iommu/arm-smmu: Add support for page table donation

For secure domains, the page tables need to be assigned
to the correct VMIDs. Add support for the same.

Change-Id: Ic46e61300463d969b35ebc5d4d20cfc30a4ba476
Signed-off-by: Neeti Desai <neetid@codeaurora.org>

2 files changed, 46 insertions, 2 deletions

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index a810ae3b21b3..bcfa0e2b2eed 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -47,6 +47,7 @@
 
 #include <linux/amba/bus.h>
 #include <soc/qcom/msm_tz_smmu.h>
+#include <soc/qcom/secure_buffer.h>
 
 #include <asm/pgalloc.h>
 
@@ -485,6 +486,7 @@ struct arm_smmu_domain {
 	struct arm_smmu_cfg		cfg;
 	struct mutex			lock;
 	u32				attributes;
+	int				secure_vmid;
 };
 
 static DEFINE_SPINLOCK(arm_smmu_devices_lock);
@@ -1244,6 +1246,18 @@ static void arm_smmu_destroy_domain_context(struct iommu_domain *domain)
 	smmu_domain->smmu = NULL;
 }
 
+static int arm_smmu_assign_call(phys_addr_t addr, u64 size, int dest_vmid)
+{
+	int dest_vmids[2] = {VMID_HLOS, dest_vmid};
+	int dest_perms[2] = {PERM_READ | PERM_WRITE, PERM_READ};
+
+	if (dest_vmid == VMID_INVAL)
+		return 0;
+
+	return hyp_assign_phys(addr, size,
+			dest_vmids, dest_perms, 2);
+}
+
 static int arm_smmu_domain_init(struct iommu_domain *domain)
 {
 	struct arm_smmu_domain *smmu_domain;
@@ -1262,6 +1276,7 @@ static int arm_smmu_domain_init(struct iommu_domain *domain)
 	if (!pgd)
 		goto out_free_domain;
 	smmu_domain->cfg.pgd = pgd;
+	smmu_domain->secure_vmid = VMID_INVAL;
 
 	mutex_init(&smmu_domain->lock);
 	domain->priv = smmu_domain;
@@ -1515,6 +1530,12 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 	} else {
 		arm_smmu_enable_clocks(smmu);
 	}
+	ret = arm_smmu_assign_call(virt_to_phys(smmu_domain->cfg.pgd),
+					PAGE_SIZE, smmu_domain->secure_vmid);
+	if (ret) {
+		mutex_unlock(&smmu->attach_lock);
+		goto err_disable_clocks;
+	}
 	mutex_unlock(&smmu->attach_lock);
 
 	/*
@@ -1628,6 +1649,7 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_domain *smmu_domain,
 {
 	pte_t *pte, *start;
 	pteval_t pteval = ARM_SMMU_PTE_PAGE | ARM_SMMU_PTE_AF | ARM_SMMU_PTE_XN;
+	int ret;
 
 	if (pmd_none(*pmd)) {
 		/* Allocate a new set of tables */
@@ -1640,6 +1662,12 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_domain *smmu_domain,
 				PAGE_SIZE);
 		pmd_populate(NULL, pmd, table);
 		arm_smmu_flush_pgtable(smmu_domain, pmd, sizeof(*pmd));
+		ret = arm_smmu_assign_call(virt_to_phys(page_address(table)),
+					PAGE_SIZE, smmu_domain->secure_vmid);
+		if (ret) {
+			free_page((unsigned long)table);
+			return ret;
+		}
 	}
 
 	if (stage == 1) {
@@ -1750,7 +1778,12 @@ static int arm_smmu_alloc_init_pmd(struct arm_smmu_domain *smmu_domain,
 		arm_smmu_flush_pgtable(smmu_domain, pmd, PAGE_SIZE);
 		pud_populate(NULL, pud, pmd);
 		arm_smmu_flush_pgtable(smmu_domain, pud, sizeof(*pud));
-
+		ret = arm_smmu_assign_call(virt_to_phys(pmd), PAGE_SIZE,
+						smmu_domain->secure_vmid);
+		if (ret) {
+			free_page((unsigned long)pmd);
+			return ret;
+		}
 		pmd += pmd_index(addr);
 	} else
 #endif
@@ -1785,7 +1818,12 @@ static int arm_smmu_alloc_init_pud(struct arm_smmu_domain *smmu_domain,
 		arm_smmu_flush_pgtable(smmu_domain, pud, PAGE_SIZE);
 		pgd_populate(NULL, pgd, pud);
 		arm_smmu_flush_pgtable(smmu_domain, pgd, sizeof(*pgd));
-
+		ret = arm_smmu_assign_call(virt_to_phys(pud), PAGE_SIZE,
+						smmu_domain->secure_vmid);
+		if (ret) {
+			free_page((unsigned long)pud);
+			return ret;
+		}
 		pud += pud_index(addr);
 	} else
 #endif
@@ -2205,6 +2243,11 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain,
 				~(1 << DOMAIN_ATTR_COHERENT_HTW_DISABLE);
 		return 0;
 	}
+	case DOMAIN_ATTR_SECURE_VMID:
+	{
+		smmu_domain->secure_vmid = *((int *)data);
+		return 0;
+	}
 	default:
 		return -ENODEV;
 	}
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 85ec8fda186c..cf12d3a77af4 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -87,6 +87,7 @@ enum iommu_attr {
 	DOMAIN_ATTR_NESTING,	/* two stages of translation */
 	DOMAIN_ATTR_COHERENT_HTW_DISABLE,
 	DOMAIN_ATTR_PT_BASE_ADDR,
+	DOMAIN_ATTR_SECURE_VMID,
 	DOMAIN_ATTR_MAX,
 };