6 files changed, 96 insertions, 7 deletions

diff --git a/arch/x86_64/mm/numa.c b/arch/x86_64/mm/numa.c
index 51548947ad3b..30bf8043984d 100644
--- a/arch/x86_64/mm/numa.c
+++ b/arch/x86_64/mm/numa.c
@@ -484,6 +484,7 @@ out:
                                                 nodes[i].end >> PAGE_SHIFT);
                 setup_node_bootmem(i, nodes[i].start, nodes[i].end);
         }
+        acpi_fake_nodes(nodes, num_nodes);
         numa_init_array();
         return 0;
 }
diff --git a/arch/x86_64/mm/srat.c b/arch/x86_64/mm/srat.c
index 0e0725db20b7..7ac8ff333e84 100644
--- a/arch/x86_64/mm/srat.c
+++ b/arch/x86_64/mm/srat.c
@@ -350,7 +350,7 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
 
 /* Sanity check to catch more bad SRATs (they are amazingly common).
    Make sure the PXMs cover all memory. */
-static int nodes_cover_memory(void)
+static int __init nodes_cover_memory(const struct bootnode *nodes)
 {
         int i;
         unsigned long pxmram, e820ram;
@@ -406,7 +406,7 @@ int __init acpi_scan_nodes(unsigned long start, unsigned long end)
                 }
         }
 
-        if (!nodes_cover_memory()) {
+        if (!nodes_cover_memory(nodes)) {
                 bad_srat();
                 return -1;
         }
@@ -440,6 +440,75 @@ int __init acpi_scan_nodes(unsigned long start, unsigned long end)
         return 0;
 }
 
+#ifdef CONFIG_NUMA_EMU
+static int __init find_node_by_addr(unsigned long addr)
+{
+        int ret = NUMA_NO_NODE;
+        int i;
+
+        for_each_node_mask(i, nodes_parsed) {
+                /*
+                 * Find the real node that this emulated node appears on.  For
+                 * the sake of simplicity, we only use a real node's starting
+                 * address to determine which emulated node it appears on.
+                 */
+                if (addr >= nodes[i].start && addr < nodes[i].end) {
+                        ret = i;
+                        break;
+                }
+        }
+        return i;
+}
+
+/*
+ * In NUMA emulation, we need to setup proximity domain (_PXM) to node ID
+ * mappings that respect the real ACPI topology but reflect our emulated
+ * environment.  For each emulated node, we find which real node it appears on
+ * and create PXM to NID mappings for those fake nodes which mirror that
+ * locality.  SLIT will now represent the correct distances between emulated
+ * nodes as a result of the real topology.
+ */
+void __init acpi_fake_nodes(const struct bootnode *fake_nodes, int num_nodes)
+{
+        int i;
+        int fake_node_to_pxm_map[MAX_NUMNODES] = {
+                [0 ... MAX_NUMNODES-1] = PXM_INVAL
+        };
+
+        printk(KERN_INFO "Faking PXM affinity for fake nodes on real "
+                         "topology.\n");
+        for (i = 0; i < num_nodes; i++) {
+                int nid, pxm;
+
+                nid = find_node_by_addr(fake_nodes[i].start);
+                if (nid == NUMA_NO_NODE)
+                        continue;
+                pxm = node_to_pxm(nid);
+                if (pxm == PXM_INVAL)
+                        continue;
+                fake_node_to_pxm_map[i] = pxm;
+        }
+        for (i = 0; i < num_nodes; i++)
+                __acpi_map_pxm_to_node(fake_node_to_pxm_map[i], i);
+
+        nodes_clear(nodes_parsed);
+        for (i = 0; i < num_nodes; i++)
+                if (fake_nodes[i].start != fake_nodes[i].end)
+                        node_set(i, nodes_parsed);
+        WARN_ON(!nodes_cover_memory(fake_nodes));
+}
+
+static int null_slit_node_compare(int a, int b)
+{
+        return node_to_pxm(a) == node_to_pxm(b);
+}
+#else
+static int null_slit_node_compare(int a, int b)
+{
+        return a == b;
+}
+#endif /* CONFIG_NUMA_EMU */
+
 void __init srat_reserve_add_area(int nodeid)
 {
         if (found_add_area && nodes_add[nodeid].end) {
@@ -464,7 +533,8 @@ int __node_distance(int a, int b)
         int index;
 
         if (!acpi_slit)
-                return a == b ? LOCAL_DISTANCE : REMOTE_DISTANCE;
+                return null_slit_node_compare(a, b) ? LOCAL_DISTANCE :
+                                                      REMOTE_DISTANCE;
         index = acpi_slit->locality_count * node_to_pxm(a);
         return acpi_slit->entry[index + node_to_pxm(b)];
 }
diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c
index 6c44b522f4d3..ab04d848b19d 100644
--- a/drivers/acpi/numa.c
+++ b/drivers/acpi/numa.c
@@ -36,8 +36,6 @@
 ACPI_MODULE_NAME("numa");
 
 static nodemask_t nodes_found_map = NODE_MASK_NONE;
-#define PXM_INVAL       -1
-#define NID_INVAL       -1
 
 /* maps to convert between proximity domain and logical node ID */
 static int __cpuinitdata pxm_to_node_map[MAX_PXM_DOMAINS]
@@ -59,6 +57,12 @@ int node_to_pxm(int node)
         return node_to_pxm_map[node];
 }
 
+void __acpi_map_pxm_to_node(int pxm, int node)
+{
+        pxm_to_node_map[pxm] = node;
+        node_to_pxm_map[node] = pxm;
+}
+
 int acpi_map_pxm_to_node(int pxm)
 {
         int node = pxm_to_node_map[pxm];
@@ -67,8 +71,7 @@ int acpi_map_pxm_to_node(int pxm)
                 if (nodes_weight(nodes_found_map) >= MAX_NUMNODES)
                         return NID_INVAL;
                 node = first_unset_node(nodes_found_map);
-                pxm_to_node_map[pxm] = node;
-                node_to_pxm_map[node] = pxm;
+                __acpi_map_pxm_to_node(pxm, node);
                 node_set(node, nodes_found_map);
         }
 
diff --git a/include/acpi/acpi_numa.h b/include/acpi/acpi_numa.h
index e2fcee2b340d..62c5ee4311da 100644
--- a/include/acpi/acpi_numa.h
+++ b/include/acpi/acpi_numa.h
@@ -13,6 +13,7 @@
 
 extern int pxm_to_node(int);
 extern int node_to_pxm(int);
+extern void __acpi_map_pxm_to_node(int, int);
 extern int acpi_map_pxm_to_node(int);
 extern void __cpuinit acpi_unmap_pxm_to_node(int);
 
diff --git a/include/asm-x86_64/acpi.h b/include/asm-x86_64/acpi.h
index a29f05087a31..1da8f49c0fe2 100644
--- a/include/asm-x86_64/acpi.h
+++ b/include/asm-x86_64/acpi.h
@@ -29,6 +29,7 @@
 #ifdef __KERNEL__
 
 #include <acpi/pdc_intel.h>
+#include <asm/numa.h>
 
 #define COMPILER_DEPENDENT_INT64   long long
 #define COMPILER_DEPENDENT_UINT64  unsigned long long
@@ -141,6 +142,16 @@ extern int acpi_pci_disabled;
 extern int acpi_skip_timer_override;
 extern int acpi_use_timer_override;
 
+#ifdef CONFIG_ACPI_NUMA
+extern void __init acpi_fake_nodes(const struct bootnode *fake_nodes,
+                                   int num_nodes);
+#else
+static inline void acpi_fake_nodes(const struct bootnode *fake_nodes,
+                                   int num_nodes)
+{
+}
+#endif
+
 #endif /*__KERNEL__*/
 
 #endif /*_ASM_ACPI_H*/
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index e88b62e6b3aa..d5680cd7746a 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -231,6 +231,9 @@ extern int acpi_paddr_to_node(u64 start_addr, u64 size);
 
 extern int pnpacpi_disabled;
 
+#define PXM_INVAL       (-1)
+#define NID_INVAL       (-1)
+
 #else   /* CONFIG_ACPI */
 
 static inline int acpi_boot_init(void)