s390/topology: delay initialization of topology cpu masks

There is no reason to initialize the topology cpu masks already while
setup_arch() is being called. It is sufficient to initialize the masks
before the scheduler becomes SMP aware.
Therefore a pre-SMP initcall aka early_initcall is suffucient.

This also allows to convert the cpu_topology array into a per cpu
variable with a later patch. Without this patch this wouldn't be
possible since the per cpu memory areas are not allocated while setup_arch
is executed.

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

2 files changed, 47 insertions, 54 deletions

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index bfac77ada4f2..a5ea8bc17cb3 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -909,7 +909,6 @@ void __init setup_arch(char **cmdline_p)
         setup_lowcore();
         smp_fill_possible_mask();
         cpu_init();
-        s390_init_cpu_topology();
 
         /*
          * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index 24ee33f1af24..d2303f6340ab 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -7,14 +7,14 @@
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/workqueue.h>
-#include <linux/bootmem.h>
 #include <linux/cpuset.h>
 #include <linux/device.h>
 #include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
-#include <linux/init.h>
 #include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/slab.h>
 #include <linux/cpu.h>
 #include <linux/smp.h>
 #include <linux/mm.h>
@@ -334,50 +334,6 @@ void topology_expect_change(void)
         set_topology_timer();
 }
 
-static int __init early_parse_topology(char *p)
-{
-        if (strncmp(p, "off", 3))
-                return 0;
-        topology_enabled = 0;
-        return 0;
-}
-early_param("topology", early_parse_topology);
-
-static void __init alloc_masks(struct sysinfo_15_1_x *info,
-                               struct mask_info *mask, int offset)
-{
-        int i, nr_masks;
-
-        nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
-        for (i = 0; i < info->mnest - offset; i++)
-                nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
-        nr_masks = max(nr_masks, 1);
-        for (i = 0; i < nr_masks; i++) {
-                mask->next = alloc_bootmem_align(
-                        roundup_pow_of_two(sizeof(struct mask_info)),
-                        roundup_pow_of_two(sizeof(struct mask_info)));
-                mask = mask->next;
-        }
-}
-
-void __init s390_init_cpu_topology(void)
-{
-        struct sysinfo_15_1_x *info;
-        int i;
-
-        if (!MACHINE_HAS_TOPOLOGY)
-                return;
-        tl_info = alloc_bootmem_pages(PAGE_SIZE);
-        info = tl_info;
-        store_topology(info);
-        pr_info("The CPU configuration topology of the machine is:");
-        for (i = 0; i < TOPOLOGY_NR_MAG; i++)
-                printk(KERN_CONT " %d", info->mag[i]);
-        printk(KERN_CONT " / %d\n", info->mnest);
-        alloc_masks(info, &socket_info, 1);
-        alloc_masks(info, &book_info, 2);
-}
-
 static int cpu_management;
 
 static ssize_t dispatching_show(struct device *dev,
@@ -481,6 +437,15 @@ static const struct cpumask *cpu_book_mask(int cpu)
         return &cpu_topology[cpu].book_mask;
 }
 
+static int __init early_parse_topology(char *p)
+{
+        if (strncmp(p, "off", 3))
+                return 0;
+        topology_enabled = 0;
+        return 0;
+}
+early_param("topology", early_parse_topology);
+
 static struct sched_domain_topology_level s390_topology[] = {
         { cpu_thread_mask, cpu_smt_flags, SD_INIT_NAME(SMT) },
         { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) },
@@ -489,6 +454,42 @@ static struct sched_domain_topology_level s390_topology[] = {
         { NULL, },
 };
 
+static void __init alloc_masks(struct sysinfo_15_1_x *info,
+                               struct mask_info *mask, int offset)
+{
+        int i, nr_masks;
+
+        nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
+        for (i = 0; i < info->mnest - offset; i++)
+                nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
+        nr_masks = max(nr_masks, 1);
+        for (i = 0; i < nr_masks; i++) {
+                mask->next = kzalloc(sizeof(*mask->next), GFP_KERNEL);
+                mask = mask->next;
+        }
+}
+
+static int __init s390_topology_init(void)
+{
+        struct sysinfo_15_1_x *info;
+        int i;
+
+        if (!MACHINE_HAS_TOPOLOGY)
+                return 0;
+        tl_info = (struct sysinfo_15_1_x *)__get_free_page(GFP_KERNEL);
+        info = tl_info;
+        store_topology(info);
+        pr_info("The CPU configuration topology of the machine is:");
+        for (i = 0; i < TOPOLOGY_NR_MAG; i++)
+                printk(KERN_CONT " %d", info->mag[i]);
+        printk(KERN_CONT " / %d\n", info->mnest);
+        alloc_masks(info, &socket_info, 1);
+        alloc_masks(info, &book_info, 2);
+        set_sched_topology(s390_topology);
+        return 0;
+}
+early_initcall(s390_topology_init);
+
 static int __init topology_init(void)
 {
         if (MACHINE_HAS_TOPOLOGY)
@@ -498,10 +499,3 @@ static int __init topology_init(void)
         return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
 }
 device_initcall(topology_init);
-
-static int __init early_topology_init(void)
-{
-        set_sched_topology(s390_topology);
-        return 0;
-}
-early_initcall(early_topology_init);