x86/amd-iommu: Flush all internal TLBs when IOMMUs are enabled

The old code only flushed a DTE or a domain TLB before it is
actually used by the IOMMU driver. While this is efficient
and works when done right it is more likely to introduce new
bugs when changing code (which happened in the past).
This patch adds code to flush all DTEs and all domain TLBs
in each IOMMU right after it is enabled (at boot and after
resume). This reduces the complexity of the driver and makes
it less likely to introduce stale-TLB bugs in the future.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 246d727b65b7..8848dda808e2 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -180,6 +180,12 @@ static u32 dev_table_size;	/* size of the device table */
 static u32 alias_table_size;    /* size of the alias table */
 static u32 rlookup_table_size;  /* size if the rlookup table */
 
+/*
+ * This function flushes all internal caches of
+ * the IOMMU used by this driver.
+ */
+extern void iommu_flush_all_caches(struct amd_iommu *iommu);
+
 static inline void update_last_devid(u16 devid)
 {
         if (devid > amd_iommu_last_bdf)
@@ -1244,6 +1250,7 @@ static void enable_iommus(void)
                 iommu_set_exclusion_range(iommu);
                 iommu_init_msi(iommu);
                 iommu_enable(iommu);
+                iommu_flush_all_caches(iommu);
         }
 }
 
@@ -1274,8 +1281,8 @@ static void amd_iommu_resume(void)
          * we have to flush after the IOMMUs are enabled because a
          * disabled IOMMU will never execute the commands we send
          */
-        amd_iommu_flush_all_devices();
-        amd_iommu_flush_all_domains();
+        for_each_iommu(iommu)
+                iommu_flush_all_caches(iommu);
 }
 
 static int amd_iommu_suspend(void)