366 lines
9.3 KiB
C
366 lines
9.3 KiB
C
/*
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* Copyright © 2015 Intel Corporation.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* Authors: David Woodhouse <dwmw2@infradead.org>
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*/
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#include <linux/intel-iommu.h>
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#include <linux/mmu_notifier.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/intel-svm.h>
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#include <linux/rculist.h>
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#include <linux/pci.h>
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#include <linux/pci-ats.h>
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struct pasid_entry {
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u64 val;
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};
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struct pasid_state_entry {
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u64 val;
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};
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int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
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{
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struct page *pages;
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int order;
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order = ecap_pss(iommu->ecap) + 7 - PAGE_SHIFT;
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if (order < 0)
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order = 0;
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pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
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if (!pages) {
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pr_warn("IOMMU: %s: Failed to allocate PASID table\n",
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iommu->name);
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return -ENOMEM;
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}
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iommu->pasid_table = page_address(pages);
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pr_info("%s: Allocated order %d PASID table.\n", iommu->name, order);
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if (ecap_dis(iommu->ecap)) {
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pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
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if (pages)
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iommu->pasid_state_table = page_address(pages);
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else
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pr_warn("IOMMU: %s: Failed to allocate PASID state table\n",
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iommu->name);
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}
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idr_init(&iommu->pasid_idr);
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return 0;
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}
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int intel_svm_free_pasid_tables(struct intel_iommu *iommu)
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{
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int order;
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order = ecap_pss(iommu->ecap) + 7 - PAGE_SHIFT;
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if (order < 0)
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order = 0;
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if (iommu->pasid_table) {
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free_pages((unsigned long)iommu->pasid_table, order);
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iommu->pasid_table = NULL;
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}
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if (iommu->pasid_state_table) {
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free_pages((unsigned long)iommu->pasid_state_table, order);
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iommu->pasid_state_table = NULL;
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}
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idr_destroy(&iommu->pasid_idr);
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return 0;
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}
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static void intel_flush_svm_range_dev (struct intel_svm *svm, struct intel_svm_dev *sdev,
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unsigned long address, int pages, int ih)
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{
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struct qi_desc desc;
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int mask = ilog2(__roundup_pow_of_two(pages));
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if (pages == -1 || !cap_pgsel_inv(svm->iommu->cap) ||
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mask > cap_max_amask_val(svm->iommu->cap)) {
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desc.low = QI_EIOTLB_PASID(svm->pasid) | QI_EIOTLB_DID(sdev->did) |
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QI_EIOTLB_GRAN(QI_GRAN_NONG_PASID) | QI_EIOTLB_TYPE;
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desc.high = 0;
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} else {
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desc.low = QI_EIOTLB_PASID(svm->pasid) | QI_EIOTLB_DID(sdev->did) |
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QI_EIOTLB_GRAN(QI_GRAN_PSI_PASID) | QI_EIOTLB_TYPE;
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desc.high = QI_EIOTLB_ADDR(address) | QI_EIOTLB_GL(1) |
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QI_EIOTLB_IH(ih) | QI_EIOTLB_AM(mask);
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}
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qi_submit_sync(&desc, svm->iommu);
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if (sdev->dev_iotlb) {
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desc.low = QI_DEV_EIOTLB_PASID(svm->pasid) | QI_DEV_EIOTLB_SID(sdev->sid) |
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QI_DEV_EIOTLB_QDEP(sdev->qdep) | QI_DEIOTLB_TYPE;
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if (mask) {
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unsigned long adr, delta;
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/* Least significant zero bits in the address indicate the
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* range of the request. So mask them out according to the
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* size. */
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adr = address & ((1<<(VTD_PAGE_SHIFT + mask)) - 1);
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/* Now ensure that we round down further if the original
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* request was not aligned w.r.t. its size */
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delta = address - adr;
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if (delta + (pages << VTD_PAGE_SHIFT) >= (1 << (VTD_PAGE_SHIFT + mask)))
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adr &= ~(1 << (VTD_PAGE_SHIFT + mask));
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desc.high = QI_DEV_EIOTLB_ADDR(adr) | QI_DEV_EIOTLB_SIZE;
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} else {
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desc.high = QI_DEV_EIOTLB_ADDR(address);
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}
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qi_submit_sync(&desc, svm->iommu);
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}
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}
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static void intel_flush_svm_range(struct intel_svm *svm, unsigned long address,
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int pages, int ih)
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{
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struct intel_svm_dev *sdev;
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/* Try deferred invalidate if available */
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if (svm->iommu->pasid_state_table &&
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!cmpxchg64(&svm->iommu->pasid_state_table[svm->pasid].val, 0, 1ULL << 63))
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return;
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rcu_read_lock();
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list_for_each_entry_rcu(sdev, &svm->devs, list)
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intel_flush_svm_range_dev(svm, sdev, address, pages, ih);
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rcu_read_unlock();
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}
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static void intel_change_pte(struct mmu_notifier *mn, struct mm_struct *mm,
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unsigned long address, pte_t pte)
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{
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struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
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intel_flush_svm_range(svm, address, 1, 1);
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}
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static void intel_invalidate_page(struct mmu_notifier *mn, struct mm_struct *mm,
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unsigned long address)
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{
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struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
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intel_flush_svm_range(svm, address, 1, 1);
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}
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/* Pages have been freed at this point */
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static void intel_invalidate_range(struct mmu_notifier *mn,
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struct mm_struct *mm,
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unsigned long start, unsigned long end)
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{
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struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
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intel_flush_svm_range(svm, start,
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(end - start + PAGE_SIZE - 1) >> VTD_PAGE_SHIFT , 0);
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}
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static void intel_flush_pasid_dev(struct intel_svm *svm, struct intel_svm_dev *sdev)
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{
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struct qi_desc desc;
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desc.high = 0;
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desc.low = QI_PC_TYPE | QI_PC_DID(sdev->did) | QI_PC_PASID_SEL | QI_PC_PASID(svm->pasid);
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qi_submit_sync(&desc, svm->iommu);
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}
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static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
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{
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struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
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svm->iommu->pasid_table[svm->pasid].val = 0;
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/* There's no need to do any flush because we can't get here if there
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* are any devices left anyway. */
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WARN_ON(!list_empty(&svm->devs));
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}
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static const struct mmu_notifier_ops intel_mmuops = {
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.release = intel_mm_release,
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.change_pte = intel_change_pte,
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.invalidate_page = intel_invalidate_page,
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.invalidate_range = intel_invalidate_range,
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};
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static DEFINE_MUTEX(pasid_mutex);
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int intel_svm_bind_mm(struct device *dev, int *pasid)
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{
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struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
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struct intel_svm_dev *sdev;
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struct intel_svm *svm = NULL;
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int pasid_max;
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int ret;
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BUG_ON(pasid && !current->mm);
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if (WARN_ON(!iommu))
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return -EINVAL;
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if (dev_is_pci(dev)) {
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pasid_max = pci_max_pasids(to_pci_dev(dev));
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if (pasid_max < 0)
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return -EINVAL;
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} else
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pasid_max = 1 << 20;
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mutex_lock(&pasid_mutex);
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if (pasid) {
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int i;
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idr_for_each_entry(&iommu->pasid_idr, svm, i) {
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if (svm->mm != current->mm)
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continue;
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if (svm->pasid >= pasid_max) {
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dev_warn(dev,
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"Limited PASID width. Cannot use existing PASID %d\n",
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svm->pasid);
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ret = -ENOSPC;
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goto out;
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}
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list_for_each_entry(sdev, &svm->devs, list) {
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if (dev == sdev->dev) {
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sdev->users++;
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goto success;
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}
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}
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break;
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}
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}
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sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);
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if (!sdev) {
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ret = -ENOMEM;
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goto out;
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}
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sdev->dev = dev;
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ret = intel_iommu_enable_pasid(iommu, sdev);
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if (ret || !pasid) {
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/* If they don't actually want to assign a PASID, this is
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* just an enabling check/preparation. */
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kfree(sdev);
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goto out;
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}
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/* Finish the setup now we know we're keeping it */
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sdev->users = 1;
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init_rcu_head(&sdev->rcu);
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if (!svm) {
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svm = kzalloc(sizeof(*svm), GFP_KERNEL);
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if (!svm) {
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ret = -ENOMEM;
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kfree(sdev);
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goto out;
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}
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svm->iommu = iommu;
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if (pasid_max > 2 << ecap_pss(iommu->ecap))
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pasid_max = 2 << ecap_pss(iommu->ecap);
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ret = idr_alloc(&iommu->pasid_idr, svm, 0, pasid_max - 1,
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GFP_KERNEL);
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if (ret < 0) {
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kfree(svm);
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goto out;
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}
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svm->pasid = ret;
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svm->notifier.ops = &intel_mmuops;
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svm->mm = get_task_mm(current);
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INIT_LIST_HEAD_RCU(&svm->devs);
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ret = -ENOMEM;
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if (!svm->mm || (ret = mmu_notifier_register(&svm->notifier, svm->mm))) {
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idr_remove(&svm->iommu->pasid_idr, svm->pasid);
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kfree(svm);
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kfree(sdev);
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goto out;
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}
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iommu->pasid_table[svm->pasid].val = (u64)__pa(svm->mm->pgd) | 1;
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wmb();
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}
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list_add_rcu(&sdev->list, &svm->devs);
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success:
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*pasid = svm->pasid;
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ret = 0;
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out:
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mutex_unlock(&pasid_mutex);
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return ret;
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}
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EXPORT_SYMBOL_GPL(intel_svm_bind_mm);
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int intel_svm_unbind_mm(struct device *dev, int pasid)
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{
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struct intel_svm_dev *sdev;
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struct intel_iommu *iommu;
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struct intel_svm *svm;
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int ret = -EINVAL;
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mutex_lock(&pasid_mutex);
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iommu = intel_svm_device_to_iommu(dev);
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if (!iommu || !iommu->pasid_table)
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goto out;
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svm = idr_find(&iommu->pasid_idr, pasid);
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if (!svm)
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goto out;
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list_for_each_entry(sdev, &svm->devs, list) {
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if (dev == sdev->dev) {
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ret = 0;
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sdev->users--;
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if (!sdev->users) {
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list_del_rcu(&sdev->list);
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/* Flush the PASID cache and IOTLB for this device.
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* Note that we do depend on the hardware *not* using
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* the PASID any more. Just as we depend on other
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* devices never using PASIDs that they have no right
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* to use. We have a *shared* PASID table, because it's
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* large and has to be physically contiguous. So it's
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* hard to be as defensive as we might like. */
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intel_flush_pasid_dev(svm, sdev);
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intel_flush_svm_range_dev(svm, sdev, 0, -1, 0);
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kfree_rcu(sdev, rcu);
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if (list_empty(&svm->devs)) {
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mmu_notifier_unregister(&svm->notifier, svm->mm);
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idr_remove(&svm->iommu->pasid_idr, svm->pasid);
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mmput(svm->mm);
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/* We mandate that no page faults may be outstanding
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* for the PASID when intel_svm_unbind_mm() is called.
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* If that is not obeyed, subtle errors will happen.
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* Let's make them less subtle... */
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memset(svm, 0x6b, sizeof(*svm));
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kfree(svm);
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}
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}
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break;
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}
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}
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out:
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mutex_unlock(&pasid_mutex);
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return ret;
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}
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EXPORT_SYMBOL_GPL(intel_svm_unbind_mm);
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