x86/irq: change irq_desc_alloc() to take node instead of cpu

This simplifies the node awareness of the code. All our allocators
only deal with a NUMA node ID locality not with CPU ids anyway - so
there's no need to maintain (and transform) a CPU id all across the
IRq layer.

v2: keep move_irq_desc related

[ Impact: cleanup, prepare IRQ code to be NUMA-aware ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
LKML-Reference: <49F65536.2020300@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 24 insertions, 42 deletions

diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 3e0cbc44bd73..a6368db2618b 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -81,12 +81,10 @@ static struct irq_desc irq_desc_init = {
         .lock       = __SPIN_LOCK_UNLOCKED(irq_desc_init.lock),
 };
 
-void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
+void init_kstat_irqs(struct irq_desc *desc, int node, int nr)
 {
-        int node;
         void *ptr;
 
-        node = cpu_to_node(cpu);
         ptr = kzalloc_node(nr * sizeof(*desc->kstat_irqs), GFP_ATOMIC, node);
 
         /*
@@ -94,33 +92,32 @@ void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr)
          * init_copy_kstat_irqs() could still use old one
          */
         if (ptr) {
-                printk(KERN_DEBUG "  alloc kstat_irqs on cpu %d node %d\n",
-                         cpu, node);
+                printk(KERN_DEBUG "  alloc kstat_irqs on node %d\n", node);
                 desc->kstat_irqs = ptr;
         }
 }
 
-static void init_one_irq_desc(int irq, struct irq_desc *desc, int cpu)
+static void init_one_irq_desc(int irq, struct irq_desc *desc, int node)
 {
         memcpy(desc, &irq_desc_init, sizeof(struct irq_desc));
 
         spin_lock_init(&desc->lock);
         desc->irq = irq;
 #ifdef CONFIG_SMP
-        desc->cpu = cpu;
+        desc->node = node;
 #endif
         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
-        init_kstat_irqs(desc, cpu, nr_cpu_ids);
+        init_kstat_irqs(desc, node, nr_cpu_ids);
         if (!desc->kstat_irqs) {
                 printk(KERN_ERR "can not alloc kstat_irqs\n");
                 BUG_ON(1);
         }
-        if (!alloc_desc_masks(desc, cpu, false)) {
+        if (!alloc_desc_masks(desc, node, false)) {
                 printk(KERN_ERR "can not alloc irq_desc cpumasks\n");
                 BUG_ON(1);
         }
         init_desc_masks(desc);
-        arch_init_chip_data(desc, cpu);
+        arch_init_chip_data(desc, node);
 }
 
 /*
@@ -189,11 +186,10 @@ struct irq_desc *irq_to_desc(unsigned int irq)
         return NULL;
 }
 
-struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
+struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node)
 {
         struct irq_desc *desc;
         unsigned long flags;
-        int node;
 
         if (irq >= nr_irqs) {
                 WARN(1, "irq (%d) >= nr_irqs (%d) in irq_to_desc_alloc\n",
@@ -212,15 +208,13 @@ struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
         if (desc)
                 goto out_unlock;
 
-        node = cpu_to_node(cpu);
         desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
-        printk(KERN_DEBUG "  alloc irq_desc for %d on cpu %d node %d\n",
-                 irq, cpu, node);
+        printk(KERN_DEBUG "  alloc irq_desc for %d on node %d\n", irq, node);
         if (!desc) {
                 printk(KERN_ERR "can not alloc irq_desc\n");
                 BUG_ON(1);
         }
-        init_one_irq_desc(irq, desc, cpu);
+        init_one_irq_desc(irq, desc, node);
 
         irq_desc_ptrs[irq] = desc;
 
@@ -270,7 +264,7 @@ struct irq_desc *irq_to_desc(unsigned int irq)
         return (irq < NR_IRQS) ? irq_desc + irq : NULL;
 }
 
-struct irq_desc *irq_to_desc_alloc_cpu(unsigned int irq, int cpu)
+struct irq_desc *irq_to_desc_alloc_node(unsigned int irq, int node)
 {
         return irq_to_desc(irq);
 }
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index de5f412f6a92..73468253143b 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -16,7 +16,7 @@ extern void __disable_irq(struct irq_desc *desc, unsigned int irq, bool susp);
 extern void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume);
 
 extern struct lock_class_key irq_desc_lock_class;
-extern void init_kstat_irqs(struct irq_desc *desc, int cpu, int nr);
+extern void init_kstat_irqs(struct irq_desc *desc, int node, int nr);
 extern void clear_kstat_irqs(struct irq_desc *desc);
 extern spinlock_t sparse_irq_lock;
 
diff --git a/kernel/irq/numa_migrate.c b/kernel/irq/numa_migrate.c
index ce72bc3f4ced..2f69bee57bf2 100644
--- a/kernel/irq/numa_migrate.c
+++ b/kernel/irq/numa_migrate.c
@@ -15,9 +15,9 @@
 
 static void init_copy_kstat_irqs(struct irq_desc *old_desc,
                                  struct irq_desc *desc,
-                                 int cpu, int nr)
+                                 int node, int nr)
 {
-        init_kstat_irqs(desc, cpu, nr);
+        init_kstat_irqs(desc, node, nr);
 
         if (desc->kstat_irqs != old_desc->kstat_irqs)
                 memcpy(desc->kstat_irqs, old_desc->kstat_irqs,
@@ -34,20 +34,20 @@ static void free_kstat_irqs(struct irq_desc *old_desc, struct irq_desc *desc)
 }
 
 static bool init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
-                 struct irq_desc *desc, int cpu)
+                 struct irq_desc *desc, int node)
 {
         memcpy(desc, old_desc, sizeof(struct irq_desc));
-        if (!alloc_desc_masks(desc, cpu, false)) {
+        if (!alloc_desc_masks(desc, node, false)) {
                 printk(KERN_ERR "irq %d: can not get new irq_desc cpumask "
                                 "for migration.\n", irq);
                 return false;
         }
         spin_lock_init(&desc->lock);
-        desc->cpu = cpu;
+        desc->node = node;
         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
-        init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);
+        init_copy_kstat_irqs(old_desc, desc, node, nr_cpu_ids);
         init_copy_desc_masks(old_desc, desc);
-        arch_init_copy_chip_data(old_desc, desc, cpu);
+        arch_init_copy_chip_data(old_desc, desc, node);
         return true;
 }
 
@@ -59,12 +59,11 @@ static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc)
 }
 
 static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
-                                                int cpu)
+                                                int node)
 {
         struct irq_desc *desc;
         unsigned int irq;
         unsigned long flags;
-        int node;
 
         irq = old_desc->irq;
 
@@ -76,7 +75,6 @@ static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
         if (desc && old_desc != desc)
                 goto out_unlock;
 
-        node = cpu_to_node(cpu);
         desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
         if (!desc) {
                 printk(KERN_ERR "irq %d: can not get new irq_desc "
@@ -85,7 +83,7 @@ static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
                 desc = old_desc;
                 goto out_unlock;
         }
-        if (!init_copy_one_irq_desc(irq, old_desc, desc, cpu)) {
+        if (!init_copy_one_irq_desc(irq, old_desc, desc, node)) {
                 /* still use old one */
                 kfree(desc);
                 desc = old_desc;
@@ -107,24 +105,14 @@ out_unlock:
         return desc;
 }
 
-struct irq_desc *move_irq_desc(struct irq_desc *desc, int cpu)
+struct irq_desc *move_irq_desc(struct irq_desc *desc, int node)
 {
-        int old_cpu;
-        int node, old_node;
-
         /* those all static, do move them */
         if (desc->irq < NR_IRQS_LEGACY)
                 return desc;
 
-        old_cpu = desc->cpu;
-        if (old_cpu != cpu) {
-                node = cpu_to_node(cpu);
-                old_node = cpu_to_node(old_cpu);
-                if (old_node != node)
-                        desc = __real_move_irq_desc(desc, cpu);
-                else
-                        desc->cpu = cpu;
-        }
+        if (desc->node != node)
+                desc = __real_move_irq_desc(desc, node);
 
         return desc;
 }