Commit d2d00e15 authored by Shivaprasad G Bhat's avatar Shivaprasad G Bhat Committed by Joerg Roedel
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powerpc: iommu: Bring back table group release_ownership() call 



The commit 2ad56efa ("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: 2ad56efa ("powerpc/iommu: Setup a default domain and remove set_platform_dma_ops")
Signed-off-by: default avatarShivaprasad G Bhat <sbhat@linux.ibm.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/170628173462.3742.18330000394415935845.stgit@ltcd48-lp2.aus.stglab.ibm.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent fae6e669

arch/powerpc/kernel/iommu.c

+28 −9
Original line number Diff line number Diff line
@@ -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)