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