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
 15static unsigned int __aligned(16) toc_lock = 1;
 16DEFINE_PER_CPU_PAGE_ALIGNED(char [16384], toc_stack) __visible;
 17
 18static 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
 41static 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
 64void 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
108static __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}
126early_initcall(setup_toc);