drm/etnaviv: iommuv1: remove map_lock

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 <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-By: Wladimir J. van der Laan <laanwj@gmail.com>

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_iommu.c b/drivers/gpu/drm/etnaviv/etnaviv_iommu.c
index 33084cb..2ffdb27 100644 (file)
--- 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;
 }