[PATCH v2 05/16] iommu/vt-d: add iommu invalidate function

[Jacob Pan]

This patch adds Intel VT-d specific function to implement
iommu passdown invalidate API.

The use case is for supporting caching structure invalidation
of assigned SVM capable devices. Emulated IOMMU exposes queue
invalidation capability and passes down all descriptors from the guest
to the physical IOMMU.

The assumption is that guest to host device ID mapping should be
resolved prior to calling IOMMU driver. Based on the device handle,
host IOMMU driver can replace certain fields before submit to the
invalidation queue.

Signed-off-by: Liu, Yi L <yi.l.liu@xxxxxxxxxxxxxxx>
Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Signed-off-by: Ashok Raj <ashok.raj@xxxxxxxxx>
---
 drivers/iommu/intel-iommu.c | 148 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/intel-iommu.h |  10 +++
 2 files changed, 158 insertions(+)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 6832f73..81e27eb 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5023,6 +5023,153 @@ static void intel_iommu_detach_device(struct iommu_domain *domain,
 	dmar_remove_one_dev_info(to_dmar_domain(domain), dev);
 }
 
+/*
+ * 3D array for converting IOMMU generic type-granularity to VT-d granularity
+ * X indexed by enum iommu_inv_type
+ * Y indicates request without and with PASID
+ * Z indexed by enum enum iommu_inv_granularity
+ *
+ * For an example, if we want to find the VT-d granularity encoding for IOTLB
+ * type, DMA request with PASID, and page selective. The look up indices are:
+ * [1][1][8], where
+ * 1: IOMMU_INV_TYPE_TLB
+ * 1: with PASID
+ * 8: IOMMU_INV_GRANU_PAGE_PASID
+ *
+ */
+const static u64 inv_type_granu_table[IOMMU_INV_NR_TYPE][2][IOMMU_INV_NR_GRANU] = {
+	/* extended dev IOTLBs, only global is valid */
+	{
+		{1}
+	},
+	/* IOTLB and EIOTLB */
+	{
+		{DMA_TLB_GLOBAL_FLUSH, DMA_TLB_DSI_FLUSH, 0, DMA_TLB_PSI_FLUSH},
+		{0, 0, 0, 0, QI_GRAN_ALL_ALL, 0, QI_GRAN_NONG_ALL, QI_GRAN_NONG_PASID, QI_GRAN_PSI_PASID}
+	},
+	/* PASID cache */
+	{
+		{0, 0, 0, 0, 1}
+	},
+	/* context cache */
+	{
+		{DMA_CCMD_GLOBAL_INVL, DMA_CCMD_DOMAIN_INVL, DMA_CCMD_DEVICE_INVL}
+	}
+};
+
+static inline int to_vtd_granularity(int type, int granu, int with_pasid, u64 *vtd_granu)
+{
+	if (type >= IOMMU_INV_NR_TYPE || granu >= IOMMU_INV_NR_GRANU || with_pasid > 1)
+		return -EINVAL;
+	*vtd_granu = inv_type_granu_table[type][with_pasid][granu];
+
+	return 0;
+}
+
+static int intel_iommu_invalidate(struct iommu_domain *domain,
+		struct device *dev, struct tlb_invalidate_info *inv_info)
+{
+	struct intel_iommu *iommu;
+	struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+	struct device_domain_info *info;
+	struct pci_dev *pdev;
+	u16 did, sid, pfsid;
+	u8 bus, devfn;
+	int ret = 0;
+	u64 granu;
+	unsigned long flags;
+
+	if (!inv_info || !dmar_domain)
+		return -EINVAL;
+
+	iommu = device_to_iommu(dev, &bus, &devfn);
+	if (!iommu)
+		return -ENODEV;
+
+	if (!dev || !dev_is_pci(dev))
+		return -ENODEV;
+
+	did = dmar_domain->iommu_did[iommu->seq_id];
+	sid = PCI_DEVID(bus, devfn);
+	ret = to_vtd_granularity(inv_info->hdr.type, inv_info->granularity,
+				!!(inv_info->flags & IOMMU_INVALIDATE_DMA_PASID), &granu);
+	if (ret) {
+		pr_err("Invalid range type %d, granu %d\n", inv_info->hdr.type,
+			inv_info->granularity);
+		return ret;
+	}
+
+	spin_lock(&iommu->lock);
+	spin_lock_irqsave(&device_domain_lock, flags);
+
+	switch (inv_info->hdr.type) {
+	case IOMMU_INV_TYPE_CONTEXT:
+		iommu->flush.flush_context(iommu, did, sid,
+					DMA_CCMD_MASK_NOBIT, granu);
+		break;
+	case IOMMU_INV_TYPE_TLB:
+		/* We need to deal with two scenarios:
+		 * - IOTLB for request w/o PASID
+		 * - extended IOTLB for request with PASID.
+		 */
+		if (inv_info->size &&
+			(inv_info->addr & ((1 << (VTD_PAGE_SHIFT + inv_info->size)) - 1))) {
+			pr_err("Addr out of range, addr 0x%llx, size order %d\n",
+				inv_info->addr, inv_info->size);
+			ret = -ERANGE;
+			goto out_unlock;
+		}
+
+		if (inv_info->flags & IOMMU_INVALIDATE_DMA_PASID)
+			qi_flush_eiotlb(iommu, did, mm_to_dma_pfn(inv_info->addr),
+					inv_info->pasid,
+					inv_info->size, granu,
+					inv_info->flags & IOMMU_INVALIDATE_GLOBAL_PAGE);
+		else
+			qi_flush_iotlb(iommu, did, mm_to_dma_pfn(inv_info->addr),
+				inv_info->size, granu);
+		/* For SRIOV VF, invalidation of device IOTLB requires PFSID */
+		pdev = to_pci_dev(dev);
+		if (pdev && pdev->is_virtfn)
+			pfsid = PCI_DEVID(pdev->physfn->bus->number, pdev->physfn->devfn);
+		else
+			pfsid = sid;
+
+		/**
+		 * Always flush device IOTLB if ATS is enabled since guest
+		 * vIOMMU exposes CM = 1, no device IOTLB flush will be passed
+		 * down.
+		 * TODO: check if device is VF, use PF ATS data if spec does not require
+		 * VF to include all PF capabilities,  VF qdep and VF ats_enabled.
+		 */
+		info = iommu_support_dev_iotlb(dmar_domain, iommu, bus, devfn);
+		if (info && info->ats_enabled) {
+			if (inv_info->flags & IOMMU_INVALIDATE_NO_PASID)
+				qi_flush_dev_iotlb(iommu, sid, info->pfsid,
+						info->ats_qdep, inv_info->addr,
+						inv_info->size);
+			else
+				qi_flush_dev_eiotlb(iommu, sid, info->pfsid,
+						inv_info->pasid, info->ats_qdep,
+						inv_info->addr, inv_info->size);
+		}
+		break;
+	case IOMMU_INV_TYPE_PASID:
+		qi_flush_pasid(iommu, did, granu, inv_info->pasid);
+
+		break;
+	default:
+		dev_err(dev, "Unknown IOMMU invalidation type %d\n",
+			inv_info->hdr.type);
+		ret = -EINVAL;
+	}
+out_unlock:
+	spin_unlock(&iommu->lock);
+	spin_unlock_irqrestore(&device_domain_lock, flags);
+
+	return ret;
+}
+
 static int intel_iommu_map(struct iommu_domain *domain,
 			   unsigned long iova, phys_addr_t hpa,
 			   size_t size, int iommu_prot)
@@ -5451,6 +5598,7 @@ const struct iommu_ops intel_iommu_ops = {
 #ifdef CONFIG_INTEL_IOMMU_SVM
 	.bind_pasid_table	= intel_iommu_bind_pasid_table,
 	.unbind_pasid_table	= intel_iommu_unbind_pasid_table,
+	.invalidate		= intel_iommu_invalidate,
 #endif
 	.map			= intel_iommu_map,
 	.unmap			= intel_iommu_unmap,
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index e42d317..5c734bd 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -258,6 +258,10 @@ enum {
 #define QI_PGRP_RESP_TYPE	0x9
 #define QI_PSTRM_RESP_TYPE	0xa
 
+#define QI_DID(did)		(((u64)did & 0xffff) << 16)
+#define QI_DID_MASK		GENMASK(31, 16)
+#define QI_TYPE_MASK		GENMASK(3, 0)
+
 #define QI_IEC_SELECTIVE	(((u64)1) << 4)
 #define QI_IEC_IIDEX(idx)	(((u64)(idx & 0xffff) << 32))
 #define QI_IEC_IM(m)		(((u64)(m & 0x1f) << 27))
@@ -495,6 +499,12 @@ extern int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_
 extern struct intel_iommu *intel_svm_device_to_iommu(struct device *dev);
 #endif
 
+struct intel_invalidate_data {
+	u16 sid;
+	u32 pasid;
+	struct qi_desc inv_desc;
+};
+
 extern const struct attribute_group *intel_iommu_groups[];
 
 #endif
-- 
2.7.4