[PATCH v6 09/12] iommu/vt-d: Setup context and enable RID2PASID support

Lu Baolu
2018-12-10T01:59:03Z

This patch enables the translation for requests without PASID in
the scalable mode by setting up the root and context entries.

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 | 136 ++++++++++++++++++++++++++++--------
drivers/iommu/intel-pasid.h | 1 +
include/linux/intel-iommu.h | 1 +
3 files changed, 108 insertions(+), 30 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 55c4ffda1246..21e5f1b9a2ca 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1197,6 +1197,8 @@ static void iommu_set_root_entry(struct intel_iommu *iommu)
unsigned long flag;

addr = virt_to_phys(iommu->root_entry);
+ if (sm_supported(iommu))
+ addr |= DMA_RTADDR_SMT;

raw_spin_lock_irqsave(&iommu->register_lock, flag);
dmar_writeq(iommu->reg + DMAR_RTADDR_REG, addr);
@@ -1918,6 +1920,56 @@ static void domain_exit(struct dmar_domain *domain)
free_domain_mem(domain);
}

+/*
+ * Get the PASID directory size for scalable mode context entry.
+ * Value of X in the PDTS field of a scalable mode context entry
+ * indicates PASID directory with 2^(X + 7) entries.
+ */
+static inline unsigned long context_get_sm_pds(struct pasid_table *table)
+{
+ int pds, max_pde;
+
+ max_pde = table->max_pasid >> PASID_PDE_SHIFT;
+ pds = find_first_bit((unsigned long *)&max_pde, MAX_NR_PASID_BITS);
+ if (pds < 7)
+ return 0;
+
+ return pds - 7;
+}
+
+/*
+ * Set the RID_PASID field of a scalable mode context entry. The
+ * IOMMU hardware will use the PASID value set in this field for
+ * DMA translations of DMA requests without PASID.
+ */
+static inline void
+context_set_sm_rid2pasid(struct context_entry *context, unsigned long pasid)
+{
+ context->hi |= pasid & ((1 << 20) - 1);
+ context->hi |= (1 << 20);
+}
+
+/*
+ * Set the DTE(Device-TLB Enable) field of a scalable mode context
+ * entry.
+ */
+static inline void context_set_sm_dte(struct context_entry *context)
+{
+ context->lo |= (1 << 2);
+}
+
+/*
+ * Set the PRE(Page Request Enable) field of a scalable mode context
+ * entry.
+ */
+static inline void context_set_sm_pre(struct context_entry *context)
+{
+ context->lo |= (1 << 4);
+}
+
+/* Convert value to context PASID directory size field coding. */
+#define context_pdts(pds) (((pds) & 0x7) << 9)
+
static int domain_context_mapping_one(struct dmar_domain *domain,
struct intel_iommu *iommu,
struct pasid_table *table,
@@ -1928,8 +1980,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
struct device_domain_info *info = NULL;
struct context_entry *context;
unsigned long flags;
- struct dma_pte *pgd;
- int ret, agaw;
+ int ret;

WARN_ON(did == 0);

@@ -1975,41 +2026,67 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
}
}

- pgd = domain->pgd;
-
context_clear_entry(context);
- context_set_domain_id(context, did);

- /*
- * Skip top levels of page tables for iommu which has less agaw
- * than default. Unnecessary for PT mode.
- */
- if (translation != CONTEXT_TT_PASS_THROUGH) {
- for (agaw = domain->agaw; agaw > iommu->agaw; agaw--) {
- ret = -ENOMEM;
- pgd = phys_to_virt(dma_pte_addr(pgd));
- if (!dma_pte_present(pgd))
- goto out_unlock;
- }
+ if (sm_supported(iommu)) {
+ unsigned long pds;

- info = iommu_support_dev_iotlb(domain, iommu, bus, devfn);
- if (info && info->ats_supported)
- translation = CONTEXT_TT_DEV_IOTLB;
- else
- translation = CONTEXT_TT_MULTI_LEVEL;
+ WARN_ON(!table);
+
+ /* Setup the PASID DIR pointer: */
+ pds = context_get_sm_pds(table);
+ context->lo = (u64)virt_to_phys(table->table) |
+ context_pdts(pds);
+
+ /* Setup the RID_PASID field: */
+ context_set_sm_rid2pasid(context, PASID_RID2PASID);

- context_set_address_root(context, virt_to_phys(pgd));
- context_set_address_width(context, agaw);
- } else {
/*
- * In pass through mode, AW must be programmed to
- * indicate the largest AGAW value supported by
- * hardware. And ASR is ignored by hardware.
+ * Setup the Device-TLB enable bit and Page request
+ * Enable bit:
*/
- context_set_address_width(context, iommu->msagaw);
+ info = iommu_support_dev_iotlb(domain, iommu, bus, devfn);
+ if (info && info->ats_supported)
+ context_set_sm_dte(context);
+ if (info && info->pri_supported)
+ context_set_sm_pre(context);
+ } else {
+ struct dma_pte *pgd = domain->pgd;
+ int agaw;
+
+ context_set_domain_id(context, did);
+ context_set_translation_type(context, translation);
+
+ if (translation != CONTEXT_TT_PASS_THROUGH) {
+ /*
+ * Skip top levels of page tables for iommu which has
+ * less agaw than default. Unnecessary for PT mode.
+ */
+ for (agaw = domain->agaw; agaw > iommu->agaw; agaw--) {
+ ret = -ENOMEM;
+ pgd = phys_to_virt(dma_pte_addr(pgd));
+ if (!dma_pte_present(pgd))
+ goto out_unlock;
+ }
+
+ info = iommu_support_dev_iotlb(domain, iommu, bus, devfn);
+ if (info && info->ats_supported)
+ translation = CONTEXT_TT_DEV_IOTLB;
+ else
+ translation = CONTEXT_TT_MULTI_LEVEL;
+
+ context_set_address_root(context, virt_to_phys(pgd));
+ context_set_address_width(context, agaw);
+ } else {
+ /*
+ * In pass through mode, AW must be programmed to
+ * indicate the largest AGAW value supported by
+ * hardware. And ASR is ignored by hardware.
+ */
+ context_set_address_width(context, iommu->msagaw);
+ }
}

- context_set_translation_type(context, translation);
context_set_fault_enable(context);
context_set_present(context);
domain_flush_cache(domain, context, sizeof(*context));
@@ -5180,7 +5257,6 @@ static void intel_iommu_put_resv_regions(struct device *dev,
}

#ifdef CONFIG_INTEL_IOMMU_SVM
-#define MAX_NR_PASID_BITS (20)
static inline unsigned long intel_iommu_get_pts(struct device *dev)
{
int pts, max_pasid;
diff --git a/drivers/iommu/intel-pasid.h b/drivers/iommu/intel-pasid.h
index d6f4fead4491..55bb8715329d 100644
--- a/drivers/iommu/intel-pasid.h
+++ b/drivers/iommu/intel-pasid.h
@@ -17,6 +17,7 @@
#define PASID_PTE_PRESENT 1
#define PDE_PFN_MASK PAGE_MASK
#define PASID_PDE_SHIFT 6
+#define MAX_NR_PASID_BITS 20

/*
* Domain ID reserved for pasid entries programmed for first-level
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index cb3ebda47fa7..5fdd33ed2cce 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -258,6 +258,7 @@

/* DMA_RTADDR_REG */
#define DMA_RTADDR_RTT (((u64)1) << 11)
+#define DMA_RTADDR_SMT (((u64)1) << 10)

/* CCMD_REG */
#define DMA_CCMD_ICC (((u64)1) << 63)
--
2.17.1