1 files changed, 39 insertions, 15 deletions

diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index 5487d0b97400..8be930394750 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -30,11 +30,16 @@ static const unsigned long low_mem_start = CONFIG_LINUX_LINK_BASE;
 static unsigned long low_mem_sz;
 
 #ifdef CONFIG_HIGHMEM
-static unsigned long min_high_pfn;
+static unsigned long min_high_pfn, max_high_pfn;
 static u64 high_mem_start;
 static u64 high_mem_sz;
 #endif
 
+#ifdef CONFIG_DISCONTIGMEM
+struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
+EXPORT_SYMBOL(node_data);
+#endif
+
 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
 static int __init setup_mem_sz(char *str)
 {
@@ -109,13 +114,11 @@ void __init setup_arch_memory(void)
         /* Last usable page of low mem */
         max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
 
-#ifdef CONFIG_HIGHMEM
-        min_high_pfn = PFN_DOWN(high_mem_start);
-        max_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
+#ifdef CONFIG_FLATMEM
+        /* pfn_valid() uses this */
+        max_mapnr = max_low_pfn - min_low_pfn;
 #endif
 
-        max_mapnr = max_pfn - min_low_pfn;
-
         /*------------- bootmem allocator setup -----------------------*/
 
         /*
@@ -129,7 +132,7 @@ void __init setup_arch_memory(void)
          * the crash
          */
 
-        memblock_add(low_mem_start, low_mem_sz);
+        memblock_add_node(low_mem_start, low_mem_sz, 0);
         memblock_reserve(low_mem_start, __pa(_end) - low_mem_start);
 
 #ifdef CONFIG_BLK_DEV_INITRD
@@ -149,13 +152,6 @@ void __init setup_arch_memory(void)
         zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
         zones_holes[ZONE_NORMAL] = 0;
 
-#ifdef CONFIG_HIGHMEM
-        zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
-
-        /* This handles the peripheral address space hole */
-        zones_holes[ZONE_HIGHMEM] = min_high_pfn - max_low_pfn;
-#endif
-
         /*
          * We can't use the helper free_area_init(zones[]) because it uses
          * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
@@ -168,6 +164,34 @@ void __init setup_arch_memory(void)
                             zones_holes);       /* holes */
 
 #ifdef CONFIG_HIGHMEM
+        /*
+         * Populate a new node with highmem
+         *
+         * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
+         * than addresses in normal ala low memory (0x8000_0000 based).
+         * Even with PAE, the huge peripheral space hole would waste a lot of
+         * mem with single mem_map[]. This warrants a mem_map per region design.
+         * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
+         *
+         * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
+         * populated with normal memory zone while node 1 only has highmem
+         */
+        node_set_online(1);
+
+        min_high_pfn = PFN_DOWN(high_mem_start);
+        max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
+
+        zones_size[ZONE_NORMAL] = 0;
+        zones_holes[ZONE_NORMAL] = 0;
+
+        zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn;
+        zones_holes[ZONE_HIGHMEM] = 0;
+
+        free_area_init_node(1,                  /* node-id */
+                            zones_size,         /* num pages per zone */
+                            min_high_pfn,       /* first pfn of node */
+                            zones_holes);       /* holes */
+
         high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
         kmap_init();
 #endif
@@ -185,7 +209,7 @@ void __init mem_init(void)
         unsigned long tmp;
 
         reset_all_zones_managed_pages();
-        for (tmp = min_high_pfn; tmp < max_pfn; tmp++)
+        for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
                 free_highmem_page(pfn_to_page(tmp));
 #endif