genirq: Remove mask argument from setup_affinity()

No point to have this alloc/free dance of cpumasks. Provide a static mask
for setup_affinity() and protect it proper.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170619235444.851571573@linutronix.de

1 files changed, 23 insertions, 30 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 284f4eb1ffbe..e2f20d553d60 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -345,15 +345,18 @@ EXPORT_SYMBOL_GPL(irq_set_affinity_notifier);
 /*
  * Generic version of the affinity autoselector.
  */
-static int setup_affinity(struct irq_desc *desc, struct cpumask *mask)
+static int irq_setup_affinity(struct irq_desc *desc)
 {
         struct cpumask *set = irq_default_affinity;
-        int node = irq_desc_get_node(desc);
+        int ret, node = irq_desc_get_node(desc);
+        static DEFINE_RAW_SPINLOCK(mask_lock);
+        static struct cpumask mask;
 
         /* Excludes PER_CPU and NO_BALANCE interrupts */
         if (!__irq_can_set_affinity(desc))
                 return 0;
 
+        raw_spin_lock(&mask_lock);
         /*
          * Preserve the managed affinity setting and a userspace affinity
          * setup, but make sure that one of the targets is online.
@@ -367,43 +370,42 @@ static int setup_affinity(struct irq_desc *desc, struct cpumask *mask)
                         irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET);
         }
 
-        cpumask_and(mask, cpu_online_mask, set);
+        cpumask_and(&mask, cpu_online_mask, set);
         if (node != NUMA_NO_NODE) {
                 const struct cpumask *nodemask = cpumask_of_node(node);
 
                 /* make sure at least one of the cpus in nodemask is online */
-                if (cpumask_intersects(mask, nodemask))
-                        cpumask_and(mask, mask, nodemask);
+                if (cpumask_intersects(&mask, nodemask))
+                        cpumask_and(&mask, &mask, nodemask);
         }
-        irq_do_set_affinity(&desc->irq_data, mask, false);
-        return 0;
+        ret = irq_do_set_affinity(&desc->irq_data, &mask, false);
+        raw_spin_unlock(&mask_lock);
+        return ret;
 }
 #else
 /* Wrapper for ALPHA specific affinity selector magic */
-static inline int setup_affinity(struct irq_desc *d, struct cpumask *mask)
+int irq_setup_affinity(struct irq_desc *desc)
 {
-        return irq_select_affinity(irq_desc_get_irq(d));
+        return irq_select_affinity(irq_desc_get_irq(desc));
 }
 #endif
 
 /*
- * Called when affinity is set via /proc/irq
+ * Called when a bogus affinity is set via /proc/irq
  */
-int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask)
+int irq_select_affinity_usr(unsigned int irq)
 {
         struct irq_desc *desc = irq_to_desc(irq);
         unsigned long flags;
         int ret;
 
         raw_spin_lock_irqsave(&desc->lock, flags);
-        ret = setup_affinity(desc, mask);
+        ret = irq_setup_affinity(desc);
         raw_spin_unlock_irqrestore(&desc->lock, flags);
         return ret;
 }
-
 #else
-static inline int
-setup_affinity(struct irq_desc *desc, struct cpumask *mask)
+static inline int setup_affinity(struct irq_desc *desc)
 {
         return 0;
 }
@@ -1128,7 +1130,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
         struct irqaction *old, **old_ptr;
         unsigned long flags, thread_mask = 0;
         int ret, nested, shared = 0;
-        cpumask_var_t mask;
 
         if (!desc)
                 return -EINVAL;
@@ -1187,11 +1188,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                 }
         }
 
-        if (!alloc_cpumask_var(&mask, GFP_KERNEL)) {
-                ret = -ENOMEM;
-                goto out_thread;
-        }
-
         /*
          * Drivers are often written to work w/o knowledge about the
          * underlying irq chip implementation, so a request for a
@@ -1256,7 +1252,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                  */
                 if (thread_mask == ~0UL) {
                         ret = -EBUSY;
-                        goto out_mask;
+                        goto out_unlock;
                 }
                 /*
                  * The thread_mask for the action is or'ed to
@@ -1300,7 +1296,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
                        irq);
                 ret = -EINVAL;
-                goto out_mask;
+                goto out_unlock;
         }
 
         if (!shared) {
@@ -1308,7 +1304,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                 if (ret) {
                         pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
                                new->name, irq, desc->irq_data.chip->name);
-                        goto out_mask;
+                        goto out_unlock;
                 }
 
                 init_waitqueue_head(&desc->wait_for_threads);
@@ -1320,7 +1316,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 
                         if (ret) {
                                 irq_release_resources(desc);
-                                goto out_mask;
+                                goto out_unlock;
                         }
                 }
 
@@ -1357,7 +1353,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                 }
 
                 /* Set default affinity mask once everything is setup */
-                setup_affinity(desc, mask);
+                irq_setup_affinity(desc);
 
         } else if (new->flags & IRQF_TRIGGER_MASK) {
                 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
@@ -1401,8 +1397,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
         irq_add_debugfs_entry(irq, desc);
         new->dir = NULL;
         register_handler_proc(irq, new);
-        free_cpumask_var(mask);
-
         return 0;
 
 mismatch:
@@ -1415,9 +1409,8 @@ mismatch:
         }
         ret = -EBUSY;
 
-out_mask:
+out_unlock:
         raw_spin_unlock_irqrestore(&desc->lock, flags);
-        free_cpumask_var(mask);
 
 out_thread:
         if (new->thread) {