1 files changed, 253 insertions, 57 deletions

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index dc704da363e..cf4bffba6f7 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 */