iommu/arm-smmu-v3: Make smmu_domain->devices into an allocated list

The next patch will need to store the same master twice (with different
SSIDs), so allocate memory for each list element.
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Michael Shavit <mshavit@google.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v9-5cd718286059+79186-smmuv3_newapi_p2b_jgg@nvidia.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c

@@ -38,12 +38,13 @@ static DEFINE_MUTEX(sva_lock);
 static void
 arm_smmu_update_s1_domain_cd_entry(struct arm_smmu_domain *smmu_domain)
 {
-	struct arm_smmu_master *master;
+	struct arm_smmu_master_domain *master_domain;
 	struct arm_smmu_cd target_cd;
 	unsigned long flags;
 
 	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
-	list_for_each_entry(master, &smmu_domain->devices, domain_head) {
+	list_for_each_entry(master_domain, &smmu_domain->devices, devices_elm) {
+		struct arm_smmu_master *master = master_domain->master;
 		struct arm_smmu_cd *cdptr;
 
 		/* S1 domains only support RID attachment right now */
@@ -301,7 +302,7 @@ static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
 {
 	struct arm_smmu_mmu_notifier *smmu_mn = mn_to_smmu(mn);
 	struct arm_smmu_domain *smmu_domain = smmu_mn->domain;
-	struct arm_smmu_master *master;
+	struct arm_smmu_master_domain *master_domain;
 	unsigned long flags;
 
 	mutex_lock(&sva_lock);
@@ -315,7 +316,9 @@ static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
 	 * but disable translation.
 	 */
 	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
-	list_for_each_entry(master, &smmu_domain->devices, domain_head) {
+	list_for_each_entry(master_domain, &smmu_domain->devices,
+			    devices_elm) {
+		struct arm_smmu_master *master = master_domain->master;
 		struct arm_smmu_cd target;
 		struct arm_smmu_cd *cdptr;
 

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

@@ -2015,10 +2015,10 @@ static int arm_smmu_atc_inv_master(struct arm_smmu_master *master)
 int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
 			    unsigned long iova, size_t size)
 {
+	struct arm_smmu_master_domain *master_domain;
 	int i;
 	unsigned long flags;
 	struct arm_smmu_cmdq_ent cmd;
-	struct arm_smmu_master *master;
 	struct arm_smmu_cmdq_batch cmds;
 
 	if (!(smmu_domain->smmu->features & ARM_SMMU_FEAT_ATS))
@@ -2046,7 +2046,10 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
 	cmds.num = 0;
 
 	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
-	list_for_each_entry(master, &smmu_domain->devices, domain_head) {
+	list_for_each_entry(master_domain, &smmu_domain->devices,
+			    devices_elm) {
+		struct arm_smmu_master *master = master_domain->master;
+
 		if (!master->ats_enabled)
 			continue;
 
@@ -2534,9 +2537,26 @@ static void arm_smmu_disable_pasid(struct arm_smmu_master *master)
 	pci_disable_pasid(pdev);
 }
 
+static struct arm_smmu_master_domain *
+arm_smmu_find_master_domain(struct arm_smmu_domain *smmu_domain,
+			    struct arm_smmu_master *master)
+{
+	struct arm_smmu_master_domain *master_domain;
+
+	lockdep_assert_held(&smmu_domain->devices_lock);
+
+	list_for_each_entry(master_domain, &smmu_domain->devices,
+			    devices_elm) {
+		if (master_domain->master == master)
+			return master_domain;
+	}
+	return NULL;
+}
+
 static void arm_smmu_detach_dev(struct arm_smmu_master *master)
 {
 	struct iommu_domain *domain = iommu_get_domain_for_dev(master->dev);
+	struct arm_smmu_master_domain *master_domain;
 	struct arm_smmu_domain *smmu_domain;
 	unsigned long flags;
 
@@ -2547,7 +2567,11 @@ static void arm_smmu_detach_dev(struct arm_smmu_master *master)
 	arm_smmu_disable_ats(master, smmu_domain);
 
 	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
-	list_del_init(&master->domain_head);
+	master_domain = arm_smmu_find_master_domain(smmu_domain, master);
+	if (master_domain) {
+		list_del(&master_domain->devices_elm);
+		kfree(master_domain);
+	}
 	spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
 
 	master->ats_enabled = false;
@@ -2561,6 +2585,7 @@ 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 arm_smmu_master_domain *master_domain;
 	struct arm_smmu_master *master;
 	struct arm_smmu_cd *cdptr;
 
@@ -2597,6 +2622,11 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 			return -ENOMEM;
 	}
 
+	master_domain = kzalloc(sizeof(*master_domain), GFP_KERNEL);
+	if (!master_domain)
+		return -ENOMEM;
+	master_domain->master = master;
+
 	/*
 	 * Prevent arm_smmu_share_asid() from trying to change the ASID
 	 * of either the old or new domain while we are working on it.
@@ -2610,7 +2640,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 	master->ats_enabled = arm_smmu_ats_supported(master);
 
 	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
-	list_add(&master->domain_head, &smmu_domain->devices);
+	list_add(&master_domain->devices_elm, &smmu_domain->devices);
 	spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
 
 	switch (smmu_domain->stage) {
@@ -2925,7 +2955,6 @@ static struct iommu_device *arm_smmu_probe_device(struct device *dev)
 	master->dev = dev;
 	master->smmu = smmu;
 	INIT_LIST_HEAD(&master->bonds);
-	INIT_LIST_HEAD(&master->domain_head);
 	dev_iommu_priv_set(dev, master);
 
 	ret = arm_smmu_insert_master(smmu, master);

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h

@@ -697,7 +697,6 @@ struct arm_smmu_stream {
 struct arm_smmu_master {
 	struct arm_smmu_device		*smmu;
 	struct device			*dev;
-	struct list_head		domain_head;
 	struct arm_smmu_stream		*streams;
 	/* Locked by the iommu core using the group mutex */
 	struct arm_smmu_ctx_desc_cfg	cd_table;
@@ -731,6 +730,7 @@ struct arm_smmu_domain {
 
 	struct iommu_domain		domain;
 
+	/* List of struct arm_smmu_master_domain */
 	struct list_head		devices;
 	spinlock_t			devices_lock;
 
@@ -767,6 +767,11 @@ void arm_smmu_make_sva_cd(struct arm_smmu_cd *target,
 			  u16 asid);
 #endif
 
+struct arm_smmu_master_domain {
+	struct list_head devices_elm;
+	struct arm_smmu_master *master;
+};
+
 static inline struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
 {
 	return container_of(dom, struct arm_smmu_domain, domain);