AMD IOMMU: implement lazy IO/TLB flushing
The IO/TLB flushing on every unmaping operation is the most expensive
part in AMD IOMMU code and not strictly necessary. It is sufficient to
do the flush before any entries are reused. This is patch implements
lazy IO/TLB flushing which does exactly this.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index a69cc0f..f2fa8dc 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -995,6 +995,11 @@
else
printk("disabled\n");
+ if (iommu_fullflush)
+ printk(KERN_INFO "AMD IOMMU: IO/TLB flush on unmap enabled\n");
+ else
+ printk(KERN_INFO "AMD IOMMU: Lazy IO/TLB flushing enabled\n");
+
out:
return ret;
@@ -1057,7 +1062,7 @@
static int __init parse_amd_iommu_options(char *str)
{
for (; *str; ++str) {
- if (strcmp(str, "isolate") == 0)
+ if (strncmp(str, "isolate", 7) == 0)
amd_iommu_isolate = 1;
}