1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES 4 */ 5 #include <linux/iommu.h> 6 7 #include "iommufd_private.h" 8 9 void iommufd_hw_pagetable_destroy(struct iommufd_object *obj) 10 { 11 struct iommufd_hw_pagetable *hwpt = 12 container_of(obj, struct iommufd_hw_pagetable, obj); 13 14 WARN_ON(!list_empty(&hwpt->devices)); 15 16 if (!list_empty(&hwpt->hwpt_item)) { 17 mutex_lock(&hwpt->ioas->mutex); 18 list_del(&hwpt->hwpt_item); 19 mutex_unlock(&hwpt->ioas->mutex); 20 21 iopt_table_remove_domain(&hwpt->ioas->iopt, hwpt->domain); 22 } 23 24 if (hwpt->domain) 25 iommu_domain_free(hwpt->domain); 26 27 refcount_dec(&hwpt->ioas->obj.users); 28 mutex_destroy(&hwpt->devices_lock); 29 } 30 31 /** 32 * iommufd_hw_pagetable_alloc() - Get an iommu_domain for a device 33 * @ictx: iommufd context 34 * @ioas: IOAS to associate the domain with 35 * @idev: Device to get an iommu_domain for 36 * @immediate_attach: True if idev should be attached to the hwpt 37 * 38 * Allocate a new iommu_domain and return it as a hw_pagetable. The HWPT 39 * will be linked to the given ioas and upon return the underlying iommu_domain 40 * is fully popoulated. 41 */ 42 struct iommufd_hw_pagetable * 43 iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, 44 struct iommufd_device *idev, bool immediate_attach) 45 { 46 struct iommufd_hw_pagetable *hwpt; 47 int rc; 48 49 lockdep_assert_held(&ioas->mutex); 50 51 hwpt = iommufd_object_alloc(ictx, hwpt, IOMMUFD_OBJ_HW_PAGETABLE); 52 if (IS_ERR(hwpt)) 53 return hwpt; 54 55 INIT_LIST_HEAD(&hwpt->devices); 56 INIT_LIST_HEAD(&hwpt->hwpt_item); 57 mutex_init(&hwpt->devices_lock); 58 /* Pairs with iommufd_hw_pagetable_destroy() */ 59 refcount_inc(&ioas->obj.users); 60 hwpt->ioas = ioas; 61 62 hwpt->domain = iommu_domain_alloc(idev->dev->bus); 63 if (!hwpt->domain) { 64 rc = -ENOMEM; 65 goto out_abort; 66 } 67 68 mutex_lock(&hwpt->devices_lock); 69 70 /* 71 * immediate_attach exists only to accommodate iommu drivers that cannot 72 * directly allocate a domain. These drivers do not finish creating the 73 * domain until attach is completed. Thus we must have this call 74 * sequence. Once those drivers are fixed this should be removed. 75 */ 76 if (immediate_attach) { 77 rc = iommufd_hw_pagetable_attach(hwpt, idev); 78 if (rc) 79 goto out_unlock; 80 } 81 82 rc = iopt_table_add_domain(&hwpt->ioas->iopt, hwpt->domain); 83 if (rc) 84 goto out_detach; 85 list_add_tail(&hwpt->hwpt_item, &hwpt->ioas->hwpt_list); 86 87 if (immediate_attach) { 88 /* See iommufd_device_do_attach() */ 89 refcount_inc(&hwpt->obj.users); 90 idev->hwpt = hwpt; 91 list_add(&idev->devices_item, &hwpt->devices); 92 } 93 94 mutex_unlock(&hwpt->devices_lock); 95 return hwpt; 96 97 out_detach: 98 if (immediate_attach) 99 iommufd_hw_pagetable_detach(hwpt, idev); 100 out_unlock: 101 mutex_unlock(&hwpt->devices_lock); 102 out_abort: 103 iommufd_object_abort_and_destroy(ictx, &hwpt->obj); 104 return ERR_PTR(rc); 105 } 106