[patch V3 08/35] device: Add device:: Msi_data pointer and struct msi_device_data

[Thomas Gleixner <tglx@xxxxxxxxxxxxx>]

From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

Create struct msi_device_data and add a pointer of that type to struct
dev_msi_info, which is part of struct device. Provide an allocator function
which can be invoked from the MSI interrupt allocation code pathes.

Add a properties field to the data structure as a first member so the
allocation size is not zero bytes. The field will be uses later on.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
 include/linux/device.h |    5 +++++
 include/linux/msi.h    |   18 ++++++++++++++++++
 kernel/irq/msi.c       |   32 ++++++++++++++++++++++++++++++++
 3 files changed, 55 insertions(+)

--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -45,6 +45,7 @@ struct iommu_ops;
 struct iommu_group;
 struct dev_pin_info;
 struct dev_iommu;
+struct msi_device_data;
 
 /**
  * struct subsys_interface - interfaces to device functions
@@ -374,11 +375,15 @@ struct dev_links_info {
 /**
  * struct dev_msi_info - Device data related to MSI
  * @domain:    The MSI interrupt domain associated to the device
+ * @data:      Pointer to MSI device data
  */
 struct dev_msi_info {
 #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
        struct irq_domain       *domain;
 #endif
+#ifdef CONFIG_GENERIC_MSI_IRQ
+       struct msi_device_data  *data;
+#endif
 };
 
 /**
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -171,6 +171,16 @@ struct msi_desc {
        };
 };
 
+/**
+ * msi_device_data - MSI per device data
+ * @properties:                MSI properties which are interesting to drivers
+ */
+struct msi_device_data {
+       unsigned long                   properties;
+};
+
+int msi_setup_device_data(struct device *dev);
+
 /* Helpers to hide struct msi_desc implementation details */
 #define msi_desc_to_dev(desc)          ((desc)->dev)
 #define dev_to_msi_list(dev)           (&(dev)->msi_list)
@@ -233,10 +243,16 @@ 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;
@@ -384,6 +400,8 @@ 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
@@ -73,6 +73,38 @@ void get_cached_msi_msg(unsigned int irq
 }
 EXPORT_SYMBOL_GPL(get_cached_msi_msg);
 
+static void msi_device_data_release(struct device *dev, void *res)
+{
+       WARN_ON_ONCE(!list_empty(&dev->msi_list));
+       dev->msi.data = NULL;
+}
+
+/**
+ * msi_setup_device_data - Setup MSI device data
+ * @dev:       Device for which MSI device data should be set up
+ *
+ * Return: 0 on success, appropriate error code otherwise
+ *
+ * This can be called more than once for @dev. If the MSI device data is
+ * already allocated the call succeeds. The allocated memory is
+ * automatically released when the device is destroyed.
+ */
+int msi_setup_device_data(struct device *dev)
+{
+       struct msi_device_data *md;
+
+       if (dev->msi.data)
+               return 0;
+
+       md = devres_alloc(msi_device_data_release, sizeof(*md), GFP_KERNEL);
+       if (!md)
+               return -ENOMEM;
+
+       dev->msi.data = md;
+       devres_add(dev, md);
+       return 0;
+}
+
 #ifdef CONFIG_SYSFS
 static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
                             char *buf)