[patch 08/37] genirq/msi: Provide msi_device_populate/destroy_sysfs()

[Thomas Gleixner <tglx@xxxxxxxxxxxxx>]

Add new allocation functions which can be activated by domain info
flags. They store the groups pointer in struct msi_device_data.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
 include/linux/msi.h |   12 +++++++++++-
 kernel/irq/msi.c    |   42 ++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 51 insertions(+), 3 deletions(-)

--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -174,9 +174,11 @@ struct msi_desc {
 /**
  * msi_device_data - MSI per device data
  * @lock:		Spinlock to protect register access
+ * @attrs:		Pointer to the sysfs attribute group
  */
 struct msi_device_data {
-	raw_spinlock_t		lock;
+	raw_spinlock_t			lock;
+	const struct attribute_group    **attrs;
 };
 
 int msi_setup_device_data(struct device *dev);
@@ -242,10 +244,16 @@ void pci_msi_mask_irq(struct irq_data *d
 void pci_msi_unmask_irq(struct irq_data *data);
 
 #ifdef CONFIG_SYSFS
+int msi_device_populate_sysfs(struct device *dev);
+void msi_device_destroy_sysfs(struct device *dev);
+
 const struct attribute_group **msi_populate_sysfs(struct device *dev);
 void msi_destroy_sysfs(struct device *dev,
 		       const struct attribute_group **msi_irq_groups);
 #else
+static inline int msi_device_populate_sysfs(struct device *dev) { return 0; }
+static inline void msi_device_destroy_sysfs(struct device *dev) { }
+
 static inline const struct attribute_group **msi_populate_sysfs(struct device *dev)
 {
 	return NULL;
@@ -393,6 +401,8 @@ enum {
 	MSI_FLAG_MUST_REACTIVATE	= (1 << 5),
 	/* Is level-triggered capable, using two messages */
 	MSI_FLAG_LEVEL_CAPABLE		= (1 << 6),
+	/* Populate sysfs on alloc() and destroy it on free() */
+	MSI_FLAG_DEV_SYSFS		= (1 << 7),
 };
 
 int msi_domain_set_affinity(struct irq_data *data, const struct cpumask *mask,
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -214,6 +214,20 @@ const struct attribute_group **msi_popul
 }
 
 /**
+ * msi_device_populate_sysfs - Populate msi_irqs sysfs entries for a device
+ * @dev:	The device(PCI, platform etc) which will get sysfs entries
+ */
+int msi_device_populate_sysfs(struct device *dev)
+{
+	const struct attribute_group **group = msi_populate_sysfs(dev);
+
+	if (IS_ERR(group))
+		return PTR_ERR(group);
+	dev->msi.data->attrs = group;
+	return 0;
+}
+
+/**
  * msi_destroy_sysfs - Destroy msi_irqs sysfs entries for devices
  * @dev:		The device(PCI, platform etc) who will remove sysfs entries
  * @msi_irq_groups:	attribute_group for device msi_irqs entries
@@ -239,6 +253,17 @@ void msi_destroy_sysfs(struct device *de
 		kfree(msi_irq_groups);
 	}
 }
+
+/**
+ * msi_device_destroy_sysfs - Destroy msi_irqs sysfs entries for a device
+ * @dev:		The device(PCI, platform etc) for which to remove
+ *			sysfs entries
+ */
+void msi_device_destroy_sysfs(struct device *dev)
+{
+	msi_destroy_sysfs(dev, dev->msi.data->attrs);
+	dev->msi.data->attrs = NULL;
+}
 #endif
 
 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
@@ -686,8 +711,19 @@ int msi_domain_alloc_irqs(struct irq_dom
 {
 	struct msi_domain_info *info = domain->host_data;
 	struct msi_domain_ops *ops = info->ops;
+	int ret;
 
-	return ops->domain_alloc_irqs(domain, dev, nvec);
+	ret = ops->domain_alloc_irqs(domain, dev, nvec);
+	if (ret)
+		return ret;
+
+	if (!(info->flags & MSI_FLAG_DEV_SYSFS))
+		return 0;
+
+	ret = msi_device_populate_sysfs(dev);
+	if (ret)
+		msi_domain_free_irqs(domain, dev);
+	return ret;
 }
 
 void __msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
@@ -726,7 +762,9 @@ void msi_domain_free_irqs(struct irq_dom
 	struct msi_domain_info *info = domain->host_data;
 	struct msi_domain_ops *ops = info->ops;
 
-	return ops->domain_free_irqs(domain, dev);
+	if (info->flags & MSI_FLAG_DEV_SYSFS)
+		msi_device_destroy_sysfs(dev);
+	ops->domain_free_irqs(domain, dev);
 }
 
 /**