PCI/MSI: Drop use of msi_controller from core code

As there is no driver using msi_controller, we can now safely
remove its use from the PCI probe code.

Link: https://lore.kernel.org/r/20210330151145.997953-8-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

Author: Marc Zyngier

drivers/pci/msi.c

@@ -64,39 +64,18 @@ static void pci_msi_teardown_msi_irqs(struct pci_dev *dev)
 /* Arch hooks */
 int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 {
-	struct msi_controller *chip = dev->bus->msi;
-	int err;
-
-	if (!chip || !chip->setup_irq)
-		return -EINVAL;
-
-	err = chip->setup_irq(chip, dev, desc);
-	if (err < 0)
-		return err;
-
-	irq_set_chip_data(desc->irq, chip);
-
-	return 0;
+	return -EINVAL;
 }
 
 void __weak arch_teardown_msi_irq(unsigned int irq)
 {
-	struct msi_controller *chip = irq_get_chip_data(irq);
-
-	if (!chip || !chip->teardown_irq)
-		return;
-
-	chip->teardown_irq(chip, irq);
 }
 
 int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 {
-	struct msi_controller *chip = dev->bus->msi;
 	struct msi_desc *entry;
 	int ret;
 
-	if (chip && chip->setup_irqs)
-		return chip->setup_irqs(chip, dev, nvec, type);
 	/*
 	 * If an architecture wants to support multiple MSI, it needs to
 	 * override arch_setup_msi_irqs()

drivers/pci/probe.c

@@ -895,7 +895,6 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 	/* Temporarily move resources off the list */
 	list_splice_init(&bridge->windows, &resources);
 	bus->sysdata = bridge->sysdata;
-	bus->msi = bridge->msi;
 	bus->ops = bridge->ops;
 	bus->number = bus->busn_res.start = bridge->busnr;
 #ifdef CONFIG_PCI_DOMAINS_GENERIC
@@ -1053,7 +1052,6 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
 		return NULL;
 
 	child->parent = parent;
-	child->msi = parent->msi;
 	child->sysdata = parent->sysdata;
 	child->bus_flags = parent->bus_flags;
 

include/linux/pci.h

@@ -540,7 +540,6 @@ struct pci_host_bridge {
 	int (*map_irq)(const struct pci_dev *, u8, u8);
 	void (*release_fn)(struct pci_host_bridge *);
 	void		*release_data;
-	struct msi_controller *msi;
 	unsigned int	ignore_reset_delay:1;	/* For entire hierarchy */
 	unsigned int	no_ext_tags:1;		/* No Extended Tags */
 	unsigned int	native_aer:1;		/* OS may use PCIe AER */
@@ -621,7 +620,6 @@ struct pci_bus {
 	struct resource busn_res;	/* Bus numbers routed to this bus */
 
 	struct pci_ops	*ops;		/* Configuration access functions */
-	struct msi_controller *msi;	/* MSI controller */
 	void		*sysdata;	/* Hook for sys-specific extension */
 	struct proc_dir_entry *procdir;	/* Directory entry in /proc/bus/pci */