xen/arm: Fully initialise struct membanks_hdr fields

Commit a14593e399 ("xen/device-tree: Allow region overlapping with
/memreserve/ ranges") introduced a type in the 'struct membanks_hdr'
but forgot to update the 'struct kernel_info' initialiser, while
it doesn't lead to failures because the field is not currently
used while managing kernel_info structures, it's good to have it
for completeness.

There are other instance of structures using 'struct membanks_hdr'
that are dynamically allocated and don't fully initialise these
fields, provide a static inline helper for that.

Fixes: a14593e399 ("xen/device-tree: Allow region overlapping with /memreserve/ ranges")
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
Release-Acked-By: Oleksii Kurochko <oleksii.kurochko@gmail.com>

xen/arch/arm/domain_build.c

@@ -1039,7 +1039,7 @@ void __init allocate_memory(struct domain *d, struct kernel_info *kinfo)
      */
     if ( is_hardware_domain(d) )
     {
-        struct membanks *gnttab = xzalloc_flex_struct(struct membanks, bank, 1);
+        struct membanks *gnttab = membanks_xzalloc(1, MEMORY);
         /*
          * Exclude the following regions:
          * 1) Remove reserved memory
@@ -1057,13 +1057,10 @@ void __init allocate_memory(struct domain *d, struct kernel_info *kinfo)
         gnttab->bank[0].start = kinfo->gnttab_start;
         gnttab->bank[0].size = kinfo->gnttab_size;
 
-        hwdom_free_mem = xzalloc_flex_struct(struct membanks, bank,
-                                             NR_MEM_BANKS);
+        hwdom_free_mem = membanks_xzalloc(NR_MEM_BANKS, MEMORY);
         if ( !hwdom_free_mem )
             goto fail;
 
-        hwdom_free_mem->max_banks = NR_MEM_BANKS;
-
         if ( find_unallocated_memory(kinfo, mem_banks, ARRAY_SIZE(mem_banks),
                                      hwdom_free_mem, add_hwdom_free_regions) )
             goto fail;
@@ -1293,7 +1290,7 @@ static int __init find_host_extended_regions(const struct kernel_info *kinfo,
                                              struct membanks *ext_regions)
 {
     int res;
-    struct membanks *gnttab = xzalloc_flex_struct(struct membanks, bank, 1);
+    struct membanks *gnttab = membanks_xzalloc(1, MEMORY);
 
     /*
      * Exclude the following regions:
@@ -1374,12 +1371,10 @@ int __init make_hypervisor_node(struct domain *d,
     }
     else
     {
-        ext_regions = xzalloc_flex_struct(struct membanks, bank, NR_MEM_BANKS);
+        ext_regions = membanks_xzalloc(NR_MEM_BANKS, MEMORY);
         if ( !ext_regions )
             return -ENOMEM;
 
-        ext_regions->max_banks = NR_MEM_BANKS;
-
         if ( domain_use_host_layout(d) )
         {
             if ( !is_iommu_enabled(d) )

xen/arch/arm/include/asm/kernel.h

@@ -92,7 +92,9 @@ kernel_info_get_mem_const(const struct kernel_info *kinfo)
 }
 
 #ifdef CONFIG_STATIC_SHM
-#define KERNEL_INFO_SHM_MEM_INIT .shm_mem.common.max_banks = NR_SHMEM_BANKS,
+#define KERNEL_INFO_SHM_MEM_INIT                \
+    .shm_mem.common.max_banks = NR_SHMEM_BANKS, \
+    .shm_mem.common.type = STATIC_SHARED_MEMORY,
 #else
 #define KERNEL_INFO_SHM_MEM_INIT
 #endif
@@ -100,6 +102,7 @@ kernel_info_get_mem_const(const struct kernel_info *kinfo)
 #define KERNEL_INFO_INIT                        \
 {                                               \
     .mem.common.max_banks = NR_MEM_BANKS,       \
+    .mem.common.type = MEMORY,                  \
     KERNEL_INFO_SHM_MEM_INIT                    \
 }
 

xen/arch/arm/static-shmem.c

@@ -20,7 +20,8 @@ static struct {
     struct membanks_hdr common;
     struct membank bank[NR_SHMEM_BANKS];
 } shm_heap_banks __initdata = {
-    .common.max_banks = NR_SHMEM_BANKS
+    .common.max_banks = NR_SHMEM_BANKS,
+    .common.type = STATIC_SHARED_MEMORY
 };
 
 static inline struct membanks *get_shmem_heap_banks(void)

xen/include/xen/bootfdt.h

@@ -4,6 +4,7 @@
 #include <xen/types.h>
 #include <xen/kernel.h>
 #include <xen/macros.h>
+#include <xen/xmalloc.h>
 
 #define MIN_FDT_ALIGN 8
 
@@ -219,4 +220,19 @@ static inline struct shmem_membank_extra *bootinfo_get_shmem_extra(void)
 }
 #endif
 
+static inline struct membanks *membanks_xzalloc(unsigned int nr,
+                                                enum region_type type)
+{
+    struct membanks *banks = xzalloc_flex_struct(struct membanks, bank, nr);
+
+    if ( !banks )
+        goto out;
+
+    banks->max_banks = nr;
+    banks->type = type;
+
+ out:
+    return banks;
+}
+
 #endif /* XEN_BOOTFDT_H */