diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2024-05-22 10:26:47 +0200 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2024-06-25 14:20:41 +0200 |
| commit | 9a448e453151ec4e4b98a914b463539e790dd198 (patch) | |
| tree | 6b5a4f4360f0613d299b2a8c9f49371e6a6c0188 | |
| parent | 83a7eefedc9b56fe7bfeff13b6c7356688ffa670 (diff) | |
iommu/amd: Use try_cmpxchg64() in v2_alloc_pte()
Use try_cmpxchg64() instead of cmpxchg64 (*ptr, old, new) != old in
v2_alloc_pte(). cmpxchg returns success in ZF flag, so this change
saves a compare after cmpxchg (and related move instruction
in front of cmpxchg).
This is the same improvement as implemented for alloc_pte() in:
commit 0d10fe759117 ("iommu/amd: Use try_cmpxchg64 in alloc_pte and free_clear_pte")
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Will Deacon <will@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20240522082729.971123-1-ubizjak@gmail.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
| -rw-r--r-- | drivers/iommu/amd/io_pgtable_v2.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/iommu/amd/io_pgtable_v2.c b/drivers/iommu/amd/io_pgtable_v2.c index 78ac37c5ccc1..664e91c88748 100644 --- a/drivers/iommu/amd/io_pgtable_v2.c +++ b/drivers/iommu/amd/io_pgtable_v2.c @@ -158,7 +158,7 @@ static u64 *v2_alloc_pte(int nid, u64 *pgd, unsigned long iova, __npte = set_pgtable_attr(page); /* pte could have been changed somewhere. */ - if (cmpxchg64(pte, __pte, __npte) != __pte) + if (!try_cmpxchg64(pte, &__pte, __npte)) iommu_free_page(page); else if (IOMMU_PTE_PRESENT(__pte)) *updated = true; |