Add remove_device callback for removing the device entry from smmu-master using
following steps:
1. Find if SMMU master exists for the device node.
2. Check if device is currently in use.
3. Remove the SMMU master.
Signed-off-by: Vikram Garhwal <vikram.garh...@amd.com>
---
Changes from v9:
Remove iommu_dt_device_is_assigned_locked().
Add comment regarding caller holding the locks to protect concurrent access.
Changes from v7:
Added comments on arm_smmu_dt_remove_device_generic().
---
---
xen/drivers/passthrough/arm/smmu.c | 60 ++++++++++++++++++++++++++++++
1 file changed, 60 insertions(+)
diff --git a/xen/drivers/passthrough/arm/smmu.c
b/xen/drivers/passthrough/arm/smmu.c
index c37fa9af13..71799064f8 100644
--- a/xen/drivers/passthrough/arm/smmu.c
+++ b/xen/drivers/passthrough/arm/smmu.c
@@ -815,6 +815,19 @@ static int insert_smmu_master(struct arm_smmu_device *smmu,
return 0;
}
+static int remove_smmu_master(struct arm_smmu_device *smmu,
+ struct arm_smmu_master *master)
+{
+ if (!smmu->masters.rb_node) {
+ ASSERT_UNREACHABLE();
+ return -ENOENT;
+ }
+
+ rb_erase(&master->node, &smmu->masters);
+
+ return 0;
+}
+
static int arm_smmu_dt_add_device_legacy(struct arm_smmu_device *smmu,
struct device *dev,
struct iommu_fwspec *fwspec)
@@ -852,6 +865,32 @@ static int arm_smmu_dt_add_device_legacy(struct
arm_smmu_device *smmu,
return insert_smmu_master(smmu, master);
}
+static int arm_smmu_dt_remove_device_legacy(struct arm_smmu_device *smmu,
+ struct device *dev)
+{
+ struct arm_smmu_master *master;
+ struct device_node *dev_node = dev_get_dev_node(dev);
+ int ret;
+
+ master = find_smmu_master(smmu, dev_node);
+ if (master == NULL) {
+ dev_err(dev,
+ "No registrations found for master device %s\n",
+ dev_node->name);
+ return -EINVAL;
+ }
+
+ ret = remove_smmu_master(smmu, master);
+ if (ret)
+ return ret;
+
+ /* Protected by dt_host_lock and dtdevs_lock as caller holds these
locks. */
+ dev_node->is_protected = false;
+
+ kfree(master);
+ return 0;
+}
+
static int register_smmu_master(struct arm_smmu_device *smmu,
struct device *dev,
struct of_phandle_args *masterspec)
@@ -875,6 +914,26 @@ static int register_smmu_master(struct arm_smmu_device
*smmu,
fwspec);
}
+/*
+ * The driver which supports generic IOMMU DT bindings must have this
+ * callback implemented.
+ */
+static int arm_smmu_dt_remove_device_generic(u8 devfn, struct device *dev)
+{
+ struct arm_smmu_device *smmu;
+ struct iommu_fwspec *fwspec;
+
+ fwspec = dev_iommu_fwspec_get(dev);
+ if (fwspec == NULL)
+ return -ENXIO;
+
+ smmu = find_smmu(fwspec->iommu_dev);
+ if (smmu == NULL)
+ return -ENXIO;
+
+ return arm_smmu_dt_remove_device_legacy(smmu, dev);
+}
+
static int arm_smmu_dt_add_device_generic(u8 devfn, struct device *dev)
{
struct arm_smmu_device *smmu;
@@ -2859,6 +2918,7 @@ static const struct iommu_ops arm_smmu_iommu_ops = {
.init = arm_smmu_iommu_domain_init,
.hwdom_init = arch_iommu_hwdom_init,
.add_device = arm_smmu_dt_add_device_generic,
+ .remove_device = arm_smmu_dt_remove_device_generic,
.teardown = arm_smmu_iommu_domain_teardown,
.iotlb_flush = arm_smmu_iotlb_flush,
.assign_device = arm_smmu_assign_dev,
--
2.17.1
