1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <linux/kernel.h>
4 #include <linux/kgdb.h>
5 #include <linux/printk.h>
6 #include <linux/sched/debug.h>
7 #include <linux/delay.h>
8 #include <linux/reboot.h>
9
10 #include <asm/pdc.h>
11 #include <asm/pdc_chassis.h>
12 #include <asm/ldcw.h>
13 #include <asm/processor.h>
14
15 static unsigned int __aligned(16) toc_lock = 1;
16 DEFINE_PER_CPU_PAGE_ALIGNED(char [16384], toc_stack) __visible;
17
18 static void toc20_to_pt_regs(struct pt_regs *regs, struct pdc_toc_pim_20 *toc)
19 {
20 int i;
21
22 regs->gr[0] = (unsigned long)toc->cr[22];
23
24 for (i = 1; i < 32; i++)
25 regs->gr[i] = (unsigned long)toc->gr[i];
26
27 for (i = 0; i < 8; i++)
28 regs->sr[i] = (unsigned long)toc->sr[i];
29
30 regs->iasq[0] = (unsigned long)toc->cr[17];
31 regs->iasq[1] = (unsigned long)toc->iasq_back;
32 regs->iaoq[0] = (unsigned long)toc->cr[18];
33 regs->iaoq[1] = (unsigned long)toc->iaoq_back;
34
35 regs->sar = (unsigned long)toc->cr[11];
36 regs->iir = (unsigned long)toc->cr[19];
37 regs->isr = (unsigned long)toc->cr[20];
38 regs->ior = (unsigned long)toc->cr[21];
39 }
40
41 static void toc11_to_pt_regs(struct pt_regs *regs, struct pdc_toc_pim_11 *toc)
42 {
43 int i;
44
45 regs->gr[0] = toc->cr[22];
46
47 for (i = 1; i < 32; i++)
48 regs->gr[i] = toc->gr[i];
49
50 for (i = 0; i < 8; i++)
51 regs->sr[i] = toc->sr[i];
52
53 regs->iasq[0] = toc->cr[17];
54 regs->iasq[1] = toc->iasq_back;
55 regs->iaoq[0] = toc->cr[18];
56 regs->iaoq[1] = toc->iaoq_back;
57
58 regs->sar = toc->cr[11];
59 regs->iir = toc->cr[19];
60 regs->isr = toc->cr[20];
61 regs->ior = toc->cr[21];
62 }
63
64 void notrace __noreturn __cold toc_intr(struct pt_regs *regs)
65 {
66 struct pdc_toc_pim_20 pim_data20;
67 struct pdc_toc_pim_11 pim_data11;
68
69 /* verify we wrote regs to the correct stack */
70 BUG_ON(regs != (struct pt_regs *)&per_cpu(toc_stack, raw_smp_processor_id()));
71
72 if (boot_cpu_data.cpu_type >= pcxu) {
73 if (pdc_pim_toc20(&pim_data20))
74 panic("Failed to get PIM data");
75 toc20_to_pt_regs(regs, &pim_data20);
76 } else {
77 if (pdc_pim_toc11(&pim_data11))
78 panic("Failed to get PIM data");
79 toc11_to_pt_regs(regs, &pim_data11);
80 }
81
82 #ifdef CONFIG_KGDB
83 nmi_enter();
84
85 if (atomic_read(&kgdb_active) != -1)
86 kgdb_nmicallback(raw_smp_processor_id(), regs);
87 kgdb_handle_exception(9, SIGTRAP, 0, regs);
88 #endif
89
90 /* serialize output, otherwise all CPUs write backtrace at once */
91 while (__ldcw(&toc_lock) == 0)
92 ; /* wait */
93 show_regs(regs);
94 toc_lock = 1; /* release lock for next CPU */
95
96 if (raw_smp_processor_id() != 0)
97 while (1) ; /* all but monarch CPU will wait endless. */
98
99 /* give other CPUs time to show their backtrace */
100 mdelay(2000);
101
102 machine_restart("TOC");
103
104 /* should never reach this */
105 panic("TOC");
106 }
107
108 static __init int setup_toc(void)
109 {
110 unsigned int csum = 0;
111 unsigned long toc_code = (unsigned long)dereference_function_descriptor(toc_handler);
112 int i;
113
114 PAGE0->vec_toc = __pa(toc_code) & 0xffffffff;
115 #ifdef CONFIG_64BIT
116 PAGE0->vec_toc_hi = __pa(toc_code) >> 32;
117 #endif
118 PAGE0->vec_toclen = toc_handler_size;
119
120 for (i = 0; i < toc_handler_size/4; i++)
121 csum += ((u32 *)toc_code)[i];
122 toc_handler_csum = -csum;
123 pr_info("TOC handler registered\n");
124 return 0;
125 }
126 early_initcall(setup_toc);
127
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.