1 /*
2 * Microblaze KGDB support
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License. See the file "COPYING" in the main directory of this archive
6 * for more details.
7 */
8
9 #include <linux/kgdb.h>
10 #include <linux/kdebug.h>
11 #include <linux/irq.h>
12 #include <linux/io.h>
13 #include <asm/cacheflush.h>
14 #include <asm/asm-offsets.h>
15 #include <asm/kgdb.h>
16 #include <asm/pvr.h>
17
18 #define GDB_REG 0
19 #define GDB_PC 32
20 #define GDB_MSR 33
21 #define GDB_EAR 34
22 #define GDB_ESR 35
23 #define GDB_FSR 36
24 #define GDB_BTR 37
25 #define GDB_PVR 38
26 #define GDB_REDR 50
27 #define GDB_RPID 51
28 #define GDB_RZPR 52
29 #define GDB_RTLBX 53
30 #define GDB_RTLBSX 54 /* mfs can't read it */
31 #define GDB_RTLBLO 55
32 #define GDB_RTLBHI 56
33
34 /* keep pvr separately because it is unchangeable */
35 static struct pvr_s pvr;
36
37 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
38 {
39 unsigned int i;
40 unsigned long *pt_regb = (unsigned long *)regs;
41 int temp;
42
43 /* registers r0 - r31, pc, msr, ear, esr, fsr + do not save pt_mode */
44 for (i = 0; i < (sizeof(struct pt_regs) / 4) - 1; i++)
45 gdb_regs[i] = pt_regb[i];
46
47 /* Branch target register can't be changed */
48 __asm__ __volatile__ ("mfs %0, rbtr;" : "=r"(temp) : );
49 gdb_regs[GDB_BTR] = temp;
50
51 /* pvr part - we have 11 pvr regs */
52 for (i = 0; i < sizeof(struct pvr_s)/4; i++)
53 gdb_regs[GDB_PVR + i] = pvr.pvr[i];
54
55 /* read special registers - can't be changed */
56 __asm__ __volatile__ ("mfs %0, redr;" : "=r"(temp) : );
57 gdb_regs[GDB_REDR] = temp;
58 __asm__ __volatile__ ("mfs %0, rpid;" : "=r"(temp) : );
59 gdb_regs[GDB_RPID] = temp;
60 __asm__ __volatile__ ("mfs %0, rzpr;" : "=r"(temp) : );
61 gdb_regs[GDB_RZPR] = temp;
62 __asm__ __volatile__ ("mfs %0, rtlbx;" : "=r"(temp) : );
63 gdb_regs[GDB_RTLBX] = temp;
64 __asm__ __volatile__ ("mfs %0, rtlblo;" : "=r"(temp) : );
65 gdb_regs[GDB_RTLBLO] = temp;
66 __asm__ __volatile__ ("mfs %0, rtlbhi;" : "=r"(temp) : );
67 gdb_regs[GDB_RTLBHI] = temp;
68 }
69
70 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
71 {
72 unsigned int i;
73 unsigned long *pt_regb = (unsigned long *)regs;
74
75 /* pt_regs and gdb_regs have the same 37 values.
76 * The rest of gdb_regs are unused and can't be changed.
77 * r0 register value can't be changed too. */
78 for (i = 1; i < (sizeof(struct pt_regs) / 4) - 1; i++)
79 pt_regb[i] = gdb_regs[i];
80 }
81
82 asmlinkage void microblaze_kgdb_break(struct pt_regs *regs)
83 {
84 if (kgdb_handle_exception(1, SIGTRAP, 0, regs) != 0)
85 return;
86
87 /* Jump over the first arch_kgdb_breakpoint which is barrier to
88 * get kgdb work. The same solution is used for powerpc */
89 if (*(u32 *) (regs->pc) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr))
90 regs->pc += BREAK_INSTR_SIZE;
91 }
92
93 /* untested */
94 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
95 {
96 unsigned int i;
97 unsigned long *pt_regb = (unsigned long *)(p->thread.regs);
98
99 /* registers r0 - r31, pc, msr, ear, esr, fsr + do not save pt_mode */
100 for (i = 0; i < (sizeof(struct pt_regs) / 4) - 1; i++)
101 gdb_regs[i] = pt_regb[i];
102
103 /* pvr part - we have 11 pvr regs */
104 for (i = 0; i < sizeof(struct pvr_s)/4; i++)
105 gdb_regs[GDB_PVR + i] = pvr.pvr[i];
106 }
107
108 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
109 {
110 regs->pc = ip;
111 }
112
113 int kgdb_arch_handle_exception(int vector, int signo, int err_code,
114 char *remcom_in_buffer, char *remcom_out_buffer,
115 struct pt_regs *regs)
116 {
117 char *ptr;
118 unsigned long address;
119
120 switch (remcom_in_buffer[0]) {
121 case 'c':
122 /* handle the optional parameter */
123 ptr = &remcom_in_buffer[1];
124 if (kgdb_hex2long(&ptr, &address))
125 regs->pc = address;
126
127 return 0;
128 }
129 return -1; /* this means that we do not want to exit from the handler */
130 }
131
132 int kgdb_arch_init(void)
133 {
134 get_pvr(&pvr); /* Fill PVR structure */
135 return 0;
136 }
137
138 void kgdb_arch_exit(void)
139 {
140 /* Nothing to do */
141 }
142
143 /*
144 * Global data
145 */
146 const struct kgdb_arch arch_kgdb_ops = {
147 #ifdef __MICROBLAZEEL__
148 .gdb_bpt_instr = {0x18, 0x00, 0x0c, 0xba}, /* brki r16, 0x18 */
149 #else
150 .gdb_bpt_instr = {0xba, 0x0c, 0x00, 0x18}, /* brki r16, 0x18 */
151 #endif
152 };
153
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