1 files changed, 231 insertions, 0 deletions
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
new file mode 100644
index 000000000000..71de7947971f
--- /dev/null
+++ b/drivers/iommu/intel/svm.c
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright © 2015 Intel Corporation.
+ *
+ * Authors: David Woodhouse <dwmw2@infradead.org>
+ */
+
+#include <linux/mmu_notifier.h>
+#include <linux/sched.h>
+#include <linux/sched/mm.h>
+#include <linux/slab.h>
+#include <linux/rculist.h>
+#include <linux/pci.h>
+#include <linux/pci-ats.h>
+#include <linux/dmar.h>
+#include <linux/interrupt.h>
+#include <linux/mm_types.h>
+#include <linux/xarray.h>
+#include <asm/page.h>
+#include <asm/fpu/api.h>
+
+#include "iommu.h"
+#include "pasid.h"
+#include "perf.h"
+#include "../iommu-pages.h"
+#include "trace.h"
+
+void intel_svm_check(struct intel_iommu *iommu)
+{
+	if (!pasid_supported(iommu))
+		return;
+
+	if (cpu_feature_enabled(X86_FEATURE_GBPAGES) &&
+	    !cap_fl1gp_support(iommu->cap)) {
+		pr_err("%s SVM disabled, incompatible 1GB page capability\n",
+		       iommu->name);
+		return;
+	}
+
+	if (cpu_feature_enabled(X86_FEATURE_LA57) &&
+	    !cap_fl5lp_support(iommu->cap)) {
+		pr_err("%s SVM disabled, incompatible paging mode\n",
+		       iommu->name);
+		return;
+	}
+
+	iommu->flags |= VTD_FLAG_SVM_CAPABLE;
+}
+
+/* Pages have been freed at this point */
+static void intel_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
+					struct mm_struct *mm,
+					unsigned long start, unsigned long end)
+{
+	struct dmar_domain *domain = container_of(mn, struct dmar_domain, notifier);
+
+	if (start == 0 && end == ULONG_MAX) {
+		cache_tag_flush_all(domain);
+		return;
+	}
+
+	/*
+	 * The mm_types defines vm_end as the first byte after the end address,
+	 * different from IOMMU subsystem using the last address of an address
+	 * range.
+	 */
+	cache_tag_flush_range(domain, start, end - 1, 0);
+}
+
+static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
+{
+	struct dmar_domain *domain = container_of(mn, struct dmar_domain, notifier);
+	struct dev_pasid_info *dev_pasid;
+	struct device_domain_info *info;
+	unsigned long flags;
+
+	/* This might end up being called from exit_mmap(), *before* the page
+	 * tables are cleared. And __mmu_notifier_release() will delete us from
+	 * the list of notifiers so that our invalidate_range() callback doesn't
+	 * get called when the page tables are cleared. So we need to protect
+	 * against hardware accessing those page tables.
+	 *
+	 * We do it by clearing the entry in the PASID table and then flushing
+	 * the IOTLB and the PASID table caches. This might upset hardware;
+	 * perhaps we'll want to point the PASID to a dummy PGD (like the zero
+	 * page) so that we end up taking a fault that the hardware really
+	 * *has* to handle gracefully without affecting other processes.
+	 */
+	spin_lock_irqsave(&domain->lock, flags);
+	list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain) {
+		info = dev_iommu_priv_get(dev_pasid->dev);
+		intel_pasid_tear_down_entry(info->iommu, dev_pasid->dev,
+					    dev_pasid->pasid, true);
+	}
+	spin_unlock_irqrestore(&domain->lock, flags);
+
+}
+
+static void intel_mm_free_notifier(struct mmu_notifier *mn)
+{
+	struct dmar_domain *domain = container_of(mn, struct dmar_domain, notifier);
+
+	kfree(domain->qi_batch);
+	kfree(domain);
+}
+
+static const struct mmu_notifier_ops intel_mmuops = {
+	.release = intel_mm_release,
+	.arch_invalidate_secondary_tlbs = intel_arch_invalidate_secondary_tlbs,
+	.free_notifier = intel_mm_free_notifier,
+};
+
+static int intel_iommu_sva_supported(struct device *dev)
+{
+	struct device_domain_info *info = dev_iommu_priv_get(dev);
+	struct intel_iommu *iommu;
+
+	if (!info || dmar_disabled)
+		return -EINVAL;
+
+	iommu = info->iommu;
+	if (!iommu)
+		return -EINVAL;
+
+	if (!(iommu->flags & VTD_FLAG_SVM_CAPABLE))
+		return -ENODEV;
+
+	if (!info->pasid_enabled || !info->ats_enabled)
+		return -EINVAL;
+
+	/*
+	 * Devices having device-specific I/O fault handling should not
+	 * support PCI/PRI. The IOMMU side has no means to check the
+	 * capability of device-specific IOPF.  Therefore, IOMMU can only
+	 * default that if the device driver enables SVA on a non-PRI
+	 * device, it will handle IOPF in its own way.
+	 */
+	if (!info->pri_supported)
+		return 0;
+
+	/* Devices supporting PRI should have it enabled. */
+	if (!info->pri_enabled)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
+				   struct device *dev, ioasid_t pasid,
+				   struct iommu_domain *old)
+{
+	struct device_domain_info *info = dev_iommu_priv_get(dev);
+	struct intel_iommu *iommu = info->iommu;
+	struct mm_struct *mm = domain->mm;
+	struct dev_pasid_info *dev_pasid;
+	unsigned long sflags;
+	int ret = 0;
+
+	ret = intel_iommu_sva_supported(dev);
+	if (ret)
+		return ret;
+
+	dev_pasid = domain_add_dev_pasid(domain, dev, pasid);
+	if (IS_ERR(dev_pasid))
+		return PTR_ERR(dev_pasid);
+
+	ret = iopf_for_domain_replace(domain, old, dev);
+	if (ret)
+		goto out_remove_dev_pasid;
+
+	/* Setup the pasid table: */
+	sflags = cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0;
+	sflags |= PASID_FLAG_PWSNP;
+	ret = __domain_setup_first_level(iommu, dev, pasid,
+					 FLPT_DEFAULT_DID, __pa(mm->pgd),
+					 sflags, old);
+	if (ret)
+		goto out_unwind_iopf;
+
+	domain_remove_dev_pasid(old, dev, pasid);
+
+	return 0;
+out_unwind_iopf:
+	iopf_for_domain_replace(old, domain, dev);
+out_remove_dev_pasid:
+	domain_remove_dev_pasid(domain, dev, pasid);
+	return ret;
+}
+
+static void intel_svm_domain_free(struct iommu_domain *domain)
+{
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+
+	/* dmar_domain free is deferred to the mmu free_notifier callback. */
+	mmu_notifier_put(&dmar_domain->notifier);
+}
+
+static const struct iommu_domain_ops intel_svm_domain_ops = {
+	.set_dev_pasid		= intel_svm_set_dev_pasid,
+	.free			= intel_svm_domain_free
+};
+
+struct iommu_domain *intel_svm_domain_alloc(struct device *dev,
+					    struct mm_struct *mm)
+{
+	struct dmar_domain *domain;
+	int ret;
+
+	ret = intel_iommu_sva_supported(dev);
+	if (ret)
+		return ERR_PTR(ret);
+
+	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+	if (!domain)
+		return ERR_PTR(-ENOMEM);
+
+	domain->domain.ops = &intel_svm_domain_ops;
+	INIT_LIST_HEAD(&domain->dev_pasids);
+	INIT_LIST_HEAD(&domain->cache_tags);
+	spin_lock_init(&domain->cache_lock);
+	spin_lock_init(&domain->lock);
+
+	domain->notifier.ops = &intel_mmuops;
+	ret = mmu_notifier_register(&domain->notifier, mm);
+	if (ret) {
+		kfree(domain);
+		return ERR_PTR(ret);
+	}
+
+	return &domain->domain;
+}