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