iommu/exynos: Block SYSMMU while invalidating FLPD cache

[ Upstream commit 7d2aa6b8 ]

Documentation specifies that SYSMMU should be in blocked state while
performing TLB/FLPD cache invalidation, so add needed calls to
sysmmu_block/unblock.

Fixes: 66a7ed84 ("iommu/exynos: Apply workaround of caching fault page table entries")
CC: stable@vger.kernel.org # v4.10+
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/iommu/exynos-iommu.c

@@ -542,7 +542,10 @@ static void sysmmu_tlb_invalidate_flpdcache(struct sysmmu_drvdata *data,
 	spin_lock_irqsave(&data->lock, flags);
 	if (is_sysmmu_active(data) && data->version >= MAKE_MMU_VER(3, 3)) {
 		clk_enable(data->clk_master);
-		__sysmmu_tlb_invalidate_entry(data, iova, 1);
+		if (sysmmu_block(data)) {
+			__sysmmu_tlb_invalidate_entry(data, iova, 1);
+			sysmmu_unblock(data);
+		}
 		clk_disable(data->clk_master);
 	}
 	spin_unlock_irqrestore(&data->lock, flags);