iommu/vt-d: Remove domain and devinfo mempool

The domain and devinfo memory blocks are only allocated during device
probe and released during remove. There's no hot-path context, hence
no need for memory pools.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220214025704.3184654-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20220301020159.633356-5-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/intel/iommu.c

@@ -452,9 +452,6 @@ static int __init intel_iommu_setup(char *str)
 }
 __setup("intel_iommu=", intel_iommu_setup);
 
-static struct kmem_cache *iommu_domain_cache;
-static struct kmem_cache *iommu_devinfo_cache;
-
 void *alloc_pgtable_page(int node)
 {
 	struct page *page;
@@ -471,26 +468,6 @@ void free_pgtable_page(void *vaddr)
 	free_page((unsigned long)vaddr);
 }
 
-static inline void *alloc_domain_mem(void)
-{
-	return kmem_cache_alloc(iommu_domain_cache, GFP_ATOMIC);
-}
-
-static void free_domain_mem(void *vaddr)
-{
-	kmem_cache_free(iommu_domain_cache, vaddr);
-}
-
-static inline void * alloc_devinfo_mem(void)
-{
-	return kmem_cache_alloc(iommu_devinfo_cache, GFP_ATOMIC);
-}
-
-static inline void free_devinfo_mem(void *vaddr)
-{
-	kmem_cache_free(iommu_devinfo_cache, vaddr);
-}
-
 static inline int domain_type_is_si(struct dmar_domain *domain)
 {
 	return domain->domain.type == IOMMU_DOMAIN_IDENTITY;
@@ -1885,11 +1862,10 @@ static struct dmar_domain *alloc_domain(unsigned int type)
 {
 	struct dmar_domain *domain;
 
-	domain = alloc_domain_mem();
+	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
 	if (!domain)
 		return NULL;
 
-	memset(domain, 0, sizeof(*domain));
 	domain->nid = NUMA_NO_NODE;
 	if (first_level_by_default(type))
 		domain->flags |= DOMAIN_FLAG_USE_FIRST_LEVEL;
@@ -1973,7 +1949,7 @@ static void domain_exit(struct dmar_domain *domain)
 		put_pages_list(&freelist);
 	}
 
-	free_domain_mem(domain);
+	kfree(domain);
 }
 
 /*
@@ -2558,7 +2534,7 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 	unsigned long flags;
 	int ret;
 
-	info = alloc_devinfo_mem();
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
 	if (!info)
 		return NULL;
 
@@ -2574,13 +2550,9 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 		info->segment = pci_domain_nr(pdev->bus);
 	}
 
-	info->ats_supported = info->pasid_supported = info->pri_supported = 0;
-	info->ats_enabled = info->pasid_enabled = info->pri_enabled = 0;
-	info->ats_qdep = 0;
 	info->dev = dev;
 	info->domain = domain;
 	info->iommu = iommu;
-	info->pasid_table = NULL;
 
 	if (dev && dev_is_pci(dev)) {
 		struct pci_dev *pdev = to_pci_dev(info->dev);
@@ -2610,7 +2582,7 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 
 	if (ret) {
 		spin_unlock_irqrestore(&device_domain_lock, flags);
-		free_devinfo_mem(info);
+		kfree(info);
 		return NULL;
 	}
 
@@ -3343,65 +3315,6 @@ error:
 	return ret;
 }
 
-static inline int iommu_domain_cache_init(void)
-{
-	int ret = 0;
-
-	iommu_domain_cache = kmem_cache_create("iommu_domain",
-					 sizeof(struct dmar_domain),
-					 0,
-					 SLAB_HWCACHE_ALIGN,
-
-					 NULL);
-	if (!iommu_domain_cache) {
-		pr_err("Couldn't create iommu_domain cache\n");
-		ret = -ENOMEM;
-	}
-
-	return ret;
-}
-
-static inline int iommu_devinfo_cache_init(void)
-{
-	int ret = 0;
-
-	iommu_devinfo_cache = kmem_cache_create("iommu_devinfo",
-					 sizeof(struct device_domain_info),
-					 0,
-					 SLAB_HWCACHE_ALIGN,
-					 NULL);
-	if (!iommu_devinfo_cache) {
-		pr_err("Couldn't create devinfo cache\n");
-		ret = -ENOMEM;
-	}
-
-	return ret;
-}
-
-static int __init iommu_init_mempool(void)
-{
-	int ret;
-
-	ret = iommu_domain_cache_init();
-	if (ret)
-		goto domain_error;
-
-	ret = iommu_devinfo_cache_init();
-	if (!ret)
-		return ret;
-
-	kmem_cache_destroy(iommu_domain_cache);
-domain_error:
-
-	return -ENOMEM;
-}
-
-static void __init iommu_exit_mempool(void)
-{
-	kmem_cache_destroy(iommu_devinfo_cache);
-	kmem_cache_destroy(iommu_domain_cache);
-}
-
 static void __init init_no_remapping_devices(void)
 {
 	struct dmar_drhd_unit *drhd;
@@ -4253,12 +4166,6 @@ int __init intel_iommu_init(void)
 	force_on = (!intel_iommu_tboot_noforce && tboot_force_iommu()) ||
 		    platform_optin_force_iommu();
 
-	if (iommu_init_mempool()) {
-		if (force_on)
-			panic("tboot: Failed to initialize iommu memory\n");
-		return -ENOMEM;
-	}
-
 	down_write(&dmar_global_lock);
 	if (dmar_table_init()) {
 		if (force_on)
@@ -4379,7 +4286,6 @@ int __init intel_iommu_init(void)
 out_free_dmar:
 	intel_iommu_free_dmars();
 	up_write(&dmar_global_lock);
-	iommu_exit_mempool();
 	return ret;
 }
 
@@ -4436,7 +4342,7 @@ static void __dmar_remove_one_dev_info(struct device_domain_info *info)
 	domain_detach_iommu(domain, iommu);
 	spin_unlock_irqrestore(&iommu->lock, flags);
 
-	free_devinfo_mem(info);
+	kfree(info);
 }
 
 static void dmar_remove_one_dev_info(struct device *dev)