iommu/vt-d: Remove IOVA domain rcache flushing for CPU offlining

Now that the core code handles flushing per-IOVA domain CPU rcaches,
remove the handling here.
Reviewed-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/1616675401-151997-3-git-send-email-john.garry@huawei.comSigned-off-by: NJoerg Roedel <jroedel@suse.de>

drivers/iommu/intel/iommu.c

@@ -4064,35 +4064,6 @@ static struct notifier_block intel_iommu_memory_nb = {
 	.priority = 0
 };
 
-static void free_all_cpu_cached_iovas(unsigned int cpu)
-{
-	int i;
-
-	for (i = 0; i < g_num_of_iommus; i++) {
-		struct intel_iommu *iommu = g_iommus[i];
-		struct dmar_domain *domain;
-		int did;
-
-		if (!iommu)
-			continue;
-
-		for (did = 0; did < cap_ndoms(iommu->cap); did++) {
-			domain = get_iommu_domain(iommu, (u16)did);
-
-			if (!domain || domain->domain.type != IOMMU_DOMAIN_DMA)
-				continue;
-
-			iommu_dma_free_cpu_cached_iovas(cpu, &domain->domain);
-		}
-	}
-}
-
-static int intel_iommu_cpu_dead(unsigned int cpu)
-{
-	free_all_cpu_cached_iovas(cpu);
-	return 0;
-}
-
 static void intel_disable_iommus(void)
 {
 	struct intel_iommu *iommu = NULL;
@@ -4387,8 +4358,6 @@ int __init intel_iommu_init(void)
 	bus_set_iommu(&pci_bus_type, &intel_iommu_ops);
 	if (si_domain && !hw_pass_through)
 		register_memory_notifier(&intel_iommu_memory_nb);
-	cpuhp_setup_state(CPUHP_IOMMU_INTEL_DEAD, "iommu/intel:dead", NULL,
-			  intel_iommu_cpu_dead);
 
 	down_read(&dmar_global_lock);
 	if (probe_acpi_namespace_devices())

include/linux/cpuhotplug.h

@@ -57,7 +57,6 @@ enum cpuhp_state {
 	CPUHP_PAGE_ALLOC_DEAD,
 	CPUHP_NET_DEV_DEAD,
 	CPUHP_PCI_XGENE_DEAD,
-	CPUHP_IOMMU_INTEL_DEAD,
 	CPUHP_IOMMU_IOVA_DEAD,
 	CPUHP_LUSTRE_CFS_DEAD,
 	CPUHP_AP_ARM_CACHE_B15_RAC_DEAD,