x86/amd-iommu: Add function to flush all DTEs on one IOMMU

This function flushes all DTE entries on one IOMMU for all
devices behind this IOMMU. This is required for command
buffer resetting later.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

arch/x86/kernel/amd_iommu.c

@@ -516,6 +516,19 @@ void amd_iommu_flush_all_domains(void)
 		flush_all_domains_on_iommu(iommu);
 }
 
+static void flush_all_devices_for_iommu(struct amd_iommu *iommu)
+{
+	int i;
+
+	for (i = 0; i <= amd_iommu_last_bdf; ++i) {
+		if (iommu != amd_iommu_rlookup_table[i])
+			continue;
+
+		iommu_queue_inv_dev_entry(iommu, i);
+		iommu_completion_wait(iommu);
+	}
+}
+
 void amd_iommu_flush_all_devices(void)
 {
 	struct amd_iommu *iommu;