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>

1 files changed, 69 insertions, 23 deletions

diff --git a/mm/bootmem.c b/mm/bootmem.c
index 0f30bc873ecc..b6791646143e 100644
--- 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 */