genirq: Expose default irq affinity mask (take 3)

[linux-2.6-omap-h63xx.git] / kernel / irq / proc.c

diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index c2f2ccb0549a18a8552e0c8a018a198e4c70195e..6c6d35d68ee9c9628d5e5b67f2e32fdd91553f52 100644 (file)
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -44,7 +44,7 @@ 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;
+       cpumask_t new_value;
 
        if (!irq_desc[irq].chip->set_affinity || no_irq_affinity ||
            irq_balancing_disabled(irq))
@@ -62,17 +62,51 @@ static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
         * 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))
+       if (!cpus_intersects(new_value, cpu_online_map))
                /* Special case for empty set - allow the architecture
                   code to set default SMP affinity. */
-               return select_smp_affinity(irq) ? -EINVAL : full_count;
+               return irq_select_affinity(irq) ? -EINVAL : full_count;
 
        irq_set_affinity(irq, new_value);
 
        return full_count;
 }
 
+static int default_affinity_read(char *page, char **start, off_t off,
+                                 int count, int *eof, void *data)
+{
+       int len = cpumask_scnprintf(page, count, irq_default_affinity);
+       if (count - len < 2)
+               return -EINVAL;
+       len += sprintf(page + len, "\n");
+       return len;
+}
+
+static int default_affinity_write(struct file *file, const char __user *buffer,
+                                  unsigned long count, void *data)
+{
+       unsigned int full_count = count, err;
+       cpumask_t new_value;
+
+       err = cpumask_parse_user(buffer, count, new_value);
+       if (err)
+               return err;
+
+       if (!is_affinity_mask_valid(new_value))
+               return -EINVAL;
+
+       /*
+        * 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.
+        */
+       if (!cpus_intersects(new_value, cpu_online_map))
+               return -EINVAL;
+
+       irq_default_affinity = new_value;
+
+       return full_count;
+}
 #endif
 
 static int irq_spurious_read(char *page, char **start, off_t off,
@@ -171,6 +205,21 @@ void unregister_handler_proc(unsigned int irq, struct irqaction *action)
                remove_proc_entry(action->dir->name, irq_desc[irq].dir);
 }
 
+void register_default_affinity_proc(void)
+{
+#ifdef CONFIG_SMP
+       struct proc_dir_entry *entry;
+
+       /* create /proc/irq/default_smp_affinity */
+       entry = create_proc_entry("default_smp_affinity", 0600, root_irq_dir);
+       if (entry) {
+               entry->data = NULL;
+               entry->read_proc  = default_affinity_read;
+               entry->write_proc = default_affinity_write;
+       }
+#endif
+}
+
 void init_irq_proc(void)
 {
        int i;
@@ -180,6 +229,8 @@ void init_irq_proc(void)
        if (!root_irq_dir)
                return;
 
+       register_default_affinity_proc();
+
        /*
         * Create entries for all existing IRQs.
         */