1 files changed, 206 insertions, 18 deletions

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index a623b44f2d4b..00bb0aeea1d0 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -15,6 +15,7 @@
 #include <linux/radix-tree.h>
 #include <linux/bitmap.h>
 #include <linux/irqdomain.h>
+#include <linux/sysfs.h>
 
 #include "internals.h"
 
@@ -123,6 +124,181 @@ static DECLARE_BITMAP(allocated_irqs, IRQ_BITMAP_BITS);
 
 #ifdef CONFIG_SPARSE_IRQ
 
+static void irq_kobj_release(struct kobject *kobj);
+
+#ifdef CONFIG_SYSFS
+static struct kobject *irq_kobj_base;
+
+#define IRQ_ATTR_RO(_name) \
+static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
+
+static ssize_t per_cpu_count_show(struct kobject *kobj,
+				  struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	int cpu, irq = desc->irq_data.irq;
+	ssize_t ret = 0;
+	char *p = "";
+
+	for_each_possible_cpu(cpu) {
+		unsigned int c = kstat_irqs_cpu(irq, cpu);
+
+		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%u", p, c);
+		p = ",";
+	}
+
+	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
+	return ret;
+}
+IRQ_ATTR_RO(per_cpu_count);
+
+static ssize_t chip_name_show(struct kobject *kobj,
+			      struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	ssize_t ret = 0;
+
+	raw_spin_lock_irq(&desc->lock);
+	if (desc->irq_data.chip && desc->irq_data.chip->name) {
+		ret = scnprintf(buf, PAGE_SIZE, "%s\n",
+				desc->irq_data.chip->name);
+	}
+	raw_spin_unlock_irq(&desc->lock);
+
+	return ret;
+}
+IRQ_ATTR_RO(chip_name);
+
+static ssize_t hwirq_show(struct kobject *kobj,
+			  struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	ssize_t ret = 0;
+
+	raw_spin_lock_irq(&desc->lock);
+	if (desc->irq_data.domain)
+		ret = sprintf(buf, "%d\n", (int)desc->irq_data.hwirq);
+	raw_spin_unlock_irq(&desc->lock);
+
+	return ret;
+}
+IRQ_ATTR_RO(hwirq);
+
+static ssize_t type_show(struct kobject *kobj,
+			 struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	ssize_t ret = 0;
+
+	raw_spin_lock_irq(&desc->lock);
+	ret = sprintf(buf, "%s\n",
+		      irqd_is_level_type(&desc->irq_data) ? "level" : "edge");
+	raw_spin_unlock_irq(&desc->lock);
+
+	return ret;
+
+}
+IRQ_ATTR_RO(type);
+
+static ssize_t name_show(struct kobject *kobj,
+			 struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	ssize_t ret = 0;
+
+	raw_spin_lock_irq(&desc->lock);
+	if (desc->name)
+		ret = scnprintf(buf, PAGE_SIZE, "%s\n", desc->name);
+	raw_spin_unlock_irq(&desc->lock);
+
+	return ret;
+}
+IRQ_ATTR_RO(name);
+
+static ssize_t actions_show(struct kobject *kobj,
+			    struct kobj_attribute *attr, char *buf)
+{
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
+	struct irqaction *action;
+	ssize_t ret = 0;
+	char *p = "";
+
+	raw_spin_lock_irq(&desc->lock);
+	for (action = desc->action; action != NULL; action = action->next) {
+		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%s%s",
+				 p, action->name);
+		p = ",";
+	}
+	raw_spin_unlock_irq(&desc->lock);
+
+	if (ret)
+		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
+
+	return ret;
+}
+IRQ_ATTR_RO(actions);
+
+static struct attribute *irq_attrs[] = {
+	&per_cpu_count_attr.attr,
+	&chip_name_attr.attr,
+	&hwirq_attr.attr,
+	&type_attr.attr,
+	&name_attr.attr,
+	&actions_attr.attr,
+	NULL
+};
+
+static struct kobj_type irq_kobj_type = {
+	.release	= irq_kobj_release,
+	.sysfs_ops	= &kobj_sysfs_ops,
+	.default_attrs	= irq_attrs,
+};
+
+static void irq_sysfs_add(int irq, struct irq_desc *desc)
+{
+	if (irq_kobj_base) {
+		/*
+		 * Continue even in case of failure as this is nothing
+		 * crucial.
+		 */
+		if (kobject_add(&desc->kobj, irq_kobj_base, "%d", irq))
+			pr_warn("Failed to add kobject for irq %d\n", irq);
+	}
+}
+
+static int __init irq_sysfs_init(void)
+{
+	struct irq_desc *desc;
+	int irq;
+
+	/* Prevent concurrent irq alloc/free */
+	irq_lock_sparse();
+
+	irq_kobj_base = kobject_create_and_add("irq", kernel_kobj);
+	if (!irq_kobj_base) {
+		irq_unlock_sparse();
+		return -ENOMEM;
+	}
+
+	/* Add the already allocated interrupts */
+	for_each_irq_desc(irq, desc)
+		irq_sysfs_add(irq, desc);
+	irq_unlock_sparse();
+
+	return 0;
+}
+postcore_initcall(irq_sysfs_init);
+
+#else /* !CONFIG_SYSFS */
+
+static struct kobj_type irq_kobj_type = {
+	.release	= irq_kobj_release,
+};
+
+static void irq_sysfs_add(int irq, struct irq_desc *desc) {}
+
+#endif /* CONFIG_SYSFS */
+
 static RADIX_TREE(irq_desc_tree, GFP_KERNEL);
 
 static void irq_insert_desc(unsigned int irq, struct irq_desc *desc)
@@ -187,6 +363,7 @@ static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags,
 
 	desc_set_defaults(irq, desc, node, affinity, owner);
 	irqd_set(&desc->irq_data, flags);
+	kobject_init(&desc->kobj, &irq_kobj_type);
 
 	return desc;
 
@@ -197,15 +374,22 @@ err_desc:
 	return NULL;
 }
 
-static void delayed_free_desc(struct rcu_head *rhp)
+static void irq_kobj_release(struct kobject *kobj)
 {
-	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
+	struct irq_desc *desc = container_of(kobj, struct irq_desc, kobj);
 
 	free_masks(desc);
 	free_percpu(desc->kstat_irqs);
 	kfree(desc);
 }
 
+static void delayed_free_desc(struct rcu_head *rhp)
+{
+	struct irq_desc *desc = container_of(rhp, struct irq_desc, rcu);
+
+	kobject_put(&desc->kobj);
+}
+
 static void free_desc(unsigned int irq)
 {
 	struct irq_desc *desc = irq_to_desc(irq);
@@ -217,8 +401,12 @@ static void free_desc(unsigned int irq)
 	 * kstat_irq_usr(). Once we deleted the descriptor from the
 	 * sparse tree we can free it. Access in proc will fail to
 	 * lookup the descriptor.
+	 *
+	 * The sysfs entry must be serialized against a concurrent
+	 * irq_sysfs_init() as well.
 	 */
 	mutex_lock(&sparse_irq_lock);
+	kobject_del(&desc->kobj);
 	delete_irq_desc(irq);
 	mutex_unlock(&sparse_irq_lock);
 
@@ -236,31 +424,31 @@ static int alloc_descs(unsigned int start, unsigned int cnt, int node,
 	const struct cpumask *mask = NULL;
 	struct irq_desc *desc;
 	unsigned int flags;
-	int i, cpu = -1;
+	int i;
 
-	if (affinity && cpumask_empty(affinity))
-		return -EINVAL;
+	/* Validate affinity mask(s) */
+	if (affinity) {
+		for (i = 0, mask = affinity; i < cnt; i++, mask++) {
+			if (cpumask_empty(mask))
+				return -EINVAL;
+		}
+	}
 
 	flags = affinity ? IRQD_AFFINITY_MANAGED : 0;
+	mask = NULL;
 
 	for (i = 0; i < cnt; i++) {
 		if (affinity) {
-			cpu = cpumask_next(cpu, affinity);
-			if (cpu >= nr_cpu_ids)
-				cpu = cpumask_first(affinity);
-			node = cpu_to_node(cpu);
-
-			/*
-			 * For single allocations we use the caller provided
-			 * mask otherwise we use the mask of the target cpu
-			 */
-			mask = cnt == 1 ? affinity : cpumask_of(cpu);
+			node = cpu_to_node(cpumask_first(affinity));
+			mask = affinity;
+			affinity++;
 		}
 		desc = alloc_desc(start + i, node, flags, mask, owner);
 		if (!desc)
 			goto err;
 		mutex_lock(&sparse_irq_lock);
 		irq_insert_desc(start + i, desc);
+		irq_sysfs_add(start + i, desc);
 		mutex_unlock(&sparse_irq_lock);
 	}
 	return start;
@@ -481,9 +669,9 @@ EXPORT_SYMBOL_GPL(irq_free_descs);
  * @cnt:	Number of consecutive irqs to allocate.
  * @node:	Preferred node on which the irq descriptor should be allocated
  * @owner:	Owning module (can be NULL)
- * @affinity:	Optional pointer to an affinity mask which hints where the
- *		irq descriptors should be allocated and which default
- *		affinities to use
+ * @affinity:	Optional pointer to an affinity mask array of size @cnt which
+ *		hints where the irq descriptors should be allocated and which
+ *		default affinities to use
  *
  * Returns the first irq number or error code
  */