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/seq_file.h> 12 #include <linux/interrupt.h> 13 14 #include "internals.h" 15 16 static struct proc_dir_entry *root_irq_dir; 17 18 #ifdef CONFIG_SMP 19 20 static int irq_affinity_proc_show(struct seq_file *m, void *v) 21 { 22 struct irq_desc *desc = irq_to_desc((long)m->private); 23 cpumask_t *mask = &desc->affinity; 24 25 #ifdef CONFIG_GENERIC_PENDING_IRQ 26 if (desc->status & IRQ_MOVE_PENDING) 27 mask = &desc->pending_mask; 28 #endif 29 seq_cpumask(m, mask); 30 seq_putc(m, '\n'); 31 return 0; 32 } 33 34 #ifndef is_affinity_mask_valid 35 #define is_affinity_mask_valid(val) 1 36 #endif 37 38 int no_irq_affinity; 39 static ssize_t irq_affinity_proc_write(struct file *file, 40 const char __user *buffer, size_t count, loff_t *pos) 41 { 42 unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data; 43 cpumask_t new_value; 44 int err; 45 46 if (!irq_to_desc(irq)->chip->set_affinity || no_irq_affinity || 47 irq_balancing_disabled(irq)) 48 return -EIO; 49 50 err = cpumask_parse_user(buffer, count, new_value); 51 if (err) 52 return err; 53 54 if (!is_affinity_mask_valid(new_value)) 55 return -EINVAL; 56 57 /* 58 * Do not allow disabling IRQs completely - it's a too easy 59 * way to make the system unusable accidentally :-) At least 60 * one online CPU still has to be targeted. 61 */ 62 if (!cpus_intersects(new_value, cpu_online_map)) 63 /* Special case for empty set - allow the architecture 64 code to set default SMP affinity. */ 65 return irq_select_affinity(irq) ? -EINVAL : count; 66 67 irq_set_affinity(irq, new_value); 68 69 return count; 70 } 71 72 static int irq_affinity_proc_open(struct inode *inode, struct file *file) 73 { 74 return single_open(file, irq_affinity_proc_show, PDE(inode)->data); 75 } 76 77 static const struct file_operations irq_affinity_proc_fops = { 78 .open = irq_affinity_proc_open, 79 .read = seq_read, 80 .llseek = seq_lseek, 81 .release = single_release, 82 .write = irq_affinity_proc_write, 83 }; 84 85 static int default_affinity_show(struct seq_file *m, void *v) 86 { 87 seq_cpumask(m, &irq_default_affinity); 88 seq_putc(m, '\n'); 89 return 0; 90 } 91 92 static ssize_t default_affinity_write(struct file *file, 93 const char __user *buffer, size_t count, loff_t *ppos) 94 { 95 cpumask_t new_value; 96 int err; 97 98 err = cpumask_parse_user(buffer, count, new_value); 99 if (err) 100 return err; 101 102 if (!is_affinity_mask_valid(new_value)) 103 return -EINVAL; 104 105 /* 106 * Do not allow disabling IRQs completely - it's a too easy 107 * way to make the system unusable accidentally :-) At least 108 * one online CPU still has to be targeted. 109 */ 110 if (!cpus_intersects(new_value, cpu_online_map)) 111 return -EINVAL; 112 113 irq_default_affinity = new_value; 114 115 return count; 116 } 117 118 static int default_affinity_open(struct inode *inode, struct file *file) 119 { 120 return single_open(file, default_affinity_show, NULL); 121 } 122 123 static const struct file_operations default_affinity_proc_fops = { 124 .open = default_affinity_open, 125 .read = seq_read, 126 .llseek = seq_lseek, 127 .release = single_release, 128 .write = default_affinity_write, 129 }; 130 #endif 131 132 static int irq_spurious_read(char *page, char **start, off_t off, 133 int count, int *eof, void *data) 134 { 135 struct irq_desc *desc = irq_to_desc((long) data); 136 return sprintf(page, "count %u\n" 137 "unhandled %u\n" 138 "last_unhandled %u ms\n", 139 desc->irq_count, 140 desc->irqs_unhandled, 141 jiffies_to_msecs(desc->last_unhandled)); 142 } 143 144 #define MAX_NAMELEN 128 145 146 static int name_unique(unsigned int irq, struct irqaction *new_action) 147 { 148 struct irq_desc *desc = irq_to_desc(irq); 149 struct irqaction *action; 150 unsigned long flags; 151 int ret = 1; 152 153 spin_lock_irqsave(&desc->lock, flags); 154 for (action = desc->action ; action; action = action->next) { 155 if ((action != new_action) && action->name && 156 !strcmp(new_action->name, action->name)) { 157 ret = 0; 158 break; 159 } 160 } 161 spin_unlock_irqrestore(&desc->lock, flags); 162 return ret; 163 } 164 165 void register_handler_proc(unsigned int irq, struct irqaction *action) 166 { 167 char name [MAX_NAMELEN]; 168 struct irq_desc *desc = irq_to_desc(irq); 169 170 if (!desc->dir || action->dir || !action->name || 171 !name_unique(irq, action)) 172 return; 173 174 memset(name, 0, MAX_NAMELEN); 175 snprintf(name, MAX_NAMELEN, "%s", action->name); 176 177 /* create /proc/irq/1234/handler/ */ 178 action->dir = proc_mkdir(name, desc->dir); 179 } 180 181 #undef MAX_NAMELEN 182 183 #define MAX_NAMELEN 10 184 185 void register_irq_proc(unsigned int irq, struct irq_desc *desc) 186 { 187 char name [MAX_NAMELEN]; 188 struct proc_dir_entry *entry; 189 190 if (!root_irq_dir || (desc->chip == &no_irq_chip) || desc->dir) 191 return; 192 193 memset(name, 0, MAX_NAMELEN); 194 sprintf(name, "%d", irq); 195 196 /* create /proc/irq/1234 */ 197 desc->dir = proc_mkdir(name, root_irq_dir); 198 199 #ifdef CONFIG_SMP 200 /* create /proc/irq/<irq>/smp_affinity */ 201 proc_create_data("smp_affinity", 0600, desc->dir, 202 &irq_affinity_proc_fops, (void *)(long)irq); 203 #endif 204 205 entry = create_proc_entry("spurious", 0444, desc->dir); 206 if (entry) { 207 entry->data = (void *)(long)irq; 208 entry->read_proc = irq_spurious_read; 209 } 210 } 211 212 #undef MAX_NAMELEN 213 214 void unregister_handler_proc(unsigned int irq, struct irqaction *action) 215 { 216 if (action->dir) { 217 struct irq_desc *desc = irq_to_desc(irq); 218 219 remove_proc_entry(action->dir->name, desc->dir); 220 } 221 } 222 223 static void register_default_affinity_proc(void) 224 { 225 #ifdef CONFIG_SMP 226 proc_create("irq/default_smp_affinity", 0600, NULL, 227 &default_affinity_proc_fops); 228 #endif 229 } 230 231 void init_irq_proc(void) 232 { 233 unsigned int irq; 234 struct irq_desc *desc; 235 236 /* create /proc/irq */ 237 root_irq_dir = proc_mkdir("irq", NULL); 238 if (!root_irq_dir) 239 return; 240 241 register_default_affinity_proc(); 242 243 /* 244 * Create entries for all existing IRQs. 245 */ 246 for_each_irq_desc(irq, desc) 247 register_irq_proc(irq, desc); 248 } 249 250