83 */
84void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
85{
86	gdb_regs[BFIN_SP] = p->thread.ksp;
87	gdb_regs[BFIN_PC] = p->thread.pc;
88	gdb_regs[BFIN_SEQSTAT] = p->thread.seqstat;
89}
90
91void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
92{
93	regs->r0 = gdb_regs[BFIN_R0];
94	regs->r1 = gdb_regs[BFIN_R1];
95	regs->r2 = gdb_regs[BFIN_R2];
96	regs->r3 = gdb_regs[BFIN_R3];
97	regs->r4 = gdb_regs[BFIN_R4];
98	regs->r5 = gdb_regs[BFIN_R5];
99	regs->r6 = gdb_regs[BFIN_R6];
100	regs->r7 = gdb_regs[BFIN_R7];
101	regs->p0 = gdb_regs[BFIN_P0];
102	regs->p1 = gdb_regs[BFIN_P1];
103	regs->p2 = gdb_regs[BFIN_P2];
104	regs->p3 = gdb_regs[BFIN_P3];
105	regs->p4 = gdb_regs[BFIN_P4];
106	regs->p5 = gdb_regs[BFIN_P5];
107	regs->fp = gdb_regs[BFIN_FP];
108	regs->i0 = gdb_regs[BFIN_I0];
109	regs->i1 = gdb_regs[BFIN_I1];
110	regs->i2 = gdb_regs[BFIN_I2];
111	regs->i3 = gdb_regs[BFIN_I3];
112	regs->m0 = gdb_regs[BFIN_M0];
113	regs->m1 = gdb_regs[BFIN_M1];
114	regs->m2 = gdb_regs[BFIN_M2];
115	regs->m3 = gdb_regs[BFIN_M3];
116	regs->b0 = gdb_regs[BFIN_B0];
117	regs->b1 = gdb_regs[BFIN_B1];
118	regs->b2 = gdb_regs[BFIN_B2];
119	regs->b3 = gdb_regs[BFIN_B3];
120	regs->l0 = gdb_regs[BFIN_L0];
121	regs->l1 = gdb_regs[BFIN_L1];
122	regs->l2 = gdb_regs[BFIN_L2];
123	regs->l3 = gdb_regs[BFIN_L3];
124	regs->a0x = gdb_regs[BFIN_A0_DOT_X];
125	regs->a0w = gdb_regs[BFIN_A0_DOT_W];
126	regs->a1x = gdb_regs[BFIN_A1_DOT_X];
127	regs->a1w = gdb_regs[BFIN_A1_DOT_W];
128	regs->rets = gdb_regs[BFIN_RETS];
129	regs->lc0 = gdb_regs[BFIN_LC0];
130	regs->lt0 = gdb_regs[BFIN_LT0];
131	regs->lb0 = gdb_regs[BFIN_LB0];
132	regs->lc1 = gdb_regs[BFIN_LC1];
133	regs->lt1 = gdb_regs[BFIN_LT1];
134	regs->lb1 = gdb_regs[BFIN_LB1];
135	regs->usp = gdb_regs[BFIN_USP];
136	regs->syscfg = gdb_regs[BFIN_SYSCFG];
137	regs->retx = gdb_regs[BFIN_RETX];
138	regs->retn = gdb_regs[BFIN_RETN];
139	regs->rete = gdb_regs[BFIN_RETE];
140	regs->pc = gdb_regs[BFIN_PC];
141
142#if 0				/* can't change these */
143	regs->astat = gdb_regs[BFIN_ASTAT];
144	regs->seqstat = gdb_regs[BFIN_SEQSTAT];
145	regs->ipend = gdb_regs[BFIN_IPEND];
146#endif
147}
148
149static struct hw_breakpoint {
150	unsigned int occupied:1;
151	unsigned int skip:1;
152	unsigned int enabled:1;
153	unsigned int type:1;
154	unsigned int dataacc:2;
155	unsigned short count;
156	unsigned int addr;
157} breakinfo[HW_WATCHPOINT_NUM];
158
159static int bfin_set_hw_break(unsigned long addr, int len, enum kgdb_bptype type)
160{
161	int breakno;
162	int bfin_type;
163	int dataacc = 0;
164
165	switch (type) {
166	case BP_HARDWARE_BREAKPOINT:
167		bfin_type = TYPE_INST_WATCHPOINT;
168		break;
169	case BP_WRITE_WATCHPOINT:
170		dataacc = 1;
171		bfin_type = TYPE_DATA_WATCHPOINT;
172		break;
173	case BP_READ_WATCHPOINT:
174		dataacc = 2;
175		bfin_type = TYPE_DATA_WATCHPOINT;
176		break;
177	case BP_ACCESS_WATCHPOINT:
178		dataacc = 3;
179		bfin_type = TYPE_DATA_WATCHPOINT;
180		break;
181	default:
182		return -ENOSPC;
183	}
184
185	/* Because hardware data watchpoint impelemented in current
186	 * Blackfin can not trigger an exception event as the hardware
187	 * instrction watchpoint does, we ignaore all data watch point here.
188	 * They can be turned on easily after future blackfin design
189	 * supports this feature.
190	 */
191	for (breakno = 0; breakno < HW_INST_WATCHPOINT_NUM; breakno++)
192		if (bfin_type == breakinfo[breakno].type
193			&& !breakinfo[breakno].occupied) {
194			breakinfo[breakno].occupied = 1;
195			breakinfo[breakno].skip = 0;
196			breakinfo[breakno].enabled = 1;
197			breakinfo[breakno].addr = addr;
198			breakinfo[breakno].dataacc = dataacc;
199			breakinfo[breakno].count = 0;
200			return 0;
201		}
202
203	return -ENOSPC;
204}
205
206static int bfin_remove_hw_break(unsigned long addr, int len, enum kgdb_bptype type)
207{
208	int breakno;
209	int bfin_type;
210
211	switch (type) {
212	case BP_HARDWARE_BREAKPOINT:
213		bfin_type = TYPE_INST_WATCHPOINT;
214		break;
215	case BP_WRITE_WATCHPOINT:
216	case BP_READ_WATCHPOINT:
217	case BP_ACCESS_WATCHPOINT:
218		bfin_type = TYPE_DATA_WATCHPOINT;
219		break;
220	default:
221		return 0;
222	}
223	for (breakno = 0; breakno < HW_WATCHPOINT_NUM; breakno++)
224		if (bfin_type == breakinfo[breakno].type
225			&& breakinfo[breakno].occupied
226			&& breakinfo[breakno].addr == addr) {
227			breakinfo[breakno].occupied = 0;
228			breakinfo[breakno].enabled = 0;
229		}
230
231	return 0;
232}
233
234static void bfin_remove_all_hw_break(void)
235{
236	int breakno;
237
238	memset(breakinfo, 0, sizeof(struct hw_breakpoint)*HW_WATCHPOINT_NUM);
239
240	for (breakno = 0; breakno < HW_INST_WATCHPOINT_NUM; breakno++)
241		breakinfo[breakno].type = TYPE_INST_WATCHPOINT;
242	for (; breakno < HW_WATCHPOINT_NUM; breakno++)
243		breakinfo[breakno].type = TYPE_DATA_WATCHPOINT;
244}
245
246static void bfin_correct_hw_break(void)
247{
248	int breakno;
249	unsigned int wpiactl = 0;
250	unsigned int wpdactl = 0;
251	int enable_wp = 0;
252
253	for (breakno = 0; breakno < HW_WATCHPOINT_NUM; breakno++)
254		if (breakinfo[breakno].enabled) {
255			enable_wp = 1;
256
257			switch (breakno) {
258			case 0:
259				wpiactl |= WPIAEN0|WPICNTEN0;
260				bfin_write_WPIA0(breakinfo[breakno].addr);
261				bfin_write_WPIACNT0(breakinfo[breakno].count
262					+ breakinfo->skip);
263				break;
264			case 1:
265				wpiactl |= WPIAEN1|WPICNTEN1;
266				bfin_write_WPIA1(breakinfo[breakno].addr);
267				bfin_write_WPIACNT1(breakinfo[breakno].count
268					+ breakinfo->skip);
269				break;
270			case 2:
271				wpiactl |= WPIAEN2|WPICNTEN2;
272				bfin_write_WPIA2(breakinfo[breakno].addr);
273				bfin_write_WPIACNT2(breakinfo[breakno].count
274					+ breakinfo->skip);
275				break;
276			case 3:
277				wpiactl |= WPIAEN3|WPICNTEN3;
278				bfin_write_WPIA3(breakinfo[breakno].addr);
279				bfin_write_WPIACNT3(breakinfo[breakno].count
280					+ breakinfo->skip);
281				break;
282			case 4:
283				wpiactl |= WPIAEN4|WPICNTEN4;
284				bfin_write_WPIA4(breakinfo[breakno].addr);
285				bfin_write_WPIACNT4(breakinfo[breakno].count
286					+ breakinfo->skip);
287				break;
288			case 5:
289				wpiactl |= WPIAEN5|WPICNTEN5;
290				bfin_write_WPIA5(breakinfo[breakno].addr);
291				bfin_write_WPIACNT5(breakinfo[breakno].count
292					+ breakinfo->skip);
293				break;
294			case 6:
295				wpdactl |= WPDAEN0|WPDCNTEN0|WPDSRC0;
296				wpdactl |= breakinfo[breakno].dataacc
297					<< WPDACC0_OFFSET;
298				bfin_write_WPDA0(breakinfo[breakno].addr);
299				bfin_write_WPDACNT0(breakinfo[breakno].count
300					+ breakinfo->skip);
301				break;
302			case 7:
303				wpdactl |= WPDAEN1|WPDCNTEN1|WPDSRC1;
304				wpdactl |= breakinfo[breakno].dataacc
305					<< WPDACC1_OFFSET;
306				bfin_write_WPDA1(breakinfo[breakno].addr);
307				bfin_write_WPDACNT1(breakinfo[breakno].count
308					+ breakinfo->skip);
309				break;
310			}
311		}
312
313	/* Should enable WPPWR bit first before set any other
314	 * WPIACTL and WPDACTL bits */
315	if (enable_wp) {
316		bfin_write_WPIACTL(WPPWR);
317		CSYNC();
318		bfin_write_WPIACTL(wpiactl|WPPWR);
319		bfin_write_WPDACTL(wpdactl);
320		CSYNC();
321	}
322}
323
324static void bfin_disable_hw_debug(struct pt_regs *regs)
325{
326	/* Disable hardware debugging while we are in kgdb */
327	bfin_write_WPIACTL(0);
328	bfin_write_WPDACTL(0);
329	CSYNC();
330}
331
332#ifdef CONFIG_SMP
333void kgdb_passive_cpu_callback(void *info)
334{
335	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
336}
337
338void kgdb_roundup_cpus(unsigned long flags)
339{
340	unsigned int cpu;
341
342	for (cpu = cpumask_first(cpu_online_mask); cpu < nr_cpu_ids;
343		cpu = cpumask_next(cpu, cpu_online_mask))
344		smp_call_function_single(cpu, kgdb_passive_cpu_callback,
345					 NULL, 0);
346}
347
348void kgdb_roundup_cpu(int cpu, unsigned long flags)
349{
350	smp_call_function_single(cpu, kgdb_passive_cpu_callback, NULL, 0);
351}
352#endif
353
354#ifdef CONFIG_IPIPE
355static unsigned long kgdb_arch_imask;
356#endif
357
358int kgdb_arch_handle_exception(int vector, int signo,
359			       int err_code, char *remcom_in_buffer,
360			       char *remcom_out_buffer,
361			       struct pt_regs *regs)
362{
363	long addr;
364	char *ptr;
365	int newPC;
366	int i;
367
368	switch (remcom_in_buffer[0]) {
369	case 'c':
370	case 's':
371		if (kgdb_contthread && kgdb_contthread != current) {
372			strcpy(remcom_out_buffer, "E00");
373			break;
374		}
375
376		kgdb_contthread = NULL;
377
378		/* try to read optional parameter, pc unchanged if no parm */
379		ptr = &remcom_in_buffer[1];
380		if (kgdb_hex2long(&ptr, &addr)) {
381			regs->retx = addr;
382		}
383		newPC = regs->retx;
384
385		/* clear the trace bit */
386		regs->syscfg &= 0xfffffffe;
387
388		/* set the trace bit if we're stepping */
389		if (remcom_in_buffer[0] == 's') {
390			regs->syscfg |= 0x1;
391			kgdb_single_step = regs->ipend;
392			kgdb_single_step >>= 6;
393			for (i = 10; i > 0; i--, kgdb_single_step >>= 1)
394				if (kgdb_single_step & 1)
395					break;
396			/* i indicate event priority of current stopped instruction
397			 * user space instruction is 0, IVG15 is 1, IVTMR is 10.
398			 * kgdb_single_step > 0 means in single step mode
399			 */
400			kgdb_single_step = i + 1;
401
402			preempt_disable();
403#ifdef CONFIG_IPIPE
404			kgdb_arch_imask = cpu_pda[raw_smp_processor_id()].ex_imask;
405			cpu_pda[raw_smp_processor_id()].ex_imask = 0;
406#endif
407		}
408
409		bfin_correct_hw_break();
410
411		return 0;
412	}			/* switch */
413	return -1;		/* this means that we do not want to exit from the handler */
414}
415
416struct kgdb_arch arch_kgdb_ops = {
417	.gdb_bpt_instr = {0xa1},
418	.flags = KGDB_HW_BREAKPOINT,
419	.set_hw_breakpoint = bfin_set_hw_break,
420	.remove_hw_breakpoint = bfin_remove_hw_break,
421	.disable_hw_break = bfin_disable_hw_debug,
422	.remove_all_hw_break = bfin_remove_all_hw_break,
423	.correct_hw_break = bfin_correct_hw_break,
424};
425
426#define IN_MEM(addr, size, l1_addr, l1_size) \
427({ \
428	unsigned long __addr = (unsigned long)(addr); \
429	(l1_size && __addr >= l1_addr && __addr + (size) <= l1_addr + l1_size); \
430})
431#define ASYNC_BANK_SIZE \
432	(ASYNC_BANK0_SIZE + ASYNC_BANK1_SIZE + \
433	 ASYNC_BANK2_SIZE + ASYNC_BANK3_SIZE)
434
435int kgdb_validate_break_address(unsigned long addr)
436{
437	int cpu = raw_smp_processor_id();
438
439	if (addr >= 0x1000 && (addr + BREAK_INSTR_SIZE) <= physical_mem_end)
440		return 0;
441	if (IN_MEM(addr, BREAK_INSTR_SIZE, ASYNC_BANK0_BASE, ASYNC_BANK_SIZE))
442		return 0;
443	if (cpu == 0 && IN_MEM(addr, BREAK_INSTR_SIZE, L1_CODE_START, L1_CODE_LENGTH))
444		return 0;
445#ifdef CONFIG_SMP
446	else if (cpu == 1 && IN_MEM(addr, BREAK_INSTR_SIZE, COREB_L1_CODE_START, L1_CODE_LENGTH))
447		return 0;
448#endif
449	if (IN_MEM(addr, BREAK_INSTR_SIZE, L2_START, L2_LENGTH))
450		return 0;
451
452	return -EFAULT;
453}
454
455void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
456{
457	regs->retx = ip;
458}
459
460int kgdb_arch_init(void)
461{
462	kgdb_single_step = 0;
463#ifdef CONFIG_IPIPE
464	kgdb_arch_imask = 0;
465#endif
466
467	bfin_remove_all_hw_break();
468	return 0;
469}
470
471void kgdb_arch_exit(void)
472{
473}
474