1 files changed, 253 insertions, 57 deletions

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index dc704da363eb..cf4bffba6f7c 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -268,6 +268,144 @@ static unsigned long __devinit read_n_cells(int n, const unsigned int **buf)
         return result;
 }
 
+struct of_drconf_cell {
+        u64     base_addr;
+        u32     drc_index;
+        u32     reserved;
+        u32     aa_index;
+        u32     flags;
+};
+
+#define DRCONF_MEM_ASSIGNED     0x00000008
+#define DRCONF_MEM_AI_INVALID   0x00000040
+#define DRCONF_MEM_RESERVED     0x00000080
+
+/*
+ * Read the next lmb list entry from the ibm,dynamic-memory property
+ * and return the information in the provided of_drconf_cell structure.
+ */
+static void read_drconf_cell(struct of_drconf_cell *drmem, const u32 **cellp)
+{
+        const u32 *cp;
+
+        drmem->base_addr = read_n_cells(n_mem_addr_cells, cellp);
+
+        cp = *cellp;
+        drmem->drc_index = cp[0];
+        drmem->reserved = cp[1];
+        drmem->aa_index = cp[2];
+        drmem->flags = cp[3];
+
+        *cellp = cp + 4;
+}
+
+/*
+ * Retreive and validate the ibm,dynamic-memory property of the device tree.
+ *
+ * The layout of the ibm,dynamic-memory property is a number N of lmb
+ * list entries followed by N lmb list entries.  Each lmb list entry
+ * contains information as layed out in the of_drconf_cell struct above.
+ */
+static int of_get_drconf_memory(struct device_node *memory, const u32 **dm)
+{
+        const u32 *prop;
+        u32 len, entries;
+
+        prop = of_get_property(memory, "ibm,dynamic-memory", &len);
+        if (!prop || len < sizeof(unsigned int))
+                return 0;
+
+        entries = *prop++;
+
+        /* Now that we know the number of entries, revalidate the size
+         * of the property read in to ensure we have everything
+         */
+        if (len < (entries * (n_mem_addr_cells + 4) + 1) * sizeof(unsigned int))
+                return 0;
+
+        *dm = prop;
+        return entries;
+}
+
+/*
+ * Retreive and validate the ibm,lmb-size property for drconf memory
+ * from the device tree.
+ */
+static u64 of_get_lmb_size(struct device_node *memory)
+{
+        const u32 *prop;
+        u32 len;
+
+        prop = of_get_property(memory, "ibm,lmb-size", &len);
+        if (!prop || len < sizeof(unsigned int))
+                return 0;
+
+        return read_n_cells(n_mem_size_cells, &prop);
+}
+
+struct assoc_arrays {
+        u32     n_arrays;
+        u32     array_sz;
+        const u32 *arrays;
+};
+
+/*
+ * Retreive and validate the list of associativity arrays for drconf
+ * memory from the ibm,associativity-lookup-arrays property of the
+ * device tree..
+ *
+ * The layout of the ibm,associativity-lookup-arrays property is a number N
+ * indicating the number of associativity arrays, followed by a number M
+ * indicating the size of each associativity array, followed by a list
+ * of N associativity arrays.
+ */
+static int of_get_assoc_arrays(struct device_node *memory,
+                               struct assoc_arrays *aa)
+{
+        const u32 *prop;
+        u32 len;
+
+        prop = of_get_property(memory, "ibm,associativity-lookup-arrays", &len);
+        if (!prop || len < 2 * sizeof(unsigned int))
+                return -1;
+
+        aa->n_arrays = *prop++;
+        aa->array_sz = *prop++;
+
+        /* Now that we know the number of arrrays and size of each array,
+         * revalidate the size of the property read in.
+         */
+        if (len < (aa->n_arrays * aa->array_sz + 2) * sizeof(unsigned int))
+                return -1;
+
+        aa->arrays = prop;
+        return 0;
+}
+
+/*
+ * This is like of_node_to_nid_single() for memory represented in the
+ * ibm,dynamic-reconfiguration-memory node.
+ */
+static int of_drconf_to_nid_single(struct of_drconf_cell *drmem,
+                                   struct assoc_arrays *aa)
+{
+        int default_nid = 0;
+        int nid = default_nid;
+        int index;
+
+        if (min_common_depth > 0 && min_common_depth <= aa->array_sz &&
+            !(drmem->flags & DRCONF_MEM_AI_INVALID) &&
+            drmem->aa_index < aa->n_arrays) {
+                index = drmem->aa_index * aa->array_sz + min_common_depth - 1;
+                nid = aa->arrays[index];
+
+                if (nid == 0xffff || nid >= MAX_NUMNODES)
+                        nid = default_nid;
+        }
+
+        return nid;
+}
+
 /*
  * Figure out to which domain a cpu belongs and stick it there.
  * Return the id of the domain used.
@@ -355,57 +493,50 @@ static unsigned long __init numa_enforce_memory_limit(unsigned long start,
  */
 static void __init parse_drconf_memory(struct device_node *memory)
 {
-        const unsigned int *lm, *dm, *aa;
-        unsigned int ls, ld, la;
-        unsigned int n, aam, aalen;
-        unsigned long lmb_size, size, start;
-        int nid, default_nid = 0;
-        unsigned int ai, flags;
-
-        lm = of_get_property(memory, "ibm,lmb-size", &ls);
-        dm = of_get_property(memory, "ibm,dynamic-memory", &ld);
-        aa = of_get_property(memory, "ibm,associativity-lookup-arrays", &la);
-        if (!lm || !dm || !aa ||
-            ls < sizeof(unsigned int) || ld < sizeof(unsigned int) ||
-            la < 2 * sizeof(unsigned int))
+        const u32 *dm;
+        unsigned int n, rc;
+        unsigned long lmb_size, size;
+        int nid;
+        struct assoc_arrays aa;
+
+        n = of_get_drconf_memory(memory, &dm);
+        if (!n)
+                return;
+
+        lmb_size = of_get_lmb_size(memory);
+        if (!lmb_size)
                 return;
 
-        lmb_size = read_n_cells(n_mem_size_cells, &lm);
-        n = *dm++;              /* number of LMBs */
-        aam = *aa++;            /* number of associativity lists */
-        aalen = *aa++;          /* length of each associativity list */
-        if (ld < (n * (n_mem_addr_cells + 4) + 1) * sizeof(unsigned int) ||
-            la < (aam * aalen + 2) * sizeof(unsigned int))
+        rc = of_get_assoc_arrays(memory, &aa);
+        if (rc)
                 return;
 
         for (; n != 0; --n) {
-                start = read_n_cells(n_mem_addr_cells, &dm);
-                ai = dm[2];
-                flags = dm[3];
-                dm += 4;
-                /* 0x80 == reserved, 0x8 = assigned to us */
-                if ((flags & 0x80) || !(flags & 0x8))
+                struct of_drconf_cell drmem;
+
+                read_drconf_cell(&drmem, &dm);
+
+                /* skip this block if the reserved bit is set in flags (0x80)
+                   or if the block is not assigned to this partition (0x8) */
+                if ((drmem.flags & DRCONF_MEM_RESERVED)
+                    || !(drmem.flags & DRCONF_MEM_ASSIGNED))
                         continue;
-                nid = default_nid;
-                /* flags & 0x40 means associativity index is invalid */
-                if (min_common_depth > 0 && min_common_depth <= aalen &&
-                    (flags & 0x40) == 0 && ai < aam) {
-                        /* this is like of_node_to_nid_single */
-                        nid = aa[ai * aalen + min_common_depth - 1];
-                        if (nid == 0xffff || nid >= MAX_NUMNODES)
-                                nid = default_nid;
-                }
 
-                fake_numa_create_new_node(((start + lmb_size) >> PAGE_SHIFT),
-                                                &nid);
+                nid = of_drconf_to_nid_single(&drmem, &aa);
+
+                fake_numa_create_new_node(
+                                ((drmem.base_addr + lmb_size) >> PAGE_SHIFT),
+                                           &nid);
+
                 node_set_online(nid);
 
-                size = numa_enforce_memory_limit(start, lmb_size);
+                size = numa_enforce_memory_limit(drmem.base_addr, lmb_size);
                 if (!size)
                         continue;
 
-                add_active_range(nid, start >> PAGE_SHIFT,
-                                 (start >> PAGE_SHIFT) + (size >> PAGE_SHIFT));
+                add_active_range(nid, drmem.base_addr >> PAGE_SHIFT,
+                                 (drmem.base_addr >> PAGE_SHIFT)
+                                 + (size >> PAGE_SHIFT));
         }
 }
 
@@ -770,6 +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.
@@ -777,12 +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;
@@ -801,13 +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 */
@@ -815,14 +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 */