From 1046f71d7268b1680d7b044dea83c664403f6302 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 6 Dec 2021 23:51:08 +0100 Subject: genirq/msi: Provide a set of advanced MSI accessors and iterators In preparation for dynamic handling of MSI-X interrupts provide a new set of MSI descriptor accessor functions and iterators. They are benefitial per se as they allow to cleanup quite some code in various MSI domain implementations. Signed-off-by: Thomas Gleixner Tested-by: Michael Kelley Tested-by: Nishanth Menon Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20211206210747.818635078@linutronix.de --- include/linux/msi.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'include/linux/msi.h') diff --git a/include/linux/msi.h b/include/linux/msi.h index 69c588efe85b..703221f7e9ea 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -140,6 +140,18 @@ struct msi_desc { struct pci_msi_desc pci; }; +/* + * Filter values for the MSI descriptor iterators and accessor functions. + */ +enum msi_desc_filter { + /* All descriptors */ + MSI_DESC_ALL, + /* Descriptors which have no interrupt associated */ + MSI_DESC_NOTASSOCIATED, + /* Descriptors which have an interrupt associated */ + MSI_DESC_ASSOCIATED, +}; + /** * msi_device_data - MSI per device data * @properties: MSI properties which are interesting to drivers @@ -147,6 +159,7 @@ struct msi_desc { * @platform_data: Platform-MSI specific data * @list: List of MSI descriptors associated to the device * @mutex: Mutex protecting the MSI list + * @__next: Cached pointer to the next entry for iterators */ struct msi_device_data { unsigned long properties; @@ -154,6 +167,7 @@ struct msi_device_data { struct platform_msi_priv_data *platform_data; struct list_head list; struct mutex mutex; + struct msi_desc *__next; }; int msi_setup_device_data(struct device *dev); @@ -162,6 +176,25 @@ unsigned int msi_get_virq(struct device *dev, unsigned int index); void msi_lock_descs(struct device *dev); void msi_unlock_descs(struct device *dev); +struct msi_desc *msi_first_desc(struct device *dev, enum msi_desc_filter filter); +struct msi_desc *msi_next_desc(struct device *dev, enum msi_desc_filter filter); + +/** + * msi_for_each_desc - Iterate the MSI descriptors + * + * @desc: struct msi_desc pointer used as iterator + * @dev: struct device pointer - device to iterate + * @filter: Filter for descriptor selection + * + * Notes: + * - The loop must be protected with a msi_lock_descs()/msi_unlock_descs() + * pair. + * - It is safe to remove a retrieved MSI descriptor in the loop. + */ +#define msi_for_each_desc(desc, dev, filter) \ + for ((desc) = msi_first_desc((dev), (filter)); (desc); \ + (desc) = msi_next_desc((dev), (filter))) + /* Helpers to hide struct msi_desc implementation details */ #define msi_desc_to_dev(desc) ((desc)->dev) #define dev_to_msi_list(dev) (&(dev)->msi.data->list) -- cgit v1.2.3-70-g09d2