xref: /linux/arch/xtensa/include/asm/traps.h (revision 0e2b2a76278153d1ac312b0691cb65dabb9aef3e)
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 typedef void xtensa_exception_handler(struct pt_regs *regs);
16 
17 /*
18  * Per-CPU exception handling data structure.
19  * EXCSAVE1 points to it.
20  */
21 struct exc_table {
22 	/* Kernel Stack */
23 	void *kstk;
24 	/* Double exception save area for a0 */
25 	unsigned long double_save;
26 	/* Fixup handler */
27 	void *fixup;
28 	/* For passing a parameter to fixup */
29 	void *fixup_param;
30 #if XTENSA_HAVE_COPROCESSORS
31 	/* Pointers to owner struct thread_info */
32 	struct thread_info *coprocessor_owner[XCHAL_CP_MAX];
33 #endif
34 	/* Fast user exception handlers */
35 	void *fast_user_handler[EXCCAUSE_N];
36 	/* Fast kernel exception handlers */
37 	void *fast_kernel_handler[EXCCAUSE_N];
38 	/* Default C-Handlers */
39 	xtensa_exception_handler *default_handler[EXCCAUSE_N];
40 };
41 
42 DECLARE_PER_CPU(struct exc_table, exc_table);
43 
44 xtensa_exception_handler *
45 __init trap_set_handler(int cause, xtensa_exception_handler *handler);
46 
47 asmlinkage void fast_illegal_instruction_user(void);
48 asmlinkage void fast_syscall_user(void);
49 asmlinkage void fast_alloca(void);
50 asmlinkage void fast_load_store(void);
51 asmlinkage void fast_unaligned(void);
52 asmlinkage void fast_second_level_miss(void);
53 asmlinkage void fast_store_prohibited(void);
54 asmlinkage void fast_coprocessor(void);
55 
56 asmlinkage void kernel_exception(void);
57 asmlinkage void user_exception(void);
58 asmlinkage void system_call(struct pt_regs *regs);
59 
60 void do_IRQ(int hwirq, struct pt_regs *regs);
61 void do_page_fault(struct pt_regs *regs);
62 void do_unhandled(struct pt_regs *regs);
63 
64 /* Initialize minimal exc_table structure sufficient for basic paging */
65 static inline void __init early_trap_init(void)
66 {
67 	static struct exc_table init_exc_table __initdata = {
68 #ifdef CONFIG_XTENSA_LOAD_STORE
69 		.fast_kernel_handler[EXCCAUSE_LOAD_STORE_ERROR] =
70 			fast_load_store,
71 #endif
72 #ifdef CONFIG_MMU
73 		.fast_kernel_handler[EXCCAUSE_DTLB_MISS] =
74 			fast_second_level_miss,
75 #endif
76 	};
77 	xtensa_set_sr(&init_exc_table, excsave1);
78 }
79 
80 void secondary_trap_init(void);
81 
82 static inline void spill_registers(void)
83 {
84 #if defined(__XTENSA_WINDOWED_ABI__)
85 #if XCHAL_NUM_AREGS > 16
86 	__asm__ __volatile__ (
87 		"	call8	1f\n"
88 		"	_j	2f\n"
89 		"	retw\n"
90 		"	.align	4\n"
91 		"1:\n"
92 #if XCHAL_NUM_AREGS == 32
93 		"	_entry	a1, 32\n"
94 		"	addi	a8, a0, 3\n"
95 		"	_entry	a1, 16\n"
96 		"	mov	a12, a12\n"
97 		"	retw\n"
98 #else
99 		"	_entry	a1, 48\n"
100 		"	call12	1f\n"
101 		"	retw\n"
102 		"	.align	4\n"
103 		"1:\n"
104 		"	.rept	(" __stringify(XCHAL_NUM_AREGS) " - 16) / 12\n"
105 		"	_entry	a1, 48\n"
106 		"	mov	a12, a0\n"
107 		"	.endr\n"
108 		"	_entry	a1, 16\n"
109 #if XCHAL_NUM_AREGS % 12 == 0
110 		"	mov	a12, a12\n"
111 #elif XCHAL_NUM_AREGS % 12 == 4
112 		"	mov	a4, a4\n"
113 #elif XCHAL_NUM_AREGS % 12 == 8
114 		"	mov	a8, a8\n"
115 #endif
116 		"	retw\n"
117 #endif
118 		"2:\n"
119 		: : : "a8", "a9", "memory");
120 #else
121 	__asm__ __volatile__ (
122 		"	mov	a12, a12\n"
123 		: : : "memory");
124 #endif
125 #endif
126 }
127 
128 struct debug_table {
129 	/* Pointer to debug exception handler */
130 	void (*debug_exception)(void);
131 	/* Temporary register save area */
132 	unsigned long debug_save[1];
133 #ifdef CONFIG_HAVE_HW_BREAKPOINT
134 	/* Save area for DBREAKC registers */
135 	unsigned long dbreakc_save[XCHAL_NUM_DBREAK];
136 	/* Saved ICOUNT register */
137 	unsigned long icount_save;
138 	/* Saved ICOUNTLEVEL register */
139 	unsigned long icount_level_save;
140 #endif
141 };
142 
143 void debug_exception(void);
144 
145 #endif /* _XTENSA_TRAPS_H */
146