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 static struct proc_dir_entry *root_irq_dir, *irq_dir[NR_IRQS]; 14 15 #ifdef CONFIG_SMP 16 17 /* 18 * The /proc/irq/<irq>/smp_affinity values: 19 */ 20 static struct proc_dir_entry *smp_affinity_entry[NR_IRQS]; 21 22 #ifdef CONFIG_GENERIC_PENDING_IRQ 23 void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val) 24 { 25 /* 26 * Save these away for later use. Re-progam when the 27 * interrupt is pending 28 */ 29 set_pending_irq(irq, mask_val); 30 } 31 #else 32 void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val) 33 { 34 irq_affinity[irq] = mask_val; 35 irq_desc[irq].handler->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_affinity[(long)data]); 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].handler->set_affinity || no_irq_affinity) 58 return -EIO; 59 60 err = cpumask_parse(buffer, count, new_value); 61 if (err) 62 return err; 63 64 /* 65 * Do not allow disabling IRQs completely - it's a too easy 66 * way to make the system unusable accidentally :-) At least 67 * one online CPU still has to be targeted. 68 */ 69 cpus_and(tmp, new_value, cpu_online_map); 70 if (cpus_empty(tmp)) 71 return -EINVAL; 72 73 proc_set_irq_affinity(irq, new_value); 74 75 return full_count; 76 } 77 78 #endif 79 80 #define MAX_NAMELEN 128 81 82 static int name_unique(unsigned int irq, struct irqaction *new_action) 83 { 84 struct irq_desc *desc = irq_desc + irq; 85 struct irqaction *action; 86 87 for (action = desc->action ; action; action = action->next) 88 if ((action != new_action) && action->name && 89 !strcmp(new_action->name, action->name)) 90 return 0; 91 return 1; 92 } 93 94 void register_handler_proc(unsigned int irq, struct irqaction *action) 95 { 96 char name [MAX_NAMELEN]; 97 98 if (!irq_dir[irq] || action->dir || !action->name || 99 !name_unique(irq, action)) 100 return; 101 102 memset(name, 0, MAX_NAMELEN); 103 snprintf(name, MAX_NAMELEN, "%s", action->name); 104 105 /* create /proc/irq/1234/handler/ */ 106 action->dir = proc_mkdir(name, irq_dir[irq]); 107 } 108 109 #undef MAX_NAMELEN 110 111 #define MAX_NAMELEN 10 112 113 void register_irq_proc(unsigned int irq) 114 { 115 char name [MAX_NAMELEN]; 116 117 if (!root_irq_dir || 118 (irq_desc[irq].handler == &no_irq_type) || 119 irq_dir[irq]) 120 return; 121 122 memset(name, 0, MAX_NAMELEN); 123 sprintf(name, "%d", irq); 124 125 /* create /proc/irq/1234 */ 126 irq_dir[irq] = proc_mkdir(name, root_irq_dir); 127 128 #ifdef CONFIG_SMP 129 { 130 struct proc_dir_entry *entry; 131 132 /* create /proc/irq/<irq>/smp_affinity */ 133 entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]); 134 135 if (entry) { 136 entry->nlink = 1; 137 entry->data = (void *)(long)irq; 138 entry->read_proc = irq_affinity_read_proc; 139 entry->write_proc = irq_affinity_write_proc; 140 } 141 smp_affinity_entry[irq] = entry; 142 } 143 #endif 144 } 145 146 #undef MAX_NAMELEN 147 148 void unregister_handler_proc(unsigned int irq, struct irqaction *action) 149 { 150 if (action->dir) 151 remove_proc_entry(action->dir->name, irq_dir[irq]); 152 } 153 154 void init_irq_proc(void) 155 { 156 int i; 157 158 /* create /proc/irq */ 159 root_irq_dir = proc_mkdir("irq", NULL); 160 if (!root_irq_dir) 161 return; 162 163 /* 164 * Create entries for all existing IRQs. 165 */ 166 for (i = 0; i < NR_IRQS; i++) 167 register_irq_proc(i); 168 } 169 170