From f6bf1a8acd2cb3a92a7b7c9ab03e56a32ac5ece5 Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Mon, 14 Nov 2011 11:19:08 +0100
Subject: [PATCH] [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>
---
 arch/s390/kernel/topology.c | 45 +++++++++++++++++++++++++++++++------
 1 file 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
 }