Revert "PCI/MSI: Provide stubs for IMS functions"

This reverts commit 41efa43.

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, this could be squashed with these commits:

  0194425 ("PCI/MSI: Provide IMS (Interrupt Message Store) support")
  c9e5bea ("PCI/MSI: Provide pci_ims_alloc/free_irq()")

which added the non-stub implementations.

Link: https://lore.kernel.org/r/20240410221307.2162676-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

Author: bjorn-helgaas

include/linux/pci.h

@@ -1658,8 +1658,6 @@ struct msix_entry {
 	u16	entry;	/* Driver uses to specify entry, OS writes */
 };
 
-struct msi_domain_template;
-
 #ifdef CONFIG_PCI_MSI
 int pci_msi_vec_count(struct pci_dev *dev);
 void pci_disable_msi(struct pci_dev *dev);
@@ -1692,11 +1690,6 @@ void pci_msix_free_irq(struct pci_dev *pdev, struct msi_map map);
 void pci_free_irq_vectors(struct pci_dev *dev);
 int pci_irq_vector(struct pci_dev *dev, unsigned int nr);
 const struct cpumask *pci_irq_get_affinity(struct pci_dev *pdev, int vec);
-bool pci_create_ims_domain(struct pci_dev *pdev, const struct msi_domain_template *template,
-			   unsigned int hwsize, void *data);
-struct msi_map pci_ims_alloc_irq(struct pci_dev *pdev, union msi_instance_cookie *icookie,
-				 const struct irq_affinity_desc *affdesc);
-void pci_ims_free_irq(struct pci_dev *pdev, struct msi_map map);
 
 #else
 static inline int pci_msi_vec_count(struct pci_dev *dev) { return -ENOSYS; }
@@ -1760,25 +1753,6 @@ static inline const struct cpumask *pci_irq_get_affinity(struct pci_dev *pdev,
 {
 	return cpu_possible_mask;
 }
-
-static inline bool pci_create_ims_domain(struct pci_dev *pdev,
-					 const struct msi_domain_template *template,
-					 unsigned int hwsize, void *data)
-{ return false; }
-
-static inline struct msi_map pci_ims_alloc_irq(struct pci_dev *pdev,
-					       union msi_instance_cookie *icookie,
-					       const struct irq_affinity_desc *affdesc)
-{
-	struct msi_map map = { .index = -ENOSYS, };
-
-	return map;
-}
-
-static inline void pci_ims_free_irq(struct pci_dev *pdev, struct msi_map map)
-{
-}
-
 #endif
 
 /**
@@ -2690,6 +2664,14 @@ 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);
+struct msi_map pci_ims_alloc_irq(struct pci_dev *pdev, union msi_instance_cookie *icookie,
+				 const struct irq_affinity_desc *affdesc);
+void pci_ims_free_irq(struct pci_dev *pdev, struct msi_map map);
+
 #include <linux/dma-mapping.h>
 
 #define pci_printk(level, pdev, fmt, arg...) \