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 const struct cpumask *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_var_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 if (!alloc_cpumask_var(&new_value, GFP_KERNEL)) 51 return -ENOMEM; 52 53 err = cpumask_parse_user(buffer, count, new_value); 54 if (err) 55 goto free_cpumask; 56 57 if (!is_affinity_mask_valid(new_value)) { 58 err = -EINVAL; 59 goto free_cpumask; 60 } 61 62 /* 63 * Do not allow disabling IRQs completely - it's a too easy 64 * way to make the system unusable accidentally :-) At least 65 * one online CPU still has to be targeted. 66 */ 67 if (!cpumask_intersects(new_value, cpu_online_mask)) { 68 /* Special case for empty set - allow the architecture 69 code to set default SMP affinity. */ 70 err = irq_select_affinity_usr(irq) ? -EINVAL : count; 71 } else { 72 irq_set_affinity(irq, new_value); 73 err = count; 74 } 75 76 free_cpumask: 77 free_cpumask_var(new_value); 78 return err; 79 } 80 81 static int irq_affinity_proc_open(struct inode *inode, struct file *file) 82 { 83 return single_open(file, irq_affinity_proc_show, PDE(inode)->data); 84 } 85 86 static const struct file_operations irq_affinity_proc_fops = { 87 .open = irq_affinity_proc_open, 88 .read = seq_read, 89 .llseek = seq_lseek, 90 .release = single_release, 91 .write = irq_affinity_proc_write, 92 }; 93 94 static int default_affinity_show(struct seq_file *m, void *v) 95 { 96 seq_cpumask(m, irq_default_affinity); 97 seq_putc(m, '\n'); 98 return 0; 99 } 100 101 static ssize_t default_affinity_write(struct file *file, 102 const char __user *buffer, size_t count, loff_t *ppos) 103 { 104 cpumask_var_t new_value; 105 int err; 106 107 if (!alloc_cpumask_var(&new_value, GFP_KERNEL)) 108 return -ENOMEM; 109 110 err = cpumask_parse_user(buffer, count, new_value); 111 if (err) 112 goto out; 113 114 if (!is_affinity_mask_valid(new_value)) { 115 err = -EINVAL; 116 goto out; 117 } 118 119 /* 120 * Do not allow disabling IRQs completely - it's a too easy 121 * way to make the system unusable accidentally :-) At least 122 * one online CPU still has to be targeted. 123 */ 124 if (!cpumask_intersects(new_value, cpu_online_mask)) { 125 err = -EINVAL; 126 goto out; 127 } 128 129 cpumask_copy(irq_default_affinity, new_value); 130 err = count; 131 132 out: 133 free_cpumask_var(new_value); 134 return err; 135 } 136 137 static int default_affinity_open(struct inode *inode, struct file *file) 138 { 139 return single_open(file, default_affinity_show, NULL); 140 } 141 142 static const struct file_operations default_affinity_proc_fops = { 143 .open = default_affinity_open, 144 .read = seq_read, 145 .llseek = seq_lseek, 146 .release = single_release, 147 .write = default_affinity_write, 148 }; 149 #endif 150 151 static int irq_spurious_read(char *page, char **start, off_t off, 152 int count, int *eof, void *data) 153 { 154 struct irq_desc *desc = irq_to_desc((long) data); 155 return sprintf(page, "count %u\n" 156 "unhandled %u\n" 157 "last_unhandled %u ms\n", 158 desc->irq_count, 159 desc->irqs_unhandled, 160 jiffies_to_msecs(desc->last_unhandled)); 161 } 162 163 #define MAX_NAMELEN 128 164 165 static int name_unique(unsigned int irq, struct irqaction *new_action) 166 { 167 struct irq_desc *desc = irq_to_desc(irq); 168 struct irqaction *action; 169 unsigned long flags; 170 int ret = 1; 171 172 spin_lock_irqsave(&desc->lock, flags); 173 for (action = desc->action ; action; action = action->next) { 174 if ((action != new_action) && action->name && 175 !strcmp(new_action->name, action->name)) { 176 ret = 0; 177 break; 178 } 179 } 180 spin_unlock_irqrestore(&desc->lock, flags); 181 return ret; 182 } 183 184 void register_handler_proc(unsigned int irq, struct irqaction *action) 185 { 186 char name [MAX_NAMELEN]; 187 struct irq_desc *desc = irq_to_desc(irq); 188 189 if (!desc->dir || action->dir || !action->name || 190 !name_unique(irq, action)) 191 return; 192 193 memset(name, 0, MAX_NAMELEN); 194 snprintf(name, MAX_NAMELEN, "%s", action->name); 195 196 /* create /proc/irq/1234/handler/ */ 197 action->dir = proc_mkdir(name, desc->dir); 198 } 199 200 #undef MAX_NAMELEN 201 202 #define MAX_NAMELEN 10 203 204 void register_irq_proc(unsigned int irq, struct irq_desc *desc) 205 { 206 char name [MAX_NAMELEN]; 207 struct proc_dir_entry *entry; 208 209 if (!root_irq_dir || (desc->chip == &no_irq_chip) || desc->dir) 210 return; 211 212 memset(name, 0, MAX_NAMELEN); 213 sprintf(name, "%d", irq); 214 215 /* create /proc/irq/1234 */ 216 desc->dir = proc_mkdir(name, root_irq_dir); 217 218 #ifdef CONFIG_SMP 219 /* create /proc/irq/<irq>/smp_affinity */ 220 proc_create_data("smp_affinity", 0600, desc->dir, 221 &irq_affinity_proc_fops, (void *)(long)irq); 222 #endif 223 224 entry = create_proc_entry("spurious", 0444, desc->dir); 225 if (entry) { 226 entry->data = (void *)(long)irq; 227 entry->read_proc = irq_spurious_read; 228 } 229 } 230 231 #undef MAX_NAMELEN 232 233 void unregister_handler_proc(unsigned int irq, struct irqaction *action) 234 { 235 if (action->dir) { 236 struct irq_desc *desc = irq_to_desc(irq); 237 238 remove_proc_entry(action->dir->name, desc->dir); 239 } 240 } 241 242 static void register_default_affinity_proc(void) 243 { 244 #ifdef CONFIG_SMP 245 proc_create("irq/default_smp_affinity", 0600, NULL, 246 &default_affinity_proc_fops); 247 #endif 248 } 249 250 void init_irq_proc(void) 251 { 252 unsigned int irq; 253 struct irq_desc *desc; 254 255 /* create /proc/irq */ 256 root_irq_dir = proc_mkdir("irq", NULL); 257 if (!root_irq_dir) 258 return; 259 260 register_default_affinity_proc(); 261 262 /* 263 * Create entries for all existing IRQs. 264 */ 265 for_each_irq_desc(irq, desc) { 266 if (!desc) 267 continue; 268 269 register_irq_proc(irq, desc); 270 } 271 } 272 273