iommu/amd: Refactor protection domain allocation code

To replace if-else with switch-case statement due to increasing number of
domain types.

No functional changes intended.

Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20230921092147.5930-5-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index c99611139ab55c122ca5c9b01fbbf6ef02447f89..bc1fa6e43794c41df7c494a087695576f8f55647 100644 (file)
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2078,24 +2078,8 @@ static struct protection_domain *protection_domain_alloc(unsigned int type)
        struct io_pgtable_ops *pgtbl_ops;
        struct protection_domain *domain;
        int pgtable;
-       int mode = DEFAULT_PGTABLE_LEVEL;
        int ret;
 
-       /*
-        * Force IOMMU v1 page table when iommu=pt and
-        * when allocating domain for pass-through devices.
-        */
-       if (type == IOMMU_DOMAIN_IDENTITY) {
-               pgtable = AMD_IOMMU_V1;
-               mode = PAGE_MODE_NONE;
-       } else if (type == IOMMU_DOMAIN_UNMANAGED) {
-               pgtable = AMD_IOMMU_V1;
-       } else if (type == IOMMU_DOMAIN_DMA || type == IOMMU_DOMAIN_DMA_FQ) {
-               pgtable = amd_iommu_pgtable;
-       } else {
-               return NULL;
-       }
-
        domain = kzalloc(sizeof(*domain), GFP_KERNEL);
        if (!domain)
                return NULL;
@@ -2106,27 +2090,42 @@ static struct protection_domain *protection_domain_alloc(unsigned int type)
 
        spin_lock_init(&domain->lock);
        INIT_LIST_HEAD(&domain->dev_list);
+       domain->nid = NUMA_NO_NODE;
+
+       switch (type) {
+       /* No need to allocate io pgtable ops in passthrough mode */
+       case IOMMU_DOMAIN_IDENTITY:
+               return domain;
+       case IOMMU_DOMAIN_DMA:
+       case IOMMU_DOMAIN_DMA_FQ:
+               pgtable = amd_iommu_pgtable;
+               break;
+       /*
+        * Force IOMMU v1 page table when allocating
+        * domain for pass-through devices.
+        */
+       case IOMMU_DOMAIN_UNMANAGED:
+               pgtable = AMD_IOMMU_V1;
+               break;
+       default:
+               goto out_err;
+       }
 
        switch (pgtable) {
        case AMD_IOMMU_V1:
-               ret = protection_domain_init_v1(domain, mode);
+               ret = protection_domain_init_v1(domain, DEFAULT_PGTABLE_LEVEL);
                break;
        case AMD_IOMMU_V2:
                ret = protection_domain_init_v2(domain);
                break;
        default:
                ret = -EINVAL;
+               break;
        }
 
        if (ret)
                goto out_err;
 
-       /* No need to allocate io pgtable ops in passthrough mode */
-       if (type == IOMMU_DOMAIN_IDENTITY)
-               return domain;
-
-       domain->nid = NUMA_NO_NODE;
-
        pgtbl_ops = alloc_io_pgtable_ops(pgtable, &domain->iop.pgtbl_cfg, domain);
        if (!pgtbl_ops) {
                domain_id_free(domain->id);