1 files changed, 289 insertions, 122 deletions

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index d2e3c20127d7..d8faf79a0a1d 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -15,6 +15,7 @@
  * This does not handle HOTPLUG_CPU yet.
  */
 #include <linux/sched.h>
+#include <linux/kernel_stat.h>
 #include <linux/err.h>
 #include <linux/smp.h>
 
@@ -35,28 +36,17 @@
 #include "xen-ops.h"
 #include "mmu.h"
 
+static void __cpuinit xen_init_lock_cpu(int cpu);
+
 cpumask_t xen_cpu_initialized_map;
-static DEFINE_PER_CPU(int, resched_irq) = -1;
-static DEFINE_PER_CPU(int, callfunc_irq) = -1;
-static DEFINE_PER_CPU(int, debug_irq) = -1;
 
-/*
- * Structure and data for smp_call_function(). This is designed to minimise
- * static memory requirements. It also looks cleaner.
- */
-static DEFINE_SPINLOCK(call_lock);
-
-struct call_data_struct {
-	void (*func) (void *info);
-	void *info;
-	atomic_t started;
-	atomic_t finished;
-	int wait;
-};
+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;
 
 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id);
-
-static struct call_data_struct *call_data;
+static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id);
 
 /*
  * Reschedule call back. Nothing to do,
@@ -79,13 +69,22 @@ static __cpuinit void cpu_bringup_and_idle(void)
 	int cpu = smp_processor_id();
 
 	cpu_init();
+	preempt_disable();
+
 	xen_enable_sysenter();
+	xen_enable_syscall();
 
-	preempt_disable();
-	per_cpu(cpu_state, cpu) = CPU_ONLINE;
+	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();
 
+	cpu_set(cpu, cpu_online_map);
+	x86_write_percpu(cpu_state, CPU_ONLINE);
+	wmb();
+
 	/* We can take interrupts now: we're officially "up". */
 	local_irq_enable();
 
@@ -128,6 +127,17 @@ static int xen_smp_intr_init(unsigned int cpu)
 		goto fail;
 	per_cpu(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(callfuncsingle_irq, cpu) = rc;
+
 	return 0;
 
  fail:
@@ -137,59 +147,45 @@ static int xen_smp_intr_init(unsigned int cpu)
 		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);
+
 	return rc;
 }
 
-void __init xen_fill_possible_map(void)
+static void __init xen_fill_possible_map(void)
 {
 	int i, rc;
 
 	for (i = 0; i < NR_CPUS; i++) {
 		rc = HYPERVISOR_vcpu_op(VCPUOP_is_up, i, NULL);
-		if (rc >= 0)
+		if (rc >= 0) {
+			num_processors++;
 			cpu_set(i, cpu_possible_map);
+		}
 	}
 }
 
-void __init xen_smp_prepare_boot_cpu(void)
+static void __init xen_smp_prepare_boot_cpu(void)
 {
-	int cpu;
-
 	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__gdt_page);
-
-	for_each_possible_cpu(cpu) {
-		cpus_clear(per_cpu(cpu_sibling_map, cpu));
-		/*
-		 * cpu_core_map lives in a per cpu area that is cleared
-		 * when the per cpu array is allocated.
-		 *
-		 * cpus_clear(per_cpu(cpu_core_map, cpu));
-		 */
-	}
+	make_lowmem_page_readwrite(&per_cpu_var(gdt_page));
 
 	xen_setup_vcpu_info_placement();
 }
 
-void __init xen_smp_prepare_cpus(unsigned int max_cpus)
+static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
 {
 	unsigned cpu;
 
-	for_each_possible_cpu(cpu) {
-		cpus_clear(per_cpu(cpu_sibling_map, cpu));
-		/*
-		 * cpu_core_ map will be zeroed when the per
-		 * cpu area is allocated.
-		 *
-		 * cpus_clear(per_cpu(cpu_core_map, 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))
@@ -224,7 +220,7 @@ static __cpuinit int
 cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 {
 	struct vcpu_guest_context *ctxt;
-	struct gdt_page *gdt = &per_cpu(gdt_page, cpu);
+	struct desc_struct *gdt;
 
 	if (cpu_test_and_set(cpu, xen_cpu_initialized_map))
 		return 0;
@@ -233,12 +229,15 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 	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.fs = __KERNEL_PERCPU;
-	ctxt->user_regs.gs = 0;
 	ctxt->user_regs.ss = __KERNEL_DS;
+#ifdef CONFIG_X86_32
+	ctxt->user_regs.fs = __KERNEL_PERCPU;
+#endif
 	ctxt->user_regs.eip = (unsigned long)cpu_bringup_and_idle;
 	ctxt->user_regs.eflags = 0x1000; /* IOPL_RING1 */
 
@@ -248,11 +247,11 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 
 	ctxt->ldt_ents = 0;
 
-	BUG_ON((unsigned long)gdt->gdt & ~PAGE_MASK);
-	make_lowmem_page_readonly(gdt->gdt);
+	BUG_ON((unsigned long)gdt & ~PAGE_MASK);
+	make_lowmem_page_readonly(gdt);
 
-	ctxt->gdt_frames[0] = virt_to_mfn(gdt->gdt);
-	ctxt->gdt_ents      = ARRAY_SIZE(gdt->gdt);
+	ctxt->gdt_frames[0] = virt_to_mfn(gdt);
+	ctxt->gdt_ents      = GDT_ENTRIES;
 
 	ctxt->user_regs.cs = __KERNEL_CS;
 	ctxt->user_regs.esp = idle->thread.sp0 - sizeof(struct pt_regs);
@@ -260,9 +259,11 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 	ctxt->kernel_ss = __KERNEL_DS;
 	ctxt->kernel_sp = idle->thread.sp0;
 
+#ifdef CONFIG_X86_32
 	ctxt->event_callback_cs     = __KERNEL_CS;
-	ctxt->event_callback_eip    = (unsigned long)xen_hypervisor_callback;
 	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);
@@ -275,7 +276,7 @@ cpu_initialize_context(unsigned int cpu, struct task_struct *idle)
 	return 0;
 }
 
-int __cpuinit xen_cpu_up(unsigned int cpu)
+static int __cpuinit xen_cpu_up(unsigned int cpu)
 {
 	struct task_struct *idle = idle_task(cpu);
 	int rc;
@@ -286,10 +287,28 @@ int __cpuinit xen_cpu_up(unsigned int cpu)
 		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;
 	irq_ctx_init(cpu);
+#else
+	cpu_pda(cpu)->pcurrent = idle;
+	clear_tsk_thread_flag(idle, TIF_FORK);
+#endif
 	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;
@@ -305,20 +324,18 @@ int __cpuinit xen_cpu_up(unsigned int cpu)
 	if (rc)
 		return rc;
 
-	smp_store_cpu_info(cpu);
-	set_cpu_sibling_map(cpu);
-	/* This must be done before setting cpu_online_map */
-	wmb();
-
-	cpu_set(cpu, cpu_online_map);
-
 	rc = HYPERVISOR_vcpu_op(VCPUOP_up, cpu, NULL);
 	BUG_ON(rc);
 
+	while(per_cpu(cpu_state, cpu) != CPU_ONLINE) {
+		HYPERVISOR_sched_op(SCHEDOP_yield, 0);
+		barrier();
+	}
+
 	return 0;
 }
 
-void xen_smp_cpus_done(unsigned int max_cpus)
+static void xen_smp_cpus_done(unsigned int max_cpus)
 {
 }
 
@@ -334,104 +351,254 @@ static void stop_self(void *v)
 	BUG();
 }
 
-void xen_smp_send_stop(void)
+static void xen_smp_send_stop(void)
 {
-	smp_call_function(stop_self, NULL, 0, 0);
+	smp_call_function(stop_self, NULL, 0);
 }
 
-void xen_smp_send_reschedule(int cpu)
+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)
 {
 	unsigned cpu;
 
 	cpus_and(mask, mask, cpu_online_map);
 
-	for_each_cpu_mask(cpu, mask)
+	for_each_cpu_mask_nr(cpu, mask)
 		xen_send_IPI_one(cpu, vector);
 }
 
+static void xen_smp_send_call_function_ipi(cpumask_t 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_mask_nr(cpu, mask) {
+		if (xen_vcpu_stolen(cpu)) {
+			HYPERVISOR_sched_op(SCHEDOP_yield, 0);
+			break;
+		}
+	}
+}
+
+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)
 {
-	void (*func) (void *info) = call_data->func;
-	void *info = call_data->info;
-	int wait = call_data->wait;
-
-	/*
-	 * Notify initiating CPU that I've grabbed the data and am
-	 * about to execute the function
-	 */
-	mb();
-	atomic_inc(&call_data->started);
-	/*
-	 * At this point the info structure may be out of scope unless wait==1
-	 */
 	irq_enter();
-	(*func)(info);
+	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();
 
-	if (wait) {
-		mb();		/* commit everything before setting finished */
-		atomic_inc(&call_data->finished);
-	}
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t xen_call_function_single_interrupt(int irq, void *dev_id)
+{
+	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);
+#endif
+	irq_exit();
 
 	return IRQ_HANDLED;
 }
 
-int xen_smp_call_function_mask(cpumask_t mask, void (*func)(void *),
-			       void *info, int wait)
+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;
+
+	return xl->lock != 0;
+}
+
+static int xen_spin_is_contended(struct raw_spinlock *lock)
+{
+	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
+
+	/* Not strictly true; this is only the count of contended
+	   lock-takers entering the slow path. */
+	return xl->spinners != 0;
+}
+
+static int xen_spin_trylock(struct raw_spinlock *lock)
+{
+	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
+	u8 old = 1;
+
+	asm("xchgb %b0,%1"
+	    : "+q" (old), "+m" (xl->lock) : : "memory");
+
+	return old == 0;
+}
+
+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)
 {
-	struct call_data_struct data;
-	int cpus, cpu;
-	bool yield;
+	__get_cpu_var(lock_spinners) = xl;
+	wmb();			/* set lock of interest before count */
+	asm(LOCK_PREFIX " incw %0"
+	    : "+m" (xl->spinners) : : "memory");
+}
 
-	/* Holding any lock stops cpus from going down. */
-	spin_lock(&call_lock);
+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;
+}
 
-	cpu_clear(smp_processor_id(), mask);
+static noinline int xen_spin_lock_slow(struct raw_spinlock *lock)
+{
+	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
+	int irq = __get_cpu_var(lock_kicker_irq);
+	int ret;
 
-	cpus = cpus_weight(mask);
-	if (!cpus) {
-		spin_unlock(&call_lock);
+	/* 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);
+
+	/* check again make sure it didn't become free while
+	   we weren't looking  */
+	ret = xen_spin_trylock(lock);
+	if (ret)
+		goto out;
+
+	/* block until irq becomes pending */
+	xen_poll_irq(irq);
+	kstat_this_cpu.irqs[irq]++;
+
+out:
+	unspinning_lock(xl);
+	return ret;
+}
+
+static void xen_spin_lock(struct raw_spinlock *lock)
+{
+	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)));
+}
+
+static noinline void xen_spin_unlock_slow(struct xen_spinlock *xl)
+{
+	int cpu;
+
+	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;
+		}
 	}
+}
 
-	/* Can deadlock when called with interrupts disabled */
-	WARN_ON(irqs_disabled());
+static void xen_spin_unlock(struct raw_spinlock *lock)
+{
+	struct xen_spinlock *xl = (struct xen_spinlock *)lock;
 
-	data.func = func;
-	data.info = info;
-	atomic_set(&data.started, 0);
-	data.wait = wait;
-	if (wait)
-		atomic_set(&data.finished, 0);
+	smp_wmb();		/* make sure no writes get moved after unlock */
+	xl->lock = 0;		/* release lock */
 
-	call_data = &data;
-	mb();			/* write everything before IPI */
+	/* make sure unlock happens before kick */
+	barrier();
 
-	/* Send a message to other CPUs and wait for them to respond */
-	xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);
+	if (unlikely(xl->spinners))
+		xen_spin_unlock_slow(xl);
+}
 
-	/* Make sure other vcpus get a chance to run if they need to. */
-	yield = false;
-	for_each_cpu_mask(cpu, mask)
-		if (xen_vcpu_stolen(cpu))
-			yield = true;
+static __cpuinit void xen_init_lock_cpu(int cpu)
+{
+	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;
+	}
 
-	if (yield)
-		HYPERVISOR_sched_op(SCHEDOP_yield, 0);
+	printk("cpu %d spinlock event irq %d\n", cpu, irq);
+}
 
-	/* Wait for response */
-	while (atomic_read(&data.started) != cpus ||
-	       (wait && atomic_read(&data.finished) != cpus))
-		cpu_relax();
+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;
+}
 
-	spin_unlock(&call_lock);
+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,
+	.cpu_up = xen_cpu_up,
+	.smp_cpus_done = xen_smp_cpus_done,
 
-	return 0;
+	.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();
 }