From: David Woodhouse <David.Woodhouse@intel.com>
Date: Thu, 2 Jul 2009 11:02:34 +0000 (+0100)
Subject: intel-iommu: Don't keep freeing page zero in dma_pte_free_pagetable()
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6a43e574c5af7d9bd084992b1c9c3cdbc3b6c0e9;p=linux-beck.git

intel-iommu: Don't keep freeing page zero in dma_pte_free_pagetable()

Check dma_pte_present() and only free the page if there _is_ one.
Kind of surprising that there was no warning about this.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
---

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index dcf0295a9b60..53075424a434 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -826,8 +826,10 @@ static void dma_pte_free_pagetable(struct dmar_domain *domain,
 				continue;
 			}
 			do {
-				free_pgtable_page(phys_to_virt(dma_pte_addr(pte)));
-				dma_clear_pte(pte);
+				if (dma_pte_present(pte)) {
+					free_pgtable_page(phys_to_virt(dma_pte_addr(pte)));
+					dma_clear_pte(pte);
+				}
 				pte++;
 				tmp += level_size(level);
 			} while (!first_pte_in_page(pte) &&