summaryrefslogtreecommitdiffstats
path: root/arch/microblaze/kernel/kgdb.c
blob: 8adc924431008a546114588115cd328f6a7b90f5 (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
/*
 * Microblaze KGDB support
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/kgdb.h>
#include <linux/kdebug.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/asm-offsets.h>
#include <asm/pvr.h>

#define GDB_REG		0
#define GDB_PC		32
#define GDB_MSR		33
#define GDB_EAR		34
#define GDB_ESR		35
#define GDB_FSR		36
#define GDB_BTR		37
#define GDB_PVR		38
#define GDB_REDR	50
#define GDB_RPID	51
#define GDB_RZPR	52
#define GDB_RTLBX	53
#define GDB_RTLBSX	54 /* mfs can't read it */
#define GDB_RTLBLO	55
#define GDB_RTLBHI	56

/* keep pvr separately because it is unchangeble */
struct pvr_s pvr;

void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
	int i;
	unsigned long *pt_regb = (unsigned long *)regs;
	int temp;
	/* registers r0 - r31, pc, msr, ear, esr, fsr + do not save pt_mode */
	for (i = 0; i < (sizeof(struct pt_regs) / 4) - 1; i++)
		gdb_regs[i] = pt_regb[i];

	/* Branch target register can't be changed */
	__asm__ __volatile__ ("mfs %0, rbtr;" : "=r"(temp) : );
	gdb_regs[GDB_BTR] = temp;

	/* pvr part  - we have 11 pvr regs */
	for (i = 0; i < sizeof(struct pvr_s)/4; i++)
		gdb_regs[GDB_PVR + i] = pvr.pvr[i];

	/* read special registers - can't be changed */
	__asm__ __volatile__ ("mfs %0, redr;" : "=r"(temp) : );
	gdb_regs[GDB_REDR] = temp;
	__asm__ __volatile__ ("mfs %0, rpid;" : "=r"(temp) : );
	gdb_regs[GDB_RPID] = temp;
	__asm__ __volatile__ ("mfs %0, rzpr;" : "=r"(temp) : );
	gdb_regs[GDB_RZPR] = temp;
	__asm__ __volatile__ ("mfs %0, rtlbx;" : "=r"(temp) : );
	gdb_regs[GDB_RTLBX] = temp;
	__asm__ __volatile__ ("mfs %0, rtlblo;" : "=r"(temp) : );
	gdb_regs[GDB_RTLBLO] = temp;
	__asm__ __volatile__ ("mfs %0, rtlbhi;" : "=r"(temp) : );
	gdb_regs[GDB_RTLBHI] = temp;
}

void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
	int i;
	unsigned long *pt_regb = (unsigned long *)regs;

	/* pt_regs and gdb_regs have the same 37 values.
	 * The rest of gdb_regs are unused and can't be changed.
	 * r0 register value can't be changed too. */
	for (i = 1; i < (sizeof(struct pt_regs) / 4) - 1; i++)
		pt_regb[i] = gdb_regs[i];
}

void microblaze_kgdb_break(struct pt_regs *regs)
{
	if (kgdb_handle_exception(1, SIGTRAP, 0, regs) != 0)
		return;

	/* Jump over the first arch_kgdb_breakpoint which is barrier to
	 * get kgdb work. The same solution is used for powerpc */
	if (*(u32 *) (regs->pc) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr))
		regs->pc += BREAK_INSTR_SIZE;
}

/* untested */
void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
{
	int i;
	unsigned long *pt_regb = (unsigned long *)(p->thread.regs);

	/* registers r0 - r31, pc, msr, ear, esr, fsr + do not save pt_mode */
	for (i = 0; i < (sizeof(struct pt_regs) / 4) - 1; i++)
		gdb_regs[i] = pt_regb[i];

	/* pvr part  - we have 11 pvr regs */
	for (i = 0; i < sizeof(struct pvr_s)/4; i++)
		gdb_regs[GDB_PVR + i] = pvr.pvr[i];
}

void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
{
	regs->pc = ip;
}

int kgdb_arch_handle_exception(int vector, int signo, int err_code,
			       char *remcom_in_buffer, char *remcom_out_buffer,
			       struct pt_regs *regs)
{
	char *ptr;
	unsigned long address;

	switch (remcom_in_buffer[0]) {
	case 'c':
		/* handle the optional parameter */
		ptr = &remcom_in_buffer[1];
		if (kgdb_hex2long(&ptr, &address))
			regs->pc = address;

		return 0;
	}
	return -1; /* this means that we do not want to exit from the handler */
}

int kgdb_arch_init(void)
{
	get_pvr(&pvr); /* Fill PVR structure */
	return 0;
}

void kgdb_arch_exit(void)
{
	/* Nothing to do */
}

/*
 * Global data
 */
const struct kgdb_arch arch_kgdb_ops = {
#ifdef __MICROBLAZEEL__
	.gdb_bpt_instr = {0x18, 0x00, 0x0c, 0xba}, /* brki r16, 0x18 */
#else
	.gdb_bpt_instr = {0xba, 0x0c, 0x00, 0x18}, /* brki r16, 0x18 */
#endif
};