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(fmt: "Failed to get PIM data" ); |
75 | toc20_to_pt_regs(regs, toc: &pim_data20); |
76 | } else { |
77 | if (pdc_pim_toc11(&pim_data11)) |
78 | panic(fmt: "Failed to get PIM data" ); |
79 | toc11_to_pt_regs(regs, toc: &pim_data11); |
80 | } |
81 | |
82 | #ifdef CONFIG_KGDB |
83 | nmi_enter(); |
84 | |
85 | if (atomic_read(v: &kgdb_active) != -1) |
86 | kgdb_nmicallback(raw_smp_processor_id(), regs); |
87 | kgdb_handle_exception(ex_vector: 9, SIGTRAP, err_code: 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(cmd: "TOC" ); |
103 | |
104 | /* should never reach this */ |
105 | panic(fmt: "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 | |