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
|
/* SPDX-License-Identifier: BSD-3-Clause */
/* This file is part of the coreboot project. */
#include <stdint.h>
#include <types.h>
#include <arch/barrier.h>
#include <arch/exception.h>
#include <arch/transition.h>
#include <console/console.h>
#include <console/uart.h>
#include <arch/lib_helpers.h>
uint8_t exception_stack[2*KiB] __attribute__((aligned(16)));
static const char *exception_names[NUM_EXC_VIDS] = {
[EXC_VID_CUR_SP_EL0_SYNC] = "_sync_sp_el0",
[EXC_VID_CUR_SP_EL0_IRQ] = "_irq_sp_el0",
[EXC_VID_CUR_SP_EL0_FIRQ] = "_fiq_sp_el0",
[EXC_VID_CUR_SP_EL0_SERR] = "_serror_sp_el0",
[EXC_VID_CUR_SP_ELX_SYNC] = "_sync_sp_el3",
[EXC_VID_CUR_SP_ELX_IRQ] = "_irq_sp_el3",
[EXC_VID_CUR_SP_ELX_FIQ] = "_fiq_sp_el3",
[EXC_VID_CUR_SP_ELX_SERR] = "_serror_sp_el3",
[EXC_VID_LOW64_SYNC] = "_sync_elx_64",
[EXC_VID_LOW64_IRQ] = "_irq_elx_64",
[EXC_VID_LOW64_FIQ] = "_fiq_elx_64",
[EXC_VID_LOW64_SERR] = "_serror_elx_64",
[EXC_VID_LOW32_SYNC] = "_sync_elx_32",
[EXC_VID_LOW32_IRQ] = "_irq_elx_32",
[EXC_VID_LOW32_FIQ] = "_fiq_elx_32",
[EXC_VID_LOW32_SERR] = "_serror_elx_32"
};
static void dump_stack(uintptr_t addr, size_t bytes)
{
int i, j;
const int words_per_line = 8;
uint64_t *ptr = (void *)ALIGN_DOWN(addr, words_per_line * sizeof(*ptr));
printk(BIOS_DEBUG, "Dumping stack:\n");
for (i = bytes / sizeof(*ptr); i >= 0; i -= words_per_line) {
printk(BIOS_DEBUG, "%p: ", ptr + i);
for (j = i; j < i + words_per_line; j++)
printk(BIOS_DEBUG, "%016llx ", *(ptr + j));
printk(BIOS_DEBUG, "\n");
}
}
static void print_regs(struct exc_state *exc_state)
{
int i;
struct elx_state *elx = &exc_state->elx;
struct regs *regs = &exc_state->regs;
printk(BIOS_DEBUG, "ELR = 0x%016llx ESR = 0x%08llx\n",
elx->elr, raw_read_esr_el3());
printk(BIOS_DEBUG, "FAR = 0x%016llx SPSR = 0x%08llx\n",
raw_read_far_el3(), raw_read_spsr_el3());
for (i = 0; i < 30; i += 2) {
printk(BIOS_DEBUG,
"X%02d = 0x%016llx X%02d = 0x%016llx\n",
i, regs->x[i], i + 1, regs->x[i + 1]);
}
printk(BIOS_DEBUG, "X30 = 0x%016llx SP = 0x%016llx\n",
regs->x[30], regs->sp);
}
static struct exception_handler *handlers[NUM_EXC_VIDS];
int exception_handler_register(uint64_t vid, struct exception_handler *h)
{
if (vid >= NUM_EXC_VIDS)
return -1;
/* Just place at head of queue. */
h->next = handlers[vid];
store_release(&handlers[vid], h);
return 0;
}
int exception_handler_unregister(uint64_t vid, struct exception_handler *h)
{
struct exception_handler *cur;
struct exception_handler **prev;
if (vid >= NUM_EXC_VIDS)
return -1;
prev = &handlers[vid];
for (cur = handlers[vid]; cur != NULL; cur = cur->next) {
if (cur != h)
continue;
/* Update previous pointer. */
store_release(prev, cur->next);
return 0;
}
/* Not found */
return -1;
}
static void print_exception_info(struct exc_state *state, uint64_t idx)
{
/* Poor man's sign of life in case printk() is shot. */
__uart_tx_byte('\r');
__uart_tx_byte('\n');
__uart_tx_byte('!');
printk(BIOS_DEBUG, "\nexception %s\n",
idx < NUM_EXC_VIDS ? exception_names[idx] : "_unknown");
print_regs(state);
/* Few words below SP in case we need state from a returned function. */
dump_stack(state->regs.sp - 32, 512);
}
static void print_exception_and_die(struct exc_state *state, uint64_t idx)
{
print_exception_info(state, idx);
die("exception death");
}
static int handle_exception(struct exc_state *state, uint64_t idx)
{
int ret = EXC_RET_ABORT;
struct exception_handler *h;
for (h = handlers[idx]; h != NULL; h = h->next) {
int hret;
hret = h->handler(state, idx);
if (hret > ret)
ret = hret;
}
return ret;
}
void exc_dispatch(struct exc_state *state, uint64_t idx)
{
int ret;
if (idx >= NUM_EXC_VIDS) {
printk(BIOS_DEBUG, "Bad exception index %x.\n", (int)idx);
print_exception_and_die(state, idx);
}
ret = handle_exception(state, idx);
if (ret == EXC_RET_ABORT)
print_exception_and_die(state, idx);
if (ret == EXC_RET_IGNORED || ret == EXC_RET_HANDLED_DUMP_STATE)
print_exception_info(state, idx);
exc_exit(&state->regs);
}
static int test_exception_handler(struct exc_state *state, uint64_t vector_id)
{
/* Update instruction pointer to next instrution. */
state->elx.elr += sizeof(uint32_t);
raw_write_elr_el3(state->elx.elr);
return EXC_RET_HANDLED;
}
static uint64_t test_exception(void)
{
struct exception_handler sync_elx;
struct exception_handler sync_el0;
unsigned long long *a = (void *)0xffffffff00000000ULL;
sync_elx.handler = &test_exception_handler;
sync_el0.handler = &test_exception_handler;
exception_handler_register(EXC_VID_CUR_SP_ELX_SYNC, &sync_elx);
exception_handler_register(EXC_VID_CUR_SP_EL0_SYNC, &sync_el0);
force_read(*a);
exception_handler_unregister(EXC_VID_CUR_SP_ELX_SYNC, &sync_elx);
exception_handler_unregister(EXC_VID_CUR_SP_EL0_SYNC, &sync_el0);
return 0;
}
void exception_init(void)
{
/* Load the exception table and initialize SP_EL3. */
exception_init_asm(exception_stack + ARRAY_SIZE(exception_stack));
printk(BIOS_DEBUG, "ARM64: Exception handlers installed.\n");
/* Only spend time testing on debug builds that are trying to detect more errors. */
if (CONFIG(FATAL_ASSERTS)) {
printk(BIOS_DEBUG, "ARM64: Testing exception\n");
test_exception();
printk(BIOS_DEBUG, "ARM64: Done test exception\n");
}
}
|
