bootmem: free/reserve helpers
Johannes Weiner [Thu, 24 Jul 2008 04:28:05 +0000 (21:28 -0700)]
Factor out the common operation of marking a range on the bitmap.

[akpm@linux-foundation.org: fix various warnings]
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/bootmem.c

index 94ea612..9d03ff6 100644 (file)
@@ -225,6 +225,44 @@ unsigned long __init free_all_bootmem(void)
        return free_all_bootmem_core(NODE_DATA(0)->bdata);
 }
 
+static void __init __free(bootmem_data_t *bdata,
+                       unsigned long sidx, unsigned long eidx)
+{
+       unsigned long idx;
+
+       bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data,
+               sidx + PFN_DOWN(bdata->node_boot_start),
+               eidx + PFN_DOWN(bdata->node_boot_start));
+
+       for (idx = sidx; idx < eidx; idx++)
+               if (!test_and_clear_bit(idx, bdata->node_bootmem_map))
+                       BUG();
+}
+
+static int __init __reserve(bootmem_data_t *bdata, unsigned long sidx,
+                       unsigned long eidx, int flags)
+{
+       unsigned long idx;
+       int exclusive = flags & BOOTMEM_EXCLUSIVE;
+
+       bdebug("nid=%td start=%lx end=%lx flags=%x\n",
+               bdata - bootmem_node_data,
+               sidx + PFN_DOWN(bdata->node_boot_start),
+               eidx + PFN_DOWN(bdata->node_boot_start),
+               flags);
+
+       for (idx = sidx; idx < eidx; idx++)
+               if (test_and_set_bit(idx, bdata->node_bootmem_map)) {
+                       if (exclusive) {
+                               __free(bdata, sidx, idx);
+                               return -EBUSY;
+                       }
+                       bdebug("silent double reserve of PFN %lx\n",
+                               idx + PFN_DOWN(bdata->node_boot_start));
+               }
+       return 0;
+}
+
 static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
                                     unsigned long size)
 {
@@ -258,14 +296,7 @@ static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
        if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
                eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
 
-       bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data,
-               sidx + PFN_DOWN(bdata->node_boot_start),
-               eidx + PFN_DOWN(bdata->node_boot_start));
-
-       for (i = sidx; i < eidx; i++) {
-               if (unlikely(!test_and_clear_bit(i, bdata->node_bootmem_map)))
-                       BUG();
-       }
+       __free(bdata, sidx, eidx);
 }
 
 /**
@@ -367,16 +398,7 @@ static void __init reserve_bootmem_core(bootmem_data_t *bdata,
        if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
                eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
 
-       bdebug("nid=%td start=%lx end=%lx flags=%x\n",
-               bdata - bootmem_node_data,
-               sidx + PFN_DOWN(bdata->node_boot_start),
-               eidx + PFN_DOWN(bdata->node_boot_start),
-               flags);
-
-       for (i = sidx; i < eidx; i++)
-               if (test_and_set_bit(i, bdata->node_bootmem_map))
-                       bdebug("hm, page %lx reserved twice.\n",
-                               PFN_DOWN(bdata->node_boot_start) + i);
+       return __reserve(bdata, sidx, eidx, flags);
 }
 
 /**
@@ -511,10 +533,9 @@ find_block:
                /*
                 * Reserve the area now:
                 */
-               for (i = PFN_DOWN(start_off) + merge;
-                               i < PFN_UP(end_off); i++)
-                       if (test_and_set_bit(i, bdata->node_bootmem_map))
-                               BUG();
+               if (__reserve(bdata, PFN_DOWN(start_off) + merge,
+                               PFN_UP(end_off), BOOTMEM_EXCLUSIVE))
+                       BUG();
 
                region = phys_to_virt(bdata->node_boot_start + start_off);
                memset(region, 0, size);