[PATCH v6 5/7] xen/arm: do not map IRQs and memory for disabled devices

[Oleksandr Andrushchenko <andr2000@gmail.com>]

From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>

Currently Xen maps all IRQs and memory ranges for all devices except
those marked for passthrough, e.g. it doesn't pay attention to the
"status" property of the node.

According to the device tree specification [1]:
 - "okay"     Indicates the device is operational.
 - "disabled" Indicates that the device is not presently operational,
              but it might become operational in the future (for example,
	      something is not plugged in, or switched off).
	      Refer to the device binding for details on what disabled means
	      for a given device.

So, "disabled" status is device dependent and mapping should be taken by
case-by-case approach with that respect. Although in general Xen should map
IRQs and memory ranges as the disabled devices might become operational it
makes it impossible for the other devices, which are not operational in
any case, to skip the mappings.

This patch disables mapping for the devices with status = "disabled".

[1] https://github.com/devicetree-org/devicetree-specification/releases/download/v0.3/devicetree-specification-v0.3.pdf

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>

---
New in v6
---
 xen/arch/arm/domain_build.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index c7d992456ca7..d3a4c0a173b8 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1837,7 +1837,8 @@ static int __init handle_device(struct domain *d, struct dt_device_node *dev,
     unsigned int i;
     int res;
     u64 addr, size;
-    bool own_device = !dt_device_for_passthrough(dev);
+    bool own_device = !dt_device_for_passthrough(dev) &&
+                      dt_device_is_available(dev);
     /*
      * For PCI passthrough we only need to remap to Dom0 the interrupts
      * and memory ranges from "reg" property which cover controller's
-- 
2.25.1