1 files changed, 456 insertions, 284 deletions

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index d8faf79a0a1..7005974c3ff 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -11,13 +11,13 @@
  * 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.
- *
- * This does not handle HOTPLUG_CPU yet.
  */
 #include <linux/sched.h>
-#include <linux/kernel_stat.h>
 #include <linux/err.h>
+#include <linux/slab.h>
 #include <linux/smp.h>
+#include <linux/irq_work.h>
+#include <linux/tick.h>
 
 #include <asm/paravirt.h>
 #include <asm/desc.h>
@@ -30,50 +30,54 @@
 #include <asm/xen/interface.h>
 #include <asm/xen/hypercall.h>
 
+#include <xen/xen.h>
 #include <xen/page.h>
 #include <xen/events.h>
 
+#include <xen/hvc-console.h>
 #include "xen-ops.h"
 #include "mmu.h"
 
-static void __cpuinit xen_init_lock_cpu(int cpu);
-
-cpumask_t xen_cpu_initialized_map;
+cpumask_var_t xen_cpu_initialized_map;
 
-static DEFINE_PER_CPU(int, resched_irq);
-static DEFINE_PER_CPU(int, callfunc_irq);
-static DEFINE_PER_CPU(int, callfuncsingle_irq);
-static DEFINE_PER_CPU(int, debug_irq) = -1;
+struct xen_common_irq {
+	int irq;
+	char *name;
+};
+static DEFINE_PER_CPU(struct xen_common_irq, xen_resched_irq) = { .irq = -1 };
+static DEFINE_PER_CPU(struct xen_common_irq, xen_callfunc_irq) = { .irq = -1 };
+static DEFINE_PER_CPU(struct xen_common_irq, xen_callfuncsingle_irq) = { .irq = -1 };
+static DEFINE_PER_CPU(struct xen_common_irq, xen_irq_work) = { .irq = -1 };
+static DEFINE_PER_CPU(struct xen_common_irq, xen_debug_irq) = { .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);
+static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id);
 
 /*
- * Reschedule call back. Nothing to do,
- * all the work is done automatically when
- * we return from the interrupt.
+ * Reschedule call back.
  */
 static irqreturn_t xen_reschedule_interrupt(int irq, void *dev_id)
 {
-#ifdef CONFIG_X86_32
-	__get_cpu_var(irq_stat).irq_resched_count++;
-#else
-	add_pda(irq_resched_count, 1);
-#endif
+	inc_irq_stat(irq_resched_count);
+	scheduler_ipi();
 
 	return IRQ_HANDLED;
 }
 
-static __cpuinit void cpu_bringup_and_idle(void)
+static void cpu_bringup(void)
 {
-	int cpu = smp_processor_id();
+	int cpu;
 
 	cpu_init();
+	touch_softlockup_watchdog();
 	preempt_disable();
 
-	xen_enable_sysenter();
-	xen_enable_syscall();
-
+	/* PVH runs in ring 0 and allows us to do native syscalls. Yay! */
+	if (!xen_feature(XENFEAT_supervisor_mode_kernel)) {
+		xen_enable_sysenter();
+		xen_enable_syscall();
+	}
 	cpu = smp_processor_id();
 	smp_store_cpu_info(cpu);
 	cpu_data(cpu).x86_max_cores = 1;
@@ -81,75 +85,142 @@ static __cpuinit void cpu_bringup_and_idle(void)
 
 	xen_setup_cpu_clockevents();
 
-	cpu_set(cpu, cpu_online_map);
-	x86_write_percpu(cpu_state, CPU_ONLINE);
+	notify_cpu_starting(cpu);
+
+	set_cpu_online(cpu, true);
+
+	this_cpu_write(cpu_state, CPU_ONLINE);
+
 	wmb();
 
 	/* We can take interrupts now: we're officially "up". */
 	local_irq_enable();
 
 	wmb();			/* make sure everything is out */
-	cpu_idle();
 }
 
+/* Note: cpu parameter is only relevant for PVH */
+static void cpu_bringup_and_idle(int cpu)
+{
+#ifdef CONFIG_X86_64
+	if (xen_feature(XENFEAT_auto_translated_physmap) &&
+	    xen_feature(XENFEAT_supervisor_mode_kernel))
+		xen_pvh_secondary_vcpu_init(cpu);
+#endif
+	cpu_bringup();
+	cpu_startup_entry(CPUHP_ONLINE);
+}
+
+static void xen_smp_intr_free(unsigned int cpu)
+{
+	if (per_cpu(xen_resched_irq, cpu).irq >= 0) {
+		unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu).irq, NULL);
+		per_cpu(xen_resched_irq, cpu).irq = -1;
+		kfree(per_cpu(xen_resched_irq, cpu).name);
+		per_cpu(xen_resched_irq, cpu).name = NULL;
+	}
+	if (per_cpu(xen_callfunc_irq, cpu).irq >= 0) {
+		unbind_from_irqhandler(per_cpu(xen_callfunc_irq, cpu).irq, NULL);
+		per_cpu(xen_callfunc_irq, cpu).irq = -1;
+		kfree(per_cpu(xen_callfunc_irq, cpu).name);
+		per_cpu(xen_callfunc_irq, cpu).name = NULL;
+	}
+	if (per_cpu(xen_debug_irq, cpu).irq >= 0) {
+		unbind_from_irqhandler(per_cpu(xen_debug_irq, cpu).irq, NULL);
+		per_cpu(xen_debug_irq, cpu).irq = -1;
+		kfree(per_cpu(xen_debug_irq, cpu).name);
+		per_cpu(xen_debug_irq, cpu).name = NULL;
+	}
+	if (per_cpu(xen_callfuncsingle_irq, cpu).irq >= 0) {
+		unbind_from_irqhandler(per_cpu(xen_callfuncsingle_irq, cpu).irq,
+				       NULL);
+		per_cpu(xen_callfuncsingle_irq, cpu).irq = -1;
+		kfree(per_cpu(xen_callfuncsingle_irq, cpu).name);
+		per_cpu(xen_callfuncsingle_irq, cpu).name = NULL;
+	}
+	if (xen_hvm_domain())
+		return;
+
+	if (per_cpu(xen_irq_work, cpu).irq >= 0) {
+		unbind_from_irqhandler(per_cpu(xen_irq_work, cpu).irq, NULL);
+		per_cpu(xen_irq_work, cpu).irq = -1;
+		kfree(per_cpu(xen_irq_work, cpu).name);
+		per_cpu(xen_irq_work, cpu).name = NULL;
+	}
+};
 static int xen_smp_intr_init(unsigned int cpu)
 {
 	int rc;
-	const char *resched_name, *callfunc_name, *debug_name;
+	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,
+				    IRQF_PERCPU|IRQF_NOBALANCING,
 				    resched_name,
 				    NULL);
 	if (rc < 0)
 		goto fail;
-	per_cpu(resched_irq, cpu) = rc;
+	per_cpu(xen_resched_irq, cpu).irq = rc;
+	per_cpu(xen_resched_irq, cpu).name = resched_name;
 
 	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,
+				    IRQF_PERCPU|IRQF_NOBALANCING,
 				    callfunc_name,
 				    NULL);
 	if (rc < 0)
 		goto fail;
-	per_cpu(callfunc_irq, cpu) = rc;
+	per_cpu(xen_callfunc_irq, cpu).irq = rc;
+	per_cpu(xen_callfunc_irq, cpu).name = callfunc_name;
 
 	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,
+				     IRQF_PERCPU | IRQF_NOBALANCING,
 				     debug_name, NULL);
 	if (rc < 0)
 		goto fail;
-	per_cpu(debug_irq, cpu) = rc;
+	per_cpu(xen_debug_irq, cpu).irq = rc;
+	per_cpu(xen_debug_irq, cpu).name = debug_name;
 
 	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,
+				    IRQF_PERCPU|IRQF_NOBALANCING,
 				    callfunc_name,
 				    NULL);
 	if (rc < 0)
 		goto fail;
-	per_cpu(callfuncsingle_irq, cpu) = rc;
+	per_cpu(xen_callfuncsingle_irq, cpu).irq = rc;
+	per_cpu(xen_callfuncsingle_irq, cpu).name = callfunc_name;
+
+	/*
+	 * The IRQ worker on PVHVM goes through the native path and uses the
+	 * IPI mechanism.
+	 */
+	if (xen_hvm_domain())
+		return 0;
+
+	callfunc_name = kasprintf(GFP_KERNEL, "irqwork%d", cpu);
+	rc = bind_ipi_to_irqhandler(XEN_IRQ_WORK_VECTOR,
+				    cpu,
+				    xen_irq_work_interrupt,
+				    IRQF_PERCPU|IRQF_NOBALANCING,
+				    callfunc_name,
+				    NULL);
+	if (rc < 0)
+		goto fail;
+	per_cpu(xen_irq_work, cpu).irq = rc;
+	per_cpu(xen_irq_work, cpu).name = callfunc_name;
 
 	return 0;
 
  fail:
-	if (per_cpu(resched_irq, cpu) >= 0)
-		unbind_from_irqhandler(per_cpu(resched_irq, cpu), NULL);
-	if (per_cpu(callfunc_irq, cpu) >= 0)
-		unbind_from_irqhandler(per_cpu(callfunc_irq, cpu), NULL);
-	if (per_cpu(debug_irq, cpu) >= 0)
-		unbind_from_irqhandler(per_cpu(debug_irq, cpu), NULL);
-	if (per_cpu(callfuncsingle_irq, cpu) >= 0)
-		unbind_from_irqhandler(per_cpu(callfuncsingle_irq, cpu), NULL);
-
+	xen_smp_intr_free(cpu);
 	return rc;
 }
 
@@ -157,72 +228,139 @@ static void __init xen_fill_possible_map(void)
 {
 	int i, rc;
 
-	for (i = 0; i < NR_CPUS; i++) {
+	if (xen_initial_domain())
+		return;
+
+	for (i = 0; i < nr_cpu_ids; i++) {
 		rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
 		if (rc >= 0) {
 			num_processors++;
-			cpu_set(i, cpu_possible_map);
+			set_cpu_possible(i, true);
 		}
 	}
 }
 
+static void __init xen_filter_cpu_maps(void)
+{
+	int i, rc;
+	unsigned int subtract = 0;
+
+	if (!xen_initial_domain())
+		return;
+
+	num_processors = 0;
+	disabled_cpus = 0;
+	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);
+		} else {
+			set_cpu_possible(i, false);
+			set_cpu_present(i, false);
+			subtract++;
+		}
+	}
+#ifdef CONFIG_HOTPLUG_CPU
+	/* This is akin to using 'nr_cpus' on the Linux command line.
+	 * Which is OK as when we use 'dom0_max_vcpus=X' we can only
+	 * have up to X, while nr_cpu_ids is greater than X. This
+	 * normally is not a problem, except when CPU hotplugging
+	 * is involved and then there might be more than X CPUs
+	 * in the guest - which will not work as there is no
+	 * hypercall to expand the max number of VCPUs an already
+	 * running guest has. So cap it up to X. */
+	if (subtract)
+		nr_cpu_ids = nr_cpu_ids - subtract;
+#endif
+
+}
+
 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(&per_cpu_var(gdt_page));
+	if (xen_pv_domain()) {
+		if (!xen_feature(XENFEAT_writable_page_tables))
+			/* 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);
+
+#ifdef CONFIG_X86_32
+		/*
+		 * Xen starts us with XEN_FLAT_RING1_DS, but linux code
+		 * expects __USER_DS
+		 */
+		loadsegment(ds, __USER_DS);
+		loadsegment(es, __USER_DS);
+#endif
 
-	xen_setup_vcpu_info_placement();
+		xen_filter_cpu_maps();
+		xen_setup_vcpu_info_placement();
+	}
+	/*
+	 * The alternative logic (which patches the unlock/lock) runs before
+	 * the smp bootup up code is activated. Hence we need to set this up
+	 * the core kernel is being patched. Otherwise we will have only
+	 * modules patched but not core code.
+	 */
+	xen_init_spinlocks();
 }
 
 static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
 {
 	unsigned cpu;
+	unsigned int i;
+
+	if (skip_ioapic_setup) {
+		char *m = (max_cpus == 0) ?
+			"The nosmp parameter is incompatible with Xen; " \
+			"use Xen dom0_max_vcpus=1 parameter" :
+			"The noapic parameter is incompatible with Xen";
 
+		xen_raw_printk(m);
+		panic(m);
+	}
 	xen_init_lock_cpu(0);
 
-	smp_store_cpu_info(0);
+	smp_store_boot_cpu_info();
 	cpu_data(0).x86_max_cores = 1;
+
+	for_each_possible_cpu(i) {
+		zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
+		zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
+		zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
+	}
 	set_cpu_sibling_map(0);
 
 	if (xen_smp_intr_init(0))
 		BUG();
 
-	xen_cpu_initialized_map = cpumask_of_cpu(0);
+	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_CPUS - 1; !cpu_possible(cpu); cpu--)
+		for (cpu = nr_cpu_ids - 1; !cpu_possible(cpu); cpu--)
 			continue;
-		cpu_clear(cpu, cpu_possible_map);
+		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);
-
-		cpu_set(cpu, cpu_present_map);
-	}
-
-	//init_xenbus_allowed_cpumask();
+	for_each_possible_cpu(cpu)
+		set_cpu_present(cpu, true);
 }
 
-static __cpuinit int
+static 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 (cpu_test_and_set(cpu, xen_cpu_initialized_map))
+	if (cpumask_test_and_set_cpu(cpu, xen_cpu_initialized_map))
 		return 0;
 
 	ctxt = kzalloc(sizeof(*ctxt), GFP_KERNEL);
@@ -231,44 +369,62 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 
 	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
+	/* Note: PVH is not yet supported on x86_32. */
 	ctxt->user_regs.fs = __KERNEL_PERCPU;
+	ctxt->user_regs.gs = __KERNEL_STACK_CANARY;
 #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);
+	if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+		ctxt->flags = VGCF_IN_KERNEL;
+		ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
+		ctxt->user_regs.ds = __USER_DS;
+		ctxt->user_regs.es = __USER_DS;
+		ctxt->user_regs.ss = __KERNEL_DS;
 
-	ctxt->ldt_ents = 0;
+		xen_copy_trap_info(ctxt->trap_ctxt);
 
-	BUG_ON((unsigned long)gdt & ~PAGE_MASK);
-	make_lowmem_page_readonly(gdt);
+		ctxt->ldt_ents = 0;
 
-	ctxt->gdt_frames[0] = virt_to_mfn(gdt);
-	ctxt->gdt_ents      = GDT_ENTRIES;
+		BUG_ON((unsigned long)gdt & ~PAGE_MASK);
 
-	ctxt->user_regs.cs = __KERNEL_CS;
-	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
+		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->kernel_ss = __KERNEL_DS;
-	ctxt->kernel_sp = idle->thread.sp0;
+		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;
+		ctxt->event_callback_cs     = __KERNEL_CS;
+		ctxt->failsafe_callback_cs  = __KERNEL_CS;
+#else
+		ctxt->gs_base_kernel = per_cpu_offset(cpu);
 #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->event_callback_eip    =
+					(unsigned long)xen_hypervisor_callback;
+		ctxt->failsafe_callback_eip =
+					(unsigned long)xen_failsafe_callback;
+		ctxt->user_regs.cs = __KERNEL_CS;
+		per_cpu(xen_cr3, cpu) = __pa(swapper_pg_dir);
+#ifdef CONFIG_X86_32
+	}
+#else
+	} else
+		/* N.B. The user_regs.eip (cpu_bringup_and_idle) is called with
+		 * %rdi having the cpu number - which means are passing in
+		 * as the first parameter the cpu. Subtle!
+		 */
+		ctxt->user_regs.rdi = cpu;
+#endif
+	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
 	ctxt->ctrlreg[3] = xen_pfn_to_cr3(virt_to_mfn(swapper_pg_dir));
-
 	if (HYPERVISOR_vcpu_op(VCPUOP_initialise, cpu, ctxt))
 		BUG();
 
@@ -276,35 +432,21 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 	return 0;
 }
 
-static int __cpuinit xen_cpu_up(unsigned int cpu)
+static int xen_cpu_up(unsigned int cpu, struct task_struct *idle)
 {
-	struct task_struct *idle = idle_task(cpu);
 	int rc;
 
-#if 0
-	rc = cpu_up_check(cpu);
-	if (rc)
-		return rc;
-#endif
-
-#ifdef CONFIG_X86_64
-	/* Allocate node local memory for AP pdas */
-	WARN_ON(cpu == 0);
-	if (cpu > 0) {
-		rc = get_local_pda(cpu);
-		if (rc)
-			return rc;
-	}
-#endif
-
-#ifdef CONFIG_X86_32
-	init_gdt(cpu);
 	per_cpu(current_task, cpu) = idle;
+#ifdef CONFIG_X86_32
 	irq_ctx_init(cpu);
 #else
-	cpu_pda(cpu)->pcurrent = idle;
 	clear_tsk_thread_flag(idle, TIF_FORK);
 #endif
+	per_cpu(kernel_stack, cpu) =
+		(unsigned long)task_stack_page(idle) -
+		KERNEL_STACK_OFFSET + THREAD_SIZE;
+
+	xen_setup_runstate_info(cpu);
 	xen_setup_timer(cpu);
 	xen_init_lock_cpu(cpu);
 
@@ -318,7 +460,8 @@ static int __cpuinit xen_cpu_up(unsigned int cpu)
 		return rc;
 
 	if (num_online_cpus() == 1)
-		alternatives_smp_switch(1);
+		/* Just in case we booted with a single CPU. */
+		alternatives_enable_smp();
 
 	rc = xen_smp_intr_init(cpu);
 	if (rc)
@@ -328,7 +471,7 @@ static int __cpuinit xen_cpu_up(unsigned int cpu)
 	BUG_ON(rc);
 
 	while(per_cpu(cpu_state, cpu) != CPU_ONLINE) {
-		HYPERVISOR_sched_op(SCHEDOP_yield, 0);
+		HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
 		barrier();
 	}
 
@@ -339,6 +482,61 @@ 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 (xen_pv_domain() && HYPERVISOR_vcpu_op(VCPUOP_is_up, cpu, NULL)) {
+		current->state = TASK_UNINTERRUPTIBLE;
+		schedule_timeout(HZ/10);
+	}
+	xen_smp_intr_free(cpu);
+	xen_uninit_lock_cpu(cpu);
+	xen_teardown_timer(cpu);
+}
+
+static void xen_play_dead(void) /* used only with HOTPLUG_CPU */
+{
+	play_dead_common();
+	HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
+	cpu_bringup();
+	/*
+	 * commit 4b0c0f294 (tick: Cleanup NOHZ per cpu data on cpu down)
+	 * clears certain data that the cpu_idle loop (which called us
+	 * and that we return from) expects. The only way to get that
+	 * data back is to call:
+	 */
+	tick_nohz_idle_enter();
+}
+
+#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();
@@ -347,13 +545,15 @@ static void stop_self(void *v)
 	load_cr3(swapper_pg_dir);
 	/* should set up a minimal gdt */
 
+	set_cpu_online(cpu, false);
+
 	HYPERVISOR_vcpu_op(VCPUOP_down, cpu, NULL);
 	BUG();
 }
 
-static void xen_smp_send_stop(void)
+static void xen_stop_other_cpus(int wait)
 {
-	smp_call_function(stop_self, NULL, 0);
+	smp_call_function(stop_self, NULL, wait);
 }
 
 static void xen_smp_send_reschedule(int cpu)
@@ -361,26 +561,25 @@ static void xen_smp_send_reschedule(int cpu)
 	xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
 }
 
-static void xen_send_IPI_mask(cpumask_t mask, enum ipi_vector vector)
+static void __xen_send_IPI_mask(const struct cpumask *mask,
+			      int vector)
 {
 	unsigned cpu;
 
-	cpus_and(mask, mask, cpu_online_map);
-
-	for_each_cpu_mask_nr(cpu, mask)
+	for_each_cpu_and(cpu, mask, cpu_online_mask)
 		xen_send_IPI_one(cpu, vector);
 }
 
-static void xen_smp_send_call_function_ipi(cpumask_t mask)
+static void xen_smp_send_call_function_ipi(const struct cpumask *mask)
 {
 	int cpu;
 
-	xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
+	__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_mask_nr(cpu, mask) {
+	for_each_cpu(cpu, mask) {
 		if (xen_vcpu_stolen(cpu)) {
-			HYPERVISOR_sched_op(SCHEDOP_yield, 0);
+			HYPERVISOR_sched_op(SCHEDOP_yield, NULL);
 			break;
 		}
 	}
@@ -388,208 +587,131 @@ static void xen_smp_send_call_function_ipi(cpumask_t mask)
 
 static void xen_smp_send_call_function_single_ipi(int cpu)
 {
-	xen_send_IPI_mask(cpumask_of_cpu(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();
-#ifdef CONFIG_X86_32
-	__get_cpu_var(irq_stat).irq_call_count++;
-#else
-	add_pda(irq_call_count, 1);
-#endif
-	irq_exit();
-
-	return IRQ_HANDLED;
+	__xen_send_IPI_mask(cpumask_of(cpu),
+			  XEN_CALL_FUNCTION_SINGLE_VECTOR);
 }
 
-static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
+static inline int xen_map_vector(int vector)
 {
-	irq_enter();
-	generic_smp_call_function_single_interrupt();
-#ifdef CONFIG_X86_32
-	__get_cpu_var(irq_stat).irq_call_count++;
-#else
-	add_pda(irq_call_count, 1);
+	int xen_vector;
+
+	switch (vector) {
+	case RESCHEDULE_VECTOR:
+		xen_vector = XEN_RESCHEDULE_VECTOR;
+		break;
+	case CALL_FUNCTION_VECTOR:
+		xen_vector = XEN_CALL_FUNCTION_VECTOR;
+		break;
+	case CALL_FUNCTION_SINGLE_VECTOR:
+		xen_vector = XEN_CALL_FUNCTION_SINGLE_VECTOR;
+		break;
+	case IRQ_WORK_VECTOR:
+		xen_vector = XEN_IRQ_WORK_VECTOR;
+		break;
+#ifdef CONFIG_X86_64
+	case NMI_VECTOR:
+	case APIC_DM_NMI: /* Some use that instead of NMI_VECTOR */
+		xen_vector = XEN_NMI_VECTOR;
+		break;
 #endif
-	irq_exit();
-
-	return IRQ_HANDLED;
-}
-
-struct xen_spinlock {
-	unsigned char lock;		/* 0 -> free; 1 -> locked */
-	unsigned short spinners;	/* count of waiting cpus */
-};
-
-static int xen_spin_is_locked(struct raw_spinlock *lock)
-{
-	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
+	default:
+		xen_vector = -1;
+		printk(KERN_ERR "xen: vector 0x%x is not implemented\n",
+			vector);
+	}
 
-	return xl->lock != 0;
+	return xen_vector;
 }
 
-static int xen_spin_is_contended(struct raw_spinlock *lock)
+void xen_send_IPI_mask(const struct cpumask *mask,
+			      int vector)
 {
-	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
+	int xen_vector = xen_map_vector(vector);
 
-	/* Not strictly true; this is only the count of contended
-	   lock-takers entering the slow path. */
-	return xl->spinners != 0;
+	if (xen_vector >= 0)
+		__xen_send_IPI_mask(mask, xen_vector);
 }
 
-static int xen_spin_trylock(struct raw_spinlock *lock)
+void xen_send_IPI_all(int vector)
 {
-	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-	u8 old = 1;
-
-	asm("xchgb %b0,%1"
-	    : "+q" (old), "+m" (xl->lock) : : "memory");
+	int xen_vector = xen_map_vector(vector);
 
-	return old == 0;
+	if (xen_vector >= 0)
+		__xen_send_IPI_mask(cpu_online_mask, xen_vector);
 }
 
-static DEFINE_PER_CPU(int, lock_kicker_irq) = -1;
-static DEFINE_PER_CPU(struct xen_spinlock *, lock_spinners);
-
-static inline void spinning_lock(struct xen_spinlock *xl)
+void xen_send_IPI_self(int vector)
 {
-	__get_cpu_var(lock_spinners) = xl;
-	wmb();			/* set lock of interest before count */
-	asm(LOCK_PREFIX " incw %0"
-	    : "+m" (xl->spinners) : : "memory");
-}
+	int xen_vector = xen_map_vector(vector);
 
-static inline void unspinning_lock(struct xen_spinlock *xl)
-{
-	asm(LOCK_PREFIX " decw %0"
-	    : "+m" (xl->spinners) : : "memory");
-	wmb();			/* decrement count before clearing lock */
-	__get_cpu_var(lock_spinners) = NULL;
+	if (xen_vector >= 0)
+		xen_send_IPI_one(smp_processor_id(), xen_vector);
 }
 
-static noinline int xen_spin_lock_slow(struct raw_spinlock *lock)
+void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
+				int vector)
 {
-	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-	int irq = __get_cpu_var(lock_kicker_irq);
-	int ret;
-
-	/* If kicker interrupts not initialized yet, just spin */
-	if (irq == -1)
-		return 0;
-
-	/* announce we're spinning */
-	spinning_lock(xl);
-
-	/* clear pending */
-	xen_clear_irq_pending(irq);
+	unsigned cpu;
+	unsigned int this_cpu = smp_processor_id();
+	int xen_vector = xen_map_vector(vector);
 
-	/* check again make sure it didn't become free while
-	   we weren't looking  */
-	ret = xen_spin_trylock(lock);
-	if (ret)
-		goto out;
+	if (!(num_online_cpus() > 1) || (xen_vector < 0))
+		return;
 
-	/* block until irq becomes pending */
-	xen_poll_irq(irq);
-	kstat_this_cpu.irqs[irq]++;
+	for_each_cpu_and(cpu, mask, cpu_online_mask) {
+		if (this_cpu == cpu)
+			continue;
 
-out:
-	unspinning_lock(xl);
-	return ret;
+		xen_send_IPI_one(cpu, xen_vector);
+	}
 }
 
-static void xen_spin_lock(struct raw_spinlock *lock)
+void xen_send_IPI_allbutself(int vector)
 {
-	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-	int timeout;
-	u8 oldval;
-
-	do {
-		timeout = 1 << 10;
-
-		asm("1: xchgb %1,%0\n"
-		    "   testb %1,%1\n"
-		    "   jz 3f\n"
-		    "2: rep;nop\n"
-		    "   cmpb $0,%0\n"
-		    "   je 1b\n"
-		    "   dec %2\n"
-		    "   jnz 2b\n"
-		    "3:\n"
-		    : "+m" (xl->lock), "=q" (oldval), "+r" (timeout)
-		    : "1" (1)
-		    : "memory");
-
-	} while (unlikely(oldval != 0 && !xen_spin_lock_slow(lock)));
+	xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
 }
 
-static noinline void xen_spin_unlock_slow(struct xen_spinlock *xl)
+static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)
 {
-	int cpu;
+	irq_enter();
+	generic_smp_call_function_interrupt();
+	inc_irq_stat(irq_call_count);
+	irq_exit();
 
-	for_each_online_cpu(cpu) {
-		/* XXX should mix up next cpu selection */
-		if (per_cpu(lock_spinners, cpu) == xl) {
-			xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR);
-			break;
-		}
-	}
+	return IRQ_HANDLED;
 }
 
-static void xen_spin_unlock(struct raw_spinlock *lock)
+static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
 {
-	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
-
-	smp_wmb();		/* make sure no writes get moved after unlock */
-	xl->lock = 0;		/* release lock */
-
-	/* make sure unlock happens before kick */
-	barrier();
+	irq_enter();
+	generic_smp_call_function_single_interrupt();
+	inc_irq_stat(irq_call_count);
+	irq_exit();
 
-	if (unlikely(xl->spinners))
-		xen_spin_unlock_slow(xl);
+	return IRQ_HANDLED;
 }
 
-static __cpuinit void xen_init_lock_cpu(int cpu)
+static irqreturn_t xen_irq_work_interrupt(int irq, void *dev_id)
 {
-	int irq;
-	const char *name;
-
-	name = kasprintf(GFP_KERNEL, "spinlock%d", cpu);
-	irq = bind_ipi_to_irqhandler(XEN_SPIN_UNLOCK_VECTOR,
-				     cpu,
-				     xen_reschedule_interrupt,
-				     IRQF_DISABLED|IRQF_PERCPU|IRQF_NOBALANCING,
-				     name,
-				     NULL);
-
-	if (irq >= 0) {
-		disable_irq(irq); /* make sure it's never delivered */
-		per_cpu(lock_kicker_irq, cpu) = irq;
-	}
-
-	printk("cpu %d spinlock event irq %d\n", cpu, irq);
-}
+	irq_enter();
+	irq_work_run();
+	inc_irq_stat(apic_irq_work_irqs);
+	irq_exit();
 
-static void __init xen_init_spinlocks(void)
-{
-	pv_lock_ops.spin_is_locked = xen_spin_is_locked;
-	pv_lock_ops.spin_is_contended = xen_spin_is_contended;
-	pv_lock_ops.spin_lock = xen_spin_lock;
-	pv_lock_ops.spin_trylock = xen_spin_trylock;
-	pv_lock_ops.spin_unlock = xen_spin_unlock;
+	return IRQ_HANDLED;
 }
 
-static const struct smp_ops xen_smp_ops __initdata = {
+static const struct smp_ops xen_smp_ops __initconst = {
 	.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu,
 	.smp_prepare_cpus = xen_smp_prepare_cpus,
-	.cpu_up = xen_cpu_up,
 	.smp_cpus_done = xen_smp_cpus_done,
 
-	.smp_send_stop = xen_smp_send_stop,
+	.cpu_up = xen_cpu_up,
+	.cpu_die = xen_cpu_die,
+	.cpu_disable = xen_cpu_disable,
+	.play_dead = xen_play_dead,
+
+	.stop_other_cpus = xen_stop_other_cpus,
 	.smp_send_reschedule = xen_smp_send_reschedule,
 
 	.send_call_func_ipi = xen_smp_send_call_function_ipi,
@@ -600,5 +722,55 @@ void __init xen_smp_init(void)
 {
 	smp_ops = xen_smp_ops;
 	xen_fill_possible_map();
-	xen_init_spinlocks();
+}
+
+static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
+{
+	native_smp_prepare_cpus(max_cpus);
+	WARN_ON(xen_smp_intr_init(0));
+
+	xen_init_lock_cpu(0);
+}
+
+static int xen_hvm_cpu_up(unsigned int cpu, struct task_struct *tidle)
+{
+	int rc;
+	/*
+	 * xen_smp_intr_init() needs to run before native_cpu_up()
+	 * so that IPI vectors are set up on the booting CPU before
+	 * it is marked online in native_cpu_up().
+	*/
+	rc = xen_smp_intr_init(cpu);
+	WARN_ON(rc);
+	if (!rc)
+		rc =  native_cpu_up(cpu, tidle);
+
+	/*
+	 * We must initialize the slowpath CPU kicker _after_ the native
+	 * path has executed. If we initialized it before none of the
+	 * unlocker IPI kicks would reach the booting CPU as the booting
+	 * CPU had not set itself 'online' in cpu_online_mask. That mask
+	 * is checked when IPIs are sent (on HVM at least).
+	 */
+	xen_init_lock_cpu(cpu);
+	return rc;
+}
+
+static void xen_hvm_cpu_die(unsigned int cpu)
+{
+	xen_cpu_die(cpu);
+	native_cpu_die(cpu);
+}
+
+void __init xen_hvm_smp_init(void)
+{
+	if (!xen_have_vector_callback)
+		return;
+	smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
+	smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
+	smp_ops.cpu_up = xen_hvm_cpu_up;
+	smp_ops.cpu_die = xen_hvm_cpu_die;
+	smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
+	smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
+	smp_ops.smp_prepare_boot_cpu = xen_smp_prepare_boot_cpu;
 }