Initial file dump from open source releaseHEADmaster

1 files changed, 1076 insertions, 0 deletions

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
new file mode 100644
index 00000000..14647fe0
--- /dev/null
+++ b/arch/s390/kernel/smp.c
@@ -0,0 +1,1076 @@
+/*
+ *  SMP related functions
+ *
+ *    Copyright IBM Corp. 1999, 2012
+ *    Author(s): Denis Joseph Barrow,
+ *		 Martin Schwidefsky <schwidefsky@de.ibm.com>,
+ *		 Heiko Carstens <heiko.carstens@de.ibm.com>,
+ *
+ *  based on other smp stuff by
+ *    (c) 1995 Alan Cox, CymruNET Ltd  <alan@cymru.net>
+ *    (c) 1998 Ingo Molnar
+ *
+ * The code outside of smp.c uses logical cpu numbers, only smp.c does
+ * the translation of logical to physical cpu ids. All new code that
+ * operates on physical cpu numbers needs to go into smp.c.
+ */
+
+#define KMSG_COMPONENT "cpu"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/workqueue.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/err.h>
+#include <linux/spinlock.h>
+#include <linux/kernel_stat.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/irqflags.h>
+#include <linux/cpu.h>
+#include <linux/slab.h>
+#include <linux/crash_dump.h>
+#include <asm/asm-offsets.h>
+#include <asm/switch_to.h>
+#include <asm/facility.h>
+#include <asm/ipl.h>
+#include <asm/setup.h>
+#include <asm/irq.h>
+#include <asm/tlbflush.h>
+#include <asm/vtimer.h>
+#include <asm/lowcore.h>
+#include <asm/sclp.h>
+#include <asm/vdso.h>
+#include <asm/debug.h>
+#include <asm/os_info.h>
+#include <asm/sigp.h>
+#include "entry.h"
+
+enum {
+	ec_schedule = 0,
+	ec_call_function,
+	ec_call_function_single,
+	ec_stop_cpu,
+};
+
+enum {
+	CPU_STATE_STANDBY,
+	CPU_STATE_CONFIGURED,
+};
+
+struct pcpu {
+	struct cpu cpu;
+	struct _lowcore *lowcore;	/* lowcore page(s) for the cpu */
+	unsigned long async_stack;	/* async stack for the cpu */
+	unsigned long panic_stack;	/* panic stack for the cpu */
+	unsigned long ec_mask;		/* bit mask for ec_xxx functions */
+	int state;			/* physical cpu state */
+	int polarization;		/* physical polarization */
+	u16 address;			/* physical cpu address */
+};
+
+static u8 boot_cpu_type;
+static u16 boot_cpu_address;
+static struct pcpu pcpu_devices[NR_CPUS];
+
+/*
+ * The smp_cpu_state_mutex must be held when changing the state or polarization
+ * member of a pcpu data structure within the pcpu_devices arreay.
+ */
+DEFINE_MUTEX(smp_cpu_state_mutex);
+
+/*
+ * Signal processor helper functions.
+ */
+static inline int __pcpu_sigp(u16 addr, u8 order, u32 parm, u32 *status)
+{
+	register unsigned int reg1 asm ("1") = parm;
+	int cc;
+
+	asm volatile(
+		"	sigp	%1,%2,0(%3)\n"
+		"	ipm	%0\n"
+		"	srl	%0,28\n"
+		: "=d" (cc), "+d" (reg1) : "d" (addr), "a" (order) : "cc");
+	if (status && cc == 1)
+		*status = reg1;
+	return cc;
+}
+
+static inline int __pcpu_sigp_relax(u16 addr, u8 order, u32 parm, u32 *status)
+{
+	int cc;
+
+	while (1) {
+		cc = __pcpu_sigp(addr, order, parm, NULL);
+		if (cc != SIGP_CC_BUSY)
+			return cc;
+		cpu_relax();
+	}
+}
+
+static int pcpu_sigp_retry(struct pcpu *pcpu, u8 order, u32 parm)
+{
+	int cc, retry;
+
+	for (retry = 0; ; retry++) {
+		cc = __pcpu_sigp(pcpu->address, order, parm, NULL);
+		if (cc != SIGP_CC_BUSY)
+			break;
+		if (retry >= 3)
+			udelay(10);
+	}
+	return cc;
+}
+
+static inline int pcpu_stopped(struct pcpu *pcpu)
+{
+	u32 uninitialized_var(status);
+
+	if (__pcpu_sigp(pcpu->address, SIGP_SENSE,
+			0, &status) != SIGP_CC_STATUS_STORED)
+		return 0;
+	return !!(status & (SIGP_STATUS_CHECK_STOP|SIGP_STATUS_STOPPED));
+}
+
+static inline int pcpu_running(struct pcpu *pcpu)
+{
+	if (__pcpu_sigp(pcpu->address, SIGP_SENSE_RUNNING,
+			0, NULL) != SIGP_CC_STATUS_STORED)
+		return 1;
+	/* Status stored condition code is equivalent to cpu not running. */
+	return 0;
+}
+
+/*
+ * Find struct pcpu by cpu address.
+ */
+static struct pcpu *pcpu_find_address(const struct cpumask *mask, int address)
+{
+	int cpu;
+
+	for_each_cpu(cpu, mask)
+		if (pcpu_devices[cpu].address == address)
+			return pcpu_devices + cpu;
+	return NULL;
+}
+
+static void pcpu_ec_call(struct pcpu *pcpu, int ec_bit)
+{
+	int order;
+
+	set_bit(ec_bit, &pcpu->ec_mask);
+	order = pcpu_running(pcpu) ?
+		SIGP_EXTERNAL_CALL : SIGP_EMERGENCY_SIGNAL;
+	pcpu_sigp_retry(pcpu, order, 0);
+}
+
+static int __cpuinit pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
+{
+	struct _lowcore *lc;
+
+	if (pcpu != &pcpu_devices[0]) {
+		pcpu->lowcore =	(struct _lowcore *)
+			__get_free_pages(GFP_KERNEL | GFP_DMA, LC_ORDER);
+		pcpu->async_stack = __get_free_pages(GFP_KERNEL, ASYNC_ORDER);
+		pcpu->panic_stack = __get_free_page(GFP_KERNEL);
+		if (!pcpu->lowcore || !pcpu->panic_stack || !pcpu->async_stack)
+			goto out;
+	}
+	lc = pcpu->lowcore;
+	memcpy(lc, &S390_lowcore, 512);
+	memset((char *) lc + 512, 0, sizeof(*lc) - 512);
+	lc->async_stack = pcpu->async_stack + ASYNC_SIZE
+		- STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
+	lc->panic_stack = pcpu->panic_stack + PAGE_SIZE
+		- STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
+	lc->cpu_nr = cpu;
+#ifndef CONFIG_64BIT
+	if (MACHINE_HAS_IEEE) {
+		lc->extended_save_area_addr = get_zeroed_page(GFP_KERNEL);
+		if (!lc->extended_save_area_addr)
+			goto out;
+	}
+#else
+	if (vdso_alloc_per_cpu(lc))
+		goto out;
+#endif
+	lowcore_ptr[cpu] = lc;
+	pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, (u32)(unsigned long) lc);
+	return 0;
+out:
+	if (pcpu != &pcpu_devices[0]) {
+		free_page(pcpu->panic_stack);
+		free_pages(pcpu->async_stack, ASYNC_ORDER);
+		free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
+	}
+	return -ENOMEM;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+static void pcpu_free_lowcore(struct pcpu *pcpu)
+{
+	pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
+	lowcore_ptr[pcpu - pcpu_devices] = NULL;
+#ifndef CONFIG_64BIT
+	if (MACHINE_HAS_IEEE) {
+		struct _lowcore *lc = pcpu->lowcore;
+
+		free_page((unsigned long) lc->extended_save_area_addr);
+		lc->extended_save_area_addr = 0;
+	}
+#else
+	vdso_free_per_cpu(pcpu->lowcore);
+#endif
+	if (pcpu != &pcpu_devices[0]) {
+		free_page(pcpu->panic_stack);
+		free_pages(pcpu->async_stack, ASYNC_ORDER);
+		free_pages((unsigned long) pcpu->lowcore, LC_ORDER);
+	}
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
+static void pcpu_prepare_secondary(struct pcpu *pcpu, int cpu)
+{
+	struct _lowcore *lc = pcpu->lowcore;
+
+	atomic_inc(&init_mm.context.attach_count);
+	lc->cpu_nr = cpu;
+	lc->percpu_offset = __per_cpu_offset[cpu];
+	lc->kernel_asce = S390_lowcore.kernel_asce;
+	lc->machine_flags = S390_lowcore.machine_flags;
+	lc->ftrace_func = S390_lowcore.ftrace_func;
+	lc->user_timer = lc->system_timer = lc->steal_timer = 0;
+	__ctl_store(lc->cregs_save_area, 0, 15);
+	save_access_regs((unsigned int *) lc->access_regs_save_area);
+	memcpy(lc->stfle_fac_list, S390_lowcore.stfle_fac_list,
+	       MAX_FACILITY_BIT/8);
+}
+
+static void pcpu_attach_task(struct pcpu *pcpu, struct task_struct *tsk)
+{
+	struct _lowcore *lc = pcpu->lowcore;
+	struct thread_info *ti = task_thread_info(tsk);
+
+	lc->kernel_stack = (unsigned long) task_stack_page(tsk)
+		+ THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
+	lc->thread_info = (unsigned long) task_thread_info(tsk);
+	lc->current_task = (unsigned long) tsk;
+	lc->user_timer = ti->user_timer;
+	lc->system_timer = ti->system_timer;
+	lc->steal_timer = 0;
+}
+
+static void pcpu_start_fn(struct pcpu *pcpu, void (*func)(void *), void *data)
+{
+	struct _lowcore *lc = pcpu->lowcore;
+
+	lc->restart_stack = lc->kernel_stack;
+	lc->restart_fn = (unsigned long) func;
+	lc->restart_data = (unsigned long) data;
+	lc->restart_source = -1UL;
+	pcpu_sigp_retry(pcpu, SIGP_RESTART, 0);
+}
+
+/*
+ * Call function via PSW restart on pcpu and stop the current cpu.
+ */
+static void pcpu_delegate(struct pcpu *pcpu, void (*func)(void *),
+			  void *data, unsigned long stack)
+{
+	struct _lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
+	unsigned long source_cpu = stap();
+
+	__load_psw_mask(psw_kernel_bits);
+	if (pcpu->address == source_cpu)
+		func(data);	/* should not return */
+	/* Stop target cpu (if func returns this stops the current cpu). */
+	pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
+	/* Restart func on the target cpu and stop the current cpu. */
+	mem_assign_absolute(lc->restart_stack, stack);
+	mem_assign_absolute(lc->restart_fn, (unsigned long) func);
+	mem_assign_absolute(lc->restart_data, (unsigned long) data);
+	mem_assign_absolute(lc->restart_source, source_cpu);
+	asm volatile(
+		"0:	sigp	0,%0,%2	# sigp restart to target cpu\n"
+		"	brc	2,0b	# busy, try again\n"
+		"1:	sigp	0,%1,%3	# sigp stop to current cpu\n"
+		"	brc	2,1b	# busy, try again\n"
+		: : "d" (pcpu->address), "d" (source_cpu),
+		    "K" (SIGP_RESTART), "K" (SIGP_STOP)
+		: "0", "1", "cc");
+	for (;;) ;
+}
+
+/*
+ * Call function on an online CPU.
+ */
+void smp_call_online_cpu(void (*func)(void *), void *data)
+{
+	struct pcpu *pcpu;
+
+	/* Use the current cpu if it is online. */
+	pcpu = pcpu_find_address(cpu_online_mask, stap());
+	if (!pcpu)
+		/* Use the first online cpu. */
+		pcpu = pcpu_devices + cpumask_first(cpu_online_mask);
+	pcpu_delegate(pcpu, func, data, (unsigned long) restart_stack);
+}
+
+/*
+ * Call function on the ipl CPU.
+ */
+void smp_call_ipl_cpu(void (*func)(void *), void *data)
+{
+	pcpu_delegate(&pcpu_devices[0], func, data,
+		      pcpu_devices->panic_stack + PAGE_SIZE);
+}
+
+int smp_find_processor_id(u16 address)
+{
+	int cpu;
+
+	for_each_present_cpu(cpu)
+		if (pcpu_devices[cpu].address == address)
+			return cpu;
+	return -1;
+}
+
+int smp_vcpu_scheduled(int cpu)
+{
+	return pcpu_running(pcpu_devices + cpu);
+}
+
+void smp_yield(void)
+{
+	if (MACHINE_HAS_DIAG44)
+		asm volatile("diag 0,0,0x44");
+}
+
+void smp_yield_cpu(int cpu)
+{
+	if (MACHINE_HAS_DIAG9C)
+		asm volatile("diag %0,0,0x9c"
+			     : : "d" (pcpu_devices[cpu].address));
+	else if (MACHINE_HAS_DIAG44)
+		asm volatile("diag 0,0,0x44");
+}
+
+/*
+ * Send cpus emergency shutdown signal. This gives the cpus the
+ * opportunity to complete outstanding interrupts.
+ */
+void smp_emergency_stop(cpumask_t *cpumask)
+{
+	u64 end;
+	int cpu;
+
+	end = get_tod_clock() + (1000000UL << 12);
+	for_each_cpu(cpu, cpumask) {
+		struct pcpu *pcpu = pcpu_devices + cpu;
+		set_bit(ec_stop_cpu, &pcpu->ec_mask);
+		while (__pcpu_sigp(pcpu->address, SIGP_EMERGENCY_SIGNAL,
+				   0, NULL) == SIGP_CC_BUSY &&
+		       get_tod_clock() < end)
+			cpu_relax();
+	}
+	while (get_tod_clock() < end) {
+		for_each_cpu(cpu, cpumask)
+			if (pcpu_stopped(pcpu_devices + cpu))
+				cpumask_clear_cpu(cpu, cpumask);
+		if (cpumask_empty(cpumask))
+			break;
+		cpu_relax();
+	}
+}
+
+/*
+ * Stop all cpus but the current one.
+ */
+void smp_send_stop(void)
+{
+	cpumask_t cpumask;
+	int cpu;
+
+	/* Disable all interrupts/machine checks */
+	__load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
+	trace_hardirqs_off();
+
+	debug_set_critical();
+	cpumask_copy(&cpumask, cpu_online_mask);
+	cpumask_clear_cpu(smp_processor_id(), &cpumask);
+
+	if (oops_in_progress)
+		smp_emergency_stop(&cpumask);
+
+	/* stop all processors */
+	for_each_cpu(cpu, &cpumask) {
+		struct pcpu *pcpu = pcpu_devices + cpu;
+		pcpu_sigp_retry(pcpu, SIGP_STOP, 0);
+		while (!pcpu_stopped(pcpu))
+			cpu_relax();
+	}
+}
+
+/*
+ * Stop the current cpu.
+ */
+void smp_stop_cpu(void)
+{
+	pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
+	for (;;) ;
+}
+
+/*
+ * This is the main routine where commands issued by other
+ * cpus are handled.
+ */
+static void smp_handle_ext_call(void)
+{
+	unsigned long bits;
+
+	/* handle bit signal external calls */
+	bits = xchg(&pcpu_devices[smp_processor_id()].ec_mask, 0);
+	if (test_bit(ec_stop_cpu, &bits))
+		smp_stop_cpu();
+	if (test_bit(ec_schedule, &bits))
+		scheduler_ipi();
+	if (test_bit(ec_call_function, &bits))
+		generic_smp_call_function_interrupt();
+	if (test_bit(ec_call_function_single, &bits))
+		generic_smp_call_function_single_interrupt();
+}
+
+static void do_ext_call_interrupt(struct ext_code ext_code,
+				  unsigned int param32, unsigned long param64)
+{
+	inc_irq_stat(ext_code.code == 0x1202 ? IRQEXT_EXC : IRQEXT_EMS);
+	smp_handle_ext_call();
+}
+
+void arch_send_call_function_ipi_mask(const struct cpumask *mask)
+{
+	int cpu;
+
+	for_each_cpu(cpu, mask)
+		pcpu_ec_call(pcpu_devices + cpu, ec_call_function);
+}
+
+void arch_send_call_function_single_ipi(int cpu)
+{
+	pcpu_ec_call(pcpu_devices + cpu, ec_call_function_single);
+}
+
+#ifndef CONFIG_64BIT
+/*
+ * this function sends a 'purge tlb' signal to another CPU.
+ */
+static void smp_ptlb_callback(void *info)
+{
+	__tlb_flush_local();
+}
+
+void smp_ptlb_all(void)
+{
+	on_each_cpu(smp_ptlb_callback, NULL, 1);
+}
+EXPORT_SYMBOL(smp_ptlb_all);
+#endif /* ! CONFIG_64BIT */
+
+/*
+ * this function sends a 'reschedule' IPI to another CPU.
+ * it goes straight through and wastes no time serializing
+ * anything. Worst case is that we lose a reschedule ...
+ */
+void smp_send_reschedule(int cpu)
+{
+	pcpu_ec_call(pcpu_devices + cpu, ec_schedule);
+}
+
+/*
+ * parameter area for the set/clear control bit callbacks
+ */
+struct ec_creg_mask_parms {
+	unsigned long orval;
+	unsigned long andval;
+	int cr;
+};
+
+/*
+ * callback for setting/clearing control bits
+ */
+static void smp_ctl_bit_callback(void *info)
+{
+	struct ec_creg_mask_parms *pp = info;
+	unsigned long cregs[16];
+
+	__ctl_store(cregs, 0, 15);
+	cregs[pp->cr] = (cregs[pp->cr] & pp->andval) | pp->orval;
+	__ctl_load(cregs, 0, 15);
+}
+
+/*
+ * Set a bit in a control register of all cpus
+ */
+void smp_ctl_set_bit(int cr, int bit)
+{
+	struct ec_creg_mask_parms parms = { 1UL << bit, -1UL, cr };
+
+	on_each_cpu(smp_ctl_bit_callback, &parms, 1);
+}
+EXPORT_SYMBOL(smp_ctl_set_bit);
+
+/*
+ * Clear a bit in a control register of all cpus
+ */
+void smp_ctl_clear_bit(int cr, int bit)
+{
+	struct ec_creg_mask_parms parms = { 0, ~(1UL << bit), cr };
+
+	on_each_cpu(smp_ctl_bit_callback, &parms, 1);
+}
+EXPORT_SYMBOL(smp_ctl_clear_bit);
+
+#if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_CRASH_DUMP)
+
+struct save_area *zfcpdump_save_areas[NR_CPUS + 1];
+EXPORT_SYMBOL_GPL(zfcpdump_save_areas);
+
+static void __init smp_get_save_area(int cpu, u16 address)
+{
+	void *lc = pcpu_devices[0].lowcore;
+	struct save_area *save_area;
+
+	if (is_kdump_kernel())
+		return;
+	if (!OLDMEM_BASE && (address == boot_cpu_address ||
+			     ipl_info.type != IPL_TYPE_FCP_DUMP))
+		return;
+	if (cpu >= NR_CPUS) {
+		pr_warning("CPU %i exceeds the maximum %i and is excluded "
+			   "from the dump\n", cpu, NR_CPUS - 1);
+		return;
+	}
+	save_area = kmalloc(sizeof(struct save_area), GFP_KERNEL);
+	if (!save_area)
+		panic("could not allocate memory for save area\n");
+	zfcpdump_save_areas[cpu] = save_area;
+#ifdef CONFIG_CRASH_DUMP
+	if (address == boot_cpu_address) {
+		/* Copy the registers of the boot cpu. */
+		copy_oldmem_page(1, (void *) save_area, sizeof(*save_area),
+				 SAVE_AREA_BASE - PAGE_SIZE, 0);
+		return;
+	}
+#endif
+	/* Get the registers of a non-boot cpu. */
+	__pcpu_sigp_relax(address, SIGP_STOP_AND_STORE_STATUS, 0, NULL);
+	memcpy_real(save_area, lc + SAVE_AREA_BASE, sizeof(*save_area));
+}
+
+int smp_store_status(int cpu)
+{
+	struct pcpu *pcpu;
+
+	pcpu = pcpu_devices + cpu;
+	if (__pcpu_sigp_relax(pcpu->address, SIGP_STOP_AND_STORE_STATUS,
+			      0, NULL) != SIGP_CC_ORDER_CODE_ACCEPTED)
+		return -EIO;
+	return 0;
+}
+
+#else /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
+
+static inline void smp_get_save_area(int cpu, u16 address) { }
+
+#endif /* CONFIG_ZFCPDUMP || CONFIG_CRASH_DUMP */
+
+void smp_cpu_set_polarization(int cpu, int val)
+{
+	pcpu_devices[cpu].polarization = val;
+}
+
+int smp_cpu_get_polarization(int cpu)
+{
+	return pcpu_devices[cpu].polarization;
+}
+
+static struct sclp_cpu_info *smp_get_cpu_info(void)
+{
+	static int use_sigp_detection;
+	struct sclp_cpu_info *info;
+	int address;
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (info && (use_sigp_detection || sclp_get_cpu_info(info))) {
+		use_sigp_detection = 1;
+		for (address = 0; address <= MAX_CPU_ADDRESS; address++) {
+			if (__pcpu_sigp_relax(address, SIGP_SENSE, 0, NULL) ==
+			    SIGP_CC_NOT_OPERATIONAL)
+				continue;
+			info->cpu[info->configured].address = address;
+			info->configured++;
+		}
+		info->combined = info->configured;
+	}
+	return info;
+}
+
+static int __cpuinit smp_add_present_cpu(int cpu);
+
+static int __cpuinit __smp_rescan_cpus(struct sclp_cpu_info *info,
+				       int sysfs_add)
+{
+	struct pcpu *pcpu;
+	cpumask_t avail;
+	int cpu, nr, i;
+
+	nr = 0;
+	cpumask_xor(&avail, cpu_possible_mask, cpu_present_mask);
+	cpu = cpumask_first(&avail);
+	for (i = 0; (i < info->combined) && (cpu < nr_cpu_ids); i++) {
+		if (info->has_cpu_type && info->cpu[i].type != boot_cpu_type)
+			continue;
+		if (pcpu_find_address(cpu_present_mask, info->cpu[i].address))
+			continue;
+		pcpu = pcpu_devices + cpu;
+		pcpu->address = info->cpu[i].address;
+		pcpu->state = (i >= info->configured) ?
+			CPU_STATE_STANDBY : CPU_STATE_CONFIGURED;
+		smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
+		set_cpu_present(cpu, true);
+		if (sysfs_add && smp_add_present_cpu(cpu) != 0)
+			set_cpu_present(cpu, false);
+		else
+			nr++;
+		cpu = cpumask_next(cpu, &avail);
+	}
+	return nr;
+}
+
+static void __init smp_detect_cpus(void)
+{
+	unsigned int cpu, c_cpus, s_cpus;
+	struct sclp_cpu_info *info;
+
+	info = smp_get_cpu_info();
+	if (!info)
+		panic("smp_detect_cpus failed to allocate memory\n");
+	if (info->has_cpu_type) {
+		for (cpu = 0; cpu < info->combined; cpu++) {
+			if (info->cpu[cpu].address != boot_cpu_address)
+				continue;
+			/* The boot cpu dictates the cpu type. */
+			boot_cpu_type = info->cpu[cpu].type;
+			break;
+		}
+	}
+	c_cpus = s_cpus = 0;
+	for (cpu = 0; cpu < info->combined; cpu++) {
+		if (info->has_cpu_type && info->cpu[cpu].type != boot_cpu_type)
+			continue;
+		if (cpu < info->configured) {
+			smp_get_save_area(c_cpus, info->cpu[cpu].address);
+			c_cpus++;
+		} else
+			s_cpus++;
+	}
+	pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
+	get_online_cpus();
+	__smp_rescan_cpus(info, 0);
+	put_online_cpus();
+	kfree(info);
+}
+
+/*
+ *	Activate a secondary processor.
+ */
+static void __cpuinit smp_start_secondary(void *cpuvoid)
+{
+	S390_lowcore.last_update_clock = get_tod_clock();
+	S390_lowcore.restart_stack = (unsigned long) restart_stack;
+	S390_lowcore.restart_fn = (unsigned long) do_restart;
+	S390_lowcore.restart_data = 0;
+	S390_lowcore.restart_source = -1UL;
+	restore_access_regs(S390_lowcore.access_regs_save_area);
+	__ctl_load(S390_lowcore.cregs_save_area, 0, 15);
+	__load_psw_mask(psw_kernel_bits | PSW_MASK_DAT);
+	cpu_init();
+	preempt_disable();
+	init_cpu_timer();
+	init_cpu_vtimer();
+	pfault_init();
+	notify_cpu_starting(smp_processor_id());
+	set_cpu_online(smp_processor_id(), true);
+	inc_irq_stat(CPU_RST);
+	local_irq_enable();
+	cpu_startup_entry(CPUHP_ONLINE);
+}
+
+/* Upping and downing of CPUs */
+int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
+{
+	struct pcpu *pcpu;
+	int rc;
+
+	pcpu = pcpu_devices + cpu;
+	if (pcpu->state != CPU_STATE_CONFIGURED)
+		return -EIO;
+	if (pcpu_sigp_retry(pcpu, SIGP_INITIAL_CPU_RESET, 0) !=
+	    SIGP_CC_ORDER_CODE_ACCEPTED)
+		return -EIO;
+
+	rc = pcpu_alloc_lowcore(pcpu, cpu);
+	if (rc)
+		return rc;
+	pcpu_prepare_secondary(pcpu, cpu);
+	pcpu_attach_task(pcpu, tidle);
+	pcpu_start_fn(pcpu, smp_start_secondary, NULL);
+	while (!cpu_online(cpu))
+		cpu_relax();
+	return 0;
+}
+
+static int __init setup_possible_cpus(char *s)
+{
+	int max, cpu;
+
+	if (kstrtoint(s, 0, &max) < 0)
+		return 0;
+	init_cpu_possible(cpumask_of(0));
+	for (cpu = 1; cpu < max && cpu < nr_cpu_ids; cpu++)
+		set_cpu_possible(cpu, true);
+	return 0;
+}
+early_param("possible_cpus", setup_possible_cpus);
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+int __cpu_disable(void)
+{
+	unsigned long cregs[16];
+
+	/* Handle possible pending IPIs */
+	smp_handle_ext_call();
+	set_cpu_online(smp_processor_id(), false);
+	/* Disable pseudo page faults on this cpu. */
+	pfault_fini();
+	/* Disable interrupt sources via control register. */
+	__ctl_store(cregs, 0, 15);
+	cregs[0]  &= ~0x0000ee70UL;	/* disable all external interrupts */
+	cregs[6]  &= ~0xff000000UL;	/* disable all I/O interrupts */
+	cregs[14] &= ~0x1f000000UL;	/* disable most machine checks */
+	__ctl_load(cregs, 0, 15);
+	return 0;
+}
+
+void __cpu_die(unsigned int cpu)
+{
+	struct pcpu *pcpu;
+
+	/* Wait until target cpu is down */
+	pcpu = pcpu_devices + cpu;
+	while (!pcpu_stopped(pcpu))
+		cpu_relax();
+	pcpu_free_lowcore(pcpu);
+	atomic_dec(&init_mm.context.attach_count);
+}
+
+void __noreturn cpu_die(void)
+{
+	idle_task_exit();
+	pcpu_sigp_retry(pcpu_devices + smp_processor_id(), SIGP_STOP, 0);
+	for (;;) ;
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
+void __init smp_prepare_cpus(unsigned int max_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");
+	/* request the 0x1202 external call external interrupt */
+	if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0)
+		panic("Couldn't request external interrupt 0x1202");
+	smp_detect_cpus();
+}
+
+void __init smp_prepare_boot_cpu(void)
+{
+	struct pcpu *pcpu = pcpu_devices;
+
+	boot_cpu_address = stap();
+	pcpu->state = CPU_STATE_CONFIGURED;
+	pcpu->address = boot_cpu_address;
+	pcpu->lowcore = (struct _lowcore *)(unsigned long) store_prefix();
+	pcpu->async_stack = S390_lowcore.async_stack - ASYNC_SIZE
+		+ STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
+	pcpu->panic_stack = S390_lowcore.panic_stack - PAGE_SIZE
+		+ STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
+	S390_lowcore.percpu_offset = __per_cpu_offset[0];
+	smp_cpu_set_polarization(0, POLARIZATION_UNKNOWN);
+	set_cpu_present(0, true);
+	set_cpu_online(0, true);
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+}
+
+void __init smp_setup_processor_id(void)
+{
+	S390_lowcore.cpu_nr = 0;
+}
+
+/*
+ * the frequency of the profiling timer can be changed
+ * by writing a multiplier value into /proc/profile.
+ *
+ * usually you want to run this on all CPUs ;)
+ */
+int setup_profiling_timer(unsigned int multiplier)
+{
+	return 0;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static ssize_t cpu_configure_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	ssize_t count;
+
+	mutex_lock(&smp_cpu_state_mutex);
+	count = sprintf(buf, "%d\n", pcpu_devices[dev->id].state);
+	mutex_unlock(&smp_cpu_state_mutex);
+	return count;
+}
+
+static ssize_t cpu_configure_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t count)
+{
+	struct pcpu *pcpu;
+	int cpu, val, rc;
+	char delim;
+
+	if (sscanf(buf, "%d %c", &val, &delim) != 1)
+		return -EINVAL;
+	if (val != 0 && val != 1)
+		return -EINVAL;
+	get_online_cpus();
+	mutex_lock(&smp_cpu_state_mutex);
+	rc = -EBUSY;
+	/* disallow configuration changes of online cpus and cpu 0 */
+	cpu = dev->id;
+	if (cpu_online(cpu) || cpu == 0)
+		goto out;
+	pcpu = pcpu_devices + cpu;
+	rc = 0;
+	switch (val) {
+	case 0:
+		if (pcpu->state != CPU_STATE_CONFIGURED)
+			break;
+		rc = sclp_cpu_deconfigure(pcpu->address);
+		if (rc)
+			break;
+		pcpu->state = CPU_STATE_STANDBY;
+		smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
+		topology_expect_change();
+		break;
+	case 1:
+		if (pcpu->state != CPU_STATE_STANDBY)
+			break;
+		rc = sclp_cpu_configure(pcpu->address);
+		if (rc)
+			break;
+		pcpu->state = CPU_STATE_CONFIGURED;
+		smp_cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
+		topology_expect_change();
+		break;
+	default:
+		break;
+	}
+out:
+	mutex_unlock(&smp_cpu_state_mutex);
+	put_online_cpus();
+	return rc ? rc : count;
+}
+static DEVICE_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store);
+#endif /* CONFIG_HOTPLUG_CPU */
+
+static ssize_t show_cpu_address(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", pcpu_devices[dev->id].address);
+}
+static DEVICE_ATTR(address, 0444, show_cpu_address, NULL);
+
+static struct attribute *cpu_common_attrs[] = {
+#ifdef CONFIG_HOTPLUG_CPU
+	&dev_attr_configure.attr,
+#endif
+	&dev_attr_address.attr,
+	NULL,
+};
+
+static struct attribute_group cpu_common_attr_group = {
+	.attrs = cpu_common_attrs,
+};
+
+static ssize_t show_idle_count(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
+	unsigned long long idle_count;
+	unsigned int sequence;
+
+	do {
+		sequence = ACCESS_ONCE(idle->sequence);
+		idle_count = ACCESS_ONCE(idle->idle_count);
+		if (ACCESS_ONCE(idle->clock_idle_enter))
+			idle_count++;
+	} while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
+	return sprintf(buf, "%llu\n", idle_count);
+}
+static DEVICE_ATTR(idle_count, 0444, show_idle_count, NULL);
+
+static ssize_t show_idle_time(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct s390_idle_data *idle = &per_cpu(s390_idle, dev->id);
+	unsigned long long now, idle_time, idle_enter, idle_exit;
+	unsigned int sequence;
+
+	do {
+		now = get_tod_clock();
+		sequence = ACCESS_ONCE(idle->sequence);
+		idle_time = ACCESS_ONCE(idle->idle_time);
+		idle_enter = ACCESS_ONCE(idle->clock_idle_enter);
+		idle_exit = ACCESS_ONCE(idle->clock_idle_exit);
+	} while ((sequence & 1) || (ACCESS_ONCE(idle->sequence) != sequence));
+	idle_time += idle_enter ? ((idle_exit ? : now) - idle_enter) : 0;
+	return sprintf(buf, "%llu\n", idle_time >> 12);
+}
+static DEVICE_ATTR(idle_time_us, 0444, show_idle_time, NULL);
+
+static struct attribute *cpu_online_attrs[] = {
+	&dev_attr_idle_count.attr,
+	&dev_attr_idle_time_us.attr,
+	NULL,
+};
+
+static struct attribute_group cpu_online_attr_group = {
+	.attrs = cpu_online_attrs,
+};
+
+static int __cpuinit smp_cpu_notify(struct notifier_block *self,
+				    unsigned long action, void *hcpu)
+{
+	unsigned int cpu = (unsigned int)(long)hcpu;
+	struct cpu *c = &pcpu_devices[cpu].cpu;
+	struct device *s = &c->dev;
+	int err = 0;
+
+	switch (action & ~CPU_TASKS_FROZEN) {
+	case CPU_ONLINE:
+		err = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
+		break;
+	case CPU_DEAD:
+		sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
+		break;
+	}
+	return notifier_from_errno(err);
+}
+
+static int __cpuinit smp_add_present_cpu(int cpu)
+{
+	struct cpu *c = &pcpu_devices[cpu].cpu;
+	struct device *s = &c->dev;
+	int rc;
+
+	c->hotpluggable = 1;
+	rc = register_cpu(c, cpu);
+	if (rc)
+		goto out;
+	rc = sysfs_create_group(&s->kobj, &cpu_common_attr_group);
+	if (rc)
+		goto out_cpu;
+	if (cpu_online(cpu)) {
+		rc = sysfs_create_group(&s->kobj, &cpu_online_attr_group);
+		if (rc)
+			goto out_online;
+	}
+	rc = topology_cpu_init(c);
+	if (rc)
+		goto out_topology;
+	return 0;
+
+out_topology:
+	if (cpu_online(cpu))
+		sysfs_remove_group(&s->kobj, &cpu_online_attr_group);
+out_online:
+	sysfs_remove_group(&s->kobj, &cpu_common_attr_group);
+out_cpu:
+#ifdef CONFIG_HOTPLUG_CPU
+	unregister_cpu(c);
+#endif
+out:
+	return rc;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+int __ref smp_rescan_cpus(void)
+{
+	struct sclp_cpu_info *info;
+	int nr;
+
+	info = smp_get_cpu_info();
+	if (!info)
+		return -ENOMEM;
+	get_online_cpus();
+	mutex_lock(&smp_cpu_state_mutex);
+	nr = __smp_rescan_cpus(info, 1);
+	mutex_unlock(&smp_cpu_state_mutex);
+	put_online_cpus();
+	kfree(info);
+	if (nr)
+		topology_schedule_update();
+	return 0;
+}
+
+static ssize_t __ref rescan_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf,
+				  size_t count)
+{
+	int rc;
+
+	rc = smp_rescan_cpus();
+	return rc ? rc : count;
+}
+static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
+#endif /* CONFIG_HOTPLUG_CPU */
+
+static int __init s390_smp_init(void)
+{
+	int cpu, rc;
+
+	hotcpu_notifier(smp_cpu_notify, 0);
+#ifdef CONFIG_HOTPLUG_CPU
+	rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
+	if (rc)
+		return rc;
+#endif
+	for_each_present_cpu(cpu) {
+		rc = smp_add_present_cpu(cpu);
+		if (rc)
+			return rc;
+	}
+	return 0;
+}
+subsys_initcall(s390_smp_init);