[PATCH V3 09/10] xen/arm: check "xen,static-mem" property during domain construction

[Penny Zheng <penny.zheng@arm.com>]

This commit checks "xen,static-mem" device tree property in /domUx node,
to determine whether domain is on Static Allocation, when constructing
domain during boot-up.

Right now, the implementation of allocate_static_memory is missing, and
will be introduced later. It just BUG() out at the moment.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
---
v3 change:
- parse "xen,static-mem" in way of phandle back to property
- The return for dt_property_read_u32() shall be checked.
- "memory" property shall be mandatory
---
 xen/arch/arm/domain_build.c | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 6c86d52781..cdb16f2086 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -2425,6 +2425,37 @@ static int __init construct_domU(struct domain *d,
     struct kernel_info kinfo = {};
     int rc;
     u64 mem;
+    const struct dt_property *static_mem_prop;
+    u32 static_mem_addr_cells, static_mem_size_cells;
+    bool static_mem = false;
+
+    /*
+     * Guest RAM could be static memory which will be specified through
+     * "xen,static-mem" property.
+     */
+    static_mem_prop = dt_find_property(node, "xen,static-mem", NULL);
+    if ( static_mem_prop )
+    {
+        static_mem = true;
+
+        if ( !dt_property_read_u32(node, "#xen,static-mem-address-cells",
+                                   &static_mem_addr_cells) )
+        {
+            printk("Error building DomU: cannot read "
+                   "\"#xen,static-mem-address-cells\" property\n");
+            return -EINVAL;
+        }
+
+        if ( !dt_property_read_u32(node, "#xen,static-mem-size-cells",
+                                   &static_mem_size_cells) )
+        {
+            printk("Error building DomU: cannot read "
+                   "\"#xen,static-mem-size-cells\" property\n");
+            return -EINVAL;
+        }
+
+        BUG_ON(static_mem_size_cells > 2 || static_mem_addr_cells > 2);
+    }
 
     rc = dt_property_read_u64(node, "memory", &mem);
     if ( !rc )
@@ -2452,7 +2483,11 @@ static int __init construct_domU(struct domain *d,
     /* type must be set before allocate memory */
     d->arch.type = kinfo.type;
 #endif
-    allocate_memory(d, &kinfo);
+    if ( !static_mem )
+        allocate_memory(d, &kinfo);
+    else
+        /* TODO: allocate_static_memory(...). */
+        BUG();
 
     rc = prepare_dtb_domU(d, &kinfo);
     if ( rc < 0 )
-- 
2.25.1