1 files changed, 13 insertions, 0 deletions

diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c
index 3dcb1ad86e38..9e390f1bd46a 100644
--- a/arch/x86/kernel/pci-gart_64.c
+++ b/arch/x86/kernel/pci-gart_64.c
@@ -45,6 +45,15 @@ static unsigned long iommu_pages;	/* .. and in pages */
 
 static u32 *iommu_gatt_base;            /* Remapping table */
 
+/*
+ * If this is disabled the IOMMU will use an optimized flushing strategy
+ * of only flushing when an mapping is reused. With it true the GART is
+ * flushed for every mapping. Problem is that doing the lazy flush seems
+ * to trigger bugs with some popular PCI cards, in particular 3ware (but
+ * has been also also seen with Qlogic at least).
+ */
+int iommu_fullflush = 1;
+
 /* Allocation bitmap for the remapping area: */
 static DEFINE_SPINLOCK(iommu_bitmap_lock);
 /* Guarded by iommu_bitmap_lock: */
@@ -892,6 +901,10 @@ void __init gart_parse_options(char *p)
 #endif
         if (isdigit(*p) && get_option(&p, &arg))
                 iommu_size = arg;
+        if (!strncmp(p, "fullflush", 8))
+                iommu_fullflush = 1;
+        if (!strncmp(p, "nofullflush", 11))
+                iommu_fullflush = 0;
         if (!strncmp(p, "noagp", 5))
                 no_agp = 1;
         if (!strncmp(p, "noaperture", 10))