summaryrefslogtreecommitdiffstats
path: root/kernel/irq/proc.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/irq/proc.c')
-rw-r--r--kernel/irq/proc.c159
1 files changed, 159 insertions, 0 deletions
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
new file mode 100644
index 0000000..85d08da
--- /dev/null
+++ b/kernel/irq/proc.c
@@ -0,0 +1,159 @@
+/*
+ * linux/kernel/irq/proc.c
+ *
+ * Copyright (C) 1992, 1998-2004 Linus Torvalds, Ingo Molnar
+ *
+ * This file contains the /proc/irq/ handling code.
+ */
+
+#include <linux/irq.h>
+#include <linux/proc_fs.h>
+#include <linux/interrupt.h>
+
+static struct proc_dir_entry *root_irq_dir, *irq_dir[NR_IRQS];
+
+#ifdef CONFIG_SMP
+
+/*
+ * The /proc/irq/<irq>/smp_affinity values:
+ */
+static struct proc_dir_entry *smp_affinity_entry[NR_IRQS];
+
+void __attribute__((weak))
+proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val)
+{
+ irq_affinity[irq] = mask_val;
+ irq_desc[irq].handler->set_affinity(irq, mask_val);
+}
+
+static int irq_affinity_read_proc(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ int len = cpumask_scnprintf(page, count, irq_affinity[(long)data]);
+
+ if (count - len < 2)
+ return -EINVAL;
+ len += sprintf(page + len, "\n");
+ return len;
+}
+
+int no_irq_affinity;
+static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
+ unsigned long count, void *data)
+{
+ unsigned int irq = (int)(long)data, full_count = count, err;
+ cpumask_t new_value, tmp;
+
+ if (!irq_desc[irq].handler->set_affinity || no_irq_affinity)
+ return -EIO;
+
+ err = cpumask_parse(buffer, count, new_value);
+ if (err)
+ return err;
+
+ /*
+ * Do not allow disabling IRQs completely - it's a too easy
+ * way to make the system unusable accidentally :-) At least
+ * one online CPU still has to be targeted.
+ */
+ cpus_and(tmp, new_value, cpu_online_map);
+ if (cpus_empty(tmp))
+ return -EINVAL;
+
+ proc_set_irq_affinity(irq, new_value);
+
+ return full_count;
+}
+
+#endif
+
+#define MAX_NAMELEN 128
+
+static int name_unique(unsigned int irq, struct irqaction *new_action)
+{
+ struct irq_desc *desc = irq_desc + irq;
+ struct irqaction *action;
+
+ for (action = desc->action ; action; action = action->next)
+ if ((action != new_action) && action->name &&
+ !strcmp(new_action->name, action->name))
+ return 0;
+ return 1;
+}
+
+void register_handler_proc(unsigned int irq, struct irqaction *action)
+{
+ char name [MAX_NAMELEN];
+
+ if (!irq_dir[irq] || action->dir || !action->name ||
+ !name_unique(irq, action))
+ return;
+
+ memset(name, 0, MAX_NAMELEN);
+ snprintf(name, MAX_NAMELEN, "%s", action->name);
+
+ /* create /proc/irq/1234/handler/ */
+ action->dir = proc_mkdir(name, irq_dir[irq]);
+}
+
+#undef MAX_NAMELEN
+
+#define MAX_NAMELEN 10
+
+void register_irq_proc(unsigned int irq)
+{
+ char name [MAX_NAMELEN];
+
+ if (!root_irq_dir ||
+ (irq_desc[irq].handler == &no_irq_type) ||
+ irq_dir[irq])
+ return;
+
+ memset(name, 0, MAX_NAMELEN);
+ sprintf(name, "%d", irq);
+
+ /* create /proc/irq/1234 */
+ irq_dir[irq] = proc_mkdir(name, root_irq_dir);
+
+#ifdef CONFIG_SMP
+ {
+ struct proc_dir_entry *entry;
+
+ /* create /proc/irq/<irq>/smp_affinity */
+ entry = create_proc_entry("smp_affinity", 0600, irq_dir[irq]);
+
+ if (entry) {
+ entry->nlink = 1;
+ entry->data = (void *)(long)irq;
+ entry->read_proc = irq_affinity_read_proc;
+ entry->write_proc = irq_affinity_write_proc;
+ }
+ smp_affinity_entry[irq] = entry;
+ }
+#endif
+}
+
+#undef MAX_NAMELEN
+
+void unregister_handler_proc(unsigned int irq, struct irqaction *action)
+{
+ if (action->dir)
+ remove_proc_entry(action->dir->name, irq_dir[irq]);
+}
+
+void init_irq_proc(void)
+{
+ int i;
+
+ /* create /proc/irq */
+ root_irq_dir = proc_mkdir("irq", NULL);
+ if (!root_irq_dir)
+ return;
+
+ /*
+ * Create entries for all existing IRQs.
+ */
+ for (i = 0; i < NR_IRQS; i++)
+ register_irq_proc(i);
+}
+
OpenPOWER on IntegriCloud