mm: allow reserve_bootmem() cross nodes

split reserve_bootmem_core() into two functions, one which checks
conflicts, and one which sets the bits.

and make reserve_bootmem to loop bdata_list to cross the nodes.

user could be crashkernel and ramdisk..., in case the range provided
by those externalities crosses the nodes.

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

diff --git a/mm/bootmem.c b/mm/bootmem.c
index 0f30bc8..b679164 100644 (file)
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -111,44 +111,74 @@ static unsigned long __init init_bootmem_core(pg_data_t *pgdat,
  * might be used for boot-time allocations - or it might get added
  * to the free page pool later on.
  */
-static int __init reserve_bootmem_core(bootmem_data_t *bdata,
+static int __init can_reserve_bootmem_core(bootmem_data_t *bdata,
                        unsigned long addr, unsigned long size, int flags)
 {
        unsigned long sidx, eidx;
        unsigned long i;
-       int ret;
+
+       BUG_ON(!size);
+
+       /* out of range, don't hold other */
+       if (addr + size < bdata->node_boot_start ||
+               PFN_DOWN(addr) > bdata->node_low_pfn)
+               return 0;
 
        /*
-        * round up, partially reserved pages are considered
-        * fully reserved.
+        * Round up to index to the range.
         */
+       if (addr > bdata->node_boot_start)
+               sidx= PFN_DOWN(addr - bdata->node_boot_start);
+       else
+               sidx = 0;
+
+       eidx = PFN_UP(addr + size - bdata->node_boot_start);
+       if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
+               eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
+
+       for (i = sidx; i < eidx; i++) {
+               if (test_bit(i, bdata->node_bootmem_map)) {
+                       if (flags & BOOTMEM_EXCLUSIVE)
+                               return -EBUSY;
+               }
+       }
+
+       return 0;
+
+}
+
+static void __init reserve_bootmem_core(bootmem_data_t *bdata,
+                       unsigned long addr, unsigned long size, int flags)
+{
+       unsigned long sidx, eidx;
+       unsigned long i;
+
        BUG_ON(!size);
-       BUG_ON(PFN_DOWN(addr) >= bdata->node_low_pfn);
-       BUG_ON(PFN_UP(addr + size) > bdata->node_low_pfn);
-       BUG_ON(addr < bdata->node_boot_start);
 
-       sidx = PFN_DOWN(addr - bdata->node_boot_start);
+       /* out of range */
+       if (addr + size < bdata->node_boot_start ||
+               PFN_DOWN(addr) > bdata->node_low_pfn)
+               return;
+
+       /*
+        * Round up to index to the range.
+        */
+       if (addr > bdata->node_boot_start)
+               sidx= PFN_DOWN(addr - bdata->node_boot_start);
+       else
+               sidx = 0;
+
        eidx = PFN_UP(addr + size - bdata->node_boot_start);
+       if (eidx > bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start))
+               eidx = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start);
 
-       for (i = sidx; i < eidx; i++)
+       for (i = sidx; i < eidx; i++) {
                if (test_and_set_bit(i, bdata->node_bootmem_map)) {
 #ifdef CONFIG_DEBUG_BOOTMEM
                        printk("hm, page %08lx reserved twice.\n", i*PAGE_SIZE);
 #endif
-                       if (flags & BOOTMEM_EXCLUSIVE) {
-                               ret = -EBUSY;
-                               goto err;
-                       }
                }
-
-       return 0;
-
-err:
-       /* unreserve memory we accidentally reserved */
-       for (i--; i >= sidx; i--)
-               clear_bit(i, bdata->node_bootmem_map);
-
-       return ret;
+       }
 }
 
 static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr,
@@ -415,6 +445,11 @@ unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn,
 void __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
                                 unsigned long size, int flags)
 {
+       int ret;
+
+       ret = can_reserve_bootmem_core(pgdat->bdata, physaddr, size, flags);
+       if (ret < 0)
+               return;
        reserve_bootmem_core(pgdat->bdata, physaddr, size, flags);
 }
 
@@ -440,7 +475,18 @@ unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
 int __init reserve_bootmem(unsigned long addr, unsigned long size,
                            int flags)
 {
-       return reserve_bootmem_core(NODE_DATA(0)->bdata, addr, size, flags);
+       bootmem_data_t *bdata;
+       int ret;
+
+       list_for_each_entry(bdata, &bdata_list, list) {
+               ret = can_reserve_bootmem_core(bdata, addr, size, flags);
+               if (ret < 0)
+                       return ret;
+       }
+       list_for_each_entry(bdata, &bdata_list, list)
+               reserve_bootmem_core(bdata, addr, size, flags);
+
+       return 0;
 }
 #endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */