[PATCH] Revert "iommu/dma: Fix race condition during iova_domain initialization"

[Karolina Drobnik]

This reverts commit ac9a5d522bb80be50ea84965699e1c8257d745ce.

Signed-off-by: Karolina Drobnik <karolina.drobnik at intel.com>
---
 drivers/iommu/dma-iommu.c | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 17dd683b2fce..9616b473e4c7 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -65,7 +65,6 @@ struct iommu_dma_cookie {
 
 	/* Domain for flush queue callback; NULL if flush queue not in use */
 	struct iommu_domain		*fq_domain;
-	struct mutex			mutex;
 };
 
 static DEFINE_STATIC_KEY_FALSE(iommu_deferred_attach_enabled);
@@ -312,7 +311,6 @@ int iommu_get_dma_cookie(struct iommu_domain *domain)
 	if (!domain->iova_cookie)
 		return -ENOMEM;
 
-	mutex_init(&domain->iova_cookie->mutex);
 	return 0;
 }
 
@@ -563,33 +561,26 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
 	}
 
 	/* start_pfn is always nonzero for an already-initialised domain */
-	mutex_lock(&cookie->mutex);
 	if (iovad->start_pfn) {
 		if (1UL << order != iovad->granule ||
 		    base_pfn != iovad->start_pfn) {
 			pr_warn("Incompatible range for DMA domain\n");
-			ret = -EFAULT;
-			goto done_unlock;
+			return -EFAULT;
 		}
 
-		ret = 0;
-		goto done_unlock;
+		return 0;
 	}
 
 	init_iova_domain(iovad, 1UL << order, base_pfn);
 	ret = iova_domain_init_rcaches(iovad);
 	if (ret)
-		goto done_unlock;
+		return ret;
 
 	/* If the FQ fails we can simply fall back to strict mode */
 	if (domain->type == IOMMU_DOMAIN_DMA_FQ && iommu_dma_init_fq(domain))
 		domain->type = IOMMU_DOMAIN_DMA;
 
-	ret = iova_reserve_iommu_regions(dev, domain);
-
-done_unlock:
-	mutex_unlock(&cookie->mutex);
-	return ret;
+	return iova_reserve_iommu_regions(dev, domain);
 }
 
 /**
-- 
2.25.1