[IA64] Cleanup use of various #defines related to nodes

Some of the SN code & #defines related to compact nodes & IO discovery
have gotten stale over the years. This patch attempts to clean them up.
Some of the various SN MAX_xxx #defines were also unclear & misused.

The primary changes are:

	- use MAX_NUMNODES. This is the generic linux #define for the number
	  of nodes that are known to the generic kernel. Arrays & loops
	  for constructs that are 1:1 with linux-defined nodes should
	  use the linux #define - not an SN equivalent.

	- use MAX_COMPACT_NODES for MAX_NUMNODES + NUM_TIOS. This is the
	  number of nodes in the SSI system. Compact nodes are a hack to
	  get around the IA64 architectural limit of 256 nodes. Large SGI
	  systems have more than 256 nodes. When we upgrade to ACPI3.0,
	  I _hope_ that all nodes will be real nodes that are known to
	  the generic kernel. That will allow us to delete the notion
	  of "compact nodes".

	- add MAX_NUMALINK_NODES for the total number of nodes that
	  are in the numalink domain - all partitions.

	- simplified (understandable) scan_for_ionodes()

	- small amount of cleanup related to cnodes

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 26 insertions, 10 deletions

diff --git a/include/asm-ia64/sn/arch.h b/include/asm-ia64/sn/arch.h
index ab827d298569..8fce5a6db951 100644
--- a/include/asm-ia64/sn/arch.h
+++ b/include/asm-ia64/sn/arch.h
@@ -18,6 +18,32 @@
 #include <asm/sn/sn_cpuid.h>
 
 /*
+ * This is the maximum number of NUMALINK nodes that can be part of a single
+ * SSI kernel. This number includes C-brick, M-bricks, and TIOs. Nodes in
+ * remote partitions are NOT included in this number.
+ * The number of compact nodes cannot exceed size of a coherency domain.
+ * The purpose of this define is to specify a node count that includes
+ * all C/M/TIO nodes in an SSI system.
+ *
+ * SGI system can currently support up to 256 C/M nodes plus additional TIO nodes.
+ *
+ *      Note: ACPI20 has an architectural limit of 256 nodes. When we upgrade
+ *      to ACPI3.0, this limit will be removed. The notion of "compact nodes"
+ *      should be deleted and TIOs should be included in MAX_NUMNODES.
+ */
+#define MAX_COMPACT_NODES       512
+
+/*
+ * Maximum number of nodes in all partitions and in all coherency domains.
+ * This is the total number of nodes accessible in the numalink fabric. It
+ * includes all C & M bricks, plus all TIOs.
+ *
+ * This value is also the value of the maximum number of NASIDs in the numalink
+ * fabric.
+ */
+#define MAX_NUMALINK_NODES      2048
+
+/*
  * The following defines attributes of the HUB chip. These attributes are
  * frequently referenced. They are kept in the per-cpu data areas of each cpu.
  * They are kept together in a struct to minimize cache misses.
@@ -41,15 +67,6 @@ DECLARE_PER_CPU(struct sn_hub_info_s, __sn_hub_info);
 
 
 /*
- * This is the maximum number of nodes that can be part of a kernel.
- * Effectively, it's the maximum number of compact node ids (cnodeid_t).
- * This is not necessarily the same as MAX_NASIDS.
- */
-#define MAX_COMPACT_NODES       2048
-#define CPUS_PER_NODE           4
-
-
-/*
  * Compact node ID to nasid mappings kept in the per-cpu data areas of each
  * cpu.
  */
@@ -57,7 +74,6 @@ DECLARE_PER_CPU(short, __sn_cnodeid_to_nasid[MAX_NUMNODES]);
 #define sn_cnodeid_to_nasid     (&__get_cpu_var(__sn_cnodeid_to_nasid[0]))
 
 
-
 extern u8 sn_partition_id;
 extern u8 sn_system_size;
 extern u8 sn_sharing_domain_size;