1 /* 2 * linux/arch/ia64/kernel/irq.c 3 * 4 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar 5 * 6 * This file contains the code used by various IRQ handling routines: 7 * asking for different IRQs should be done through these routines 8 * instead of just grabbing them. Thus setups with different IRQ numbers 9 * shouldn't result in any weird surprises, and installing new handlers 10 * should be easier. 11 * 12 * Copyright (C) Ashok Raj<ashok.raj@intel.com>, Intel Corporation 2004 13 * 14 * 4/14/2004: Added code to handle cpu migration and do safe irq 15 * migration without losing interrupts for iosapic 16 * architecture. 17 */ 18 19 #include <asm/delay.h> 20 #include <asm/uaccess.h> 21 #include <linux/module.h> 22 #include <linux/seq_file.h> 23 #include <linux/interrupt.h> 24 #include <linux/kernel_stat.h> 25 26 #include <asm/mca.h> 27 28 /* 29 * 'what should we do if we get a hw irq event on an illegal vector'. 30 * each architecture has to answer this themselves. 31 */ 32 void ack_bad_irq(unsigned int irq) 33 { 34 printk(KERN_ERR "Unexpected irq vector 0x%x on CPU %u!\n", irq, smp_processor_id()); 35 } 36 37 #ifdef CONFIG_IA64_GENERIC 38 ia64_vector __ia64_irq_to_vector(int irq) 39 { 40 return irq_cfg[irq].vector; 41 } 42 43 unsigned int __ia64_local_vector_to_irq (ia64_vector vec) 44 { 45 return __this_cpu_read(vector_irq[vec]); 46 } 47 #endif 48 49 /* 50 * Interrupt statistics: 51 */ 52 53 atomic_t irq_err_count; 54 55 /* 56 * /proc/interrupts printing: 57 */ 58 int arch_show_interrupts(struct seq_file *p, int prec) 59 { 60 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count)); 61 return 0; 62 } 63 64 #ifdef CONFIG_SMP 65 static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 }; 66 67 void set_irq_affinity_info (unsigned int irq, int hwid, int redir) 68 { 69 if (irq < NR_IRQS) { 70 cpumask_copy(irq_get_affinity_mask(irq), 71 cpumask_of(cpu_logical_id(hwid))); 72 irq_redir[irq] = (char) (redir & 0xff); 73 } 74 } 75 76 bool is_affinity_mask_valid(const struct cpumask *cpumask) 77 { 78 if (ia64_platform_is("sn2")) { 79 /* Only allow one CPU to be specified in the smp_affinity mask */ 80 if (cpumask_weight(cpumask) != 1) 81 return false; 82 } 83 return true; 84 } 85 86 #endif /* CONFIG_SMP */ 87 88 int __init arch_early_irq_init(void) 89 { 90 ia64_mca_irq_init(); 91 return 0; 92 } 93 94 #ifdef CONFIG_HOTPLUG_CPU 95 unsigned int vectors_in_migration[NR_IRQS]; 96 97 /* 98 * Since cpu_online_mask is already updated, we just need to check for 99 * affinity that has zeros 100 */ 101 static void migrate_irqs(void) 102 { 103 int irq, new_cpu; 104 105 for (irq=0; irq < NR_IRQS; irq++) { 106 struct irq_desc *desc = irq_to_desc(irq); 107 struct irq_data *data = irq_desc_get_irq_data(desc); 108 struct irq_chip *chip = irq_data_get_irq_chip(data); 109 110 if (irqd_irq_disabled(data)) 111 continue; 112 113 /* 114 * No handling for now. 115 * TBD: Implement a disable function so we can now 116 * tell CPU not to respond to these local intr sources. 117 * such as ITV,CPEI,MCA etc. 118 */ 119 if (irqd_is_per_cpu(data)) 120 continue; 121 122 if (cpumask_any_and(irq_data_get_affinity_mask(data), 123 cpu_online_mask) >= nr_cpu_ids) { 124 /* 125 * Save it for phase 2 processing 126 */ 127 vectors_in_migration[irq] = irq; 128 129 new_cpu = cpumask_any(cpu_online_mask); 130 131 /* 132 * Al three are essential, currently WARN_ON.. maybe panic? 133 */ 134 if (chip && chip->irq_disable && 135 chip->irq_enable && chip->irq_set_affinity) { 136 chip->irq_disable(data); 137 chip->irq_set_affinity(data, 138 cpumask_of(new_cpu), false); 139 chip->irq_enable(data); 140 } else { 141 WARN_ON((!chip || !chip->irq_disable || 142 !chip->irq_enable || 143 !chip->irq_set_affinity)); 144 } 145 } 146 } 147 } 148 149 void fixup_irqs(void) 150 { 151 unsigned int irq; 152 extern void ia64_process_pending_intr(void); 153 extern volatile int time_keeper_id; 154 155 /* Mask ITV to disable timer */ 156 ia64_set_itv(1 << 16); 157 158 /* 159 * Find a new timesync master 160 */ 161 if (smp_processor_id() == time_keeper_id) { 162 time_keeper_id = cpumask_first(cpu_online_mask); 163 printk ("CPU %d is now promoted to time-keeper master\n", time_keeper_id); 164 } 165 166 /* 167 * Phase 1: Locate IRQs bound to this cpu and 168 * relocate them for cpu removal. 169 */ 170 migrate_irqs(); 171 172 /* 173 * Phase 2: Perform interrupt processing for all entries reported in 174 * local APIC. 175 */ 176 ia64_process_pending_intr(); 177 178 /* 179 * Phase 3: Now handle any interrupts not captured in local APIC. 180 * This is to account for cases that device interrupted during the time the 181 * rte was being disabled and re-programmed. 182 */ 183 for (irq=0; irq < NR_IRQS; irq++) { 184 if (vectors_in_migration[irq]) { 185 struct pt_regs *old_regs = set_irq_regs(NULL); 186 187 vectors_in_migration[irq]=0; 188 generic_handle_irq(irq); 189 set_irq_regs(old_regs); 190 } 191 } 192 193 /* 194 * Now let processor die. We do irq disable and max_xtp() to 195 * ensure there is no more interrupts routed to this processor. 196 * But the local timer interrupt can have 1 pending which we 197 * take care in timer_interrupt(). 198 */ 199 max_xtp(); 200 local_irq_disable(); 201 } 202 #endif 203