[PATCH v4 17/27] iommu/arm-smmu-v3: Thread SSID through the arm_smmu_attach_*() interface

[Jason Gunthorpe]

Allow creating and managing arm_smmu_mater_domain's with a non-zero SSID
through the arm_smmu_attach_*() family of functions. This triggers ATC
invalidation for the correct SSID in PASID cases and tracks the
per-attachment SSID in the struct arm_smmu_master_domain.

Generalize arm_smmu_attach_remove() to be able to remove SSID's as well by
ensuring the ATC for the PASID is flushed properly.

Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 28 +++++++++++++--------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 0c134d535401e5..21b0ab9c2ba763 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2013,13 +2013,14 @@ arm_smmu_atc_inv_to_cmd(int ssid, unsigned long iova, size_t size,
 	cmd->atc.size	= log2_span;
 }
 
-static int arm_smmu_atc_inv_master(struct arm_smmu_master *master)
+static int arm_smmu_atc_inv_master(struct arm_smmu_master *master,
+				   ioasid_t ssid)
 {
 	int i;
 	struct arm_smmu_cmdq_ent cmd;
 	struct arm_smmu_cmdq_batch cmds;
 
-	arm_smmu_atc_inv_to_cmd(IOMMU_NO_PASID, 0, 0, &cmd);
+	arm_smmu_atc_inv_to_cmd(ssid, 0, 0, &cmd);
 
 	cmds.num = 0;
 	for (i = 0; i < master->num_streams; i++) {
@@ -2506,7 +2507,7 @@ static void arm_smmu_enable_ats(struct arm_smmu_master *master)
 	/*
 	 * ATC invalidation of PASID 0 causes the entire ATC to be flushed.
 	 */
-	arm_smmu_atc_inv_master(master);
+	arm_smmu_atc_inv_master(master, IOMMU_NO_PASID);
 	if (pci_enable_ats(pdev, stu))
 		dev_err(master->dev, "Failed to enable ATS (STU %zu)\n", stu);
 }
@@ -2593,7 +2594,8 @@ to_smmu_domain_devices(struct iommu_domain *domain)
 }
 
 static void arm_smmu_remove_master_domain(struct arm_smmu_master *master,
-					  struct iommu_domain *domain)
+					  struct iommu_domain *domain,
+					  ioasid_t ssid)
 {
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain_devices(domain);
 	struct arm_smmu_master_domain *master_domain;
@@ -2603,8 +2605,7 @@ static void arm_smmu_remove_master_domain(struct arm_smmu_master *master,
 		return;
 
 	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
-	master_domain = arm_smmu_find_master_domain(smmu_domain, master,
-						    IOMMU_NO_PASID);
+	master_domain = arm_smmu_find_master_domain(smmu_domain, master, ssid);
 	if (master_domain) {
 		list_del(&master_domain->devices_elm);
 		kfree(master_domain);
@@ -2617,6 +2618,7 @@ static void arm_smmu_remove_master_domain(struct arm_smmu_master *master,
 struct attach_state {
 	bool want_ats;
 	bool disable_ats;
+	ioasid_t ssid;
 };
 
 /*
@@ -2648,6 +2650,7 @@ static int arm_smmu_attach_prepare(struct arm_smmu_master *master,
 		if (!master_domain)
 			return -ENOMEM;
 		master_domain->master = master;
+		master_domain->ssid = state->ssid;
 
 		/*
 		 * During prepare we want the current smmu_domain and new
@@ -2700,12 +2703,15 @@ static void arm_smmu_attach_commit(struct arm_smmu_master *master,
 		 * SMMU is translating for the new domain and both the old&new
 		 * domain will issue invalidations.
 		 */
-		arm_smmu_atc_inv_master(master);
+		if (state->want_ats)
+			arm_smmu_atc_inv_master(master, state->ssid);
+		else
+			arm_smmu_atc_inv_master(master, IOMMU_NO_PASID);
 	}
 	master->ats_enabled = state->want_ats;
 
-	arm_smmu_remove_master_domain(master,
-				      iommu_get_domain_for_dev(master->dev));
+	arm_smmu_remove_master_domain(
+		master, iommu_get_domain_for_dev(master->dev), state->ssid);
 }
 
 static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
@@ -2715,7 +2721,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 	struct arm_smmu_device *smmu;
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
-	struct attach_state state = {};
+	struct attach_state state = {.ssid = IOMMU_NO_PASID};
 	struct arm_smmu_master *master;
 	struct arm_smmu_cd *cdptr;
 
@@ -2815,7 +2821,7 @@ static int arm_smmu_attach_dev_ste(struct iommu_domain *domain,
 				   struct device *dev, struct arm_smmu_ste *ste)
 {
 	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
-	struct attach_state state = {};
+	struct attach_state state = {.ssid = IOMMU_NO_PASID};
 
 	if (arm_smmu_ssids_in_use(&master->cd_table))
 		return -EBUSY;
-- 
2.43.0