1 /* 2 * linux/kernel/irq/proc.c 3 * 4 * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar 5 * 6 * This file contains the /proc/irq/ handling code. 7 */ 8 9 #include <linux/irq.h> 10 #include <linux/proc_fs.h> 11 #include <linux/interrupt.h> 12 13 #include "internals.h" 14 15 static struct proc_dir_entry *root_irq_dir; 16 17 #ifdef CONFIG_SMP 18 19 #ifdef CONFIG_GENERIC_PENDING_IRQ 20 void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val) 21 { 22 set_balance_irq_affinity(irq, mask_val); 23 24 /* 25 * Save these away for later use. Re-progam when the 26 * interrupt is pending 27 */ 28 set_pending_irq(irq, mask_val); 29 } 30 #else 31 void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val) 32 { 33 set_balance_irq_affinity(irq, mask_val); 34 irq_desc[irq].affinity = mask_val; 35 irq_desc[irq].chip->set_affinity(irq, mask_val); 36 } 37 #endif 38 39 static int irq_affinity_read_proc(char *page, char **start, off_t off, 40 int count, int *eof, void *data) 41 { 42 int len = cpumask_scnprintf(page, count, irq_desc[(long)data].affinity); 43 44 if (count - len < 2) 45 return -EINVAL; 46 len += sprintf(page + len, "\n"); 47 return len; 48 } 49 50 int no_irq_affinity; 51 static int irq_affinity_write_proc(struct file *file, const char __user *buffer, 52 unsigned long count, void *data) 53 { 54 unsigned int irq = (int)(long)data, full_count = count, err; 55 cpumask_t new_value, tmp; 56 57 if (!irq_desc[irq].chip->set_affinity || no_irq_affinity || 58 CHECK_IRQ_PER_CPU(irq_desc[irq].status)) 59 return -EIO; 60 61 err = cpumask_parse_user(buffer, count, new_value); 62 if (err) 63 return err; 64 65 /* 66 * Do not allow disabling IRQs completely - it's a too easy 67 * way to make the system unusable accidentally :-) At least 68 * one online CPU still has to be targeted. 69 */ 70 cpus_and(tmp, new_value, cpu_online_map); 71 if (cpus_empty(tmp)) 72 /* Special case for empty set - allow the architecture 73 code to set default SMP affinity. */ 74 return select_smp_affinity(irq) ? -EINVAL : full_count; 75 76 proc_set_irq_affinity(irq, new_value); 77 78 return full_count; 79 } 80 81 #endif 82 83 #define MAX_NAMELEN 128 84 85 static int name_unique(unsigned int irq, struct irqaction *new_action) 86 { 87 struct irq_desc *desc = irq_desc + irq; 88 struct irqaction *action; 89 90 for (action = desc->action ; action; action = action->next) 91 if ((action != new_action) && action->name && 92 !strcmp(new_action->name, action->name)) 93 return 0; 94 return 1; 95 } 96 97 void register_handler_proc(unsigned int irq, struct irqaction *action) 98 { 99 char name [MAX_NAMELEN]; 100 101 if (!irq_desc[irq].dir || action->dir || !action->name || 102 !name_unique(irq, action)) 103 return; 104 105 memset(name, 0, MAX_NAMELEN); 106 snprintf(name, MAX_NAMELEN, "%s", action->name); 107 108 /* create /proc/irq/1234/handler/ */ 109 action->dir = proc_mkdir(name, irq_desc[irq].dir); 110 } 111 112 #undef MAX_NAMELEN 113 114 #define MAX_NAMELEN 10 115 116 void register_irq_proc(unsigned int irq) 117 { 118 char name [MAX_NAMELEN]; 119 120 if (!root_irq_dir || 121 (irq_desc[irq].chip == &no_irq_chip) || 122 irq_desc[irq].dir) 123 return; 124 125 memset(name, 0, MAX_NAMELEN); 126 sprintf(name, "%d", irq); 127 128 /* create /proc/irq/1234 */ 129 irq_desc[irq].dir = proc_mkdir(name, root_irq_dir); 130 131 #ifdef CONFIG_SMP 132 { 133 struct proc_dir_entry *entry; 134 135 /* create /proc/irq/<irq>/smp_affinity */ 136 entry = create_proc_entry("smp_affinity", 0600, irq_desc[irq].dir); 137 138 if (entry) { 139 entry->data = (void *)(long)irq; 140 entry->read_proc = irq_affinity_read_proc; 141 entry->write_proc = irq_affinity_write_proc; 142 } 143 } 144 #endif 145 } 146 147 #undef MAX_NAMELEN 148 149 void unregister_handler_proc(unsigned int irq, struct irqaction *action) 150 { 151 if (action->dir) 152 remove_proc_entry(action->dir->name, irq_desc[irq].dir); 153 } 154 155 void init_irq_proc(void) 156 { 157 int i; 158 159 /* create /proc/irq */ 160 root_irq_dir = proc_mkdir("irq", NULL); 161 if (!root_irq_dir) 162 return; 163 164 /* 165 * Create entries for all existing IRQs. 166 */ 167 for (i = 0; i < NR_IRQS; i++) 168 register_irq_proc(i); 169 } 170 171