[S390] topology: fix topology on z10 machines

Make sure that all cpus in a book on a z10 appear as book siblings
and not as core siblings. This fixes some performance regressions that
appeared after the book scheduling domain got introduced.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 38 insertions, 7 deletions

diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index 77b8942b9a15..fdb5b8cb260f 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -68,8 +68,10 @@ static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
         return mask;
 }
 
-static void add_cpus_to_mask(struct topology_cpu *tl_cpu,
-                             struct mask_info *book, struct mask_info *core)
+static struct mask_info *add_cpus_to_mask(struct topology_cpu *tl_cpu,
+                                          struct mask_info *book,
+                                          struct mask_info *core,
+                                          int z10)
 {
         unsigned int cpu;
 
@@ -88,10 +90,16 @@ static void add_cpus_to_mask(struct topology_cpu *tl_cpu,
                         cpu_book_id[lcpu] = book->id;
 #endif
                         cpumask_set_cpu(lcpu, &core->mask);
-                        cpu_core_id[lcpu] = core->id;
+                        if (z10) {
+                                cpu_core_id[lcpu] = rcpu;
+                                core = core->next;
+                        } else {
+                                cpu_core_id[lcpu] = core->id;
+                        }
                         smp_cpu_polarization[lcpu] = tl_cpu->pp;
                 }
         }
+        return core;
 }
 
 static void clear_masks(void)
@@ -123,18 +131,41 @@ static void tl_to_cores(struct sysinfo_15_1_x *info)
 {
 #ifdef CONFIG_SCHED_BOOK
         struct mask_info *book = &book_info;
+        struct cpuid cpu_id;
 #else
         struct mask_info *book = NULL;
 #endif
         struct mask_info *core = &core_info;
         union topology_entry *tle, *end;
+        int z10 = 0;
 
-
+#ifdef CONFIG_SCHED_BOOK
+        get_cpu_id(&cpu_id);
+        z10 = cpu_id.machine == 0x2097 || cpu_id.machine == 0x2098;
+#endif
         spin_lock_irq(&topology_lock);
         clear_masks();
         tle = info->tle;
         end = (union topology_entry *)((unsigned long)info + info->length);
         while (tle < end) {
+#ifdef CONFIG_SCHED_BOOK
+                if (z10) {
+                        switch (tle->nl) {
+                        case 1:
+                                book = book->next;
+                                book->id = tle->container.id;
+                                break;
+                        case 0:
+                                core = add_cpus_to_mask(&tle->cpu, book, core, z10);
+                                break;
+                        default:
+                                clear_masks();
+                                goto out;
+                        }
+                        tle = next_tle(tle);
+                        continue;
+                }
+#endif
                 switch (tle->nl) {
 #ifdef CONFIG_SCHED_BOOK
                 case 2:
@@ -147,7 +178,7 @@ static void tl_to_cores(struct sysinfo_15_1_x *info)
                         core->id = tle->container.id;
                         break;
                 case 0:
-                        add_cpus_to_mask(&tle->cpu, book, core);
+                        add_cpus_to_mask(&tle->cpu, book, core, z10);
                         break;
                 default:
                         clear_masks();
@@ -328,8 +359,8 @@ void __init s390_init_cpu_topology(void)
         for (i = 0; i < TOPOLOGY_NR_MAG; i++)
                 printk(" %d", info->mag[i]);
         printk(" / %d\n", info->mnest);
-        alloc_masks(info, &core_info, 2);
+        alloc_masks(info, &core_info, 1);
 #ifdef CONFIG_SCHED_BOOK
-        alloc_masks(info, &book_info, 3);
+        alloc_masks(info, &book_info, 2);
 #endif
 }