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 #include <asm/xtp.h> 29 30 /* 31 * 'what should we do if we get a hw irq event on an illegal vector'. 32 * each architecture has to answer this themselves. 33 */ 34 void ack_bad_irq(unsigned int irq) 35 { 36 printk(KERN_ERR "Unexpected irq vector 0x%x on CPU %u!\n", irq, smp_processor_id()); 37 } 38 39 /* 40 * Interrupt statistics: 41 */ 42 43 atomic_t irq_err_count; 44 45 /* 46 * /proc/interrupts printing: 47 */ 48 int arch_show_interrupts(struct seq_file *p, int prec) 49 { 50 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count)); 51 return 0; 52 } 53 54 #ifdef CONFIG_SMP 55 static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 }; 56 57 void set_irq_affinity_info (unsigned int irq, int hwid, int redir) 58 { 59 if (irq < NR_IRQS) { 60 cpumask_copy(irq_get_affinity_mask(irq), 61 cpumask_of(cpu_logical_id(hwid))); 62 irq_redir[irq] = (char) (redir & 0xff); 63 } 64 } 65 #endif /* CONFIG_SMP */ 66 67 int __init arch_early_irq_init(void) 68 { 69 ia64_mca_irq_init(); 70 return 0; 71 } 72 73 #ifdef CONFIG_HOTPLUG_CPU 74 unsigned int vectors_in_migration[NR_IRQS]; 75 76 /* 77 * Since cpu_online_mask is already updated, we just need to check for 78 * affinity that has zeros 79 */ 80 static void migrate_irqs(void) 81 { 82 int irq, new_cpu; 83 84 for (irq=0; irq < NR_IRQS; irq++) { 85 struct irq_desc *desc = irq_to_desc(irq); 86 struct irq_data *data = irq_desc_get_irq_data(desc); 87 struct irq_chip *chip = irq_data_get_irq_chip(data); 88 89 if (irqd_irq_disabled(data)) 90 continue; 91 92 /* 93 * No handling for now. 94 * TBD: Implement a disable function so we can now 95 * tell CPU not to respond to these local intr sources. 96 * such as ITV,CPEI,MCA etc. 97 */ 98 if (irqd_is_per_cpu(data)) 99 continue; 100 101 if (cpumask_any_and(irq_data_get_affinity_mask(data), 102 cpu_online_mask) >= nr_cpu_ids) { 103 /* 104 * Save it for phase 2 processing 105 */ 106 vectors_in_migration[irq] = irq; 107 108 new_cpu = cpumask_any(cpu_online_mask); 109 110 /* 111 * Al three are essential, currently WARN_ON.. maybe panic? 112 */ 113 if (chip && chip->irq_disable && 114 chip->irq_enable && chip->irq_set_affinity) { 115 chip->irq_disable(data); 116 chip->irq_set_affinity(data, 117 cpumask_of(new_cpu), false); 118 chip->irq_enable(data); 119 } else { 120 WARN_ON((!chip || !chip->irq_disable || 121 !chip->irq_enable || 122 !chip->irq_set_affinity)); 123 } 124 } 125 } 126 } 127 128 void fixup_irqs(void) 129 { 130 unsigned int irq; 131 extern void ia64_process_pending_intr(void); 132 extern volatile int time_keeper_id; 133 134 /* Mask ITV to disable timer */ 135 ia64_set_itv(1 << 16); 136 137 /* 138 * Find a new timesync master 139 */ 140 if (smp_processor_id() == time_keeper_id) { 141 time_keeper_id = cpumask_first(cpu_online_mask); 142 printk ("CPU %d is now promoted to time-keeper master\n", time_keeper_id); 143 } 144 145 /* 146 * Phase 1: Locate IRQs bound to this cpu and 147 * relocate them for cpu removal. 148 */ 149 migrate_irqs(); 150 151 /* 152 * Phase 2: Perform interrupt processing for all entries reported in 153 * local APIC. 154 */ 155 ia64_process_pending_intr(); 156 157 /* 158 * Phase 3: Now handle any interrupts not captured in local APIC. 159 * This is to account for cases that device interrupted during the time the 160 * rte was being disabled and re-programmed. 161 */ 162 for (irq=0; irq < NR_IRQS; irq++) { 163 if (vectors_in_migration[irq]) { 164 struct pt_regs *old_regs = set_irq_regs(NULL); 165 166 vectors_in_migration[irq]=0; 167 generic_handle_irq(irq); 168 set_irq_regs(old_regs); 169 } 170 } 171 172 /* 173 * Now let processor die. We do irq disable and max_xtp() to 174 * ensure there is no more interrupts routed to this processor. 175 * But the local timer interrupt can have 1 pending which we 176 * take care in timer_interrupt(). 177 */ 178 max_xtp(); 179 local_irq_disable(); 180 } 181 #endif 182