srat, x86: add support for nodes spanning other nodes

For example, If the physical address layout on a two node system with 8 GB
memory is something like:
node 0: 0-2GB, 4-6GB
node 1: 2-4GB, 6-8GB

Current kernels fail to boot/detect this NUMA topology.

ACPI SRAT tables can expose such a topology which needs to be supported.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 11 insertions, 5 deletions

diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
index 2ea56f48f29b..cb3170186355 100644
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -60,7 +60,7 @@ unsigned long __initdata nodemap_size;
  * -1 if node overlap or lost ram (shift too big)
  */
 static int __init populate_memnodemap(const struct bootnode *nodes,
-                                      int numnodes, int shift)
+                                      int numnodes, int shift, int *nodeids)
 {
         unsigned long addr, end;
         int i, res = -1;
@@ -76,7 +76,12 @@ static int __init populate_memnodemap(const struct bootnode *nodes,
                 do {
                         if (memnodemap[addr >> shift] != NUMA_NO_NODE)
                                 return -1;
-                        memnodemap[addr >> shift] = i;
+
+                        if (!nodeids)
+                                memnodemap[addr >> shift] = i;
+                        else
+                                memnodemap[addr >> shift] = nodeids[i];
+
                         addr += (1UL << shift);
                 } while (addr < end);
                 res = 1;
@@ -139,7 +144,8 @@ static int __init extract_lsb_from_nodes(const struct bootnode *nodes,
         return i;
 }
 
-int __init compute_hash_shift(struct bootnode *nodes, int numnodes)
+int __init compute_hash_shift(struct bootnode *nodes, int numnodes,
+                              int *nodeids)
 {
         int shift;
 
@@ -149,7 +155,7 @@ int __init compute_hash_shift(struct bootnode *nodes, int numnodes)
         printk(KERN_DEBUG "NUMA: Using %d for the hash shift.\n",
                 shift);
 
-        if (populate_memnodemap(nodes, numnodes, shift) != 1) {
+        if (populate_memnodemap(nodes, numnodes, shift, nodeids) != 1) {
                 printk(KERN_INFO "Your memory is not aligned you need to "
                        "rebuild your kernel with a bigger NODEMAPSIZE "
                        "shift=%d\n", shift);
@@ -462,7 +468,7 @@ done:
                 }
         }
 out:
-        memnode_shift = compute_hash_shift(nodes, num_nodes);
+        memnode_shift = compute_hash_shift(nodes, num_nodes, NULL);
         if (memnode_shift < 0) {
                 memnode_shift = 0;
                 printk(KERN_ERR "No NUMA hash function found.  NUMA emulation "