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   1 /*
   2  * mm_init.c - Memory initialisation verification and debugging
   3  *
   4  * Copyright 2008 IBM Corporation, 2008
   5  * Author Mel Gorman <mel@csn.ul.ie>
   6  *
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/init.h>
  10 #include "internal.h"
  11
  12 int __meminitdata mminit_loglevel;
  13
  14 void __init mminit_verify_pageflags_layout(void)
  15 {
  16         int shift, width;
  17         unsigned long or_mask, add_mask;
  18
  19         shift = 8 * sizeof(unsigned long);
  20         width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH;
  21         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
  22                 "Section %d Node %d Zone %d Flags %d\n",
  23                 SECTIONS_WIDTH,
  24                 NODES_WIDTH,
  25                 ZONES_WIDTH,
  26                 NR_PAGEFLAGS);
  27         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
  28                 "Section %d Node %d Zone %d\n",
  29 #ifdef SECTIONS_SHIFT
  30                 SECTIONS_SHIFT,
  31 #else
  32                 0,
  33 #endif
  34                 NODES_SHIFT,
  35                 ZONES_SHIFT);
  36         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_offsets",
  37                 "Section %lu Node %lu Zone %lu\n",
  38                 (unsigned long)SECTIONS_PGSHIFT,
  39                 (unsigned long)NODES_PGSHIFT,
  40                 (unsigned long)ZONES_PGSHIFT);
  41         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_zoneid",
  42                 "Zone ID: %lu -> %lu\n",
  43                 (unsigned long)ZONEID_PGOFF,
  44                 (unsigned long)(ZONEID_PGOFF + ZONEID_SHIFT));
  45         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_usage",
  46                 "location: %d -> %d unused %d -> %d flags %d -> %d\n",
  47                 shift, width, width, NR_PAGEFLAGS, NR_PAGEFLAGS, 0);
  48 #ifdef NODE_NOT_IN_PAGE_FLAGS
  49         mminit_dprintk(MMINIT_TRACE, "pageflags_layout_nodeflags",
  50                 "Node not in page flags");
  51 #endif
  52
  53         if (SECTIONS_WIDTH) {
  54                 shift -= SECTIONS_WIDTH;
  55                 BUG_ON(shift != SECTIONS_PGSHIFT);
  56         }
  57         if (NODES_WIDTH) {
  58                 shift -= NODES_WIDTH;
  59                 BUG_ON(shift != NODES_PGSHIFT);
  60         }
  61         if (ZONES_WIDTH) {
  62                 shift -= ZONES_WIDTH;
  63                 BUG_ON(shift != ZONES_PGSHIFT);
  64         }
  65
  66         /* Check for bitmask overlaps */
  67         or_mask = (ZONES_MASK << ZONES_PGSHIFT) |
  68                         (NODES_MASK << NODES_PGSHIFT) |
  69                         (SECTIONS_MASK << SECTIONS_PGSHIFT);
  70         add_mask = (ZONES_MASK << ZONES_PGSHIFT) +
  71                         (NODES_MASK << NODES_PGSHIFT) +
  72                         (SECTIONS_MASK << SECTIONS_PGSHIFT);
  73         BUG_ON(or_mask != add_mask);
  74 }
  75
  76 void __meminit mminit_verify_page_links(struct page *page, enum zone_type zone,
  77                         unsigned long nid, unsigned long pfn)
  78 {
  79         BUG_ON(page_to_nid(page) != nid);
  80         BUG_ON(page_zonenum(page) != zone);
  81         BUG_ON(page_to_pfn(page) != pfn);
  82 }
  83
  84 static __init int set_mminit_loglevel(char *str)
  85 {
  86         get_option(&str, &mminit_loglevel);
  87         return 0;
  88 }
  89 early_param("mminit_loglevel", set_mminit_loglevel);