[S390] Get rid of additional_cpus kernel parameter.

It caused only a lot of confusion. From now on cpu hotplug of up to
NR_CPUS will work by default. If somebody wants to limit that then
the possible_cpus parameter can be used.

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

7 files changed, 79 insertions, 155 deletions

diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt
index fb94f5a71b6..ba0aacde94f 100644
--- a/Documentation/cpu-hotplug.txt
+++ b/Documentation/cpu-hotplug.txt
@@ -50,7 +50,7 @@ additional_cpus=n (*)	Use this to limit hotpluggable cpus. This option sets
                         cpu_possible_map = cpu_present_map + additional_cpus
 
 (*) Option valid only for following architectures
-- x86_64, ia64, s390
+- x86_64, ia64
 
 ia64 and x86_64 use the number of disabled local apics in ACPI tables MADT
 to determine the number of potentially hot-pluggable cpus. The implementation
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index c7cbb011414..9f7b73b180f 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -278,7 +278,6 @@ void __init startup_init(void)
         setup_lowcore_early();
         sclp_read_info_early();
         sclp_facilities_detect();
-        sclp_read_cpu_info_early();
         memsize = sclp_memory_detect();
 #ifndef CONFIG_64BIT
         /*
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 3a61bfc2c4f..cbdf3fb05e8 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -922,7 +922,6 @@ setup_arch(char **cmdline_p)
 
         cpu_init();
         __cpu_logical_map[0] = S390_lowcore.cpu_data.cpu_addr;
-        smp_setup_cpu_possible_map();
 
         /*
          * Setup capabilities (ELF_HWCAP & ELF_PLATFORM).
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 66fe28930d8..320e4e97bf5 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -54,7 +54,7 @@ EXPORT_SYMBOL(lowcore_ptr);
 cpumask_t cpu_online_map = CPU_MASK_NONE;
 EXPORT_SYMBOL(cpu_online_map);
 
-cpumask_t cpu_possible_map = CPU_MASK_NONE;
+cpumask_t cpu_possible_map = CPU_MASK_ALL;
 EXPORT_SYMBOL(cpu_possible_map);
 
 static struct task_struct *current_set[NR_CPUS];
@@ -399,7 +399,7 @@ static void __init smp_get_save_area(unsigned int cpu, unsigned int phy_cpu)
                        "kernel was compiled with NR_CPUS=%i\n", cpu, NR_CPUS);
                 return;
         }
-        zfcpdump_save_areas[cpu] = alloc_bootmem(sizeof(union save_area));
+        zfcpdump_save_areas[cpu] = kmalloc(sizeof(union save_area), GFP_KERNEL);
         __cpu_logical_map[CPU_INIT_NO] = (__u16) phy_cpu;
         while (signal_processor(CPU_INIT_NO, sigp_stop_and_store_status) ==
                sigp_busy)
@@ -435,67 +435,6 @@ static int cpu_stopped(int cpu)
         return 0;
 }
 
-/*
- * Lets check how many CPUs we have.
- */
-static void __init smp_count_cpus(unsigned int *configured_cpus,
-                                  unsigned int *standby_cpus)
-{
-        unsigned int cpu;
-        struct sclp_cpu_info *info;
-        u16 boot_cpu_addr, cpu_addr;
-
-        boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr;
-        current_thread_info()->cpu = 0;
-        *configured_cpus = 1;
-        *standby_cpus = 0;
-
-        info = alloc_bootmem_pages(sizeof(*info));
-        if (!info)
-                disabled_wait((unsigned long) __builtin_return_address(0));
-
-        /* Use sigp detection algorithm if sclp doesn't work. */
-        if (sclp_get_cpu_info(info)) {
-                smp_use_sigp_detection = 1;
-                for (cpu = 0; cpu <= 65535; cpu++) {
-                        if (cpu == boot_cpu_addr)
-                                continue;
-                        __cpu_logical_map[CPU_INIT_NO] = cpu;
-                        if (cpu_stopped(CPU_INIT_NO))
-                                (*configured_cpus)++;
-                }
-                goto out;
-        }
-
-        if (info->has_cpu_type) {
-                for (cpu = 0; cpu < info->combined; cpu++) {
-                        if (info->cpu[cpu].address == boot_cpu_addr) {
-                                smp_cpu_type = info->cpu[cpu].type;
-                                break;
-                        }
-                }
-        }
-        /* Count cpus. */
-        for (cpu = 0; cpu < info->combined; cpu++) {
-                if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
-                        continue;
-                cpu_addr = info->cpu[cpu].address;
-                if (cpu_addr == boot_cpu_addr)
-                        continue;
-                __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
-                if (!cpu_stopped(CPU_INIT_NO)) {
-                        (*standby_cpus)++;
-                        continue;
-                }
-                smp_get_save_area(*configured_cpus, cpu_addr);
-                (*configured_cpus)++;
-        }
-out:
-        printk(KERN_INFO "CPUs: %d configured, %d standby\n",
-               *configured_cpus, *standby_cpus);
-        free_bootmem((unsigned long) info, sizeof(*info));
-}
-
 static int cpu_known(int cpu_id)
 {
         int cpu;
@@ -529,7 +468,7 @@ static int smp_rescan_cpus_sigp(cpumask_t avail)
         return 0;
 }
 
-static int __init_refok smp_rescan_cpus_sclp(cpumask_t avail)
+static int smp_rescan_cpus_sclp(cpumask_t avail)
 {
         struct sclp_cpu_info *info;
         int cpu_id, logical_cpu, cpu;
@@ -538,10 +477,7 @@ static int __init_refok smp_rescan_cpus_sclp(cpumask_t avail)
         logical_cpu = first_cpu(avail);
         if (logical_cpu == NR_CPUS)
                 return 0;
-        if (slab_is_available())
-                info = kmalloc(sizeof(*info), GFP_KERNEL);
-        else
-                info = alloc_bootmem(sizeof(*info));
+        info = kmalloc(sizeof(*info), GFP_KERNEL);
         if (!info)
                 return -ENOMEM;
         rc = sclp_get_cpu_info(info);
@@ -564,10 +500,7 @@ static int __init_refok smp_rescan_cpus_sclp(cpumask_t avail)
                         break;
         }
 out:
-        if (slab_is_available())
-                kfree(info);
-        else
-                free_bootmem((unsigned long) info, sizeof(*info));
+        kfree(info);
         return rc;
 }
 
@@ -575,15 +508,71 @@ static int smp_rescan_cpus(void)
 {
         cpumask_t avail;
 
-        cpus_setall(avail);
-        cpus_and(avail, avail, cpu_possible_map);
-        cpus_andnot(avail, avail, cpu_present_map);
+        cpus_xor(avail, cpu_possible_map, cpu_present_map);
         if (smp_use_sigp_detection)
                 return smp_rescan_cpus_sigp(avail);
         else
                 return smp_rescan_cpus_sclp(avail);
 }
 
+static void __init smp_detect_cpus(void)
+{
+        unsigned int cpu, c_cpus, s_cpus;
+        struct sclp_cpu_info *info;
+        u16 boot_cpu_addr, cpu_addr;
+
+        c_cpus = 1;
+        s_cpus = 0;
+        boot_cpu_addr = S390_lowcore.cpu_data.cpu_addr;
+        info = kmalloc(sizeof(*info), GFP_KERNEL);
+        if (!info)
+                panic("smp_detect_cpus failed to allocate memory\n");
+        /* Use sigp detection algorithm if sclp doesn't work. */
+        if (sclp_get_cpu_info(info)) {
+                smp_use_sigp_detection = 1;
+                for (cpu = 0; cpu <= 65535; cpu++) {
+                        if (cpu == boot_cpu_addr)
+                                continue;
+                        __cpu_logical_map[CPU_INIT_NO] = cpu;
+                        if (!cpu_stopped(CPU_INIT_NO))
+                                continue;
+                        smp_get_save_area(c_cpus, cpu);
+                        c_cpus++;
+                }
+                goto out;
+        }
+
+        if (info->has_cpu_type) {
+                for (cpu = 0; cpu < info->combined; cpu++) {
+                        if (info->cpu[cpu].address == boot_cpu_addr) {
+                                smp_cpu_type = info->cpu[cpu].type;
+                                break;
+                        }
+                }
+        }
+
+        for (cpu = 0; cpu < info->combined; cpu++) {
+                if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
+                        continue;
+                cpu_addr = info->cpu[cpu].address;
+                if (cpu_addr == boot_cpu_addr)
+                        continue;
+                __cpu_logical_map[CPU_INIT_NO] = cpu_addr;
+                if (!cpu_stopped(CPU_INIT_NO)) {
+                        s_cpus++;
+                        continue;
+                }
+                smp_get_save_area(c_cpus, cpu_addr);
+                c_cpus++;
+        }
+out:
+        kfree(info);
+        printk(KERN_INFO "CPUs: %d configured, %d standby\n", c_cpus, s_cpus);
+        lock_cpu_hotplug();
+        smp_rescan_cpus();
+        unlock_cpu_hotplug();
+}
+
 /*
  *      Activate a secondary processor.
  */
@@ -674,41 +663,20 @@ int __cpu_up(unsigned int cpu)
         return 0;
 }
 
-static unsigned int __initdata additional_cpus;
-static unsigned int __initdata possible_cpus;
-
-void __init smp_setup_cpu_possible_map(void)
-{
-        unsigned int pos_cpus, cpu;
-        unsigned int configured_cpus, standby_cpus;
-
-        smp_count_cpus(&configured_cpus, &standby_cpus);
-        pos_cpus = min(configured_cpus + standby_cpus + additional_cpus,
-                       (unsigned int) NR_CPUS);
-        if (possible_cpus)
-                pos_cpus = min(possible_cpus, (unsigned int) NR_CPUS);
-        for (cpu = 0; cpu < pos_cpus; cpu++)
-                cpu_set(cpu, cpu_possible_map);
-        cpu_present_map = cpumask_of_cpu(0);
-        smp_rescan_cpus();
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-
-static int __init setup_additional_cpus(char *s)
-{
-        additional_cpus = simple_strtoul(s, NULL, 0);
-        return 0;
-}
-early_param("additional_cpus", setup_additional_cpus);
-
 static int __init setup_possible_cpus(char *s)
 {
-        possible_cpus = simple_strtoul(s, NULL, 0);
+        int pcpus, cpu;
+
+        pcpus = simple_strtoul(s, NULL, 0);
+        cpu_possible_map = cpumask_of_cpu(0);
+        for (cpu = 1; cpu < pcpus && cpu < NR_CPUS; cpu++)
+                cpu_set(cpu, cpu_possible_map);
         return 0;
 }
 early_param("possible_cpus", setup_possible_cpus);
 
+#ifdef CONFIG_HOTPLUG_CPU
+
 int __cpu_disable(void)
 {
         struct ec_creg_mask_parms cr_parms;
@@ -768,6 +736,8 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
         unsigned int cpu;
         int i;
 
+        smp_detect_cpus();
+
         /* request the 0x1201 emergency signal external interrupt */
         if (register_external_interrupt(0x1201, do_ext_call_interrupt) != 0)
                 panic("Couldn't request external interrupt 0x1201");
@@ -816,6 +786,8 @@ void __init smp_prepare_boot_cpu(void)
 {
         BUG_ON(smp_processor_id() != 0);
 
+        current_thread_info()->cpu = 0;
+        cpu_set(0, cpu_present_map);
         cpu_set(0, cpu_online_map);
         S390_lowcore.percpu_offset = __per_cpu_offset[0];
         current_set[0] = current;
diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index d7e6f4d65b7..b5c23396f8f 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -191,9 +191,6 @@ struct read_cpu_info_sccb {
         u8      reserved[4096 - 16];
 } __attribute__((packed, aligned(PAGE_SIZE)));
 
-static struct read_cpu_info_sccb __initdata early_read_cpu_info_sccb;
-static struct sclp_cpu_info __initdata sclp_cpu_info;
-
 static void sclp_fill_cpu_info(struct sclp_cpu_info *info,
                                struct read_cpu_info_sccb *sccb)
 {
@@ -208,48 +205,16 @@ static void sclp_fill_cpu_info(struct sclp_cpu_info *info,
                info->combined * sizeof(struct sclp_cpu_entry));
 }
 
-void __init sclp_read_cpu_info_early(void)
-{
-        int rc;
-        struct read_cpu_info_sccb *sccb;
-
-        if (!SCLP_HAS_CPU_INFO)
-                return;
-
-        sccb = &early_read_cpu_info_sccb;
-        do {
-                memset(sccb, 0, sizeof(*sccb));
-                sccb->header.length = sizeof(*sccb);
-                rc = sclp_cmd_sync_early(SCLP_CMDW_READ_CPU_INFO, sccb);
-        } while (rc == -EBUSY);
-
-        if (rc)
-                return;
-        if (sccb->header.response_code != 0x10)
-                return;
-        sclp_fill_cpu_info(&sclp_cpu_info, sccb);
-}
-
-static int __init sclp_get_cpu_info_early(struct sclp_cpu_info *info)
-{
-        if (!SCLP_HAS_CPU_INFO)
-                return -EOPNOTSUPP;
-        *info = sclp_cpu_info;
-        return 0;
-}
-
-static int sclp_get_cpu_info_late(struct sclp_cpu_info *info)
+int sclp_get_cpu_info(struct sclp_cpu_info *info)
 {
         int rc;
         struct read_cpu_info_sccb *sccb;
 
         if (!SCLP_HAS_CPU_INFO)
                 return -EOPNOTSUPP;
-        sccb = (struct read_cpu_info_sccb *)  __get_free_page(GFP_KERNEL
-                                                              | GFP_DMA);
+        sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
         if (!sccb)
                 return -ENOMEM;
-        memset(sccb, 0, sizeof(*sccb));
         sccb->header.length = sizeof(*sccb);
         rc = do_sync_request(SCLP_CMDW_READ_CPU_INFO, sccb);
         if (rc)
@@ -266,13 +231,6 @@ out:
         return rc;
 }
 
-int __init_refok sclp_get_cpu_info(struct sclp_cpu_info *info)
-{
-        if (slab_is_available())
-                return sclp_get_cpu_info_late(info);
-        return sclp_get_cpu_info_early(info);
-}
-
 struct cpu_configure_sccb {
         struct sccb_header header;
 } __attribute__((packed, aligned(8)));
diff --git a/include/asm-s390/sclp.h b/include/asm-s390/sclp.h
index b8c7695cd4c..b5f2843013a 100644
--- a/include/asm-s390/sclp.h
+++ b/include/asm-s390/sclp.h
@@ -46,7 +46,6 @@ int sclp_get_cpu_info(struct sclp_cpu_info *info);
 int sclp_cpu_configure(u8 cpu);
 int sclp_cpu_deconfigure(u8 cpu);
 void sclp_read_info_early(void);
-void sclp_read_cpu_info_early(void);
 void sclp_facilities_detect(void);
 unsigned long long sclp_memory_detect(void);
 int sclp_sdias_blk_count(void);
diff --git a/include/asm-s390/smp.h b/include/asm-s390/smp.h
index 07708c07701..218454b9186 100644
--- a/include/asm-s390/smp.h
+++ b/include/asm-s390/smp.h
@@ -35,8 +35,6 @@ extern void machine_restart_smp(char *);
 extern void machine_halt_smp(void);
 extern void machine_power_off_smp(void);
 
-extern void smp_setup_cpu_possible_map(void);
-
 #define NO_PROC_ID              0xFF            /* No processor magic marker */
 
 /*
@@ -103,7 +101,6 @@ static inline void smp_send_stop(void)
 
 #define hard_smp_processor_id()         0
 #define smp_cpu_not_running(cpu)        1
-#define smp_setup_cpu_possible_map()    do { } while (0)
 #endif
 
 extern union save_area *zfcpdump_save_areas[NR_CPUS + 1];