x86, AMD IOMMU: replace memset with __GFP_ZERO for table allocation

This patch removes the memset from the data structure initialization code and
allocate the structures with the __GFP_ZERO flag.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
Cc: bhavna.sarathy@amd.com
Cc: robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 9 deletions

diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 0c247032308e..2efc3d59b7e6 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -890,7 +890,7 @@ int __init amd_iommu_init(void)
         ret = -ENOMEM;
 
         /* Device table - directly used by all IOMMUs */
-        amd_iommu_dev_table = (void *)__get_free_pages(GFP_KERNEL,
+        amd_iommu_dev_table = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
                                       get_order(dev_table_size));
         if (amd_iommu_dev_table == NULL)
                 goto out;
@@ -914,27 +914,23 @@ int __init amd_iommu_init(void)
          * Protection Domain table - maps devices to protection domains
          * This table has the same size as the rlookup_table
          */
-        amd_iommu_pd_table = (void *)__get_free_pages(GFP_KERNEL,
+        amd_iommu_pd_table = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
                                      get_order(rlookup_table_size));
         if (amd_iommu_pd_table == NULL)
                 goto free;
 
-        amd_iommu_pd_alloc_bitmap = (void *)__get_free_pages(GFP_KERNEL,
+        amd_iommu_pd_alloc_bitmap = (void *)__get_free_pages(
+                                            GFP_KERNEL | __GFP_ZERO,
                                             get_order(MAX_DOMAIN_ID/8));
         if (amd_iommu_pd_alloc_bitmap == NULL)
                 goto free;
 
         /*
-         * memory is allocated now; initialize the device table with all zeroes
-         * and let all alias entries point to itself
+         * let all alias entries point to itself
          */
-        memset(amd_iommu_dev_table, 0, dev_table_size);
         for (i = 0; i < amd_iommu_last_bdf; ++i)
                 amd_iommu_alias_table[i] = i;
 
-        memset(amd_iommu_pd_table, 0, rlookup_table_size);
-        memset(amd_iommu_pd_alloc_bitmap, 0, MAX_DOMAIN_ID / 8);
-
         /*
          * never allocate domain 0 because its used as the non-allocated and
          * error value placeholder