[PATCH v4 09/10] xen/arm: fix duplicate /reserved-memory node in Dom0

[Penny Zheng <Penny.Zheng@xxxxxxx>]

In case there is a /reserved-memory node already present in the host dtb,
current Xen codes would create yet another /reserved-memory node specially
for the static shm in Dom0 Device Tree.

Xen will use write_properties() to copy the reserved memory nodes from host dtb
to Dom0 FDT, so we want to insert the shm node along with the copying.
And avoiding duplication, we add a checking before make_resv_memory_node().

Signed-off-by: Penny Zheng <penny.zheng@xxxxxxx>

---
v3 -> v4:
new commit
---
 xen/arch/arm/domain_build.c       | 31 ++++++++++++++++++++++++++++---
 xen/arch/arm/include/asm/kernel.h |  2 ++
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 02d903be78..dad234e4b5 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1401,6 +1401,10 @@ static int __init handle_linux_pci_domain(struct 
kernel_info *kinfo,
     return fdt_property_cell(kinfo->fdt, "linux,pci-domain", segment);
 }
 
+static int __init make_shm_memory_node(const struct domain *d,
+                                       void *fdt,
+                                       int addrcells, int sizecells,
+                                       const struct kernel_info *kinfo);
 static int __init write_properties(struct domain *d, struct kernel_info *kinfo,
                                    const struct dt_device_node *node)
 {
@@ -1549,6 +1553,23 @@ static int __init write_properties(struct domain *d, 
struct kernel_info *kinfo,
         }
     }
 
+    if ( dt_node_path_is_equal(node, "/reserved-memory") )
+    {
+        kinfo->resv_mem = true;
+
+        /* shared memory provided. */
+        if ( kinfo->shminfo.nr_banks != 0 )
+        {
+            uint32_t addrcells = dt_n_addr_cells(node),
+                     sizecells = dt_n_size_cells(node);
+
+            res = make_shm_memory_node(d, kinfo->fdt,
+                                       addrcells, sizecells, kinfo);
+            if ( res )
+                return res;
+        }
+    }
+
     return 0;
 }
 
@@ -2856,9 +2877,13 @@ static int __init handle_node(struct domain *d, struct 
kernel_info *kinfo,
                 return res;
         }
 
-        res = make_resv_memory_node(d, kinfo->fdt, addrcells, sizecells, 
kinfo);
-        if ( res )
-            return res;
+        /* Avoid duplicate /reserved-memory nodes in Device Tree */
+        if ( !kinfo->resv_mem )
+        {
+            res = make_resv_memory_node(d, kinfo->fdt, addrcells, sizecells, 
kinfo);
+            if ( res )
+                return res;
+        }
     }
 
     res = fdt_end_node(kinfo->fdt);
diff --git a/xen/arch/arm/include/asm/kernel.h 
b/xen/arch/arm/include/asm/kernel.h
index 590bc56f6c..d20c8bc2a8 100644
--- a/xen/arch/arm/include/asm/kernel.h
+++ b/xen/arch/arm/include/asm/kernel.h
@@ -38,6 +38,8 @@ struct kernel_info {
     void *fdt; /* flat device tree */
     paddr_t unassigned_mem; /* RAM not (yet) assigned to a bank */
     struct meminfo mem;
+    /* Whether we have /reserved-memory node in host Device Tree */
+    bool resv_mem;
     /* Static shared memory banks */
     struct {
         unsigned int nr_banks;
-- 
2.25.1