Revert "PCI/MSI: Provide IMS (Interrupt Message Store) support"

This reverts commit 0194425.

IMS (Interrupt Message Store) support appeared in v6.2, but there are no
users yet.

Remove it for now.  We can add it back when a user comes along.  If this is
re-added later, the relevant part of 41efa43 ("PCI/MSI: Provide stubs
for IMS functions") should be squashed into it.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Bjorn Helgaas <[email protected]>
Reviewed-by: Kevin Tian <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>

Author: bjorn-helgaas

drivers/pci/msi/irqdomain.c

@@ -355,65 +355,6 @@ bool pci_msi_domain_supports(struct pci_dev *pdev, unsigned int feature_mask,
 	return (supported & feature_mask) == feature_mask;
 }
 
-/**
- * pci_create_ims_domain - Create a secondary IMS domain for a PCI device
- * @pdev:	The PCI device to operate on
- * @template:	The MSI info template which describes the domain
- * @hwsize:	The size of the hardware entry table or 0 if the domain
- *		is purely software managed
- * @data:	Optional pointer to domain specific data to be stored
- *		in msi_domain_info::data
- *
- * Return: True on success, false otherwise
- *
- * An IMS domain is expected to have the following constraints:
- *	- The index space is managed by the core code
- *
- *	- There is no requirement for consecutive index ranges
- *
- *	- The interrupt chip must provide the following callbacks:
- *		- irq_mask()
- *		- irq_unmask()
- *		- irq_write_msi_msg()
- *
- *	- The interrupt chip must provide the following optional callbacks
- *	  when the irq_mask(), irq_unmask() and irq_write_msi_msg() callbacks
- *	  cannot operate directly on hardware, e.g. in the case that the
- *	  interrupt message store is in queue memory:
- *		- irq_bus_lock()
- *		- irq_bus_unlock()
- *
- *	  These callbacks are invoked from preemptible task context and are
- *	  allowed to sleep. In this case the mandatory callbacks above just
- *	  store the information. The irq_bus_unlock() callback is supposed
- *	  to make the change effective before returning.
- *
- *	- Interrupt affinity setting is handled by the underlying parent
- *	  interrupt domain and communicated to the IMS domain via
- *	  irq_write_msi_msg().
- *
- * The domain is automatically destroyed when the PCI device is removed.
- */
-bool pci_create_ims_domain(struct pci_dev *pdev, const struct msi_domain_template *template,
-			   unsigned int hwsize, void *data)
-{
-	struct irq_domain *domain = dev_get_msi_domain(&pdev->dev);
-
-	if (!domain || !irq_domain_is_msi_parent(domain))
-		return false;
-
-	if (template->info.bus_token != DOMAIN_BUS_PCI_DEVICE_IMS ||
-	    !(template->info.flags & MSI_FLAG_ALLOC_SIMPLE_MSI_DESCS) ||
-	    !(template->info.flags & MSI_FLAG_FREE_MSI_DESCS) ||
-	    !template->chip.irq_mask || !template->chip.irq_unmask ||
-	    !template->chip.irq_write_msi_msg || template->chip.irq_set_affinity)
-		return false;
-
-	return msi_create_device_irq_domain(&pdev->dev, MSI_SECONDARY_DOMAIN, template,
-					    hwsize, data, NULL);
-}
-EXPORT_SYMBOL_GPL(pci_create_ims_domain);
-
 /*
  * Users of the generic MSI infrastructure expect a device to have a single ID,
  * so with DMA aliases we have to pick the least-worst compromise. Devices with

include/linux/pci.h

@@ -2664,11 +2664,6 @@ static inline bool pci_is_thunderbolt_attached(struct pci_dev *pdev)
 void pci_uevent_ers(struct pci_dev *pdev, enum  pci_ers_result err_type);
 #endif
 
-struct msi_domain_template;
-
-bool pci_create_ims_domain(struct pci_dev *pdev, const struct msi_domain_template *template,
-			   unsigned int hwsize, void *data);
-
 #include <linux/dma-mapping.h>
 
 #define pci_printk(level, pdev, fmt, arg...) \