Merge tag 'pci-v5.2-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI fix from Bjorn Helgaas:
 "If an IOMMU is present, ignore the P2PDMA whitelist we added for v5.2
  because we don't yet know how to support P2PDMA in that case (Logan
  Gunthorpe)"

* tag 'pci-v5.2-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI/P2PDMA: Ignore root complex whitelist when an IOMMU is present

Author: torvalds

drivers/pci/p2pdma.c

@@ -18,6 +18,7 @@
 #include <linux/percpu-refcount.h>
 #include <linux/random.h>
 #include <linux/seq_buf.h>
+#include <linux/iommu.h>
 
 struct pci_p2pdma {
 	struct gen_pool *pool;
@@ -299,6 +300,9 @@ static bool root_complex_whitelist(struct pci_dev *dev)
 	struct pci_dev *root = pci_get_slot(host->bus, PCI_DEVFN(0, 0));
 	unsigned short vendor, device;
 
+	if (iommu_present(dev->dev.bus))
+		return false;
+
 	if (!root)
 		return false;