[PATCH v6 06/12] iommu/vt-d: Add second level page table interface

Lu Baolu
2018-12-10T01:59:00Z

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@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
---
drivers/iommu/intel-iommu.c | 2 +-
drivers/iommu/intel-pasid.c | 280 ++++++++++++++++++++++++++++++++++++
drivers/iommu/intel-pasid.h | 8 ++
include/linux/intel-iommu.h | 3 +
4 files changed, 292 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 5e924bc8ebec..e741238e2326 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1210,7 +1210,7 @@ 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 fd3ccc0753b0..6d2b2e87e6fc 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>
@@ -294,3 +295,282 @@ 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);
+}
+
+/*
+ * Get domain ID value of a scalable mode PASID entry.
+ */
+static inline u16
+pasid_get_domain_id(struct pasid_entry *pe)
+{
+ return (u16)(READ_ONCE(pe->val[1]) & GENMASK_ULL(15, 0));
+}
+
+/*
+ * Setup the SLPTPTR(Second Level Page Table Pointer) field (Bit 12~63)
+ * of a scalable mode PASID entry.
+ */
+static inline void
+pasid_set_slptr(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_cache_invalidation_with_pasid(struct intel_iommu *iommu,
+ u16 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
+iotlb_invalidation_with_pasid(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
+devtlb_invalidation_with_pasid(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);
+}
+
+void intel_pasid_tear_down_entry(struct intel_iommu *iommu,
+ struct device *dev, int pasid)
+{
+ struct pasid_entry *pte;
+ u16 did;
+
+ pte = intel_pasid_get_entry(dev, pasid);
+ if (WARN_ON(!pte))
+ return;
+
+ intel_pasid_clear_entry(dev, pasid);
+ did = pasid_get_domain_id(pte);
+
+ if (!ecap_coherent(iommu->ecap))
+ clflush_cache_range(pte, sizeof(*pte));
+
+ pasid_cache_invalidation_with_pasid(iommu, did, pasid);
+ iotlb_invalidation_with_pasid(iommu, did, pasid);
+
+ /* Device IOTLB doesn't need to be flushed in caching mode. */
+ if (!cap_caching_mode(iommu->cap))
+ devtlb_invalidation_with_pasid(iommu, dev, pasid);
+}
+
+/*
+ * Set up the scalable mode pasid entry for second only translation type.
+ */
+int intel_pasid_setup_second_level(struct intel_iommu *iommu,
+ struct dmar_domain *domain,
+ struct device *dev, int pasid)
+{
+ struct pasid_entry *pte;
+ struct dma_pte *pgd;
+ u64 pgd_val;
+ int agaw;
+ u16 did;
+
+ /*
+ * If hardware advertises no support for second level
+ * translation, return directly.
+ */
+ if (!ecap_slts(iommu->ecap)) {
+ pr_err("No second level translation support on %s\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;
+ 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 = virt_to_phys(pgd);
+ 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);
+ pasid_set_slptr(pte, pgd_val);
+ pasid_set_address_width(pte, agaw);
+ pasid_set_translation_type(pte, 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_cache_invalidation_with_pasid(iommu, did, pasid);
+ iotlb_invalidation_with_pasid(iommu, did, pasid);
+ } else {
+ iommu_flush_write_buffer(iommu);
+ }
+
+ return 0;
+}
+
+/*
+ * Set up the scalable mode pasid entry for passthrough translation type.
+ */
+int intel_pasid_setup_pass_through(struct intel_iommu *iommu,
+ struct dmar_domain *domain,
+ struct device *dev, int pasid)
+{
+ u16 did = FLPT_DEFAULT_DID;
+ struct pasid_entry *pte;
+
+ 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);
+ pasid_set_address_width(pte, iommu->agaw);
+ pasid_set_translation_type(pte, 4);
+ pasid_set_fault_enable(pte);
+ pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
+
+ /*
+ * We should set SRE bit as well since the 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_cache_invalidation_with_pasid(iommu, did, pasid);
+ iotlb_invalidation_with_pasid(iommu, did, pasid);
+ } else {
+ iommu_flush_write_buffer(iommu);
+ }
+
+ return 0;
+}
diff --git a/drivers/iommu/intel-pasid.h b/drivers/iommu/intel-pasid.h
index 03c1612d173c..3c70522091d3 100644
--- a/drivers/iommu/intel-pasid.h
+++ b/drivers/iommu/intel-pasid.h
@@ -49,5 +49,13 @@ 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);
+int intel_pasid_setup_pass_through(struct intel_iommu *iommu,
+ struct dmar_domain *domain,
+ struct device *dev, int pasid);
+void intel_pasid_tear_down_entry(struct intel_iommu *iommu,
+ struct device *dev, int pasid);

#endif /* __INTEL_PASID_H */
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 08ff588a4df7..cb3ebda47fa7 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -177,6 +177,8 @@
* 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)
@@ -662,6 +664,7 @@ 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