[PATCH v2 5/8] pci/arm: Use iommu_add_dt_pci_device()

[Stewart Hildebrand <stewart.hildebrand@xxxxxxx>]

From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>

On Arm we need to parse DT PCI-IOMMU specifier and provide it to
the driver (for describing the relationship between PCI devices
and IOMMUs) before adding a device to it.

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
Signed-off-by: Stewart Hildebrand <stewart.hildebrand@xxxxxxx>
---
v1->v2:
* new patch title (was: "pci/arm: Use iommu_add_dt_pci_device() instead of arch 
hook")
* move iommu_add_dt_pci_device() call (and associated #ifdef) to
  pci_add_device()
* use existing call to iommu_add_device()

downstream->v1:
* rebase
* add __maybe_unused attribute to const struct domain_iommu *hd;
* Rename: s/iommu_add_pci_device/iommu_add_dt_pci_device/
* guard iommu_add_dt_pci_device call with CONFIG_HAS_DEVICE_TREE instead of
  CONFIG_ARM

(cherry picked from commit 2b9d26badab8b24b5a80d028c4499a5022817213 from
 the downstream branch poc/pci-passthrough from
 https://gitlab.com/xen-project/people/bmarquis/xen-arm-poc.git)
---
 xen/drivers/passthrough/pci.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index b42acb8d7c09..6dbaae682773 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -34,6 +34,11 @@
 #include <xen/vpci.h>
 #include <xen/msi.h>
 #include <xsm/xsm.h>
+
+#ifdef CONFIG_HAS_DEVICE_TREE
+#include <asm/iommu_fwspec.h>
+#endif
+
 #include "ats.h"
 
 struct pci_seg {
@@ -762,9 +767,20 @@ int pci_add_device(u16 seg, u8 bus, u8 devfn,
             pdev->domain = NULL;
             goto out;
         }
+#ifdef CONFIG_HAS_DEVICE_TREE
+        ret = iommu_add_dt_pci_device(pdev);
+        if ( ret < 0 )
+        {
+            printk(XENLOG_ERR "pci-iommu translation failed: %d\n", ret);
+            goto out;
+        }
+#endif
         ret = iommu_add_device(pdev);
         if ( ret )
         {
+#ifdef CONFIG_HAS_DEVICE_TREE
+            iommu_fwspec_free(pci_to_dev(pdev));
+#endif
             vpci_remove_device(pdev);
             list_del(&pdev->domain_list);
             pdev->domain = NULL;
-- 
2.40.1