ARM: memblock: convert free_highpages() to use memblock

Free the high pages using the memblock memory lists - and more
importantly, exclude any memblock allocations in highmem from the
free'd memory.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 39 insertions, 5 deletions

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 1b4e0abf113a..5422821d372f 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -439,13 +439,47 @@ static void __init free_unused_memmap(struct meminfo *mi)
 static void __init free_highpages(void)
 {
 #ifdef CONFIG_HIGHMEM
-        int i;
+        unsigned long max_low = max_low_pfn + PHYS_PFN_OFFSET;
+        struct memblock_region *mem, *res;
 
         /* set highmem page free */
-        for_each_bank (i, &meminfo) {
-                unsigned long start = bank_pfn_start(&meminfo.bank[i]);
-                unsigned long end = bank_pfn_end(&meminfo.bank[i]);
-                if (start >= max_low_pfn + PHYS_PFN_OFFSET)
+        for_each_memblock(memory, mem) {
+                unsigned long start = memblock_region_memory_base_pfn(mem);
+                unsigned long end = memblock_region_memory_end_pfn(mem);
+
+                /* Ignore complete lowmem entries */
+                if (end <= max_low)
+                        continue;
+
+                /* Truncate partial highmem entries */
+                if (start < max_low)
+                        start = max_low;
+
+                /* Find and exclude any reserved regions */
+                for_each_memblock(reserved, res) {
+                        unsigned long res_start, res_end;
+
+                        res_start = memblock_region_reserved_base_pfn(res);
+                        res_end = memblock_region_reserved_end_pfn(res);
+
+                        if (res_end < start)
+                                continue;
+                        if (res_start < start)
+                                res_start = start;
+                        if (res_start > end)
+                                res_start = end;
+                        if (res_end > end)
+                                res_end = end;
+                        if (res_start != start)
+                                totalhigh_pages += free_area(start, res_start,
+                                                             NULL);
+                        start = res_end;
+                        if (start == end)
+                                break;
+                }
+
+                /* And now free anything which remains */
+                if (start < end)
                         totalhigh_pages += free_area(start, end, NULL);
         }
         totalram_pages += totalhigh_pages;