1 /*
2  * Copyright (C) 2003-2006, Axis Communications AB.
3  */
4 
5 #include <linux/ptrace.h>
6 #include <linux/module.h>
7 #include <asm/uaccess.h>
8 #include <hwregs/supp_reg.h>
9 #include <hwregs/intr_vect_defs.h>
10 #include <asm/irq.h>
11 
show_registers(struct pt_regs * regs)12 void show_registers(struct pt_regs *regs)
13 {
14 	/*
15 	 * It's possible to use either the USP register or current->thread.usp.
16 	 * USP might not correspond to the current process for all cases this
17 	 * function is called, and current->thread.usp isn't up to date for the
18 	 * current process. Experience shows that using USP is the way to go.
19 	 */
20 	unsigned long usp = rdusp();
21 	unsigned long d_mmu_cause;
22 	unsigned long i_mmu_cause;
23 
24 	printk("CPU: %d\n", smp_processor_id());
25 
26 	printk("ERP: %08lx SRP: %08lx  CCS: %08lx USP: %08lx MOF: %08lx\n",
27 	       regs->erp, regs->srp, regs->ccs, usp, regs->mof);
28 
29 	printk(" r0: %08lx  r1: %08lx   r2: %08lx  r3: %08lx\n",
30 	       regs->r0, regs->r1, regs->r2, regs->r3);
31 
32 	printk(" r4: %08lx  r5: %08lx   r6: %08lx  r7: %08lx\n",
33 	       regs->r4, regs->r5, regs->r6, regs->r7);
34 
35 	printk(" r8: %08lx  r9: %08lx  r10: %08lx r11: %08lx\n",
36 	       regs->r8, regs->r9, regs->r10, regs->r11);
37 
38 	printk("r12: %08lx r13: %08lx oR10: %08lx acr: %08lx\n",
39 	       regs->r12, regs->r13, regs->orig_r10, regs->acr);
40 
41 	printk(" sp: %08lx\n", (unsigned long)regs);
42 
43 	SUPP_BANK_SEL(BANK_IM);
44 	SUPP_REG_RD(RW_MM_CAUSE, i_mmu_cause);
45 
46 	SUPP_BANK_SEL(BANK_DM);
47 	SUPP_REG_RD(RW_MM_CAUSE, d_mmu_cause);
48 
49 	printk("       Data MMU Cause: %08lx\n", d_mmu_cause);
50 	printk("Instruction MMU Cause: %08lx\n", i_mmu_cause);
51 
52 	printk("Process %s (pid: %d, stackpage=%08lx)\n",
53 	       current->comm, current->pid, (unsigned long)current);
54 
55 	/*
56 	 * When in-kernel, we also print out the stack and code at the
57 	 * time of the fault..
58 	 */
59 	if (!user_mode(regs)) {
60 		int i;
61 
62 		show_stack(NULL, (unsigned long *)usp);
63 
64 		/*
65 		 * If the previous stack-dump wasn't a kernel one, dump the
66 		 * kernel stack now.
67 		 */
68 		if (usp != 0)
69 			show_stack(NULL, NULL);
70 
71 		printk("\nCode: ");
72 
73 		if (regs->erp < PAGE_OFFSET)
74 			goto bad_value;
75 
76 		/*
77 		 * Quite often the value at regs->erp doesn't point to the
78 		 * interesting instruction, which often is the previous
79 		 * instruction. So dump at an offset large enough that the
80 		 * instruction decoding should be in sync at the interesting
81 		 * point, but small enough to fit on a row. The regs->erp
82 		 * location is pointed out in a ksymoops-friendly way by
83 		 * wrapping the byte for that address in parenthesises.
84 		 */
85 		for (i = -12; i < 12; i++) {
86 			unsigned char c;
87 
88 			if (__get_user(c, &((unsigned char *)regs->erp)[i])) {
89 bad_value:
90 				printk(" Bad IP value.");
91 				break;
92 			}
93 
94 			if (i == 0)
95 				printk("(%02x) ", c);
96 			else
97 				printk("%02x ", c);
98 		}
99 		printk("\n");
100 	}
101 }
102 
arch_enable_nmi(void)103 void arch_enable_nmi(void)
104 {
105 	unsigned long flags;
106 
107 	local_save_flags(flags);
108 	flags |= (1 << 30); /* NMI M flag is at bit 30 */
109 	local_irq_restore(flags);
110 }
111 
112 extern void (*nmi_handler)(struct pt_regs *);
handle_nmi(struct pt_regs * regs)113 void handle_nmi(struct pt_regs *regs)
114 {
115 #ifdef CONFIG_ETRAXFS
116 	reg_intr_vect_r_nmi r;
117 #endif
118 
119 	if (nmi_handler)
120 		nmi_handler(regs);
121 
122 #ifdef CONFIG_ETRAXFS
123 	/* Wait until nmi is no longer active. */
124 	do {
125 		r = REG_RD(intr_vect, regi_irq, r_nmi);
126 	} while (r.ext == regk_intr_vect_on);
127 #endif
128 }
129 
130 
131 #ifdef CONFIG_BUG
132 extern void die_if_kernel(const char *str, struct pt_regs *regs, long err);
133 
134 /* Copy of the regs at BUG() time.  */
135 struct pt_regs BUG_regs;
136 
do_BUG(char * file,unsigned int line)137 void do_BUG(char *file, unsigned int line)
138 {
139 	printk("kernel BUG at %s:%d!\n", file, line);
140 	die_if_kernel("Oops", &BUG_regs, 0);
141 }
142 EXPORT_SYMBOL(do_BUG);
143 
fixup_BUG(struct pt_regs * regs)144 void fixup_BUG(struct pt_regs *regs)
145 {
146 	BUG_regs = *regs;
147 
148 #ifdef CONFIG_DEBUG_BUGVERBOSE
149 	/*
150 	 * Fixup the BUG arguments through exception handlers.
151 	 */
152 	{
153 		const struct exception_table_entry *fixup;
154 
155 		/*
156 		 * ERP points at the "break 14" + 2, compensate for the 2
157 		 * bytes.
158 		 */
159 		fixup = search_exception_tables(instruction_pointer(regs) - 2);
160 		if (fixup) {
161 			/* Adjust the instruction pointer in the stackframe. */
162 			instruction_pointer(regs) = fixup->fixup;
163 			arch_fixup(regs);
164 		}
165 	}
166 #else
167 	/* Dont try to lookup the filename + line, just dump regs.  */
168 	do_BUG("unknown", 0);
169 #endif
170 }
171 
172 /*
173  * Break 14 handler. Save regs and jump into the fixup_BUG.
174  */
175 __asm__  ( ".text\n\t"
176 	   ".global breakh_BUG\n\t"
177 	   "breakh_BUG:\n\t"
178 	   SAVE_ALL
179 	   KGDB_FIXUP
180 	   "move.d $sp, $r10\n\t"
181 	   "jsr fixup_BUG\n\t"
182 	   "nop\n\t"
183 	   "jump ret_from_intr\n\t"
184 	   "nop\n\t");
185 
186 
187 #ifdef CONFIG_DEBUG_BUGVERBOSE
188 void
handle_BUG(struct pt_regs * regs)189 handle_BUG(struct pt_regs *regs)
190 {
191 }
192 #endif
193 #endif
194