Date:   Thu, 30 Aug 2018 09:35:18 +0800
From:   Lu Baolu <baolu.lu@...ux.intel.com>
To:     Joerg Roedel <joro@...tes.org>,
        David Woodhouse <dwmw2@...radead.org>
Cc:     ashok.raj@...el.com, sanjay.k.kumar@...el.com,
        jacob.jun.pan@...el.com, kevin.tian@...el.com, yi.l.liu@...el.com,
        yi.y.sun@...el.com, peterx@...hat.com,
        Jean-Philippe Brucker <jean-philippe.brucker@....com>,
        iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
        Lu Baolu <baolu.lu@...ux.intel.com>,
        Jacob Pan <jacob.jun.pan@...ux.intel.com>
Subject: [PATCH v2 06/12] iommu/vt-d: Add second level page table interface

This adds the interfaces to setup or tear down the structures
for second level page table translations. This includes types
of second level only translation and pass through.

Cc: Ashok Raj <ashok.raj@...el.com>
Cc: Jacob Pan <jacob.jun.pan@...ux.intel.com>
Cc: Kevin Tian <kevin.tian@...el.com>
Cc: Liu Yi L <yi.l.liu@...el.com>
Signed-off-by: Sanjay Kumar <sanjay.k.kumar@...el.com>
Signed-off-by: Lu Baolu <baolu.lu@...ux.intel.com>
Reviewed-by: Ashok Raj <ashok.raj@...el.com>
---
 drivers/iommu/intel-iommu.c |   2 +-
 drivers/iommu/intel-pasid.c | 246 ++++++++++++++++++++++++++++++++++++
 drivers/iommu/intel-pasid.h |   7 +
 include/linux/intel-iommu.h |   3 +
 4 files changed, 257 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 562da10bf93e..de6b909bb47a 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1232,7 +1232,7 @@ static void iommu_set_root_entry(struct intel_iommu *iommu)
 	raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
 }
 
-static void iommu_flush_write_buffer(struct intel_iommu *iommu)
+void iommu_flush_write_buffer(struct intel_iommu *iommu)
 {
 	u32 val;
 	unsigned long flag;
diff --git a/drivers/iommu/intel-pasid.c b/drivers/iommu/intel-pasid.c
index d6e90cd5b062..edcea1d8b9fc 100644
--- a/drivers/iommu/intel-pasid.c
+++ b/drivers/iommu/intel-pasid.c
@@ -9,6 +9,7 @@
 
 #define pr_fmt(fmt)	"DMAR: " fmt
 
+#include <linux/bitops.h>
 #include <linux/dmar.h>
 #include <linux/intel-iommu.h>
 #include <linux/iommu.h>
@@ -291,3 +292,248 @@ void intel_pasid_clear_entry(struct device *dev, int pasid)
 
 	pasid_clear_entry(pe);
 }
+
+static inline void pasid_set_bits(u64 *ptr, u64 mask, u64 bits)
+{
+	u64 old;
+
+	old = READ_ONCE(*ptr);
+	WRITE_ONCE(*ptr, (old & ~mask) | bits);
+}
+
+/*
+ * Setup the DID(Domain Identifier) field (Bit 64~79) of scalable mode
+ * PASID entry.
+ */
+static inline void
+pasid_set_domain_id(struct pasid_entry *pe, u64 value)
+{
+	pasid_set_bits(&pe->val[1], GENMASK_ULL(15, 0), value);
+}
+
+/*
+ * Setup the SLPTPTR(Second Level Page Table Pointer) field (Bit 12~63)
+ * of a scalable mode PASID entry.
+ */
+static inline void
+pasid_set_address_root(struct pasid_entry *pe, u64 value)
+{
+	pasid_set_bits(&pe->val[0], VTD_PAGE_MASK, value);
+}
+
+/*
+ * Setup the AW(Address Width) field (Bit 2~4) of a scalable mode PASID
+ * entry.
+ */
+static inline void
+pasid_set_address_width(struct pasid_entry *pe, u64 value)
+{
+	pasid_set_bits(&pe->val[0], GENMASK_ULL(4, 2), value << 2);
+}
+
+/*
+ * Setup the PGTT(PASID Granular Translation Type) field (Bit 6~8)
+ * of a scalable mode PASID entry.
+ */
+static inline void
+pasid_set_translation_type(struct pasid_entry *pe, u64 value)
+{
+	pasid_set_bits(&pe->val[0], GENMASK_ULL(8, 6), value << 6);
+}
+
+/*
+ * Enable fault processing by clearing the FPD(Fault Processing
+ * Disable) field (Bit 1) of a scalable mode PASID entry.
+ */
+static inline void pasid_set_fault_enable(struct pasid_entry *pe)
+{
+	pasid_set_bits(&pe->val[0], 1 << 1, 0);
+}
+
+/*
+ * Setup the SRE(Supervisor Request Enable) field (Bit 128) of a
+ * scalable mode PASID entry.
+ */
+static inline void pasid_set_sre(struct pasid_entry *pe)
+{
+	pasid_set_bits(&pe->val[2], 1 << 0, 1);
+}
+
+/*
+ * Setup the P(Present) field (Bit 0) of a scalable mode PASID
+ * entry.
+ */
+static inline void pasid_set_present(struct pasid_entry *pe)
+{
+	pasid_set_bits(&pe->val[0], 1 << 0, 1);
+}
+
+/*
+ * Setup Page Walk Snoop bit (Bit 87) of a scalable mode PASID
+ * entry.
+ */
+static inline void pasid_set_page_snoop(struct pasid_entry *pe, bool value)
+{
+	pasid_set_bits(&pe->val[1], 1 << 23, value);
+}
+
+static void
+pasid_based_pasid_cache_invalidation(struct intel_iommu *iommu,
+				     int did, int pasid)
+{
+	struct qi_desc desc;
+
+	desc.qw0 = QI_PC_DID(did) | QI_PC_PASID_SEL | QI_PC_PASID(pasid);
+	desc.qw1 = 0;
+	desc.qw2 = 0;
+	desc.qw3 = 0;
+
+	qi_submit_sync(&desc, iommu);
+}
+
+static void
+pasid_based_iotlb_cache_invalidation(struct intel_iommu *iommu,
+				     u16 did, u32 pasid)
+{
+	struct qi_desc desc;
+
+	desc.qw0 = QI_EIOTLB_PASID(pasid) | QI_EIOTLB_DID(did) |
+			QI_EIOTLB_GRAN(QI_GRAN_NONG_PASID) | QI_EIOTLB_TYPE;
+	desc.qw1 = 0;
+	desc.qw2 = 0;
+	desc.qw3 = 0;
+
+	qi_submit_sync(&desc, iommu);
+}
+
+static void
+pasid_based_dev_iotlb_cache_invalidation(struct intel_iommu *iommu,
+					 struct device *dev, int pasid)
+{
+	struct device_domain_info *info;
+	u16 sid, qdep, pfsid;
+
+	info = dev->archdata.iommu;
+	if (!info || !info->ats_enabled)
+		return;
+
+	sid = info->bus << 8 | info->devfn;
+	qdep = info->ats_qdep;
+	pfsid = info->pfsid;
+
+	qi_flush_dev_iotlb(iommu, sid, pfsid, qdep, 0, 64 - VTD_PAGE_SHIFT);
+}
+
+static void tear_down_one_pasid_entry(struct intel_iommu *iommu,
+				      struct device *dev, u16 did,
+				      int pasid)
+{
+	struct pasid_entry *pte;
+
+	intel_pasid_clear_entry(dev, pasid);
+
+	if (!ecap_coherent(iommu->ecap)) {
+		pte = intel_pasid_get_entry(dev, pasid);
+		clflush_cache_range(pte, sizeof(*pte));
+	}
+
+	pasid_based_pasid_cache_invalidation(iommu, did, pasid);
+	pasid_based_iotlb_cache_invalidation(iommu, did, pasid);
+
+	/* Device IOTLB doesn't need to be flushed in caching mode. */
+	if (!cap_caching_mode(iommu->cap))
+		pasid_based_dev_iotlb_cache_invalidation(iommu, dev, pasid);
+}
+
+/*
+ * Set up the scalable mode pasid table entry for second only or
+ * passthrough translation type.
+ */
+int intel_pasid_setup_second_level(struct intel_iommu *iommu,
+				   struct dmar_domain *domain,
+				   struct device *dev, int pasid,
+				   bool pass_through)
+{
+	struct pasid_entry *pte;
+	struct dma_pte *pgd;
+	u64 pgd_val;
+	int agaw;
+	u16 did;
+
+	/*
+	 * If hardware advertises no support for second level translation,
+	 * we only allow pass through translation setup.
+	 */
+	if (!(ecap_slts(iommu->ecap) || pass_through)) {
+		pr_err("No first level translation support on %s, only pass-through mode allowed\n",
+		       iommu->name);
+		return -EINVAL;
+	}
+
+	/*
+	 * Skip top levels of page tables for iommu which has less agaw
+	 * than default. Unnecessary for PT mode.
+	 */
+	pgd = domain->pgd;
+	if (!pass_through) {
+		for (agaw = domain->agaw; agaw != iommu->agaw; agaw--) {
+			pgd = phys_to_virt(dma_pte_addr(pgd));
+			if (!dma_pte_present(pgd)) {
+				dev_err(dev, "Invalid domain page table\n");
+				return -EINVAL;
+			}
+		}
+	}
+	pgd_val = pass_through ? 0 : virt_to_phys(pgd);
+	did = pass_through ? FLPT_DEFAULT_DID :
+			domain->iommu_did[iommu->seq_id];
+
+	pte = intel_pasid_get_entry(dev, pasid);
+	if (!pte) {
+		dev_err(dev, "Failed to get pasid entry of PASID %d\n", pasid);
+		return -ENODEV;
+	}
+
+	pasid_clear_entry(pte);
+	pasid_set_domain_id(pte, did);
+
+	if (!pass_through)
+		pasid_set_address_root(pte, pgd_val);
+
+	pasid_set_address_width(pte, iommu->agaw);
+	pasid_set_translation_type(pte, pass_through ? 4 : 2);
+	pasid_set_fault_enable(pte);
+	pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
+
+	/*
+	 * Since it is a second level only translation setup, we should
+	 * set SRE bit as well (addresses are expected to be GPAs).
+	 */
+	pasid_set_sre(pte);
+	pasid_set_present(pte);
+
+	if (!ecap_coherent(iommu->ecap))
+		clflush_cache_range(pte, sizeof(*pte));
+
+	if (cap_caching_mode(iommu->cap)) {
+		pasid_based_pasid_cache_invalidation(iommu, did, pasid);
+		pasid_based_iotlb_cache_invalidation(iommu, did, pasid);
+	} else {
+		iommu_flush_write_buffer(iommu);
+	}
+
+	return 0;
+}
+
+/*
+ * Tear down the scalable mode pasid table entry for second only or
+ * passthrough translation type.
+ */
+void intel_pasid_tear_down_second_level(struct intel_iommu *iommu,
+					struct dmar_domain *domain,
+					struct device *dev, int pasid)
+{
+	u16 did = domain->iommu_did[iommu->seq_id];
+
+	tear_down_one_pasid_entry(iommu, dev, did, pasid);
+}
diff --git a/drivers/iommu/intel-pasid.h b/drivers/iommu/intel-pasid.h
index 03c1612d173c..85b158a1826a 100644
--- a/drivers/iommu/intel-pasid.h
+++ b/drivers/iommu/intel-pasid.h
@@ -49,5 +49,12 @@ struct pasid_table *intel_pasid_get_table(struct device *dev);
 int intel_pasid_get_dev_max_id(struct device *dev);
 struct pasid_entry *intel_pasid_get_entry(struct device *dev, int pasid);
 void intel_pasid_clear_entry(struct device *dev, int pasid);
+int intel_pasid_setup_second_level(struct intel_iommu *iommu,
+				   struct dmar_domain *domain,
+				   struct device *dev, int pasid,
+				   bool pass_through);
+void intel_pasid_tear_down_second_level(struct intel_iommu *iommu,
+					struct dmar_domain *domain,
+					struct device *dev, int pasid);
 
 #endif /* __INTEL_PASID_H */
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 72aff482b293..d77d23dfd221 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -115,6 +115,8 @@
  * Extended Capability Register
  */
 
+#define ecap_smpwc(e)		(((e) >> 48) & 0x1)
+#define ecap_slts(e)		(((e) >> 46) & 0x1)
 #define ecap_smts(e)		(((e) >> 43) & 0x1)
 #define ecap_dit(e)		((e >> 41) & 0x1)
 #define ecap_pasid(e)		((e >> 40) & 0x1)
@@ -571,6 +573,7 @@ void free_pgtable_page(void *vaddr);
 struct intel_iommu *domain_get_iommu(struct dmar_domain *domain);
 int for_each_device_domain(int (*fn)(struct device_domain_info *info,
 				     void *data), void *data);
+void iommu_flush_write_buffer(struct intel_iommu *iommu);
 
 #ifdef CONFIG_INTEL_IOMMU_SVM
 int intel_svm_init(struct intel_iommu *iommu);
-- 
2.17.1

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