From a05b67cd45ad09a19f41b2d37255da714512e0ca Mon Sep 17 00:00:00 2001 From: Mukesh Ojha Date: Fri, 17 Jul 2026 20:16:07 +0530 Subject: [PATCH] iommu/qcom: Publish pgtbl_ops before releasing init_mutex qcom_domain->pgtbl_ops was assigned after mutex_unlock(). Another thread calling qcom_iommu_init_domain() would see qcom_domain->iommu already set (domain fully initialized) and skip re-initialization under the mutex. If it then called qcom_iommu_map() before the first thread set pgtbl_ops, it would observe a NULL ops pointer and return -ENODEV for valid mappings. Move the assignment to before mutex_unlock() so that once the mutex is released the domain is fully visible to concurrent operations. Reviewed-by: Konrad Dybcio Signed-off-by: Mukesh Ojha Signed-off-by: Will Deacon --- drivers/iommu/arm/arm-smmu/qcom_iommu.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c index 222bb7febd03..ecde5ca2d476 100644 --- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c +++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c @@ -306,13 +306,12 @@ static int qcom_iommu_init_domain(struct iommu_domain *domain, ctx->domain = domain; } - mutex_unlock(&qcom_domain->init_mutex); - /* Publish page table ops for map/unmap */ qcom_domain->pgtbl_ops = pgtbl_ops; - return 0; + mutex_unlock(&qcom_domain->init_mutex); + return 0; out_clear_iommu: free_io_pgtable_ops(pgtbl_ops); qcom_domain->iommu = NULL;