1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3
4 #include <linux/sched.h>
5 #include <linux/signal.h>
6 #include <linux/kernel.h>
7 #include <linux/mm.h>
8 #include <linux/module.h>
9 #include <linux/user.h>
10 #include <linux/string.h>
11 #include <linux/linkage.h>
12 #include <linux/init.h>
13 #include <linux/ptrace.h>
14 #include <linux/kallsyms.h>
15 #include <linux/rtc.h>
16 #include <linux/uaccess.h>
17
18 #include <asm/setup.h>
19 #include <asm/traps.h>
20 #include <asm/pgalloc.h>
21 #include <asm/siginfo.h>
22
23 #include <asm/mmu_context.h>
24
25 #ifdef CONFIG_CPU_HAS_FPU
26 #include <abi/fpu.h>
27 #endif
28
29 /* Defined in entry.S */
30 asmlinkage void csky_trap(void);
31
32 asmlinkage void csky_systemcall(void);
33 asmlinkage void csky_cmpxchg(void);
34 asmlinkage void csky_get_tls(void);
35 asmlinkage void csky_irq(void);
36
37 asmlinkage void csky_tlbinvalidl(void);
38 asmlinkage void csky_tlbinvalids(void);
39 asmlinkage void csky_tlbmodified(void);
40
41 /* Defined in head.S */
42 asmlinkage void _start_smp_secondary(void);
43
pre_trap_init(void)44 void __init pre_trap_init(void)
45 {
46 int i;
47
48 mtcr("vbr", vec_base);
49
50 for (i = 1; i < 128; i++)
51 VEC_INIT(i, csky_trap);
52 }
53
trap_init(void)54 void __init trap_init(void)
55 {
56 VEC_INIT(VEC_AUTOVEC, csky_irq);
57
58 /* setup trap0 trap2 trap3 */
59 VEC_INIT(VEC_TRAP0, csky_systemcall);
60 VEC_INIT(VEC_TRAP2, csky_cmpxchg);
61 VEC_INIT(VEC_TRAP3, csky_get_tls);
62
63 /* setup MMU TLB exception */
64 VEC_INIT(VEC_TLBINVALIDL, csky_tlbinvalidl);
65 VEC_INIT(VEC_TLBINVALIDS, csky_tlbinvalids);
66 VEC_INIT(VEC_TLBMODIFIED, csky_tlbmodified);
67
68 #ifdef CONFIG_CPU_HAS_FPU
69 init_fpu();
70 #endif
71
72 #ifdef CONFIG_SMP
73 mtcr("cr<28, 0>", virt_to_phys(vec_base));
74
75 VEC_INIT(VEC_RESET, (void *)virt_to_phys(_start_smp_secondary));
76 #endif
77 }
78
die_if_kernel(char * str,struct pt_regs * regs,int nr)79 void die_if_kernel(char *str, struct pt_regs *regs, int nr)
80 {
81 if (user_mode(regs))
82 return;
83
84 console_verbose();
85 pr_err("%s: %08x\n", str, nr);
86 show_regs(regs);
87 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
88 make_task_dead(SIGSEGV);
89 }
90
buserr(struct pt_regs * regs)91 void buserr(struct pt_regs *regs)
92 {
93 #ifdef CONFIG_CPU_CK810
94 static unsigned long prev_pc;
95
96 if ((regs->pc == prev_pc) && prev_pc != 0) {
97 prev_pc = 0;
98 } else {
99 prev_pc = regs->pc;
100 return;
101 }
102 #endif
103
104 die_if_kernel("Kernel mode BUS error", regs, 0);
105
106 pr_err("User mode Bus Error\n");
107 show_regs(regs);
108
109 force_sig_fault(SIGSEGV, 0, (void __user *)regs->pc);
110 }
111
112 #define USR_BKPT 0x1464
trap_c(struct pt_regs * regs)113 asmlinkage void trap_c(struct pt_regs *regs)
114 {
115 int sig;
116 unsigned long vector;
117 siginfo_t info;
118 struct task_struct *tsk = current;
119
120 vector = (regs->sr >> 16) & 0xff;
121
122 switch (vector) {
123 case VEC_ZERODIV:
124 die_if_kernel("Kernel mode ZERO DIV", regs, vector);
125 sig = SIGFPE;
126 break;
127 /* ptrace */
128 case VEC_TRACE:
129 info.si_code = TRAP_TRACE;
130 sig = SIGTRAP;
131 break;
132 case VEC_ILLEGAL:
133 tsk->thread.trap_no = vector;
134 die_if_kernel("Kernel mode ILLEGAL", regs, vector);
135 #ifndef CONFIG_CPU_NO_USER_BKPT
136 if (*(uint16_t *)instruction_pointer(regs) != USR_BKPT)
137 #endif
138 {
139 sig = SIGILL;
140 break;
141 }
142 /* gdbserver breakpoint */
143 case VEC_TRAP1:
144 /* jtagserver breakpoint */
145 case VEC_BREAKPOINT:
146 die_if_kernel("Kernel mode BKPT", regs, vector);
147 info.si_code = TRAP_BRKPT;
148 sig = SIGTRAP;
149 break;
150 case VEC_ACCESS:
151 tsk->thread.trap_no = vector;
152 return buserr(regs);
153 #ifdef CONFIG_CPU_NEED_SOFTALIGN
154 case VEC_ALIGN:
155 tsk->thread.trap_no = vector;
156 return csky_alignment(regs);
157 #endif
158 #ifdef CONFIG_CPU_HAS_FPU
159 case VEC_FPE:
160 tsk->thread.trap_no = vector;
161 die_if_kernel("Kernel mode FPE", regs, vector);
162 return fpu_fpe(regs);
163 case VEC_PRIV:
164 tsk->thread.trap_no = vector;
165 die_if_kernel("Kernel mode PRIV", regs, vector);
166 if (fpu_libc_helper(regs))
167 return;
168 #endif
169 default:
170 sig = SIGSEGV;
171 break;
172 }
173
174 tsk->thread.trap_no = vector;
175
176 send_sig(sig, current, 0);
177 }
178