linux-zen-desktop/drivers/iommu/iommufd/hw_pagetable.c

106 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES
*/
#include <linux/iommu.h>
#include "iommufd_private.h"
void iommufd_hw_pagetable_destroy(struct iommufd_object *obj)
{
struct iommufd_hw_pagetable *hwpt =
container_of(obj, struct iommufd_hw_pagetable, obj);
WARN_ON(!list_empty(&hwpt->devices));
if (!list_empty(&hwpt->hwpt_item)) {
mutex_lock(&hwpt->ioas->mutex);
list_del(&hwpt->hwpt_item);
mutex_unlock(&hwpt->ioas->mutex);
iopt_table_remove_domain(&hwpt->ioas->iopt, hwpt->domain);
}
if (hwpt->domain)
iommu_domain_free(hwpt->domain);
refcount_dec(&hwpt->ioas->obj.users);
mutex_destroy(&hwpt->devices_lock);
}
/**
* iommufd_hw_pagetable_alloc() - Get an iommu_domain for a device
* @ictx: iommufd context
* @ioas: IOAS to associate the domain with
* @idev: Device to get an iommu_domain for
* @immediate_attach: True if idev should be attached to the hwpt
*
* Allocate a new iommu_domain and return it as a hw_pagetable. The HWPT
* will be linked to the given ioas and upon return the underlying iommu_domain
* is fully popoulated.
*/
struct iommufd_hw_pagetable *
iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
struct iommufd_device *idev, bool immediate_attach)
{
struct iommufd_hw_pagetable *hwpt;
int rc;
lockdep_assert_held(&ioas->mutex);
hwpt = iommufd_object_alloc(ictx, hwpt, IOMMUFD_OBJ_HW_PAGETABLE);
if (IS_ERR(hwpt))
return hwpt;
INIT_LIST_HEAD(&hwpt->devices);
INIT_LIST_HEAD(&hwpt->hwpt_item);
mutex_init(&hwpt->devices_lock);
/* Pairs with iommufd_hw_pagetable_destroy() */
refcount_inc(&ioas->obj.users);
hwpt->ioas = ioas;
hwpt->domain = iommu_domain_alloc(idev->dev->bus);
if (!hwpt->domain) {
rc = -ENOMEM;
goto out_abort;
}
mutex_lock(&hwpt->devices_lock);
/*
* immediate_attach exists only to accommodate iommu drivers that cannot
* directly allocate a domain. These drivers do not finish creating the
* domain until attach is completed. Thus we must have this call
* sequence. Once those drivers are fixed this should be removed.
*/
if (immediate_attach) {
rc = iommufd_hw_pagetable_attach(hwpt, idev);
if (rc)
goto out_unlock;
}
rc = iopt_table_add_domain(&hwpt->ioas->iopt, hwpt->domain);
if (rc)
goto out_detach;
list_add_tail(&hwpt->hwpt_item, &hwpt->ioas->hwpt_list);
if (immediate_attach) {
/* See iommufd_device_do_attach() */
refcount_inc(&hwpt->obj.users);
idev->hwpt = hwpt;
list_add(&idev->devices_item, &hwpt->devices);
}
mutex_unlock(&hwpt->devices_lock);
return hwpt;
out_detach:
if (immediate_attach)
iommufd_hw_pagetable_detach(hwpt, idev);
out_unlock:
mutex_unlock(&hwpt->devices_lock);
out_abort:
iommufd_object_abort_and_destroy(ictx, &hwpt->obj);
return ERR_PTR(rc);
}