1 /*
2 * arch/xtensa/include/asm/traps.h
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 * Copyright (C) 2012 Tensilica Inc.
9 */
10 #ifndef _XTENSA_TRAPS_H
11 #define _XTENSA_TRAPS_H
12
13 #include <asm/ptrace.h>
14
15 /*
16 * Per-CPU exception handling data structure.
17 * EXCSAVE1 points to it.
18 */
19 struct exc_table {
20 /* Kernel Stack */
21 void *kstk;
22 /* Double exception save area for a0 */
23 unsigned long double_save;
24 /* Fixup handler */
25 void *fixup;
26 /* For passing a parameter to fixup */
27 void *fixup_param;
28 /* Fast user exception handlers */
29 void *fast_user_handler[EXCCAUSE_N];
30 /* Fast kernel exception handlers */
31 void *fast_kernel_handler[EXCCAUSE_N];
32 /* Default C-Handlers */
33 void *default_handler[EXCCAUSE_N];
34 };
35
36 /*
37 * handler must be either of the following:
38 * void (*)(struct pt_regs *regs);
39 * void (*)(struct pt_regs *regs, unsigned long exccause);
40 */
41 extern void * __init trap_set_handler(int cause, void *handler);
42 extern void do_unhandled(struct pt_regs *regs, unsigned long exccause);
43 void fast_second_level_miss(void);
44
45 /* Initialize minimal exc_table structure sufficient for basic paging */
early_trap_init(void)46 static inline void __init early_trap_init(void)
47 {
48 static struct exc_table exc_table __initdata = {
49 .fast_kernel_handler[EXCCAUSE_DTLB_MISS] =
50 fast_second_level_miss,
51 };
52 __asm__ __volatile__("wsr %0, excsave1\n" : : "a" (&exc_table));
53 }
54
55 void secondary_trap_init(void);
56
spill_registers(void)57 static inline void spill_registers(void)
58 {
59 #if XCHAL_NUM_AREGS > 16
60 __asm__ __volatile__ (
61 " call8 1f\n"
62 " _j 2f\n"
63 " retw\n"
64 " .align 4\n"
65 "1:\n"
66 #if XCHAL_NUM_AREGS == 32
67 " _entry a1, 32\n"
68 " addi a8, a0, 3\n"
69 " _entry a1, 16\n"
70 " mov a12, a12\n"
71 " retw\n"
72 #else
73 " _entry a1, 48\n"
74 " call12 1f\n"
75 " retw\n"
76 " .align 4\n"
77 "1:\n"
78 " .rept (" __stringify(XCHAL_NUM_AREGS) " - 16) / 12\n"
79 " _entry a1, 48\n"
80 " mov a12, a0\n"
81 " .endr\n"
82 " _entry a1, 16\n"
83 #if XCHAL_NUM_AREGS % 12 == 0
84 " mov a12, a12\n"
85 #elif XCHAL_NUM_AREGS % 12 == 4
86 " mov a4, a4\n"
87 #elif XCHAL_NUM_AREGS % 12 == 8
88 " mov a8, a8\n"
89 #endif
90 " retw\n"
91 #endif
92 "2:\n"
93 : : : "a8", "a9", "memory");
94 #else
95 __asm__ __volatile__ (
96 " mov a12, a12\n"
97 : : : "memory");
98 #endif
99 }
100
101 struct debug_table {
102 /* Pointer to debug exception handler */
103 void (*debug_exception)(void);
104 /* Temporary register save area */
105 unsigned long debug_save[1];
106 #ifdef CONFIG_HAVE_HW_BREAKPOINT
107 /* Save area for DBREAKC registers */
108 unsigned long dbreakc_save[XCHAL_NUM_DBREAK];
109 /* Saved ICOUNT register */
110 unsigned long icount_save;
111 /* Saved ICOUNTLEVEL register */
112 unsigned long icount_level_save;
113 #endif
114 };
115
116 void debug_exception(void);
117
118 #endif /* _XTENSA_TRAPS_H */
119