[PATCH 08/10] vpci/arm: Allow updating BAR's header for non-ECAM bridges

[Oleksandr Andrushchenko <andr2000@xxxxxxxxx>]

From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>

Non-ECAM host bridges in hwdom go directly to PCI config space,
not through vpci (they use their specific method for accessing PCI
configuration, e.g. dedicated registers etc.). Thus hwdom's vpci BARs are
never updated via vPCI MMIO handlers, so implement a dedicated method
for a PCI host bridge, so it has a chance to update the initial state of
the device BARs.

Note, we rely on the fact that control/hardware domain will not update
physical BAR locations for the given devices.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
---
 xen/arch/arm/pci/pci-host-common.c | 13 +++++++++++++
 xen/drivers/vpci/header.c          |  9 ++++++++-
 xen/include/asm-arm/pci.h          |  8 ++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/pci/pci-host-common.c 
b/xen/arch/arm/pci/pci-host-common.c
index b6c4d7b636b1..5f4239afa41f 100644
--- a/xen/arch/arm/pci/pci-host-common.c
+++ b/xen/arch/arm/pci/pci-host-common.c
@@ -250,6 +250,19 @@ int pci_host_bridge_update_mappings(struct domain *d)
     return pci_host_iterate_bridges(d, pci_host_bridge_update_mapping);
 }
 
+void pci_host_bridge_update_bar_header(const struct pci_dev *pdev,
+                                       struct vpci_header *header)
+{
+    struct pci_host_bridge *bridge;
+
+    bridge = pci_find_host_bridge(pdev->seg, pdev->bus);
+    if ( unlikely(!bridge) )
+        return;
+
+    if ( bridge->ops->update_bar_header )
+        bridge->ops->update_bar_header(pdev, header);
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c
index 7dc7c70e24f2..1f326c894d16 100644
--- a/xen/drivers/vpci/header.c
+++ b/xen/drivers/vpci/header.c
@@ -77,7 +77,14 @@ static struct vpci_header *get_vpci_header(struct domain *d,
     if ( !is_hardware_domain(d) )
     {
         struct vpci_header *hwdom_header = get_hwdom_vpci_header(pdev);
-
+#ifdef CONFIG_ARM
+        /*
+         * Non-ECAM host bridges in hwdom go directly to PCI
+         * config space, not through vpci. Thus hwdom's vpci BARs are
+         * never updated.
+         */
+        pci_host_bridge_update_bar_header(pdev, hwdom_header);
+#endif
         /* Make a copy of the hwdom's BARs as the initial state for vBARs. */
         memcpy(header, hwdom_header, sizeof(*header));
     }
diff --git a/xen/include/asm-arm/pci.h b/xen/include/asm-arm/pci.h
index d94e8a6628de..723b2a99b6e1 100644
--- a/xen/include/asm-arm/pci.h
+++ b/xen/include/asm-arm/pci.h
@@ -60,6 +60,9 @@ struct pci_config_window {
 /* Forward declaration as pci_host_bridge and pci_ops depend on each other. */
 struct pci_host_bridge;
 
+struct pci_dev;
+struct vpci_header;
+
 struct pci_ops {
     int (*read)(struct pci_host_bridge *bridge,
                     uint32_t sbdf, int where, int size, u32 *val);
@@ -69,6 +72,8 @@ struct pci_ops {
     int (*register_mmio_handler)(struct domain *d,
                                  struct pci_host_bridge *bridge,
                                  const struct mmio_handler_ops *ops);
+    void (*update_bar_header)(const struct pci_dev *pdev,
+                              struct vpci_header *header);
 };
 
 /*
@@ -110,6 +115,9 @@ int pci_host_iterate_bridges(struct domain *d,
                              int (*clb)(struct domain *d,
                                         struct pci_host_bridge *bridge));
 int pci_host_bridge_update_mappings(struct domain *d);
+void pci_host_bridge_update_bar_header(const struct pci_dev *pdev,
+                                       struct vpci_header *header);
+
 #else   /*!CONFIG_ARM_PCI*/
 struct arch_pci_dev { };
 static inline void  pci_init(void) { }
-- 
2.17.1