[PATCH v3 17/52] xen/arm: do not give memory back to static heap

[Penny Zheng <Penny.Zheng@xxxxxxx>]

If Xenheap is statically configured in Device Tree, its size is
definite. So, we shall not give memory back into static heap, like
we normally do in free_init_memory, etc, once it finishes initialization.

We extract static_heap flag from init data bootinfo, as we also need it
after we destroy init data section. we introduce a new helper
xen_is_using_staticheap to tell whether Xenheap is statically configured in
Device Tree. It is always returning false when !CONFIG_STATIC_MEMORY,
since static heap depends on static memory feature.

Signed-off-by: Penny Zheng <penny.zheng@xxxxxxx>
Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
---
v3:
- new commit
---
 xen/arch/arm/bootfdt.c           |  2 +-
 xen/arch/arm/include/asm/setup.h |  8 +++++++-
 xen/arch/arm/kernel.c            |  3 ++-
 xen/arch/arm/mm.c                |  8 ++++++--
 xen/arch/arm/mmu/setup.c         |  4 ++--
 xen/arch/arm/setup.c             | 29 +++++++++++++++++------------
 6 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/xen/arch/arm/bootfdt.c b/xen/arch/arm/bootfdt.c
index 2673ad17a1..c4497e3b31 100644
--- a/xen/arch/arm/bootfdt.c
+++ b/xen/arch/arm/bootfdt.c
@@ -341,7 +341,7 @@ static int __init process_chosen_node(const void *fdt, int 
node,
         if ( rc )
             return rc;
 
-        bootinfo.static_heap = true;
+        static_heap = true;
     }
 
     printk("Checking for initrd in /chosen\n");
diff --git a/xen/arch/arm/include/asm/setup.h b/xen/arch/arm/include/asm/setup.h
index 0922549631..d691f6bf93 100644
--- a/xen/arch/arm/include/asm/setup.h
+++ b/xen/arch/arm/include/asm/setup.h
@@ -104,9 +104,15 @@ struct bootinfo {
 #ifdef CONFIG_ACPI
     struct meminfo acpi;
 #endif
-    bool static_heap;
 };
 
+extern bool static_heap;
+#ifdef CONFIG_STATIC_MEMORY
+#define xen_is_using_staticheap() (static_heap)
+#else
+#define xen_is_using_staticheap() (false)
+#endif
+
 struct map_range_data
 {
     struct domain *d;
diff --git a/xen/arch/arm/kernel.c b/xen/arch/arm/kernel.c
index 2e64612ab3..d13ef0330b 100644
--- a/xen/arch/arm/kernel.c
+++ b/xen/arch/arm/kernel.c
@@ -246,7 +246,8 @@ static __init int kernel_decompress(struct bootmodule *mod, 
uint32_t offset)
      * Free the original kernel, update the pointers to the
      * decompressed kernel
      */
-    fw_unreserved_regions(addr, addr + size, init_domheap_pages, 0);
+    if ( !xen_is_using_staticheap() )
+        fw_unreserved_regions(addr, addr + size, init_domheap_pages, 0);
 
     return 0;
 }
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index e665d1f97a..4b174f4d08 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -177,8 +177,12 @@ void free_init_memory(void)
     if ( rc )
         panic("Unable to remove the init section (rc = %d)\n", rc);
 
-    init_domheap_pages(pa, pa + len);
-    printk("Freed %ldkB init memory.\n", (long)(__init_end-__init_begin)>>10);
+    if ( !xen_is_using_staticheap() )
+    {
+        init_domheap_pages(pa, pa + len);
+        printk("Freed %ldkB init memory.\n",
+               (long)(__init_end-__init_begin)>>10);
+    }
 }
 
 void arch_dump_shared_mem_info(void)
diff --git a/xen/arch/arm/mmu/setup.c b/xen/arch/arm/mmu/setup.c
index a7590a2443..cf7018b190 100644
--- a/xen/arch/arm/mmu/setup.c
+++ b/xen/arch/arm/mmu/setup.c
@@ -196,7 +196,7 @@ void __init setup_mm(void)
 
     total_pages = ram_size >> PAGE_SHIFT;
 
-    if ( bootinfo.static_heap )
+    if ( xen_is_using_staticheap() )
     {
         for ( i = 0 ; i < bootinfo.reserved_mem.nr_banks; i++ )
         {
@@ -241,7 +241,7 @@ void __init setup_mm(void)
 
     do
     {
-        e = bootinfo.static_heap ?
+        e = xen_is_using_staticheap() ?
             fit_xenheap_in_static_heap(pfn_to_paddr(xenheap_pages), MB(32)) :
             consider_modules(ram_start, ram_end,
                              pfn_to_paddr(xenheap_pages),
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 34923d9984..6f8dd98d6b 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -59,6 +59,8 @@ bool __read_mostly acpi_disabled;
 
 domid_t __read_mostly max_init_domid;
 
+bool __read_mostly static_heap;
+
 static __used void init_done(void)
 {
     int rc;
@@ -508,22 +510,25 @@ void __init discard_initial_modules(void)
     struct bootmodules *mi = &bootinfo.modules;
     int i;
 
-    for ( i = 0; i < mi->nr_mods; i++ )
+    if ( !xen_is_using_staticheap() )
     {
-        paddr_t s = mi->module[i].start;
-        paddr_t e = s + PAGE_ALIGN(mi->module[i].size);
+        for ( i = 0; i < mi->nr_mods; i++ )
+        {
+            paddr_t s = mi->module[i].start;
+            paddr_t e = s + PAGE_ALIGN(mi->module[i].size);
 
-        if ( mi->module[i].kind == BOOTMOD_XEN )
-            continue;
+            if ( mi->module[i].kind == BOOTMOD_XEN )
+                continue;
 
-        if ( !mfn_valid(maddr_to_mfn(s)) ||
-             !mfn_valid(maddr_to_mfn(e)) )
-            continue;
+            if ( !mfn_valid(maddr_to_mfn(s)) ||
+                 !mfn_valid(maddr_to_mfn(e)) )
+                continue;
 
-        fw_unreserved_regions(s, e, init_domheap_pages, 0);
-    }
+            fw_unreserved_regions(s, e, init_domheap_pages, 0);
+        }
 
-    mi->nr_mods = 0;
+        mi->nr_mods = 0;
+    }
 
     remove_early_mappings();
 }
@@ -660,7 +665,7 @@ void __init populate_boot_allocator(void)
     const struct meminfo *banks = &bootinfo.mem;
     paddr_t s, e;
 
-    if ( bootinfo.static_heap )
+    if ( xen_is_using_staticheap() )
     {
         for ( i = 0 ; i < bootinfo.reserved_mem.nr_banks; i++ )
         {
-- 
2.25.1