x86/platform/UV: Fix incorrect nodes and pnodes for cpuless and memoryless nodes

This patch fixes the problem of incorrect nodes and pnodes being returned
when referring to nodes that either have no cpus (AKA "headless") or no
memory.

Tested-by: John Estabrook <[email protected]>
Tested-by: Gary Kroening <[email protected]>
Tested-by: Nathan Zimmer <[email protected]>
Signed-off-by: Dimitri Sivanich <[email protected]>
Signed-off-by: Mike Travis <[email protected]>
Cc: Andrew Banman <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Russ Anderson <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Author: Dimitri Sivanich

arch/x86/kernel/apic/x2apic_uv_x.c

@@ -1232,8 +1232,7 @@ static void __init decode_uv_systab(void)
  */
 static __init void boot_init_possible_blades(struct uv_hub_info_s *hub_info)
 {
-	size_t bytes;
-	int blade, i, j, uv_pb = 0, num_nodes = num_possible_nodes();
+	int i, uv_pb = 0;
 
 	pr_info("UV: NODE_PRESENT_DEPTH = %d\n", UVH_NODE_PRESENT_TABLE_DEPTH);
 	for (i = 0; i < UVH_NODE_PRESENT_TABLE_DEPTH; i++) {
@@ -1247,28 +1246,6 @@ static __init void boot_init_possible_blades(struct uv_hub_info_s *hub_info)
 	}
 	if (uv_possible_blades != uv_pb)
 		uv_possible_blades = uv_pb;
-
-	bytes = num_nodes * sizeof(_node_to_pnode[0]);
-	_node_to_pnode = kmalloc(bytes, GFP_KERNEL);
-	BUG_ON(!_node_to_pnode);
-
-	for (blade = 0, i = 0; i < UVH_NODE_PRESENT_TABLE_DEPTH; i++) {
-		unsigned short pnode;
-		unsigned long present =
-			uv_read_local_mmr(UVH_NODE_PRESENT_TABLE + i * 8);
-
-		for (j = 0; j < 64; j++) {
-			if (!test_bit(j, &present))
-				continue;
-			pnode = (i * 64 + j) & hub_info->pnode_mask;
-			_node_to_pnode[blade++] = pnode;
-		}
-		if (blade > num_nodes) {
-			pr_err("UV: blade count(%d) exceeds node count(%d)!\n",
-				blade, num_nodes);
-			BUG();
-		}
-	}
 }
 
 static void __init build_socket_tables(void)
@@ -1449,7 +1426,6 @@ void __init uv_system_init(void)
 	bytes = sizeof(struct uv_hub_info_s);
 	for_each_node(nodeid) {
 		struct uv_hub_info_s *new_hub;
-		unsigned short pnode;
 
 		if (__uv_hub_info_list[nodeid]) {
 			pr_err("UV: Node %d UV HUB already initialized!?\n",
@@ -1467,10 +1443,11 @@ void __init uv_system_init(void)
 		BUG_ON(!new_hub);
 		*new_hub = hub_info;
 
-		pnode = _node_to_pnode[nodeid];
-		min_pnode = min(pnode, min_pnode);
-		max_pnode = max(pnode, max_pnode);
-		new_hub->pnode = pnode;
+		/* Use information from GAM table if available */
+		if (_node_to_pnode)
+			new_hub->pnode = _node_to_pnode[nodeid];
+		else	/* Fill in during cpu loop */
+			new_hub->pnode = 0xffff;
 		new_hub->numa_blade_id = uv_node_to_blade_id(nodeid);
 		new_hub->memory_nid = -1;
 		new_hub->nr_possible_cpus = 0;
@@ -1480,18 +1457,39 @@ void __init uv_system_init(void)
 	/* Initialize per cpu info */
 	for_each_possible_cpu(cpu) {
 		int apicid = per_cpu(x86_cpu_to_apicid, cpu);
+		int numa_node_id;
+		unsigned short pnode;
 
 		nodeid = cpu_to_node(cpu);
+		numa_node_id = numa_cpu_node(cpu);
+		pnode = uv_apicid_to_pnode(apicid);
+
 		uv_cpu_info_per(cpu)->p_uv_hub_info = uv_hub_info_list(nodeid);
 		uv_cpu_info_per(cpu)->blade_cpu_id =
 			uv_cpu_hub_info(cpu)->nr_possible_cpus++;
 		if (uv_cpu_hub_info(cpu)->memory_nid == -1)
 			uv_cpu_hub_info(cpu)->memory_nid = cpu_to_node(cpu);
+		if (nodeid != numa_node_id &&	/* init memoryless node */
+		    uv_hub_info_list(numa_node_id)->pnode == 0xffff)
+			uv_hub_info_list(numa_node_id)->pnode = pnode;
+		else if (uv_cpu_hub_info(cpu)->pnode == 0xffff)
+			uv_cpu_hub_info(cpu)->pnode = pnode;
 		uv_cpu_scir_info(cpu)->offset = uv_scir_offset(apicid);
 	}
 
-	/* Display per node info */
 	for_each_node(nodeid) {
+		unsigned short pnode = uv_hub_info_list(nodeid)->pnode;
+
+		/* Add pnode info for pre-GAM list nodes without cpus */
+		if (pnode == 0xffff) {
+			unsigned long paddr;
+
+			paddr = node_start_pfn(nodeid) << PAGE_SHIFT;
+			pnode = uv_gpa_to_pnode(uv_soc_phys_ram_to_gpa(paddr));
+			uv_hub_info_list(nodeid)->pnode = pnode;
+		}
+		min_pnode = min(pnode, min_pnode);
+		max_pnode = max(pnode, max_pnode);
 		pr_info("UV: UVHUB node:%2d pn:%02x nrcpus:%d\n",
 			nodeid,
 			uv_hub_info_list(nodeid)->pnode,