iommu/amd: Add lockdep asserts for domain->dev_list

Add an assertion to all the iteration points that don't obviously
have the lock held already. These all take the locker higher in their
call chains.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/2-v1-3b9edcf8067d+3975-amd_dev_list_locking_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Author: jgunthorpe

drivers/iommu/amd/iommu.c

@@ -1415,6 +1415,7 @@ static int domain_flush_pages_v2(struct protection_domain *pdom,
 	struct iommu_cmd cmd;
 	int ret = 0;
 
+	lockdep_assert_held(&pdom->lock);
 	list_for_each_entry(dev_data, &pdom->dev_list, list) {
 		struct amd_iommu *iommu = get_amd_iommu_from_dev(dev_data->dev);
 		u16 domid = dev_data->gcr3_info.domid;
@@ -1464,6 +1465,8 @@ static void __domain_flush_pages(struct protection_domain *domain,
 	ioasid_t pasid = IOMMU_NO_PASID;
 	bool gn = false;
 
+	lockdep_assert_held(&domain->lock);
+
 	if (pdom_is_v2_pgtbl_mode(domain)) {
 		gn = true;
 		ret = domain_flush_pages_v2(domain, address, size);
@@ -1585,6 +1588,8 @@ void amd_iommu_update_and_flush_device_table(struct protection_domain *domain)
 {
 	struct iommu_dev_data *dev_data;
 
+	lockdep_assert_held(&domain->lock);
+
 	list_for_each_entry(dev_data, &domain->dev_list, list) {
 		struct amd_iommu *iommu = rlookup_amd_iommu(dev_data->dev);