1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/arch/ia64/kernel/irq.c 4 * 5 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar 6 * 7 * This file contains the code used by various IRQ handling routines: 8 * asking for different IRQs should be done through these routines 9 * instead of just grabbing them. Thus setups with different IRQ numbers 10 * shouldn't result in any weird surprises, and installing new handlers 11 * should be easier. 12 * 13 * Copyright (C) Ashok Raj<ashok.raj@intel.com>, Intel Corporation 2004 14 * 15 * 4/14/2004: Added code to handle cpu migration and do safe irq 16 * migration without losing interrupts for iosapic 17 * architecture. 18 */ 19 20 #include <asm/delay.h> 21 #include <linux/uaccess.h> 22 #include <linux/module.h> 23 #include <linux/seq_file.h> 24 #include <linux/interrupt.h> 25 #include <linux/kernel_stat.h> 26 27 #include <asm/mca.h> 28 29 /* 30 * 'what should we do if we get a hw irq event on an illegal vector'. 31 * each architecture has to answer this themselves. 32 */ 33 void ack_bad_irq(unsigned int irq) 34 { 35 printk(KERN_ERR "Unexpected irq vector 0x%x on CPU %u!\n", irq, smp_processor_id()); 36 } 37 38 /* 39 * Interrupt statistics: 40 */ 41 42 atomic_t irq_err_count; 43 44 /* 45 * /proc/interrupts printing: 46 */ 47 int arch_show_interrupts(struct seq_file *p, int prec) 48 { 49 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count)); 50 return 0; 51 } 52 53 #ifdef CONFIG_SMP 54 static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 }; 55 56 void set_irq_affinity_info (unsigned int irq, int hwid, int redir) 57 { 58 if (irq < NR_IRQS) { 59 cpumask_copy(irq_get_affinity_mask(irq), 60 cpumask_of(cpu_logical_id(hwid))); 61 irq_redir[irq] = (char) (redir & 0xff); 62 } 63 } 64 #endif /* CONFIG_SMP */ 65 66 int __init arch_early_irq_init(void) 67 { 68 ia64_mca_irq_init(); 69 return 0; 70 } 71 72 #ifdef CONFIG_HOTPLUG_CPU 73 unsigned int vectors_in_migration[NR_IRQS]; 74 75 /* 76 * Since cpu_online_mask is already updated, we just need to check for 77 * affinity that has zeros 78 */ 79 static void migrate_irqs(void) 80 { 81 int irq, new_cpu; 82 83 for (irq=0; irq < NR_IRQS; irq++) { 84 struct irq_desc *desc = irq_to_desc(irq); 85 struct irq_data *data = irq_desc_get_irq_data(desc); 86 struct irq_chip *chip = irq_data_get_irq_chip(data); 87 88 if (irqd_irq_disabled(data)) 89 continue; 90 91 /* 92 * No handling for now. 93 * TBD: Implement a disable function so we can now 94 * tell CPU not to respond to these local intr sources. 95 * such as ITV,CPEI,MCA etc. 96 */ 97 if (irqd_is_per_cpu(data)) 98 continue; 99 100 if (cpumask_any_and(irq_data_get_affinity_mask(data), 101 cpu_online_mask) >= nr_cpu_ids) { 102 /* 103 * Save it for phase 2 processing 104 */ 105 vectors_in_migration[irq] = irq; 106 107 new_cpu = cpumask_any(cpu_online_mask); 108 109 /* 110 * Al three are essential, currently WARN_ON.. maybe panic? 111 */ 112 if (chip && chip->irq_disable && 113 chip->irq_enable && chip->irq_set_affinity) { 114 chip->irq_disable(data); 115 chip->irq_set_affinity(data, 116 cpumask_of(new_cpu), false); 117 chip->irq_enable(data); 118 } else { 119 WARN_ON((!chip || !chip->irq_disable || 120 !chip->irq_enable || 121 !chip->irq_set_affinity)); 122 } 123 } 124 } 125 } 126 127 void fixup_irqs(void) 128 { 129 unsigned int irq; 130 extern void ia64_process_pending_intr(void); 131 extern volatile int time_keeper_id; 132 133 /* Mask ITV to disable timer */ 134 ia64_set_itv(1 << 16); 135 136 /* 137 * Find a new timesync master 138 */ 139 if (smp_processor_id() == time_keeper_id) { 140 time_keeper_id = cpumask_first(cpu_online_mask); 141 printk ("CPU %d is now promoted to time-keeper master\n", time_keeper_id); 142 } 143 144 /* 145 * Phase 1: Locate IRQs bound to this cpu and 146 * relocate them for cpu removal. 147 */ 148 migrate_irqs(); 149 150 /* 151 * Phase 2: Perform interrupt processing for all entries reported in 152 * local APIC. 153 */ 154 ia64_process_pending_intr(); 155 156 /* 157 * Phase 3: Now handle any interrupts not captured in local APIC. 158 * This is to account for cases that device interrupted during the time the 159 * rte was being disabled and re-programmed. 160 */ 161 for (irq=0; irq < NR_IRQS; irq++) { 162 if (vectors_in_migration[irq]) { 163 struct pt_regs *old_regs = set_irq_regs(NULL); 164 165 vectors_in_migration[irq]=0; 166 generic_handle_irq(irq); 167 set_irq_regs(old_regs); 168 } 169 } 170 171 /* 172 * Now let processor die. We do irq disable and max_xtp() to 173 * ensure there is no more interrupts routed to this processor. 174 * But the local timer interrupt can have 1 pending which we 175 * take care in timer_interrupt(). 176 */ 177 max_xtp(); 178 local_irq_disable(); 179 } 180 #endif 181