powerpc/pseries: Update numa association of hotplug memory add for drconf memory

Update the association of a memory section with a numa node that
occurs during hotplug add of a memory section.  This adds a check in
the hot_add_scn_to_nid() routine for the
ibm,dynamic-reconfiguration-memory node in the device tree.  If
present the new hot_add_drconf_scn_to_nid() routine is invoked, which
can properly parse the ibm,dynamic-reconfiguration-memory node of the
device tree and make the proper numa node associations.

This also introduces the valid_hot_add_scn() routine as a helper
function for code that is common to the hot_add_scn_to_nid() and
hot_add_drconf_scn_to_nid() routines.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 83 insertions, 18 deletions

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 39328da32edf..cf4bffba6f7c 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -901,6 +901,79 @@ early_param("numa", early_numa);
 
 #ifdef CONFIG_MEMORY_HOTPLUG
 /*
+ * Validate the node associated with the memory section we are
+ * trying to add.
+ */
+int valid_hot_add_scn(int *nid, unsigned long start, u32 lmb_size,
+                      unsigned long scn_addr)
+{
+        nodemask_t nodes;
+
+        if (*nid < 0 || !node_online(*nid))
+                *nid = any_online_node(NODE_MASK_ALL);
+
+        if ((scn_addr >= start) && (scn_addr < (start + lmb_size))) {
+                nodes_setall(nodes);
+                while (NODE_DATA(*nid)->node_spanned_pages == 0) {
+                        node_clear(*nid, nodes);
+                        *nid = any_online_node(nodes);
+                }
+
+                return 1;
+        }
+
+        return 0;
+}
+
+/*
+ * Find the node associated with a hot added memory section represented
+ * by the ibm,dynamic-reconfiguration-memory node.
+ */
+static int hot_add_drconf_scn_to_nid(struct device_node *memory,
+                                     unsigned long scn_addr)
+{
+        const u32 *dm;
+        unsigned int n, rc;
+        unsigned long lmb_size;
+        int default_nid = any_online_node(NODE_MASK_ALL);
+        int nid;
+        struct assoc_arrays aa;
+
+        n = of_get_drconf_memory(memory, &dm);
+        if (!n)
+                return default_nid;;
+
+        lmb_size = of_get_lmb_size(memory);
+        if (!lmb_size)
+                return default_nid;
+
+        rc = of_get_assoc_arrays(memory, &aa);
+        if (rc)
+                return default_nid;
+
+        for (; n != 0; --n) {
+                struct of_drconf_cell drmem;
+
+                read_drconf_cell(&drmem, &dm);
+
+                /* skip this block if it is reserved or not assigned to
+                 * this partition */
+                if ((drmem.flags & DRCONF_MEM_RESERVED)
+                    || !(drmem.flags & DRCONF_MEM_ASSIGNED))
+                        continue;
+
+                nid = of_drconf_to_nid_single(&drmem, &aa);
+
+                if (valid_hot_add_scn(&nid, drmem.base_addr, lmb_size,
+                                      scn_addr))
+                        return nid;
+        }
+
+        BUG();  /* section address should be found above */
+        return 0;
+}
+
+/*
  * Find the node associated with a hot added memory section.  Section
  * corresponds to a SPARSEMEM section, not an LMB.  It is assumed that
  * sections are fully contained within a single LMB.
@@ -908,12 +981,17 @@ early_param("numa", early_numa);
 int hot_add_scn_to_nid(unsigned long scn_addr)
 {
         struct device_node *memory = NULL;
-        nodemask_t nodes;
-        int default_nid = any_online_node(NODE_MASK_ALL);
         int nid;
 
         if (!numa_enabled || (min_common_depth < 0))
-                return default_nid;
+                return any_online_node(NODE_MASK_ALL);
+
+        memory = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+        if (memory) {
+                nid = hot_add_drconf_scn_to_nid(memory, scn_addr);
+                of_node_put(memory);
+                return nid;
+        }
 
         while ((memory = of_find_node_by_type(memory, "memory")) != NULL) {
                 unsigned long start, size;
@@ -932,13 +1010,9 @@ ha_new_range:
                 size = read_n_cells(n_mem_size_cells, &memcell_buf);
                 nid = of_node_to_nid_single(memory);
 
-                /* Domains not present at boot default to 0 */
-                if (nid < 0 || !node_online(nid))
-                        nid = default_nid;
-
-                if ((scn_addr >= start) && (scn_addr < (start + size))) {
+                if (valid_hot_add_scn(&nid, start, size, scn_addr)) {
                         of_node_put(memory);
-                        goto got_nid;
+                        return nid;
                 }
 
                 if (--ranges)           /* process all ranges in cell */
@@ -946,14 +1020,5 @@ ha_new_range:
         }
         BUG();  /* section address should be found above */
         return 0;
-
-        /* Temporary code to ensure that returned node is not empty */
-got_nid:
-        nodes_setall(nodes);
-        while (NODE_DATA(nid)->node_spanned_pages == 0) {
-                node_clear(nid, nodes);
-                nid = any_online_node(nodes);
-        }
-        return nid;
 }
 #endif /* CONFIG_MEMORY_HOTPLUG */