[patch V2 02/36] device: Add device::msi_data pointer and struct msi_device_data

Thomas Gleixner
2021-12-06T22:39:06Z

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@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
---
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)