[PATCH 17/21] MIPS memblock: Alter high memory freeing method

[Serge Semin]

Memblock regions are used to find all available high memory
and to set it free into buddy allocator.

Signed-off-by: Serge Semin <fancer.lan...@gmail.com>
---
 arch/mips/mm/init.c | 54 ++++++++++++++---------------------
 1 file changed, 21 insertions(+), 33 deletions(-)

diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 6f186c7..98680fb 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -404,32 +404,6 @@ void maar_init(void)
 }
 
 #ifndef CONFIG_NEED_MULTIPLE_NODES
-int page_is_ram(unsigned long pagenr)
-{
-       int i;
-
-       for (i = 0; i < boot_mem_map.nr_map; i++) {
-               unsigned long addr, end;
-
-               switch (boot_mem_map.map[i].type) {
-               case BOOT_MEM_RAM:
-               case BOOT_MEM_INIT_RAM:
-                       break;
-               default:
-                       /* not usable memory */
-                       continue;
-               }
-
-               addr = PFN_UP(boot_mem_map.map[i].addr);
-               end = PFN_DOWN(boot_mem_map.map[i].addr +
-                              boot_mem_map.map[i].size);
-
-               if (pagenr >= addr && pagenr < end)
-                       return 1;
-       }
-
-       return 0;
-}
 
 void __init paging_init(void)
 {
@@ -458,18 +432,32 @@ static struct kcore_list kcore_kseg0;
 static inline void mem_init_free_highmem(void)
 {
 #ifdef CONFIG_HIGHMEM
-       unsigned long tmp;
+       struct memblock_region *reg;
+       unsigned long pfn;
 
        if (cpu_has_dc_aliases)
                return;
 
-       for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
-               struct page *page = pfn_to_page(tmp);
+       /* Walk through all memory regions freeing highmem pages only */
+       for_each_memblock(memory, reg) {
+               unsigned long start = memblock_region_memory_base_pfn(reg);
+               unsigned long end = memblock_region_memory_end_pfn(reg);
+
+               /* Ignore complete lowmem entries */
+               if (end <= max_low_pfn)
+                       continue;
 
-               if (!page_is_ram(tmp))
-                       SetPageReserved(page);
-               else
-                       free_highmem_page(page);
+               /* Truncate partial highmem entries */
+               if (start < max_low_pfn)
+                       start = max_low_pfn;
+
+               /*
+                * MIPS memblock allocator doesn't allocate regions from high
+                * memory (see mips_lowmem_limit variable initialization), so
+                * just set corresponding pages free
+                */
+               for (pfn = start; pfn < end; pfn++)
+                       free_highmem_page(pfn_to_page(pfn));
        }
 #endif
 }
-- 
2.6.6