[PATCH 02/11] xen/arm: Add dev_to_pci helper

[Oleksandr Andrushchenko <andr2000@gmail.com>]

From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>

Add a helper which is when given a struct device returns the
corresponding struct pci_dev which this device is a part of.

Because of the header cross-dependencies, e.g. we need both
struct pci_dev and struct arch_pci_dev at the same time, this cannot be
done with an inline. Macro can be implemented, but looks scary:

 #define dev_to_pci_dev(dev) container_of((container_of((dev), \
                        struct arch_pci_dev, dev), struct pci_dev, arch)

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
---
 xen/arch/arm/pci/pci.c    | 10 ++++++++++
 xen/include/asm-arm/pci.h |  7 +++++++
 2 files changed, 17 insertions(+)

diff --git a/xen/arch/arm/pci/pci.c b/xen/arch/arm/pci/pci.c
index dc63bbc2a2c1..6573f179af55 100644
--- a/xen/arch/arm/pci/pci.c
+++ b/xen/arch/arm/pci/pci.c
@@ -26,6 +26,16 @@ int arch_pci_clean_pirqs(struct domain *d)
     return 0;
 }
 
+struct pci_dev *dev_to_pci(struct device *dev)
+{
+    struct arch_pci_dev *arch_dev;
+
+    ASSERT(dev->type == DEV_PCI);
+
+    arch_dev = container_of((dev), struct arch_pci_dev, dev);
+    return container_of(arch_dev, struct pci_dev, arch);
+}
+
 static int __init dt_pci_init(void)
 {
     struct dt_device_node *np;
diff --git a/xen/include/asm-arm/pci.h b/xen/include/asm-arm/pci.h
index 2d4610a23a25..e1aa05190bda 100644
--- a/xen/include/asm-arm/pci.h
+++ b/xen/include/asm-arm/pci.h
@@ -27,6 +27,13 @@ struct arch_pci_dev {
     struct device dev;
 };
 
+/*
+ * Because of the header cross-dependencies, e.g. we need both
+ * struct pci_dev and struct arch_pci_dev at the same time, this cannot be
+ * done with an inline here. Macro can be implemented, but looks scary.
+ */
+struct pci_dev *dev_to_pci(struct device *dev);
+
 /* Arch-specific MSI data for vPCI. */
 struct vpci_arch_msi {
 };
-- 
2.25.1