3 files changed, 61 insertions, 1 deletions

diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 8d3b58ebd38e..ae4c717243a5 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -68,6 +68,7 @@
 
 #define KB (1024)
 #define MB (1024*KB)
+#define GB (1024L*MB)
 
 /*
  * Note:  pte   --> Linux PTE
@@ -329,6 +330,44 @@ static int __init htab_dt_scan_page_sizes(unsigned long node,
         return 0;
 }
 
+/* Scan for 16G memory blocks that have been set aside for huge pages
+ * and reserve those blocks for 16G huge pages.
+ */
+static int __init htab_dt_scan_hugepage_blocks(unsigned long node,
+                                        const char *uname, int depth,
+                                        void *data) {
+        char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+        unsigned long *addr_prop;
+        u32 *page_count_prop;
+        unsigned int expected_pages;
+        long unsigned int phys_addr;
+        long unsigned int block_size;
+
+        /* We are scanning "memory" nodes only */
+        if (type == NULL || strcmp(type, "memory") != 0)
+                return 0;
+
+        /* This property is the log base 2 of the number of virtual pages that
+         * will represent this memory block. */
+        page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL);
+        if (page_count_prop == NULL)
+                return 0;
+        expected_pages = (1 << page_count_prop[0]);
+        addr_prop = of_get_flat_dt_prop(node, "reg", NULL);
+        if (addr_prop == NULL)
+                return 0;
+        phys_addr = addr_prop[0];
+        block_size = addr_prop[1];
+        if (block_size != (16 * GB))
+                return 0;
+        printk(KERN_INFO "Huge page(16GB) memory: "
+                        "addr = 0x%lX size = 0x%lX pages = %d\n",
+                        phys_addr, block_size, expected_pages);
+        lmb_reserve(phys_addr, block_size * expected_pages);
+        add_gpage(phys_addr, block_size, expected_pages);
+        return 0;
+}
+
 static void __init htab_init_page_sizes(void)
 {
         int rc;
@@ -418,7 +457,10 @@ static void __init htab_init_page_sizes(void)
                );
 
 #ifdef CONFIG_HUGETLB_PAGE
-        /* Init large page size. Currently, we pick 16M or 1M depending
+        /* Reserve 16G huge page memory sections for huge pages */
+        of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL);
+
+/* Init large page size. Currently, we pick 16M or 1M depending
          * on what is available
          */
         if (mmu_psize_defs[MMU_PAGE_16M].shift)
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 5df82186fc93..e2a650a9e533 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -110,6 +110,22 @@ pmd_t *hpmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long addr)
 }
 #endif
 
+/* Build list of addresses of gigantic pages.  This function is used in early
+ * boot before the buddy or bootmem allocator is setup.
+ */
+void add_gpage(unsigned long addr, unsigned long page_size,
+        unsigned long number_of_pages)
+{
+        if (!addr)
+                return;
+        while (number_of_pages > 0) {
+                gpage_freearray[nr_gpages] = addr;
+                nr_gpages++;
+                number_of_pages--;
+                addr += page_size;
+        }
+}
+
 /* Moves the gigantic page addresses from the temporary list to the
  * huge_boot_pages list.  */
 int alloc_bootmem_huge_page(struct hstate *h)
diff --git a/include/asm-powerpc/mmu-hash64.h b/include/asm-powerpc/mmu-hash64.h
index d1dc16afb118..b61181aa7746 100644
--- a/include/asm-powerpc/mmu-hash64.h
+++ b/include/asm-powerpc/mmu-hash64.h
@@ -281,6 +281,8 @@ extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
                              unsigned long pstart, unsigned long mode,
                              int psize, int ssize);
 extern void set_huge_psize(int psize);
+extern void add_gpage(unsigned long addr, unsigned long page_size,
+                          unsigned long number_of_pages);
 extern void demote_segment_4k(struct mm_struct *mm, unsigned long addr);
 
 extern void htab_initialize(void);