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, *irq_dir[NR_IRQS]; 16 17 #ifdef CONFIG_SMP 18 19 /* 20 * The /proc/irq/<irq>/smp_affinity values: 21 */ 22 static struct proc_dir_entry *smp_affinity_entry[NR_IRQS]; 23 24 #ifdef CONFIG_GENERIC_PENDING_IRQ 25 void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val) 26 { 27 /* 28 * Save these away for later use. Re-progam when the 29 * interrupt is pending 30 */ 31 set_pending_irq(irq, mask_val); 32 } 33 #else 34 void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val) 35 { 36 irq_affinity[irq] = mask_val; 37 irq_desc[irq].handler->set_affinity(irq, mask_val); 38 } 39 #endif 40 41 static int irq_affinity_read_proc(char *page, char **start, off_t off, 42 int count, int *eof, void *data) 43 { 44 int len = cpumask_scnprintf(page, count, irq_affinity[(long)data]); 45 46 if (count - len < 2) 47 return -EINVAL; 48 len += sprintf(page + len, "\n"); 49 return len; 50 } 51 52 int no_irq_affinity; 53 static int irq_affinity_write_proc(struct file *file, const char __user *buffer, 54 unsigned long count, void *data) 55 { 56 unsigned int irq = (int)(long)data, full_count = count, err; 57 cpumask_t new_value, tmp; 58 59 if (!irq_desc[irq].handler->set_affinity || no_irq_affinity) 60 return -EIO; 61 62 err = cpumask_parse(buffer, count, new_value); 63 if (err) 64 return err; 65 66 /* 67 * Do not allow disabling IRQs completely - it's a too easy 68 * way to make the system unusable accidentally :-) At least 69 * one online CPU still has to be targeted. 70 */ 71 cpus_and(tmp, new_value, cpu_online_map); 72 if (cpus_empty(tmp)) 73 /* Special case for empty set - allow the architecture 74 code to set default SMP affinity. */ 75 return select_smp_affinity(irq) ? -EINVAL : full_count; 76 77 proc_set_irq_affinity(irq, new_value); 78 79 return full_count; 80 } 81 82 #endif 83 84 #define MAX_NAMELEN 128 85 86 static int name_unique(unsigned int irq, struct irqaction *new_action) 87 { 88 struct irq_desc *desc = irq_desc + irq; 89 struct irqaction *action; 90 91 for (action = desc->action ; action; action = action->next) 92 if ((action != new_action) && action->name && 93 !strcmp(new_action->name, action->name)) 94 return 0; 95 return 1; 96 } 97 98 void register_handler_proc(unsigned int irq, struct irqaction *action) 99 { 100 char name [MAX_NAMELEN]; 101 102 if (!irq_dir[irq] || action->dir || !action->name || 103 !name_unique(irq, action)) 104 return; 105 106 memset(name, 0, MAX_NAMELEN); 107 snprintf(name, MAX_NAMELEN, "%s", action->name); 108 109 /* create /proc/irq/1234/handler/ */ 110 action->dir = proc_mkdir(name, irq_dir[irq]); 111 } 112 113 #undef MAX_NAMELEN 114 115 #define MAX_NAMELEN 10 116 117 void register_irq_proc(unsigned int irq) 118 { 119 char name [MAX_NAMELEN]; 120 121 if (!root_irq_dir || 122 (irq_desc[irq].handler == &no_irq_type) || 123 irq_dir[irq]) 124 return; 125 126 memset(name, 0, MAX_NAMELEN); 127 sprintf(name, "%d", irq); 128 129 /* create /proc/irq/1234 */ 130 irq_dir[irq] = proc_mkdir(name, root_irq_dir); 131 132 #ifdef CONFIG_SMP 133 { 134 struct proc_dir_entry *entry; 135 136 /* create /proc/irq/<irq>/smp_affinity */ 137 entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]); 138 139 if (entry) { 140 entry->nlink = 1; 141 entry->data = (void *)(long)irq; 142 entry->read_proc = irq_affinity_read_proc; 143 entry->write_proc = irq_affinity_write_proc; 144 } 145 smp_affinity_entry[irq] = entry; 146 } 147 #endif 148 } 149 150 #undef MAX_NAMELEN 151 152 void unregister_handler_proc(unsigned int irq, struct irqaction *action) 153 { 154 if (action->dir) 155 remove_proc_entry(action->dir->name, irq_dir[irq]); 156 } 157 158 void init_irq_proc(void) 159 { 160 int i; 161 162 /* create /proc/irq */ 163 root_irq_dir = proc_mkdir("irq", NULL); 164 if (!root_irq_dir) 165 return; 166 167 /* 168 * Create entries for all existing IRQs. 169 */ 170 for (i = 0; i < NR_IRQS; i++) 171 register_irq_proc(i); 172 } 173 174