[deliverable/linux.git] / arch / x86 / xen / smp.c

/*
 * Xen SMP support
 *
 * This file implements the Xen versions of smp_ops.  SMP under Xen is
 * very straightforward.  Bringing a CPU up is simply a matter of
 * loading its initial context and setting it running.
 *
 * IPIs are handled through the Xen event mechanism.
 *
 * Because virtual CPUs can be scheduled onto any real CPU, there's no
 * useful topology information for the kernel to make use of.  As a
 * result, all CPUs are treated as if they're single-core and
 * single-threaded.
 */
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/smp.h>

#include <asm/paravirt.h>
#include <asm/desc.h>
#include <asm/pgtable.h>
#include <asm/cpu.h>

#include <xen/interface/xen.h>
#include <xen/interface/vcpu.h>

#include <asm/xen/interface.h>
#include <asm/xen/hypercall.h>

#include <xen/page.h>
#include <xen/events.h>

#include "xen-ops.h"
#include "mmu.h"

cpumask_var_t xen_cpu_initialized_map;

static DEFINE_PER_CPU(int, xen_resched_irq);
static DEFINE_PER_CPU(int, xen_callfunc_irq);
static DEFINE_PER_CPU(int, xen_callfuncsingle_irq);
static DEFINE_PER_CPU(int, xen_debug_irq) = -1;

static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);

/*
 * Reschedule call back. Nothing to do,
 * all the work is done automatically when
 * we return from the interrupt.
 */
static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
{
	inc_irq_stat(irq_resched_count);

	return IRQ_HANDLED;
}

static __cpuinit void cpu_bringup(void)
{
	int cpu = smp_processor_id();

	cpu_init();
	touch_softlockup_watchdog();
	preempt_disable();

	xen_enable_sysenter();
	xen_enable_syscall();

	cpu = smp_processor_id();
	smp_store_cpu_info(cpu);
	cpu_data(cpu).x86_max_cores = 1;
	set_cpu_sibling_map(cpu);

	xen_setup_cpu_clockevents();

	set_cpu_online(cpu, true);
	percpu_write(cpu_state, CPU_ONLINE);
	wmb();

	/* We can take interrupts now: we're officially "up". */
	local_irq_enable();

	wmb();			/* make sure everything is out */
}

static __cpuinit void cpu_bringup_and_idle(void)
{
	cpu_bringup();
	cpu_idle();
}

static int xen_smp_intr_init(unsigned int cpu)
{
	int rc;
	const char *resched_name, *callfunc_name, *debug_name;

	resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
	rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
				    cpu,
				    xen_reschedule_interrupt,
				    IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
				    resched_name,
				    NULL);
	if (rc < 0)
		goto fail;
	per_cpu(xen_resched_irq, cpu) = rc;

	callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
				    cpu,
				    xen_call_function_interrupt,
				    IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
				    callfunc_name,
				    NULL);
	if (rc < 0)
		goto fail;
	per_cpu(xen_callfunc_irq, cpu) = rc;

	debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
	rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
				     IRQF_DISABLED | IRQF_PERCPU | IRQF_NOBALANCING,
				     debug_name, NULL);
	if (rc < 0)
		goto fail;
	per_cpu(xen_debug_irq, cpu) = rc;

	callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
				    cpu,
				    xen_call_function_single_interrupt,
				    IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
				    callfunc_name,
				    NULL);
	if (rc < 0)
		goto fail;
	per_cpu(xen_callfuncsingle_irq, cpu) = rc;

	return 0;

 fail:
	if (per_cpu(xen_resched_irq, cpu) >= 0)
		unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL);
	if (per_cpu(xen_callfunc_irq, cpu) >= 0)
		unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
	if (per_cpu(xen_debug_irq, cpu) >= 0)
		unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
	if (per_cpu(xen_callfuncsingle_irq, cpu) >= 0)
		unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu),
				       NULL);

	return rc;
}

static void __init xen_fill_possible_map(void)
{
	int i, rc;

	for (i = 0; i < nr_cpu_ids; i++) {
		rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
		if (rc >= 0) {
			num_processors++;
			set_cpu_possible(i, true);
		}
	}
}

static void __init xen_smp_prepare_boot_cpu(void)
{
	BUG_ON(smp_processor_id() != 0);
	native_smp_prepare_boot_cpu();

	/* We've switched to the "real" per-cpu gdt, so make sure the
	   old memory can be recycled */
	make_lowmem_page_readwrite(xen_initial_gdt);

	xen_setup_vcpu_info_placement();
}

static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
{
	unsigned cpu;

	xen_init_lock_cpu(0);

	smp_store_cpu_info(0);
	cpu_data(0).x86_max_cores = 1;
	set_cpu_sibling_map(0);

	if (xen_smp_intr_init(0))
		BUG();

	if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL))
		panic("could not allocate xen_cpu_initialized_map\n");

	cpumask_copy(xen_cpu_initialized_map, cpumask_of(0));

	/* Restrict the possible_map according to max_cpus. */
	while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) {
		for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--)
			continue;
		set_cpu_possible(cpu, false);
	}

	for_each_possible_cpu (cpu) {
		struct task_struct *idle;

		if (cpu == 0)
			continue;

		idle = fork_idle(cpu);
		if (IS_ERR(idle))
			panic("failed fork for CPU %d", cpu);

		set_cpu_present(cpu, true);
	}
}

static __cpuinit int
cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
{
	struct vcpu_guest_context *ctxt;
	struct desc_struct *gdt;
	unsigned long gdt_mfn;

	if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
		return 0;

	ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
	if (ctxt == NULL)
		return -ENOMEM;

	gdt = get_cpu_gdt_table(cpu);

	ctxt->flags = VGCF_IN_KERNEL;
	ctxt->user_regs.ds = __USER_DS;
	ctxt->user_regs.es = __USER_DS;
	ctxt->user_regs.ss = __KERNEL_DS;
#ifdef CONFIG_X86_32
	ctxt->user_regs.fs = __KERNEL_PERCPU;
	ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
#else
	ctxt->gs_base_kernel = per_cpu_offset(cpu);
#endif
	ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
	ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */

	memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));

	xen_copy_trap_info(ctxt->trap_ctxt);

	ctxt->ldt_ents = 0;

	BUG_ON((unsigned long)gdt & ~PAGE_MASK);

	gdt_mfn = arbitrary_virt_to_mfn(gdt);
	make_lowmem_page_readonly(gdt);
	make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));

	ctxt->gdt_frames[0] = gdt_mfn;
	ctxt->gdt_ents      = GDT_ENTRIES;

	ctxt->user_regs.cs = __KERNEL_CS;
	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);

	ctxt->kernel_ss = __KERNEL_DS;
	ctxt->kernel_sp = idle->thread.sp0;

#ifdef CONFIG_X86_32
	ctxt->event_callback_cs     = __KERNEL_CS;
	ctxt->failsafe_callback_cs  = __KERNEL_CS;
#endif
	ctxt->event_callback_eip    = (unsigned long)xen_hypervisor_callback;
	ctxt->failsafe_callback_eip = (unsigned long)xen_failsafe_callback;

	per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
	ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));

	if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
		BUG();

	kfree(ctxt);
	return 0;
}

static int __cpuinit xen_cpu_up(unsigned int cpu)
{
	struct task_struct *idle = idle_task(cpu);
	int rc;

	per_cpu(current_task, cpu) = idle;
#ifdef CONFIG_X86_32
	irq_ctx_init(cpu);
#else
	clear_tsk_thread_flag(idle, TIF_FORK);
	per_cpu(kernel_stack, cpu) =
		(unsigned long)task_stack_page(idle) -
		KERNEL_STACK_OFFSET + THREAD_SIZE;
#endif
	xen_setup_runstate_info(cpu);
	xen_setup_timer(cpu);
	xen_init_lock_cpu(cpu);

	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;

	/* make sure interrupts start blocked */
	per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;

	rc = cpu_initialize_context(cpu, idle);
	if (rc)
		return rc;

	if (num_online_cpus() == 1)
		alternatives_smp_switch(1);

	rc = xen_smp_intr_init(cpu);
	if (rc)
		return rc;

	rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
	BUG_ON(rc);

	while(per_cpu(cpu_state, cpu) != CPU_ONLINE) {
		HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
		barrier();
	}

	return 0;
}

static void xen_smp_cpus_done(unsigned int max_cpus)
{
}

#ifdef CONFIG_HOTPLUG_CPU
static int xen_cpu_disable(void)
{
	unsigned int cpu = smp_processor_id();
	if (cpu == 0)
		return -EBUSY;

	cpu_disable_common();

	load_cr3(swapper_pg_dir);
	return 0;
}

static void xen_cpu_die(unsigned int cpu)
{
	while (HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
		current->state = TASK_UNINTERRUPTIBLE;
		schedule_timeout(HZ/10);
	}
	unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL);
	unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
	unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
	unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu), NULL);
	xen_uninit_lock_cpu(cpu);
	xen_teardown_timer(cpu);

	if (num_online_cpus() == 1)
		alternatives_smp_switch(0);
}

static void __cpuinit xen_play_dead(void) /* used only with HOTPLUG_CPU */
{
	play_dead_common();
	HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
	cpu_bringup();
}

#else /* !CONFIG_HOTPLUG_CPU */
static int xen_cpu_disable(void)
{
	return -ENOSYS;
}

static void xen_cpu_die(unsigned int cpu)
{
	BUG();
}

static void xen_play_dead(void)
{
	BUG();
}

#endif
static void stop_self(void *v)
{
	int cpu = smp_processor_id();

	/* make sure we're not pinning something down */
	load_cr3(swapper_pg_dir);
	/* should set up a minimal gdt */

	HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
	BUG();
}

static void xen_smp_send_stop(void)
{
	smp_call_function(stop_self, NULL, 0);
}

static void xen_smp_send_reschedule(int cpu)
{
	xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
}

static void xen_send_IPI_mask(const struct cpumask *mask,
			      enum ipi_vector vector)
{
	unsigned cpu;

	for_each_cpu_and(cpu, mask, cpu_online_mask)
		xen_send_IPI_one(cpu, vector);
}

static void xen_smp_send_call_function_ipi(const struct cpumask *mask)
{
	int cpu;

	xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);

	/* Make sure other vcpus get a chance to run if they need to. */
	for_each_cpu(cpu, mask) {
		if (xen_vcpu_stolen(cpu)) {
			HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
			break;
		}
	}
}

static void xen_smp_send_call_function_single_ipi(int cpu)
{
	xen_send_IPI_mask(cpumask_of(cpu),
			  XEN_CALL_FUNCTION_SINGLE_VECTOR);
}

static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
{
	irq_enter();
	generic_smp_call_function_interrupt();
	inc_irq_stat(irq_call_count);
	irq_exit();

	return IRQ_HANDLED;
}

static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
{
	irq_enter();
	generic_smp_call_function_single_interrupt();
	inc_irq_stat(irq_call_count);
	irq_exit();

	return IRQ_HANDLED;
}

static const struct smp_ops xen_smp_ops __initdata = {
	.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
	.smp_prepare_cpus = xen_smp_prepare_cpus,
	.smp_cpus_done = xen_smp_cpus_done,

	.cpu_up = xen_cpu_up,
	.cpu_die = xen_cpu_die,
	.cpu_disable = xen_cpu_disable,
	.play_dead = xen_play_dead,

	.smp_send_stop = xen_smp_send_stop,
	.smp_send_reschedule = xen_smp_send_reschedule,

	.send_call_func_ipi = xen_smp_send_call_function_ipi,
	.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi,
};

void __init xen_smp_init(void)
{
	smp_ops = xen_smp_ops;
	xen_fill_possible_map();
	xen_init_spinlocks();
}
Commit	Line	Data
f87e4cac JF	1	/*
	2	* Xen SMP support
	3	*
	4	* This file implements the Xen versions of smp_ops. SMP under Xen is
	5	* very straightforward. Bringing a CPU up is simply a matter of
	6	* loading its initial context and setting it running.
	7	*
	8	* IPIs are handled through the Xen event mechanism.
	9	*
	10	* Because virtual CPUs can be scheduled onto any real CPU, there's no
	11	* useful topology information for the kernel to make use of. As a
	12	* result, all CPUs are treated as if they're single-core and
	13	* single-threaded.
f87e4cac JF	14	*/
	15	#include <linux/sched.h>
	16	#include <linux/err.h>
	17	#include <linux/smp.h>
	18
	19	#include <asm/paravirt.h>
	20	#include <asm/desc.h>
	21	#include <asm/pgtable.h>
	22	#include <asm/cpu.h>
	23
	24	#include <xen/interface/xen.h>
	25	#include <xen/interface/vcpu.h>
	26
	27	#include <asm/xen/interface.h>
	28	#include <asm/xen/hypercall.h>
	29
	30	#include <xen/page.h>
	31	#include <xen/events.h>
	32
	33	#include "xen-ops.h"
	34	#include "mmu.h"
	35
b78936e1	36	cpumask_var_t xen_cpu_initialized_map;
f87e4cac	37
c6e22f9e TH	38	static DEFINE_PER_CPU(int, xen_resched_irq);
	39	static DEFINE_PER_CPU(int, xen_callfunc_irq);
	40	static DEFINE_PER_CPU(int, xen_callfuncsingle_irq);
	41	static DEFINE_PER_CPU(int, xen_debug_irq) = -1;
f87e4cac JF	42
f87e4cac JF	43	static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
3b16cf87	44	static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
f87e4cac JF	45
	46	/*
	47	* Reschedule call back. Nothing to do,
	48	* all the work is done automatically when
	49	* we return from the interrupt.
	50	*/
	51	static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
	52	{
1b437c8c	53	inc_irq_stat(irq_resched_count);
38bb5ab4	54
f87e4cac JF	55	return IRQ_HANDLED;
	56	}
	57
d68d82af	58	static __cpuinit void cpu_bringup(void)
f87e4cac JF	59	{
	60	int cpu = smp_processor_id();
	61
	62	cpu_init();
d68d82af	63	touch_softlockup_watchdog();
c7b75947 JF	64	preempt_disable();
c7b75947 JF	65
e2a81baf	66	xen_enable_sysenter();
6fcac6d3	67	xen_enable_syscall();
f87e4cac	68
c7b75947 JF	69	cpu = smp_processor_id();
	70	smp_store_cpu_info(cpu);
	71	cpu_data(cpu).x86_max_cores = 1;
	72	set_cpu_sibling_map(cpu);
f87e4cac JF	73
	74	xen_setup_cpu_clockevents();
	75
d7d3756c	76	set_cpu_online(cpu, true);
6dbde353	77	percpu_write(cpu_state, CPU_ONLINE);
c7b75947 JF	78	wmb();
c7b75947 JF	79
f87e4cac JF	80	/* We can take interrupts now: we're officially "up". */
	81	local_irq_enable();
	82
	83	wmb(); /* make sure everything is out */
d68d82af AN	84	}
	85
	86	static __cpuinit void cpu_bringup_and_idle(void)
	87	{
	88	cpu_bringup();
f87e4cac JF	89	cpu_idle();
	90	}
	91
	92	static int xen_smp_intr_init(unsigned int cpu)
	93	{
	94	int rc;
ee523ca1	95	const char resched_name, callfunc_name, *debug_name;
f87e4cac JF	96
	97	resched_name = kasprintf(GFP_KERNEL, "resched%d", cpu);
	98	rc = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR,
	99	cpu,
	100	xen_reschedule_interrupt,
	101	IRQF_DISABLED\|IRQF_PERCPU\|IRQF_NOBALANCING,
	102	resched_name,
	103	NULL);
	104	if (rc < 0)
	105	goto fail;
c6e22f9e	106	per_cpu(xen_resched_irq, cpu) = rc;
f87e4cac JF	107
	108	callfunc_name = kasprintf(GFP_KERNEL, "callfunc%d", cpu);
	109	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_VECTOR,
	110	cpu,
	111	xen_call_function_interrupt,
	112	IRQF_DISABLED\|IRQF_PERCPU\|IRQF_NOBALANCING,
	113	callfunc_name,
	114	NULL);
	115	if (rc < 0)
	116	goto fail;
c6e22f9e	117	per_cpu(xen_callfunc_irq, cpu) = rc;
f87e4cac	118
ee523ca1 JF	119	debug_name = kasprintf(GFP_KERNEL, "debug%d", cpu);
	120	rc = bind_virq_to_irqhandler(VIRQ_DEBUG, cpu, xen_debug_interrupt,
	121	IRQF_DISABLED \| IRQF_PERCPU \| IRQF_NOBALANCING,
	122	debug_name, NULL);
	123	if (rc < 0)
	124	goto fail;
c6e22f9e	125	per_cpu(xen_debug_irq, cpu) = rc;
ee523ca1	126
3b16cf87 JA	127	callfunc_name = kasprintf(GFP_KERNEL, "callfuncsingle%d", cpu);
	128	rc = bind_ipi_to_irqhandler(XEN_CALL_FUNCTION_SINGLE_VECTOR,
	129	cpu,
	130	xen_call_function_single_interrupt,
	131	IRQF_DISABLED\|IRQF_PERCPU\|IRQF_NOBALANCING,
	132	callfunc_name,
	133	NULL);
	134	if (rc < 0)
	135	goto fail;
c6e22f9e	136	per_cpu(xen_callfuncsingle_irq, cpu) = rc;
3b16cf87	137
f87e4cac JF	138	return 0;
	139
	140	fail:
c6e22f9e TH	141	if (per_cpu(xen_resched_irq, cpu) >= 0)
	142	unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL);
	143	if (per_cpu(xen_callfunc_irq, cpu) >= 0)
	144	unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
	145	if (per_cpu(xen_debug_irq, cpu) >= 0)
	146	unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
	147	if (per_cpu(xen_callfuncsingle_irq, cpu) >= 0)
	148	unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu),
	149	NULL);
3b16cf87	150
f87e4cac JF	151	return rc;
	152	}
	153
c7b75947	154	static void __init xen_fill_possible_map(void)
f87e4cac JF	155	{
	156	int i, rc;
	157
e7986739	158	for (i = 0; i < nr_cpu_ids; i++) {
f87e4cac	159	rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
4560a294 JF	160	if (rc >= 0) {
4560a294 JF	161	num_processors++;
4f062896	162	set_cpu_possible(i, true);
4560a294	163	}
f87e4cac JF	164	}
	165	}
	166
a9e7062d	167	static void __init xen_smp_prepare_boot_cpu(void)
f87e4cac	168	{
f87e4cac JF	169	BUG_ON(smp_processor_id() != 0);
	170	native_smp_prepare_boot_cpu();
	171
f87e4cac JF	172	/* We've switched to the "real" per-cpu gdt, so make sure the
f87e4cac JF	173	old memory can be recycled */
38341432	174	make_lowmem_page_readwrite(xen_initial_gdt);
60223a32 JF	175
60223a32 JF	176	xen_setup_vcpu_info_placement();
f87e4cac JF	177	}
f87e4cac JF	178
a9e7062d	179	static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
f87e4cac JF	180	{
	181	unsigned cpu;
	182
2d9e1e2f JF	183	xen_init_lock_cpu(0);
2d9e1e2f JF	184
f87e4cac	185	smp_store_cpu_info(0);
c7b75947	186	cpu_data(0).x86_max_cores = 1;
f87e4cac JF	187	set_cpu_sibling_map(0);
	188
	189	if (xen_smp_intr_init(0))
	190	BUG();
	191
b78936e1 MT	192	if (!alloc_cpumask_var(&xen_cpu_initialized_map, GFP_KERNEL))
	193	panic("could not allocate xen_cpu_initialized_map\n");
	194
	195	cpumask_copy(xen_cpu_initialized_map, cpumask_of(0));
f87e4cac JF	196
	197	/* Restrict the possible_map according to max_cpus. */
	198	while ((num_possible_cpus() > 1) && (num_possible_cpus() > max_cpus)) {
e7986739	199	for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--)
f87e4cac	200	continue;
4f062896	201	set_cpu_possible(cpu, false);
f87e4cac JF	202	}
	203
	204	for_each_possible_cpu (cpu) {
	205	struct task_struct *idle;
	206
	207	if (cpu == 0)
	208	continue;
	209
	210	idle = fork_idle(cpu);
	211	if (IS_ERR(idle))
	212	panic("failed fork for CPU %d", cpu);
	213
4f062896	214	set_cpu_present(cpu, true);
f87e4cac	215	}
f87e4cac JF	216	}
	217
	218	static __cpuinit int
	219	cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
	220	{
	221	struct vcpu_guest_context *ctxt;
c7b75947	222	struct desc_struct *gdt;
9976b39b	223	unsigned long gdt_mfn;
f87e4cac	224
b78936e1	225	if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
f87e4cac JF	226	return 0;
	227
	228	ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
	229	if (ctxt == NULL)
	230	return -ENOMEM;
	231
c7b75947 JF	232	gdt = get_cpu_gdt_table(cpu);
c7b75947 JF	233
f87e4cac JF	234	ctxt->flags = VGCF_IN_KERNEL;
	235	ctxt->user_regs.ds = __USER_DS;
	236	ctxt->user_regs.es = __USER_DS;
f87e4cac	237	ctxt->user_regs.ss = __KERNEL_DS;
c7b75947 JF	238	#ifdef CONFIG_X86_32
c7b75947 JF	239	ctxt->user_regs.fs = __KERNEL_PERCPU;
577eebea	240	ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
795f99b6 JF	241	#else
795f99b6 JF	242	ctxt->gs_base_kernel = per_cpu_offset(cpu);
c7b75947	243	#endif
f87e4cac JF	244	ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
	245	ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
	246
	247	memset(&ctxt->fpu_ctxt, 0, sizeof(ctxt->fpu_ctxt));
	248
	249	xen_copy_trap_info(ctxt->trap_ctxt);
	250
	251	ctxt->ldt_ents = 0;
	252
c7b75947	253	BUG_ON((unsigned long)gdt & ~PAGE_MASK);
9976b39b JF	254
9976b39b JF	255	gdt_mfn = arbitrary_virt_to_mfn(gdt);
c7b75947	256	make_lowmem_page_readonly(gdt);
9976b39b	257	make_lowmem_page_readonly(mfn_to_virt(gdt_mfn));
f87e4cac	258
9976b39b	259	ctxt->gdt_frames[0] = gdt_mfn;
c7b75947	260	ctxt->gdt_ents = GDT_ENTRIES;
f87e4cac JF	261
f87e4cac JF	262	ctxt->user_regs.cs = __KERNEL_CS;
faca6227	263	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
f87e4cac JF	264
f87e4cac JF	265	ctxt->kernel_ss = __KERNEL_DS;
faca6227	266	ctxt->kernel_sp = idle->thread.sp0;
f87e4cac	267
c7b75947	268	#ifdef CONFIG_X86_32
f87e4cac	269	ctxt->event_callback_cs = __KERNEL_CS;
f87e4cac	270	ctxt->failsafe_callback_cs = __KERNEL_CS;
c7b75947 JF	271	#endif
c7b75947 JF	272	ctxt->event_callback_eip = (unsigned long)xen_hypervisor_callback;
f87e4cac JF	273	ctxt->failsafe_callback_eip = (unsigned long)xen_failsafe_callback;
	274
	275	per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
	276	ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
	277
	278	if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
	279	BUG();
	280
	281	kfree(ctxt);
	282	return 0;
	283	}
	284
a9e7062d	285	static int __cpuinit xen_cpu_up(unsigned int cpu)
f87e4cac JF	286	{
	287	struct task_struct *idle = idle_task(cpu);
	288	int rc;
	289
c6f5e0ac	290	per_cpu(current_task, cpu) = idle;
c7b75947	291	#ifdef CONFIG_X86_32
f87e4cac	292	irq_ctx_init(cpu);
c7b75947	293	#else
c7b75947	294	clear_tsk_thread_flag(idle, TIF_FORK);
38341432 JF	295	per_cpu(kernel_stack, cpu) =
	296	(unsigned long)task_stack_page(idle) -
	297	KERNEL_STACK_OFFSET + THREAD_SIZE;
c7b75947	298	#endif
02889672	299	xen_setup_runstate_info(cpu);
f87e4cac	300	xen_setup_timer(cpu);
2d9e1e2f	301	xen_init_lock_cpu(cpu);
f87e4cac	302
c7b75947 JF	303	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
c7b75947 JF	304
f87e4cac JF	305	/* make sure interrupts start blocked */
	306	per_cpu(xen_vcpu, cpu)->evtchn_upcall_mask = 1;
	307
	308	rc = cpu_initialize_context(cpu, idle);
	309	if (rc)
	310	return rc;
	311
	312	if (num_online_cpus() == 1)
	313	alternatives_smp_switch(1);
	314
	315	rc = xen_smp_intr_init(cpu);
	316	if (rc)
	317	return rc;
	318
f87e4cac JF	319	rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
	320	BUG_ON(rc);
	321
c7b75947	322	while(per_cpu(cpu_state, cpu) != CPU_ONLINE) {
1207cf8e	323	HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
c7b75947 JF	324	barrier();
	325	}
	326
f87e4cac JF	327	return 0;
	328	}
	329
a9e7062d	330	static void xen_smp_cpus_done(unsigned int max_cpus)
f87e4cac JF	331	{
	332	}
	333
2737146b	334	#ifdef CONFIG_HOTPLUG_CPU
26fd1051	335	static int xen_cpu_disable(void)
d68d82af AN	336	{
	337	unsigned int cpu = smp_processor_id();
	338	if (cpu == 0)
	339	return -EBUSY;
	340
	341	cpu_disable_common();
	342
	343	load_cr3(swapper_pg_dir);
	344	return 0;
	345	}
	346
26fd1051	347	static void xen_cpu_die(unsigned int cpu)
d68d82af AN	348	{
	349	while (HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
	350	current->state = TASK_UNINTERRUPTIBLE;
	351	schedule_timeout(HZ/10);
	352	}
c6e22f9e TH	353	unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu), NULL);
	354	unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu), NULL);
	355	unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu), NULL);
	356	unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu), NULL);
d68d82af AN	357	xen_uninit_lock_cpu(cpu);
	358	xen_teardown_timer(cpu);
	359
	360	if (num_online_cpus() == 1)
	361	alternatives_smp_switch(0);
	362	}
	363
71709247	364	static void __cpuinit xen_play_dead(void) /* used only with HOTPLUG_CPU */
d68d82af AN	365	{
	366	play_dead_common();
	367	HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
	368	cpu_bringup();
	369	}
	370
2737146b	371	#else /* !CONFIG_HOTPLUG_CPU */
26fd1051	372	static int xen_cpu_disable(void)
2737146b AN	373	{
	374	return -ENOSYS;
	375	}
	376
26fd1051	377	static void xen_cpu_die(unsigned int cpu)
2737146b AN	378	{
	379	BUG();
	380	}
	381
26fd1051	382	static void xen_play_dead(void)
2737146b AN	383	{
	384	BUG();
	385	}
	386
	387	#endif
f87e4cac JF	388	static void stop_self(void *v)
	389	{
	390	int cpu = smp_processor_id();
	391
	392	/* make sure we're not pinning something down */
	393	load_cr3(swapper_pg_dir);
	394	/* should set up a minimal gdt */
	395
	396	HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
	397	BUG();
	398	}
	399
a9e7062d	400	static void xen_smp_send_stop(void)
f87e4cac	401	{
8691e5a8	402	smp_call_function(stop_self, NULL, 0);
f87e4cac JF	403	}
f87e4cac JF	404
a9e7062d	405	static void xen_smp_send_reschedule(int cpu)
f87e4cac JF	406	{
	407	xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
	408	}
	409
bcda016e MT	410	static void xen_send_IPI_mask(const struct cpumask *mask,
bcda016e MT	411	enum ipi_vector vector)
f87e4cac JF	412	{
	413	unsigned cpu;
	414
bcda016e	415	for_each_cpu_and(cpu, mask, cpu_online_mask)
f87e4cac JF	416	xen_send_IPI_one(cpu, vector);
	417	}
	418
bcda016e	419	static void xen_smp_send_call_function_ipi(const struct cpumask *mask)
3b16cf87 JA	420	{
	421	int cpu;
	422
	423	xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
	424
	425	/* Make sure other vcpus get a chance to run if they need to. */
bcda016e	426	for_each_cpu(cpu, mask) {
3b16cf87	427	if (xen_vcpu_stolen(cpu)) {
1207cf8e	428	HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
3b16cf87 JA	429	break;
	430	}
	431	}
	432	}
	433
a9e7062d	434	static void xen_smp_send_call_function_single_ipi(int cpu)
3b16cf87	435	{
bcda016e	436	xen_send_IPI_mask(cpumask_of(cpu),
e7986739	437	XEN_CALL_FUNCTION_SINGLE_VECTOR);
3b16cf87 JA	438	}
3b16cf87 JA	439
f87e4cac JF	440	static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
f87e4cac JF	441	{
f87e4cac	442	irq_enter();
3b16cf87	443	generic_smp_call_function_interrupt();
1b437c8c	444	inc_irq_stat(irq_call_count);
f87e4cac JF	445	irq_exit();
f87e4cac JF	446
f87e4cac JF	447	return IRQ_HANDLED;
	448	}
	449
3b16cf87	450	static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
f87e4cac	451	{
3b16cf87 JA	452	irq_enter();
3b16cf87 JA	453	generic_smp_call_function_single_interrupt();
1b437c8c	454	inc_irq_stat(irq_call_count);
3b16cf87	455	irq_exit();
f87e4cac	456
3b16cf87	457	return IRQ_HANDLED;
f87e4cac	458	}
a9e7062d JF	459
	460	static const struct smp_ops xen_smp_ops __initdata = {
	461	.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
	462	.smp_prepare_cpus = xen_smp_prepare_cpus,
a9e7062d JF	463	.smp_cpus_done = xen_smp_cpus_done,
a9e7062d JF	464
d68d82af AN	465	.cpu_up = xen_cpu_up,
	466	.cpu_die = xen_cpu_die,
	467	.cpu_disable = xen_cpu_disable,
	468	.play_dead = xen_play_dead,
	469
a9e7062d JF	470	.smp_send_stop = xen_smp_send_stop,
	471	.smp_send_reschedule = xen_smp_send_reschedule,
	472
	473	.send_call_func_ipi = xen_smp_send_call_function_ipi,
	474	.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi,
	475	};
	476
	477	void __init xen_smp_init(void)
	478	{
	479	smp_ops = xen_smp_ops;
c7b75947	480	xen_fill_possible_map();
2d9e1e2f	481	xen_init_spinlocks();
a9e7062d	482	}