[patch 06/10] cpu topology support for s390.

Martin Schwidefsky
2008-03-12T17:34:14Z

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From: Heiko Carstens <heiko.carstens@de.ibm.com>

Add s390 backend so we can give the scheduler some hints about the
cpu topology.

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

arch/s390/Kconfig | 4
arch/s390/defconfig | 1
arch/s390/kernel/Makefile | 2
arch/s390/kernel/setup.c | 2
arch/s390/kernel/smp.c | 4
arch/s390/kernel/topology.c | 271 ++++++++++++++++++++++++++++++++++++++++++++
drivers/s390/sysinfo.c | 2
include/asm-s390/smp.h | 2
include/asm-s390/system.h | 1
include/asm-s390/topology.h | 16 ++
10 files changed, 300 insertions(+), 5 deletions(-)

Index: quilt-2.6/arch/s390/defconfig
===================================================================
--- quilt-2.6.orig/arch/s390/defconfig
+++ quilt-2.6/arch/s390/defconfig
@@ -3,6 +3,7 @@
# Linux kernel version: 2.6.25-rc5
# Wed Mar 12 14:10:52 2008
#
+CONFIG_SCHED_MC=y
CONFIG_MMU=y
CONFIG_ZONE_DMA=y
CONFIG_LOCKDEP_SUPPORT=y
Index: quilt-2.6/arch/s390/Kconfig
===================================================================
--- quilt-2.6.orig/arch/s390/Kconfig
+++ quilt-2.6/arch/s390/Kconfig
@@ -3,6 +3,10 @@
# see Documentation/kbuild/kconfig-language.txt.
#

+config SCHED_MC
+ def_bool y
+ depends on SMP
+
config MMU
def_bool y

Index: quilt-2.6/arch/s390/kernel/Makefile
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/Makefile
+++ quilt-2.6/arch/s390/kernel/Makefile
@@ -19,7 +19,7 @@ obj-y += $(if $(CONFIG_64BIT),reipl64.o,
extra-y += head.o init_task.o vmlinux.lds

obj-$(CONFIG_MODULES) += s390_ksyms.o module.o
-obj-$(CONFIG_SMP) += smp.o
+obj-$(CONFIG_SMP) += smp.o topology.o

obj-$(CONFIG_AUDIT) += audit.o
compat-obj-$(CONFIG_AUDIT) += compat_audit.o
Index: quilt-2.6/arch/s390/kernel/setup.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/setup.c
+++ quilt-2.6/arch/s390/kernel/setup.c
@@ -39,6 +39,7 @@
#include <linux/pfn.h>
#include <linux/ctype.h>
#include <linux/reboot.h>
+#include <linux/topology.h>

#include <asm/ipl.h>
#include <asm/uaccess.h>
@@ -830,6 +831,7 @@ setup_arch(char **cmdline_p)

cpu_init();
__cpu_logical_map[0] = S390_lowcore.cpu_data.cpu_addr;
+ s390_init_cpu_topology();

/*
* Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
Index: quilt-2.6/arch/s390/kernel/smp.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/smp.c
+++ quilt-2.6/arch/s390/kernel/smp.c
@@ -67,9 +67,7 @@ enum s390_cpu_state {
CPU_STATE_CONFIGURED,
};

-#ifdef CONFIG_HOTPLUG_CPU
-static DEFINE_MUTEX(smp_cpu_state_mutex);
-#endif
+DEFINE_MUTEX(smp_cpu_state_mutex);
static int smp_cpu_state[NR_CPUS];

static DEFINE_PER_CPU(struct cpu, cpu_devices);
Index: quilt-2.6/arch/s390/kernel/topology.c
===================================================================
--- /dev/null
+++ quilt-2.6/arch/s390/kernel/topology.c
@@ -0,0 +1,271 @@
+/*
+ * arch/s390/kernel/topology.c
+ *
+ * Copyright IBM Corp. 2007
+ * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/bootmem.h>
+#include <linux/sched.h>
+#include <linux/workqueue.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <asm/delay.h>
+#include <asm/s390_ext.h>
+
+#define CPU_BITS 64
+
+struct tl_cpu {
+ unsigned char reserved[6];
+ unsigned short origin;
+ unsigned long mask[CPU_BITS / BITS_PER_LONG];
+};
+
+struct tl_container {
+ unsigned char reserved[8];
+};
+
+union tl_entry {
+ unsigned char nl;
+ struct tl_cpu cpu;
+ struct tl_container container;
+};
+
+#define NR_MAG 6
+
+struct tl_info {
+ unsigned char reserved0[2];
+ unsigned short length;
+ unsigned char mag[NR_MAG];
+ unsigned char reserved1;
+ unsigned char mnest;
+ unsigned char reserved2[4];
+ union tl_entry tle[0];
+};
+
+struct core_info {
+ struct core_info *next;
+ cpumask_t mask;
+};
+
+static void topology_work_fn(struct work_struct *work);
+static struct tl_info *tl_info;
+static struct core_info core_info;
+static int machine_has_topology;
+static int machine_has_topology_irq;
+static struct timer_list topology_timer;
+static void set_topology_timer(void);
+static DECLARE_WORK(topology_work, topology_work_fn);
+
+cpumask_t cpu_coregroup_map(unsigned int cpu)
+{
+ struct core_info *core = &core_info;
+ cpumask_t mask;
+
+ cpus_clear(mask);
+ if (!machine_has_topology)
+ return cpu_present_map;
+ mutex_lock(&smp_cpu_state_mutex);
+ while (core) {
+ if (cpu_isset(cpu, core->mask)) {
+ mask = core->mask;
+ break;
+ }
+ core = core->next;
+ }
+ mutex_unlock(&smp_cpu_state_mutex);
+ if (cpus_empty(mask))
+ mask = cpumask_of_cpu(cpu);
+ return mask;
+}
+
+static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
+{
+ unsigned int cpu;
+
+ for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
+ cpu < CPU_BITS;
+ cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
+ {
+ unsigned int rcpu, lcpu;
+
+ rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
+ for_each_present_cpu(lcpu) {
+ if (__cpu_logical_map[lcpu] == rcpu)
+ cpu_set(lcpu, core->mask);
+ }
+ }
+}
+
+static void clear_cores(void)
+{
+ struct core_info *core = &core_info;
+
+ while (core) {
+ cpus_clear(core->mask);
+ core = core->next;
+ }
+}
+
+static union tl_entry *next_tle(union tl_entry *tle)
+{
+ if (tle->nl)
+ return (union tl_entry *)((struct tl_container *)tle + 1);
+ else
+ return (union tl_entry *)((struct tl_cpu *)tle + 1);
+}
+
+static void tl_to_cores(struct tl_info *info)
+{
+ union tl_entry *tle, *end;
+ struct core_info *core = &core_info;
+
+ mutex_lock(&smp_cpu_state_mutex);
+ clear_cores();
+ tle = (union tl_entry *)&info->tle;
+ end = (union tl_entry *)((unsigned long)info + info->length);
+ while (tle < end) {
+ switch (tle->nl) {
+ case 5:
+ case 4:
+ case 3:
+ case 2:
+ break;
+ case 1:
+ core = core->next;
+ break;
+ case 0:
+ add_cpus_to_core(&tle->cpu, core);
+ break;
+ default:
+ clear_cores();
+ machine_has_topology = 0;
+ return;
+ }
+ tle = next_tle(tle);
+ }
+ mutex_unlock(&smp_cpu_state_mutex);
+}
+
+static int ptf(void)
+{
+ int rc;
+
+ asm volatile(
+ " .insn rre,0xb9a20000,%1,%1\n"
+ " ipm %0\n"
+ " srl %0,28\n"
+ : "=d" (rc)
+ : "d" (2UL) : "cc");
+ return rc;
+}
+
+void arch_update_cpu_topology(void)
+{
+ struct tl_info *info = tl_info;
+ struct sys_device *sysdev;
+ int cpu;
+
+ if (!machine_has_topology)
+ return;
+ ptf();
+ stsi(info, 15, 1, 2);
+ tl_to_cores(info);
+ for_each_online_cpu(cpu) {
+ sysdev = get_cpu_sysdev(cpu);
+ kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
+ }
+}
+
+static void topology_work_fn(struct work_struct *work)
+{
+ arch_reinit_sched_domains();
+}
+
+static void topology_timer_fn(unsigned long ignored)
+{
+ if (ptf())
+ schedule_work(&topology_work);
+ set_topology_timer();
+}
+
+static void set_topology_timer(void)
+{
+ topology_timer.function = topology_timer_fn;
+ topology_timer.data = 0;
+ topology_timer.expires = jiffies + 60 * HZ;
+ add_timer(&topology_timer);
+}
+
+static void topology_interrupt(__u16 code)
+{
+ schedule_work(&topology_work);
+}
+
+static int __init init_topology_update(void)
+{
+ int rc;
+
+ if (!machine_has_topology)
+ return 0;
+ init_timer(&topology_timer);
+ if (machine_has_topology_irq) {
+ rc = register_external_interrupt(0x2005, topology_interrupt);
+ if (rc)
+ return rc;
+ ctl_set_bit(0, 8);
+ }
+ else
+ set_topology_timer();
+ return 0;
+}
+__initcall(init_topology_update);
+
+void __init s390_init_cpu_topology(void)
+{
+ unsigned long long facility_bits;
+ struct tl_info *info;
+ struct core_info *core;
+ int nr_cores;
+ int i;
+
+ if (stfle(&facility_bits, 1) <= 0)
+ return;
+ if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
+ return;
+ machine_has_topology = 1;
+
+ if (facility_bits & (1ULL << 51))
+ machine_has_topology_irq = 1;
+
+ tl_info = alloc_bootmem_pages(PAGE_SIZE);
+ if (!tl_info)
+ goto error;
+ info = tl_info;
+ stsi(info, 15, 1, 2);
+
+ nr_cores = info->mag[NR_MAG - 2];
+ for (i = 0; i < info->mnest - 2; i++)
+ nr_cores *= info->mag[NR_MAG - 3 - i];
+
+ printk(KERN_INFO "CPU topology:");
+ for (i = 0; i < NR_MAG; i++)
+ printk(" %d", info->mag[i]);
+ printk(" / %d\n", info->mnest);
+
+ core = &core_info;
+ for (i = 0; i < nr_cores; i++) {
+ core->next = alloc_bootmem(sizeof(struct core_info));
+ core = core->next;
+ if (!core)
+ goto error;
+ }
+ return;
+error:
+ machine_has_topology = 0;
+ machine_has_topology_irq = 0;
+}
Index: quilt-2.6/drivers/s390/sysinfo.c
===================================================================
--- quilt-2.6.orig/drivers/s390/sysinfo.c
+++ quilt-2.6/drivers/s390/sysinfo.c
@@ -105,7 +105,7 @@ struct sysinfo_3_2_2 {
} vm[8];
};

-static inline int stsi(void *sysinfo, int fc, int sel1, int sel2)
+int stsi(void *sysinfo, int fc, int sel1, int sel2)
{
register int r0 asm("0") = (fc << 28) | sel1;
register int r1 asm("1") = sel2;
Index: quilt-2.6/include/asm-s390/smp.h
===================================================================
--- quilt-2.6.orig/include/asm-s390/smp.h
+++ quilt-2.6/include/asm-s390/smp.h
@@ -90,6 +90,8 @@ extern void __cpu_die (unsigned int cpu)
extern void cpu_die (void) __attribute__ ((noreturn));
extern int __cpu_up (unsigned int cpu);

+extern struct mutex smp_cpu_state_mutex;
+
extern int smp_call_function_mask(cpumask_t mask, void (*func)(void *),
void *info, int wait);
#endif
Index: quilt-2.6/include/asm-s390/system.h
===================================================================
--- quilt-2.6.orig/include/asm-s390/system.h
+++ quilt-2.6/include/asm-s390/system.h
@@ -406,6 +406,7 @@ __set_psw_mask(unsigned long mask)
#define local_mcck_enable() __set_psw_mask(psw_kernel_bits)
#define local_mcck_disable() __set_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK)

+int stsi(void *sysinfo, int fc, int sel1, int sel2);
int stfle(unsigned long long *list, int doublewords);

#ifdef CONFIG_SMP
Index: quilt-2.6/include/asm-s390/topology.h
===================================================================
--- quilt-2.6.orig/include/asm-s390/topology.h
+++ quilt-2.6/include/asm-s390/topology.h
@@ -1,6 +1,22 @@
#ifndef _ASM_S390_TOPOLOGY_H
#define _ASM_S390_TOPOLOGY_H

+#include <linux/cpumask.h>
+
+#define mc_capable() (1)
+
+cpumask_t cpu_coregroup_map(unsigned int cpu);
+
+#define topology_core_siblings(cpu) (cpu_coregroup_map(cpu))
+
+#ifdef CONFIG_SMP
+void s390_init_cpu_topology(void);
+#else
+static inline void s390_init_cpu_topology(void)
+{
+};
+#endif
+
#include <asm-generic/topology.h>

#endif /* _ASM_S390_TOPOLOGY_H */

--
blue skies,
Martin.

"Reality continues to ruin my life." - Calvin.