topology, s390: Add z11 cpu topology support

Use the extended cpu topology information that z11 machines provide
to improve the scheduler's decision making.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100831082844.604956770@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 93 insertions, 57 deletions

diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index bcef00766a64..13559c993847 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -57,8 +57,8 @@ struct tl_info {
         union tl_entry tle[0];
 };
 
-struct core_info {
-        struct core_info *next;
+struct mask_info {
+        struct mask_info *next;
         unsigned char id;
         cpumask_t mask;
 };
@@ -66,7 +66,6 @@ struct core_info {
 static int topology_enabled;
 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 struct timer_list topology_timer;
 static void set_topology_timer(void);
@@ -74,38 +73,37 @@ 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];
 
-static cpumask_t cpu_coregroup_map(unsigned int cpu)
+#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)
 {
-        struct core_info *core = &core_info;
-        unsigned long flags;
         cpumask_t mask;
 
         cpus_clear(mask);
         if (!topology_enabled || !machine_has_topology)
                 return cpu_possible_map;
-        spin_lock_irqsave(&topology_lock, flags);
-        while (core) {
-                if (cpu_isset(cpu, core->mask)) {
-                        mask = core->mask;
+        while (info) {
+                if (cpu_isset(cpu, info->mask)) {
+                        mask = info->mask;
                         break;
                 }
-                core = core->next;
+                info = info->next;
         }
-        spin_unlock_irqrestore(&topology_lock, flags);
         if (cpus_empty(mask))
                 mask = cpumask_of_cpu(cpu);
         return mask;
 }
 
-const struct cpumask *cpu_coregroup_mask(unsigned int cpu)
-{
-        return &cpu_core_map[cpu];
-}
-
-static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
+static void add_cpus_to_mask(struct tl_cpu *tl_cpu, struct mask_info *book,
+                             struct mask_info *core)
 {
         unsigned int cpu;
 
@@ -117,23 +115,35 @@ static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
 
                 rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
                 for_each_present_cpu(lcpu) {
-                        if (cpu_logical_map(lcpu) == rcpu) {
-                                cpu_set(lcpu, core->mask);
-                                cpu_core_id[lcpu] = core->id;
-                                smp_cpu_polarization[lcpu] = tl_cpu->pp;
-                        }
+                        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_cores(void)
+static void clear_masks(void)
 {
-        struct core_info *core = &core_info;
+        struct mask_info *info;
 
-        while (core) {
-                cpus_clear(core->mask);
-                core = core->next;
+        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 tl_entry *next_tle(union tl_entry *tle)
@@ -146,29 +156,36 @@ static union tl_entry *next_tle(union tl_entry *tle)
 
 static void tl_to_cores(struct tl_info *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 tl_entry *tle, *end;
-        struct core_info *core = &core_info;
+
 
         spin_lock_irq(&topology_lock);
-        clear_cores();
+        clear_masks();
         tle = info->tle;
         end = (union tl_entry *)((unsigned long)info + info->length);
         while (tle < end) {
                 switch (tle->nl) {
-                case 5:
-                case 4:
-                case 3:
+#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_core(&tle->cpu, core);
+                        add_cpus_to_mask(&tle->cpu, book, core);
                         break;
                 default:
-                        clear_cores();
+                        clear_masks();
                         machine_has_topology = 0;
                         goto out;
                 }
@@ -221,10 +238,29 @@ int topology_set_cpu_management(int fc)
 
 static void update_cpu_core_map(void)
 {
+        unsigned long flags;
         int cpu;
 
-        for_each_possible_cpu(cpu)
-                cpu_core_map[cpu] = cpu_coregroup_map(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);
+}
+
+static void store_topology(struct tl_info *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)
@@ -238,7 +274,7 @@ int arch_update_cpu_topology(void)
                 topology_update_polarization_simple();
                 return 0;
         }
-        stsi(info, 15, 1, 2);
+        store_topology(info);
         tl_to_cores(info);
         update_cpu_core_map();
         for_each_online_cpu(cpu) {
@@ -299,12 +335,24 @@ out:
 }
 __initcall(init_topology_update);
 
+static void alloc_masks(struct tl_info *info, struct mask_info *mask, int offset)
+{
+        int i, nr_masks;
+
+        nr_masks = info->mag[NR_MAG - offset];
+        for (i = 0; i < info->mnest - offset; i++)
+                nr_masks *= info->mag[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)
 {
         unsigned long long facility_bits;
         struct tl_info *info;
-        struct core_info *core;
-        int nr_cores;
         int i;
 
         if (stfle(&facility_bits, 1) <= 0)
@@ -315,25 +363,13 @@ void __init s390_init_cpu_topology(void)
 
         tl_info = alloc_bootmem_pages(PAGE_SIZE);
         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];
-
+        store_topology(info);
         pr_info("The CPU configuration topology of the machine is:");
         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;
+        alloc_masks(info, &core_info, 2);
+#ifdef CONFIG_SCHED_BOOK
+        alloc_masks(info, &book_info, 3);
+#endif
 }