[POWERPC] make pmf irq_client functions safe against pmf interrupts coming in

This fixes the pmf irq_client functions to be safe against pmf interrupts coming
in while a client is registered/unregistered.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/platforms/powermac/pfunc_core.c b/arch/powerpc/platforms/powermac/pfunc_core.c
index f08173b..047f954 100644 (file)
--- a/arch/powerpc/platforms/powermac/pfunc_core.c
+++ b/arch/powerpc/platforms/powermac/pfunc_core.c
@@ -871,10 +871,17 @@ int pmf_register_irq_client(struct device_node *target,
        spin_unlock_irqrestore(&pmf_lock, flags);
        if (func == NULL)
                return -ENODEV;
+
+       /* guard against manipulations of list */
        mutex_lock(&pmf_irq_mutex);
        if (list_empty(&func->irq_clients))
                func->dev->handlers->irq_enable(func);
+
+       /* guard against pmf_do_irq while changing list */
+       spin_lock_irqsave(&pmf_lock, flags);
        list_add(&client->link, &func->irq_clients);
+       spin_unlock_irqrestore(&pmf_lock, flags);
+
        client->func = func;
        mutex_unlock(&pmf_irq_mutex);
 
@@ -885,12 +892,19 @@ EXPORT_SYMBOL_GPL(pmf_register_irq_client);
 void pmf_unregister_irq_client(struct pmf_irq_client *client)
 {
        struct pmf_function *func = client->func;
+       unsigned long flags;
 
        BUG_ON(func == NULL);
 
+       /* guard against manipulations of list */
        mutex_lock(&pmf_irq_mutex);
        client->func = NULL;
+
+       /* guard against pmf_do_irq while changing list */
+       spin_lock_irqsave(&pmf_lock, flags);
        list_del(&client->link);
+       spin_unlock_irqrestore(&pmf_lock, flags);
+
        if (list_empty(&func->irq_clients))
                func->dev->handlers->irq_disable(func);
        mutex_unlock(&pmf_irq_mutex);