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/gfp.h> 11 #include <linux/proc_fs.h> 12 #include <linux/seq_file.h> 13 #include <linux/interrupt.h> 14 15 #include "internals.h" 16 17 static struct proc_dir_entry *root_irq_dir; 18 19 #ifdef CONFIG_SMP 20 21 static int irq_affinity_proc_show(struct seq_file *m, void *v) 22 { 23 struct irq_desc *desc = irq_to_desc((long)m->private); 24 const struct cpumask *mask = desc->affinity; 25 26 #ifdef CONFIG_GENERIC_PENDING_IRQ 27 if (desc->status & IRQ_MOVE_PENDING) 28 mask = desc->pending_mask; 29 #endif 30 seq_cpumask(m, mask); 31 seq_putc(m, '\n'); 32 return 0; 33 } 34 35 static int irq_affinity_hint_proc_show(struct seq_file *m, void *v) 36 { 37 struct irq_desc *desc = irq_to_desc((long)m->private); 38 unsigned long flags; 39 cpumask_var_t mask; 40 41 if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) 42 return -ENOMEM; 43 44 raw_spin_lock_irqsave(&desc->lock, flags); 45 if (desc->affinity_hint) 46 cpumask_copy(mask, desc->affinity_hint); 47 raw_spin_unlock_irqrestore(&desc->lock, flags); 48 49 seq_cpumask(m, mask); 50 seq_putc(m, '\n'); 51 free_cpumask_var(mask); 52 53 return 0; 54 } 55 56 #ifndef is_affinity_mask_valid 57 #define is_affinity_mask_valid(val) 1 58 #endif 59 60 int no_irq_affinity; 61 static ssize_t irq_affinity_proc_write(struct file *file, 62 const char __user *buffer, size_t count, loff_t *pos) 63 { 64 unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data; 65 cpumask_var_t new_value; 66 int err; 67 68 if (!irq_to_desc(irq)->chip->set_affinity || no_irq_affinity || 69 irq_balancing_disabled(irq)) 70 return -EIO; 71 72 if (!alloc_cpumask_var(&new_value, GFP_KERNEL)) 73 return -ENOMEM; 74 75 err = cpumask_parse_user(buffer, count, new_value); 76 if (err) 77 goto free_cpumask; 78 79 if (!is_affinity_mask_valid(new_value)) { 80 err = -EINVAL; 81 goto free_cpumask; 82 } 83 84 /* 85 * Do not allow disabling IRQs completely - it's a too easy 86 * way to make the system unusable accidentally :-) At least 87 * one online CPU still has to be targeted. 88 */ 89 if (!cpumask_intersects(new_value, cpu_online_mask)) { 90 /* Special case for empty set - allow the architecture 91 code to set default SMP affinity. */ 92 err = irq_select_affinity_usr(irq) ? -EINVAL : count; 93 } else { 94 irq_set_affinity(irq, new_value); 95 err = count; 96 } 97 98 free_cpumask: 99 free_cpumask_var(new_value); 100 return err; 101 } 102 103 static int irq_affinity_proc_open(struct inode *inode, struct file *file) 104 { 105 return single_open(file, irq_affinity_proc_show, PDE(inode)->data); 106 } 107 108 static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file) 109 { 110 return single_open(file, irq_affinity_hint_proc_show, PDE(inode)->data); 111 } 112 113 static const struct file_operations irq_affinity_proc_fops = { 114 .open = irq_affinity_proc_open, 115 .read = seq_read, 116 .llseek = seq_lseek, 117 .release = single_release, 118 .write = irq_affinity_proc_write, 119 }; 120 121 static const struct file_operations irq_affinity_hint_proc_fops = { 122 .open = irq_affinity_hint_proc_open, 123 .read = seq_read, 124 .llseek = seq_lseek, 125 .release = single_release, 126 }; 127 128 static int default_affinity_show(struct seq_file *m, void *v) 129 { 130 seq_cpumask(m, irq_default_affinity); 131 seq_putc(m, '\n'); 132 return 0; 133 } 134 135 static ssize_t default_affinity_write(struct file *file, 136 const char __user *buffer, size_t count, loff_t *ppos) 137 { 138 cpumask_var_t new_value; 139 int err; 140 141 if (!alloc_cpumask_var(&new_value, GFP_KERNEL)) 142 return -ENOMEM; 143 144 err = cpumask_parse_user(buffer, count, new_value); 145 if (err) 146 goto out; 147 148 if (!is_affinity_mask_valid(new_value)) { 149 err = -EINVAL; 150 goto out; 151 } 152 153 /* 154 * Do not allow disabling IRQs completely - it's a too easy 155 * way to make the system unusable accidentally :-) At least 156 * one online CPU still has to be targeted. 157 */ 158 if (!cpumask_intersects(new_value, cpu_online_mask)) { 159 err = -EINVAL; 160 goto out; 161 } 162 163 cpumask_copy(irq_default_affinity, new_value); 164 err = count; 165 166 out: 167 free_cpumask_var(new_value); 168 return err; 169 } 170 171 static int default_affinity_open(struct inode *inode, struct file *file) 172 { 173 return single_open(file, default_affinity_show, PDE(inode)->data); 174 } 175 176 static const struct file_operations default_affinity_proc_fops = { 177 .open = default_affinity_open, 178 .read = seq_read, 179 .llseek = seq_lseek, 180 .release = single_release, 181 .write = default_affinity_write, 182 }; 183 184 static int irq_node_proc_show(struct seq_file *m, void *v) 185 { 186 struct irq_desc *desc = irq_to_desc((long) m->private); 187 188 seq_printf(m, "%d\n", desc->node); 189 return 0; 190 } 191 192 static int irq_node_proc_open(struct inode *inode, struct file *file) 193 { 194 return single_open(file, irq_node_proc_show, PDE(inode)->data); 195 } 196 197 static const struct file_operations irq_node_proc_fops = { 198 .open = irq_node_proc_open, 199 .read = seq_read, 200 .llseek = seq_lseek, 201 .release = single_release, 202 }; 203 #endif 204 205 static int irq_spurious_proc_show(struct seq_file *m, void *v) 206 { 207 struct irq_desc *desc = irq_to_desc((long) m->private); 208 209 seq_printf(m, "count %u\n" "unhandled %u\n" "last_unhandled %u ms\n", 210 desc->irq_count, desc->irqs_unhandled, 211 jiffies_to_msecs(desc->last_unhandled)); 212 return 0; 213 } 214 215 static int irq_spurious_proc_open(struct inode *inode, struct file *file) 216 { 217 return single_open(file, irq_spurious_proc_show, NULL); 218 } 219 220 static const struct file_operations irq_spurious_proc_fops = { 221 .open = irq_spurious_proc_open, 222 .read = seq_read, 223 .llseek = seq_lseek, 224 .release = single_release, 225 }; 226 227 #define MAX_NAMELEN 128 228 229 static int name_unique(unsigned int irq, struct irqaction *new_action) 230 { 231 struct irq_desc *desc = irq_to_desc(irq); 232 struct irqaction *action; 233 unsigned long flags; 234 int ret = 1; 235 236 raw_spin_lock_irqsave(&desc->lock, flags); 237 for (action = desc->action ; action; action = action->next) { 238 if ((action != new_action) && action->name && 239 !strcmp(new_action->name, action->name)) { 240 ret = 0; 241 break; 242 } 243 } 244 raw_spin_unlock_irqrestore(&desc->lock, flags); 245 return ret; 246 } 247 248 void register_handler_proc(unsigned int irq, struct irqaction *action) 249 { 250 char name [MAX_NAMELEN]; 251 struct irq_desc *desc = irq_to_desc(irq); 252 253 if (!desc->dir || action->dir || !action->name || 254 !name_unique(irq, action)) 255 return; 256 257 memset(name, 0, MAX_NAMELEN); 258 snprintf(name, MAX_NAMELEN, "%s", action->name); 259 260 /* create /proc/irq/1234/handler/ */ 261 action->dir = proc_mkdir(name, desc->dir); 262 } 263 264 #undef MAX_NAMELEN 265 266 #define MAX_NAMELEN 10 267 268 void register_irq_proc(unsigned int irq, struct irq_desc *desc) 269 { 270 char name [MAX_NAMELEN]; 271 272 if (!root_irq_dir || (desc->chip == &no_irq_chip) || desc->dir) 273 return; 274 275 memset(name, 0, MAX_NAMELEN); 276 sprintf(name, "%d", irq); 277 278 /* create /proc/irq/1234 */ 279 desc->dir = proc_mkdir(name, root_irq_dir); 280 if (!desc->dir) 281 return; 282 283 #ifdef CONFIG_SMP 284 /* create /proc/irq/<irq>/smp_affinity */ 285 proc_create_data("smp_affinity", 0600, desc->dir, 286 &irq_affinity_proc_fops, (void *)(long)irq); 287 288 /* create /proc/irq/<irq>/affinity_hint */ 289 proc_create_data("affinity_hint", 0400, desc->dir, 290 &irq_affinity_hint_proc_fops, (void *)(long)irq); 291 292 proc_create_data("node", 0444, desc->dir, 293 &irq_node_proc_fops, (void *)(long)irq); 294 #endif 295 296 proc_create_data("spurious", 0444, desc->dir, 297 &irq_spurious_proc_fops, (void *)(long)irq); 298 } 299 300 #undef MAX_NAMELEN 301 302 void unregister_handler_proc(unsigned int irq, struct irqaction *action) 303 { 304 if (action->dir) { 305 struct irq_desc *desc = irq_to_desc(irq); 306 307 remove_proc_entry(action->dir->name, desc->dir); 308 } 309 } 310 311 static void register_default_affinity_proc(void) 312 { 313 #ifdef CONFIG_SMP 314 proc_create("irq/default_smp_affinity", 0600, NULL, 315 &default_affinity_proc_fops); 316 #endif 317 } 318 319 void init_irq_proc(void) 320 { 321 unsigned int irq; 322 struct irq_desc *desc; 323 324 /* create /proc/irq */ 325 root_irq_dir = proc_mkdir("irq", NULL); 326 if (!root_irq_dir) 327 return; 328 329 register_default_affinity_proc(); 330 331 /* 332 * Create entries for all existing IRQs. 333 */ 334 for_each_irq_desc(irq, desc) { 335 if (!desc) 336 continue; 337 338 register_irq_proc(irq, desc); 339 } 340 } 341 342