AMD IOMMU: add stats counter for single iommu domain tlb flushes

Impact: see number of single iommu domain tlb flushes in debugfs

Signed-off-by: Joerg Roedel <[e-mail]>

arch/x86/kernel/amd_iommu.c

···
 DECLARE_STATS_COUNTER(cnt_alloc_coherent);
 DECLARE_STATS_COUNTER(cnt_free_coherent);
 DECLARE_STATS_COUNTER(cross_page);
+DECLARE_STATS_COUNTER(domain_flush_single);
 
 static struct dentry *stats_dir;
 static struct dentry *de_isolate;
···
 	amd_iommu_stats_add(&cnt_alloc_coherent);
 	amd_iommu_stats_add(&cnt_free_coherent);
 	amd_iommu_stats_add(&cross_page);
+	amd_iommu_stats_add(&domain_flush_single);
 }
 
 #endif
···
 static void iommu_flush_tlb(struct amd_iommu *iommu, u16 domid)
 {
 	u64 address = CMD_INV_IOMMU_ALL_PAGES_ADDRESS;
+
+	INC_STATS_COUNTER(domain_flush_single);
 
 	iommu_queue_inv_iommu_pages(iommu, address, domid, 0, 1);
 }