2024-02-15 13:55:36

by Shivaprasad G Bhat

[permalink] [raw]
Subject: [PATCH] powerpc/iommu: Refactor spapr_tce_platform_iommu_attach_dev()

The patch makes the iommu_group_get() call only when using it
thereby avoiding the unnecessary get & put for domain already
being set case.

Reviewed-by: Jason Gunthorpe <[email protected]>
Signed-off-by: Shivaprasad G Bhat <[email protected]>
---
Changelog:
v2: https://lore.kernel.org/linux-iommu/[email protected]/
- As the v1 itself was merged, the patch was suggested to be reposted as
cleanup/refactoring to be applied on top of v1.
- Removed the versioning as this is actually new cleanup/refactoring.
- Retaining the Reviewed-by as the effective new code was actually reviewed.

v1: https://lore.kernel.org/all/[email protected]/
- Minor refactor to call the iommu_get_group only if required.
- Updated the title, description and signature(Closes/Reported-by).

arch/powerpc/kernel/iommu.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index a9bebfd56b3b..37fae3bd89c6 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1285,15 +1285,14 @@ spapr_tce_platform_iommu_attach_dev(struct iommu_domain *platform_domain,
struct device *dev)
{
struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
- struct iommu_group *grp = iommu_group_get(dev);
struct iommu_table_group *table_group;
+ struct iommu_group *grp;

/* At first attach the ownership is already set */
- if (!domain) {
- iommu_group_put(grp);
+ if (!domain)
return 0;
- }

+ grp = iommu_group_get(dev);
table_group = iommu_group_get_iommudata(grp);
/*
* The domain being set to PLATFORM from earlier




2024-04-22 09:22:20

by Michael Ellerman

[permalink] [raw]
Subject: Re: [PATCH] powerpc/iommu: Refactor spapr_tce_platform_iommu_attach_dev()

On Thu, 15 Feb 2024 07:52:32 -0600, Shivaprasad G Bhat wrote:
> The patch makes the iommu_group_get() call only when using it
> thereby avoiding the unnecessary get & put for domain already
> being set case.
>
>

Applied to powerpc/fixes.

[1/1] powerpc/iommu: Refactor spapr_tce_platform_iommu_attach_dev()
https://git.kernel.org/powerpc/c/5bd31ab5f79eb6e3bdfa0ca0b57650f9d1604062

cheers