linux/arch/s390/kernel/topology.c
Heiko Carstens 0b52783d4f [S390] topology: fix cpu masks for topology=off case
Fix cpu masks for 'topology=off' case. Folding of the scheduling domains
happen in such a way that everything belongs to the MC domain instead
of the CPU doimain.
This should fix a performance regression introduced with
eafd2b6d "[S390] topology: use default MC domain initializer" and also
makes sure we have the same behavious as if CONFIG_SCHED_MC was not
selected at all.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-29 16:50:50 +02:00

336 lines
6.9 KiB
C

/*
* Copyright IBM Corp. 2007
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
*/
#define KMSG_COMPONENT "cpu"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#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 <linux/cpuset.h>
#include <asm/delay.h>
#include <asm/s390_ext.h>
#define PTF_HORIZONTAL (0UL)
#define PTF_VERTICAL (1UL)
#define PTF_CHECK (2UL)
struct mask_info {
struct mask_info *next;
unsigned char id;
cpumask_t mask;
};
static int topology_enabled = 1;
static void topology_work_fn(struct work_struct *work);
static struct sysinfo_15_1_x *tl_info;
static struct timer_list topology_timer;
static void set_topology_timer(void);
static DECLARE_WORK(topology_work, topology_work_fn);
/* topology_lock protects the core linked list */
static DEFINE_SPINLOCK(topology_lock);
static struct mask_info core_info;
cpumask_t cpu_core_map[NR_CPUS];
unsigned char cpu_core_id[NR_CPUS];
#ifdef CONFIG_SCHED_BOOK
static struct mask_info book_info;
cpumask_t cpu_book_map[NR_CPUS];
unsigned char cpu_book_id[NR_CPUS];
#endif
static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
{
cpumask_t mask;
cpus_clear(mask);
if (!topology_enabled || !MACHINE_HAS_TOPOLOGY) {
cpumask_copy(&mask, cpumask_of(cpu));
return mask;
}
while (info) {
if (cpu_isset(cpu, info->mask)) {
mask = info->mask;
break;
}
info = info->next;
}
if (cpus_empty(mask))
mask = cpumask_of_cpu(cpu);
return mask;
}
static void add_cpus_to_mask(struct topology_cpu *tl_cpu,
struct mask_info *book, struct mask_info *core)
{
unsigned int cpu;
for (cpu = find_first_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS);
cpu < TOPOLOGY_CPU_BITS;
cpu = find_next_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS, cpu + 1))
{
unsigned int rcpu, lcpu;
rcpu = TOPOLOGY_CPU_BITS - 1 - cpu + tl_cpu->origin;
for_each_present_cpu(lcpu) {
if (cpu_logical_map(lcpu) != rcpu)
continue;
#ifdef CONFIG_SCHED_BOOK
cpu_set(lcpu, book->mask);
cpu_book_id[lcpu] = book->id;
#endif
cpu_set(lcpu, core->mask);
cpu_core_id[lcpu] = core->id;
smp_cpu_polarization[lcpu] = tl_cpu->pp;
}
}
}
static void clear_masks(void)
{
struct mask_info *info;
info = &core_info;
while (info) {
cpus_clear(info->mask);
info = info->next;
}
#ifdef CONFIG_SCHED_BOOK
info = &book_info;
while (info) {
cpus_clear(info->mask);
info = info->next;
}
#endif
}
static union topology_entry *next_tle(union topology_entry *tle)
{
if (!tle->nl)
return (union topology_entry *)((struct topology_cpu *)tle + 1);
return (union topology_entry *)((struct topology_container *)tle + 1);
}
static void tl_to_cores(struct sysinfo_15_1_x *info)
{
#ifdef CONFIG_SCHED_BOOK
struct mask_info *book = &book_info;
#else
struct mask_info *book = NULL;
#endif
struct mask_info *core = &core_info;
union topology_entry *tle, *end;
spin_lock_irq(&topology_lock);
clear_masks();
tle = info->tle;
end = (union topology_entry *)((unsigned long)info + info->length);
while (tle < end) {
switch (tle->nl) {
#ifdef CONFIG_SCHED_BOOK
case 2:
book = book->next;
book->id = tle->container.id;
break;
#endif
case 1:
core = core->next;
core->id = tle->container.id;
break;
case 0:
add_cpus_to_mask(&tle->cpu, book, core);
break;
default:
clear_masks();
goto out;
}
tle = next_tle(tle);
}
out:
spin_unlock_irq(&topology_lock);
}
static void topology_update_polarization_simple(void)
{
int cpu;
mutex_lock(&smp_cpu_state_mutex);
for_each_possible_cpu(cpu)
smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
mutex_unlock(&smp_cpu_state_mutex);
}
static int ptf(unsigned long fc)
{
int rc;
asm volatile(
" .insn rre,0xb9a20000,%1,%1\n"
" ipm %0\n"
" srl %0,28\n"
: "=d" (rc)
: "d" (fc) : "cc");
return rc;
}
int topology_set_cpu_management(int fc)
{
int cpu;
int rc;
if (!MACHINE_HAS_TOPOLOGY)
return -EOPNOTSUPP;
if (fc)
rc = ptf(PTF_VERTICAL);
else
rc = ptf(PTF_HORIZONTAL);
if (rc)
return -EBUSY;
for_each_possible_cpu(cpu)
smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
return rc;
}
static void update_cpu_core_map(void)
{
unsigned long flags;
int cpu;
spin_lock_irqsave(&topology_lock, flags);
for_each_possible_cpu(cpu) {
cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
#ifdef CONFIG_SCHED_BOOK
cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
#endif
}
spin_unlock_irqrestore(&topology_lock, flags);
}
void store_topology(struct sysinfo_15_1_x *info)
{
#ifdef CONFIG_SCHED_BOOK
int rc;
rc = stsi(info, 15, 1, 3);
if (rc != -ENOSYS)
return;
#endif
stsi(info, 15, 1, 2);
}
int arch_update_cpu_topology(void)
{
struct sysinfo_15_1_x *info = tl_info;
struct sys_device *sysdev;
int cpu;
if (!MACHINE_HAS_TOPOLOGY) {
update_cpu_core_map();
topology_update_polarization_simple();
return 0;
}
store_topology(info);
tl_to_cores(info);
update_cpu_core_map();
for_each_online_cpu(cpu) {
sysdev = get_cpu_sysdev(cpu);
kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
}
return 1;
}
static void topology_work_fn(struct work_struct *work)
{
rebuild_sched_domains();
}
void topology_schedule_update(void)
{
schedule_work(&topology_work);
}
static void topology_timer_fn(unsigned long ignored)
{
if (ptf(PTF_CHECK))
topology_schedule_update();
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 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 int __init init_topology_update(void)
{
int rc;
rc = 0;
if (!MACHINE_HAS_TOPOLOGY) {
topology_update_polarization_simple();
goto out;
}
init_timer_deferrable(&topology_timer);
set_topology_timer();
out:
update_cpu_core_map();
return rc;
}
__initcall(init_topology_update);
static void 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(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(" %d", info->mag[i]);
printk(" / %d\n", info->mnest);
alloc_masks(info, &core_info, 2);
#ifdef CONFIG_SCHED_BOOK
alloc_masks(info, &book_info, 3);
#endif
}