sparc64: Setup sysfs to mark LDOM sockets, cores and threads correctly

commit 5f4826a362405748bbf73957027b77993e61e1af
Author: chris hyser <chris.hyser@oracle.com>
Date:   Tue Apr 21 10:31:38 2015 -0400

    sparc64: Setup sysfs to mark LDOM sockets, cores and threads correctly

    The current sparc kernel has no representation for sockets though tools
    like lscpu can pull this from sysfs. This patch walks the machine
    description cache and socket hierarchy and marks sockets as well as cores
    and threads such that a representative sysfs is created by
    drivers/base/topology.c.

    Before this patch:
        $ lscpu
        Architecture:          sparc64
        CPU op-mode(s):        32-bit, 64-bit
        Byte Order:            Big Endian
        CPU(s):                1024
        On-line CPU(s) list:   0-1023
        Thread(s) per core:    8
        Core(s) per socket:    1     <--- wrong
        Socket(s):             128   <--- wrong
        NUMA node(s):          4
        NUMA node0 CPU(s):     0-255
        NUMA node1 CPU(s):     256-511
        NUMA node2 CPU(s):     512-767
        NUMA node3 CPU(s):     768-1023

        After this patch:
        $ lscpu
        Architecture:          sparc64
        CPU op-mode(s):        32-bit, 64-bit
        Byte Order:            Big Endian
        CPU(s):                1024
        On-line CPU(s) list:   0-1023
        Thread(s) per core:    8
        Core(s) per socket:    32
        Socket(s):             4
        NUMA node(s):          4
        NUMA node0 CPU(s):     0-255
        NUMA node1 CPU(s):     256-511
        NUMA node2 CPU(s):     512-767
        NUMA node3 CPU(s):     768-1023

    Most of this patch was done by Chris with updates by David.

    Signed-off-by: Chris Hyser <chris.hyser@oracle.com>
    Signed-off-by: David Ahern <david.ahern@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit acc455cffa75070d55e74fc7802b49edbc080e92)

Conflicts:
	arch/sparc/include/asm/cpudata_64.h
	arch/sparc/kernel/mdesc.c
	arch/sparc/kernel/smp_64.c
Signed-off-by: Allen Pais <allen.pais@oracle.com>
(cherry picked from commit bd1039234cf41d0afd35f8e9a302eac9c344d18d)

diff --git a/arch/sparc/kernel/mdesc.c b/arch/sparc/kernel/mdesc.c
index eca49856ae49b1a4ddab4d6e11b00059275df060..fdf011d907776e4cab771576ab2b9b8ab5f66501 100644 (file)
--- a/arch/sparc/kernel/mdesc.c
+++ b/arch/sparc/kernel/mdesc.c
@@ -759,28 +759,66 @@ static void set_sock_ids(struct mdesc_handle *hp)
 
 static void __cpuinit set_sock_ids(struct mdesc_handle *hp)
 {
-       int idx;
        u64 mp;
+       int idx = 1;
+       int fnd = 0;
 
-       idx = 1;
-
-       /*
-        * identify unique sockets by looking for cpus backpointed to by
-        * level 3 caches
+       /* Identify unique sockets by looking for cpus backpointed to by
+        * shared level n caches.
         */
        mdesc_for_each_node_by_name(hp, mp, "cache") {
-               const u64 *level;
+               const u64 *cur_lvl;
 
-               level = mdesc_get_property(hp, mp, "level", NULL);
-               if (*level != 3)
+               cur_lvl = mdesc_get_property(hp, mp, "level", NULL);
+               if (*cur_lvl != level)
                        continue;
 
                mark_sock_ids(hp, mp, idx);
+               idx++;
+               fnd = 1;
+       }
+       return fnd;
+}
 
+static void set_sock_ids_by_socket(struct mdesc_handle *hp, u64 mp)
+{
+       int idx = 1;
+
+       mdesc_for_each_node_by_name(hp, mp, "socket") {
+               u64 a;
+
+               mdesc_for_each_arc(a, hp, mp, MDESC_ARC_TYPE_FWD) {
+                       u64 t = mdesc_arc_target(hp, a);
+                       const char *name;
+                       const u64 *id;
+
+                       name = mdesc_node_name(hp, t);
+                       if (strcmp(name, "cpu"))
+                               continue;
+
+                       id = mdesc_get_property(hp, t, "id", NULL);
+                       if (*id < num_possible_cpus())
+                               cpu_data(*id).sock_id = idx;
+               }
                idx++;
        }
 }
 
+static void set_sock_ids(struct mdesc_handle *hp)
+{
+       u64 mp;
+
+       /* If machine description exposes sockets data use it.
+        * Otherwise fallback to use shared L3 or L2 caches.
+        */
+       mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "sockets");
+       if (mp != MDESC_NODE_NULL)
+               return set_sock_ids_by_socket(hp, mp);
+
+       if (!set_sock_ids_by_cache(hp, 3))
+               set_sock_ids_by_cache(hp, 2);
+}
+
 static void mark_proc_ids(struct mdesc_handle *hp, u64 mp, int proc_id)
 {
        u64 a;