x86: replace shrink_active_range() with remove_active_range()

in case we have kva before ramdisk on a node, we still need to use
those ranges.

v2: reserve_early kva ram area, in case there are holes in highmem, to avoid
    those area could be treat as free high pages.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 49 insertions, 28 deletions

diff --git a/arch/x86/mm/discontig_32.c b/arch/x86/mm/discontig_32.c
index accc7c6c57fc..c3f119e99e0d 100644
--- a/arch/x86/mm/discontig_32.c
+++ b/arch/x86/mm/discontig_32.c
@@ -230,8 +230,8 @@ static unsigned long calculate_numa_remap_pages(void)
         unsigned long size, reserve_pages = 0;
 
         for_each_online_node(nid) {
-                u64 node_end_target;
-                u64 node_end_final;
+                u64 node_kva_target;
+                u64 node_kva_final;
 
                 /*
                  * The acpi/srat node info can show hot-add memroy zones
@@ -254,42 +254,45 @@ static unsigned long calculate_numa_remap_pages(void)
                 /* now the roundup is correct, convert to PAGE_SIZE pages */
                 size = size * PTRS_PER_PTE;
 
-                node_end_target = round_down(node_end_pfn[nid] - size,
+                node_kva_target = round_down(node_end_pfn[nid] - size,
                                                  PTRS_PER_PTE);
-                node_end_target <<= PAGE_SHIFT;
+                node_kva_target <<= PAGE_SHIFT;
                 do {
-                        node_end_final = find_e820_area(node_end_target,
+                        node_kva_final = find_e820_area(node_kva_target,
                                         ((u64)node_end_pfn[nid])<<PAGE_SHIFT,
                                                 ((u64)size)<<PAGE_SHIFT,
                                                 LARGE_PAGE_BYTES);
-                        node_end_target -= LARGE_PAGE_BYTES;
-                } while (node_end_final == -1ULL &&
-                         (node_end_target>>PAGE_SHIFT) > (node_start_pfn[nid]));
+                        node_kva_target -= LARGE_PAGE_BYTES;
+                } while (node_kva_final == -1ULL &&
+                         (node_kva_target>>PAGE_SHIFT) > (node_start_pfn[nid]));
 
-                if (node_end_final == -1ULL)
+                if (node_kva_final == -1ULL)
                         panic("Can not get kva ram\n");
 
-                printk("Reserving %ld pages of KVA for lmem_map of node %d\n",
-                                size, nid);
                 node_remap_size[nid] = size;
                 node_remap_offset[nid] = reserve_pages;
                 reserve_pages += size;
-                printk("Shrinking node %d from %ld pages to %lld pages\n",
-                        nid, node_end_pfn[nid], node_end_final>>PAGE_SHIFT);
+                printk("Reserving %ld pages of KVA for lmem_map of node %d at %llx\n",
+                                size, nid, node_kva_final>>PAGE_SHIFT);
 
                 /*
                  *  prevent kva address below max_low_pfn want it on system
                  *  with less memory later.
                  *  layout will be: KVA address , KVA RAM
+                 *
+                 *  we are supposed to only record the one less then max_low_pfn
+                 *  but we could have some hole in high memory, and it will only
+                 *  check page_is_ram(pfn) && !page_is_reserved_early(pfn) to decide
+                 *  to use it as free.
+                 *  So reserve_early here, hope we don't run out of that array
                  */
-                if ((node_end_final>>PAGE_SHIFT) < max_low_pfn)
-                        reserve_early(node_end_final,
-                                      node_end_final+(((u64)size)<<PAGE_SHIFT),
-                                      "KVA RAM");
-
-                node_end_pfn[nid] = node_end_final>>PAGE_SHIFT;
-                node_remap_start_pfn[nid] = node_end_pfn[nid];
-                shrink_active_range(nid, node_end_pfn[nid]);
+                reserve_early(node_kva_final,
+                              node_kva_final+(((u64)size)<<PAGE_SHIFT),
+                              "KVA RAM");
+
+                node_remap_start_pfn[nid] = node_kva_final>>PAGE_SHIFT;
+                remove_active_range(nid, node_remap_start_pfn[nid],
+                                         node_remap_start_pfn[nid] + size);
         }
         printk("Reserving total of %ld pages for numa KVA remap\n",
                         reserve_pages);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index ce8e397a61f6..034a3156d2f0 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -998,7 +998,8 @@ extern void free_area_init_node(int nid, pg_data_t *pgdat,
 extern void free_area_init_nodes(unsigned long *max_zone_pfn);
 extern void add_active_range(unsigned int nid, unsigned long start_pfn,
                                         unsigned long end_pfn);
-extern void shrink_active_range(unsigned int nid, unsigned long new_end_pfn);
+extern void remove_active_range(unsigned int nid, unsigned long start_pfn,
+                                        unsigned long end_pfn);
 extern void push_node_boundaries(unsigned int nid, unsigned long start_pfn,
                                         unsigned long end_pfn);
 extern void remove_all_active_ranges(void);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index eee5ba7509c1..d80e1868e570 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3552,30 +3552,47 @@ void __init add_active_range(unsigned int nid, unsigned long start_pfn,
 }
 
 /**
- * shrink_active_range - Shrink an existing registered range of PFNs
+ * remove_active_range - Shrink an existing registered range of PFNs
  * @nid: The node id the range is on that should be shrunk
- * @new_end_pfn: The new PFN of the range
+ * @start_pfn: The new PFN of the range
+ * @end_pfn: The new PFN of the range
  *
  * i386 with NUMA use alloc_remap() to store a node_mem_map on a local node.
  * The map is kept near the end physical page range that has already been
  * registered. This function allows an arch to shrink an existing registered
  * range.
  */
-void __init shrink_active_range(unsigned int nid, unsigned long new_end_pfn)
+void __init remove_active_range(unsigned int nid, unsigned long start_pfn,
+                                unsigned long end_pfn)
 {
         int i, j;
         int removed = 0;
 
+        printk(KERN_DEBUG "remove_active_range (%d, %lu, %lu)\n",
+                          nid, start_pfn, end_pfn);
+
         /* Find the old active region end and shrink */
         for_each_active_range_index_in_nid(i, nid) {
-                if (early_node_map[i].start_pfn >= new_end_pfn) {
+                if (early_node_map[i].start_pfn >= start_pfn &&
+                    early_node_map[i].end_pfn <= end_pfn) {
                         /* clear it */
+                        early_node_map[i].start_pfn = 0;
                         early_node_map[i].end_pfn = 0;
                         removed = 1;
                         continue;
                 }
-                if (early_node_map[i].end_pfn > new_end_pfn) {
-                        early_node_map[i].end_pfn = new_end_pfn;
+                if (early_node_map[i].start_pfn < start_pfn &&
+                    early_node_map[i].end_pfn > start_pfn) {
+                        unsigned long temp_end_pfn = early_node_map[i].end_pfn;
+                        early_node_map[i].end_pfn = start_pfn;
+                        if (temp_end_pfn > end_pfn)
+                                add_active_range(nid, end_pfn, temp_end_pfn);
+                        continue;
+                }
+                if (early_node_map[i].start_pfn >= start_pfn &&
+                    early_node_map[i].end_pfn > end_pfn &&
+                    early_node_map[i].start_pfn < end_pfn) {
+                        early_node_map[i].start_pfn = end_pfn;
                         continue;
                 }
         }