[v2,5/8] drm/etnaviv: iommuv1: remove map_lock

Commit Message

Lucas Stach Sept. 29, 2017, 2:37 p.m. UTC

It wasn't protecting anything, as the single word writes used to
set up or tear down a translation are already inherently atomic,
so the spinlock is pure overhead.

Signed-off-by: Lucas Stach <[e-mail]>
Reviewed-by: Philipp Zabel <[e-mail]>
Reviewed-By: Wladimir J. van der Laan <[e-mail]>
---
 drivers/gpu/drm/etnaviv/etnaviv_iommu.c | 7 -------
 1 file changed, 7 deletions(-)

Patch

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_iommu.c b/drivers/gpu/drm/etnaviv/etnaviv_iommu.c
index 790cb7f9d59c..43a0508bdbd7 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_iommu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_iommu.c
@@ -42,7 +42,6 @@  struct etnaviv_iommu_domain {
 	void *bad_page_cpu;
 	dma_addr_t bad_page_dma;
 	struct etnaviv_iommu_domain_pgtable pgtable;
-	spinlock_t map_lock;
 };
 
 static struct etnaviv_iommu_domain *to_etnaviv_domain(struct iommu_domain *domain)
@@ -81,8 +80,6 @@  static int __etnaviv_iommu_init(struct etnaviv_iommu_domain *etnaviv_domain)
 		etnaviv_domain->pgtable.pgtable[i] =
 			etnaviv_domain->bad_page_dma;
 
-	spin_lock_init(&etnaviv_domain->map_lock);
-
 	return 0;
 }
 
@@ -110,9 +107,7 @@  static int etnaviv_iommuv1_map(struct iommu_domain *domain, unsigned long iova,
 	if (size != SZ_4K)
 		return -EINVAL;
 
-	spin_lock(&etnaviv_domain->map_lock);
 	etnaviv_domain->pgtable.pgtable[index] = paddr;
-	spin_unlock(&etnaviv_domain->map_lock);
 
 	return 0;
 }
@@ -126,9 +121,7 @@  static size_t etnaviv_iommuv1_unmap(struct iommu_domain *domain,
 	if (size != SZ_4K)
 		return -EINVAL;
 
-	spin_lock(&etnaviv_domain->map_lock);
 	etnaviv_domain->pgtable.pgtable[index] = etnaviv_domain->bad_page_dma;
-	spin_unlock(&etnaviv_domain->map_lock);
 
 	return SZ_4K;
 }