powerpc/iommu: Remove iommu_del_device()

Now that power calls iommu_device_register() and populates its groups
using iommu_ops->device_group it should not be calling
iommu_group_remove_device().

The core code owns the groups and all the other related iommu data, it
will clean it up automatically.

Remove the bus notifiers and explicit calls to
iommu_group_remove_device().

Fixes: a940904 ("powerpc/iommu: Add iommu_ops to report capabilities and allow blocking domains")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/0-v1-1421774b874b+167-ppc_device_group_jgg@nvidia.com

arch/powerpc/include/asm/iommu.h

@@ -205,7 +205,6 @@ extern void iommu_register_group(struct iommu_table_group *table_group,
 				 int pci_domain_number, unsigned long pe_num);
 extern int iommu_add_device(struct iommu_table_group *table_group,
 		struct device *dev);
-extern void iommu_del_device(struct device *dev);
 extern long iommu_tce_xchg(struct mm_struct *mm, struct iommu_table *tbl,
 		unsigned long entry, unsigned long *hpa,
 		enum dma_data_direction *direction);
@@ -229,10 +228,6 @@ static inline int iommu_add_device(struct iommu_table_group *table_group,
 {
 	return 0;
 }
-
-static inline void iommu_del_device(struct device *dev)
-{
-}
 #endif /* !CONFIG_IOMMU_API */
 
 u64 dma_iommu_get_required_mask(struct device *dev);

arch/powerpc/kernel/iommu.c

@@ -1168,23 +1168,6 @@ int iommu_add_device(struct iommu_table_group *table_group, struct device *dev)
 }
 EXPORT_SYMBOL_GPL(iommu_add_device);
 
-void iommu_del_device(struct device *dev)
-{
-	/*
-	 * Some devices might not have IOMMU table and group
-	 * and we needn't detach them from the associated
-	 * IOMMU groups
-	 */
-	if (!device_iommu_mapped(dev)) {
-		pr_debug("iommu_tce: skipping device %s with no tbl\n",
-			 dev_name(dev));
-		return;
-	}
-
-	iommu_group_remove_device(dev);
-}
-EXPORT_SYMBOL_GPL(iommu_del_device);
-
 /*
  * A simple iommu_table_group_ops which only allows reusing the existing
  * iommu_table. This handles VFIO for POWER7 or the nested KVM.

arch/powerpc/platforms/powernv/pci.c

@@ -865,28 +865,3 @@ void __init pnv_pci_init(void)
 	/* Configure IOMMU DMA hooks */
 	set_pci_dma_ops(&dma_iommu_ops);
 }
-
-static int pnv_tce_iommu_bus_notifier(struct notifier_block *nb,
-		unsigned long action, void *data)
-{
-	struct device *dev = data;
-
-	switch (action) {
-	case BUS_NOTIFY_DEL_DEVICE:
-		iommu_del_device(dev);
-		return 0;
-	default:
-		return 0;
-	}
-}
-
-static struct notifier_block pnv_tce_iommu_bus_nb = {
-	.notifier_call = pnv_tce_iommu_bus_notifier,
-};
-
-static int __init pnv_tce_iommu_bus_notifier_init(void)
-{
-	bus_register_notifier(&pci_bus_type, &pnv_tce_iommu_bus_nb);
-	return 0;
-}
-machine_subsys_initcall_sync(powernv, pnv_tce_iommu_bus_notifier_init);

arch/powerpc/platforms/pseries/iommu.c

@@ -1695,31 +1695,6 @@ static int __init disable_multitce(char *str)
 
 __setup("multitce=", disable_multitce);
 
-static int tce_iommu_bus_notifier(struct notifier_block *nb,
-		unsigned long action, void *data)
-{
-	struct device *dev = data;
-
-	switch (action) {
-	case BUS_NOTIFY_DEL_DEVICE:
-		iommu_del_device(dev);
-		return 0;
-	default:
-		return 0;
-	}
-}
-
-static struct notifier_block tce_iommu_bus_nb = {
-	.notifier_call = tce_iommu_bus_notifier,
-};
-
-static int __init tce_iommu_bus_notifier_init(void)
-{
-	bus_register_notifier(&pci_bus_type, &tce_iommu_bus_nb);
-	return 0;
-}
-machine_subsys_initcall_sync(pseries, tce_iommu_bus_notifier_init);
-
 #ifdef CONFIG_SPAPR_TCE_IOMMU
 struct iommu_group *pSeries_pci_device_group(struct pci_controller *hose,
 					     struct pci_dev *pdev)