powerpc: iommu: Bring back table group release_ownership() call

The commit 2ad56efa80db ("powerpc/iommu: Setup a default domain and
remove set_platform_dma_ops") refactored the code removing the
set_platform_dma_ops(). It missed out the table group
release_ownership() call which would have got called otherwise
during the guest shutdown via vfio_group_detach_container(). On
PPC64, this particular call actually sets up the 32-bit TCE table,
and enables the 64-bit DMA bypass etc. Now after guest shutdown,
the subsequent host driver (e.g megaraid-sas) probe post unbind
from vfio-pci fails like,

megaraid_sas 0031:01:00.0: Warning: IOMMU dma not supported: mask 0x7fffffffffffffff, table unavailable
megaraid_sas 0031:01:00.0: Warning: IOMMU dma not supported: mask 0xffffffff, table unavailable
megaraid_sas 0031:01:00.0: Failed to set DMA mask
megaraid_sas 0031:01:00.0: Failed from megasas_init_fw 6539

The patch brings back the call to table_group release_ownership()
call when switching back to PLATFORM domain from BLOCKED, while
also separates the domain_ops for both.

Fixes: 2ad56efa80db ("powerpc/iommu: Setup a default domain and remove set_platform_dma_ops")
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/170628173462.3742.18330000394415935845.stgit@ltcd48-lp2.aus.stglab.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index ebe259bdd46298e0654fb681b0cf8853c8381079..d71eac3b2887b98ff5ea23ec1874243283524f4c 100644 (file)
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1287,20 +1287,20 @@ spapr_tce_platform_iommu_attach_dev(struct iommu_domain *platform_domain,
        struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
        struct iommu_group *grp = iommu_group_get(dev);
        struct iommu_table_group *table_group;
-       int ret = -EINVAL;
 
        /* At first attach the ownership is already set */
        if (!domain)
                return 0;
 
-       if (!grp)
-               return -ENODEV;
-
        table_group = iommu_group_get_iommudata(grp);
-       ret = table_group->ops->take_ownership(table_group);
+       /*
+        * The domain being set to PLATFORM from earlier
+        * BLOCKED. The table_group ownership has to be released.
+        */
+       table_group->ops->release_ownership(table_group);
        iommu_group_put(grp);
 
-       return ret;
+       return 0;
 }
 
 static const struct iommu_domain_ops spapr_tce_platform_domain_ops = {
@@ -1312,13 +1312,32 @@ static struct iommu_domain spapr_tce_platform_domain = {
        .ops = &spapr_tce_platform_domain_ops,
 };
 
-static struct iommu_domain spapr_tce_blocked_domain = {
-       .type = IOMMU_DOMAIN_BLOCKED,
+static int
+spapr_tce_blocked_iommu_attach_dev(struct iommu_domain *platform_domain,
+                                    struct device *dev)
+{
+       struct iommu_group *grp = iommu_group_get(dev);
+       struct iommu_table_group *table_group;
+       int ret = -EINVAL;
+
        /*
         * FIXME: SPAPR mixes blocked and platform behaviors, the blocked domain
         * also sets the dma_api ops
         */
-       .ops = &spapr_tce_platform_domain_ops,
+       table_group = iommu_group_get_iommudata(grp);
+       ret = table_group->ops->take_ownership(table_group);
+       iommu_group_put(grp);
+
+       return ret;
+}
+
+static const struct iommu_domain_ops spapr_tce_blocked_domain_ops = {
+       .attach_dev = spapr_tce_blocked_iommu_attach_dev,
+};
+
+static struct iommu_domain spapr_tce_blocked_domain = {
+       .type = IOMMU_DOMAIN_BLOCKED,
+       .ops = &spapr_tce_blocked_domain_ops,
 };
 
 static bool spapr_tce_iommu_capable(struct device *dev, enum iommu_cap cap)