xref: /openbmc/u-boot/arch/riscv/lib/interrupts.c (revision 05512517)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2016-17 Microsemi Corporation.
4  * Padmarao Begari, Microsemi Corporation <padmarao.begari@microsemi.com>
5  *
6  * Copyright (C) 2017 Andes Technology Corporation
7  * Rick Chen, Andes Technology Corporation <rick@andestech.com>
8  */
9 
10 #include <common.h>
11 #include <asm/ptrace.h>
12 #include <asm/system.h>
13 #include <asm/encoding.h>
14 
15 static void _exit_trap(ulong code, ulong epc, struct pt_regs *regs)
16 {
17 	static const char * const exception_code[] = {
18 		"Instruction address misaligned",
19 		"Instruction access fault",
20 		"Illegal instruction",
21 		"Breakpoint",
22 		"Load address misaligned",
23 		"Load access fault",
24 		"Store/AMO address misaligned",
25 		"Store/AMO access fault",
26 		"Environment call from U-mode",
27 		"Environment call from S-mode",
28 		"Reserved",
29 		"Environment call from M-mode",
30 		"Instruction page fault",
31 		"Load page fault",
32 		"Reserved",
33 		"Store/AMO page fault",
34 	};
35 
36 	if (code < ARRAY_SIZE(exception_code)) {
37 		printf("exception code: %ld , %s , epc %lx , ra %lx\n",
38 		       code, exception_code[code], epc, regs->ra);
39 	} else {
40 		printf("reserved exception code: %ld , epc %lx , ra %lx\n",
41 		       code, epc, regs->ra);
42 	}
43 
44 	hang();
45 }
46 
47 int interrupt_init(void)
48 {
49 	return 0;
50 }
51 
52 /*
53  * enable interrupts
54  */
55 void enable_interrupts(void)
56 {
57 }
58 
59 /*
60  * disable interrupts
61  */
62 int disable_interrupts(void)
63 {
64 	return 0;
65 }
66 
67 ulong handle_trap(ulong cause, ulong epc, struct pt_regs *regs)
68 {
69 	ulong is_irq, irq;
70 
71 	is_irq = (cause & MCAUSE_INT);
72 	irq = (cause & ~MCAUSE_INT);
73 
74 	if (is_irq) {
75 		switch (irq) {
76 		case IRQ_M_EXT:
77 		case IRQ_S_EXT:
78 			external_interrupt(0);	/* handle external interrupt */
79 			break;
80 		case IRQ_M_TIMER:
81 		case IRQ_S_TIMER:
82 			timer_interrupt(0);	/* handle timer interrupt */
83 			break;
84 		default:
85 			_exit_trap(cause, epc, regs);
86 			break;
87 		};
88 	} else {
89 		_exit_trap(cause, epc, regs);
90 	}
91 
92 	return epc;
93 }
94 
95 /*
96  *Entry Point for PLIC Interrupt Handler
97  */
98 __attribute__((weak)) void external_interrupt(struct pt_regs *regs)
99 {
100 }
101 
102 __attribute__((weak)) void timer_interrupt(struct pt_regs *regs)
103 {
104 }
105