toc.c (3124B)
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);