xen/events: move 2-level specific code into its own file

obj-y += events.o

events-y += events_base.o

events-y += events_2l.o

/*

 * Xen event channels (2-level ABI)

 *

 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007

 */

#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt

#include <linux/linkage.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/module.h>

#include <asm/sync_bitops.h>

#include <asm/xen/hypercall.h>

#include <asm/xen/hypervisor.h>

#include <xen/xen.h>

#include <xen/xen-ops.h>

#include <xen/events.h>

#include <xen/interface/xen.h>

#include <xen/interface/event_channel.h>

#include "events_internal.h"

/*

 * Note sizeof(xen_ulong_t) can be more than sizeof(unsigned long). Be

 * careful to only use bitops which allow for this (e.g

 * test_bit/find_first_bit and friends but not __ffs) and to pass

 * BITS_PER_EVTCHN_WORD as the bitmask length.

 */

#define BITS_PER_EVTCHN_WORD (sizeof(xen_ulong_t)*8)

/*

 * Make a bitmask (i.e. unsigned long *) of a xen_ulong_t

 * array. Primarily to avoid long lines (hence the terse name).

 */

#define BM(x) (unsigned long *)(x)

/* Find the first set bit in a evtchn mask */

#define EVTCHN_FIRST_BIT(w) find_first_bit(BM(&(w)), BITS_PER_EVTCHN_WORD)

static DEFINE_PER_CPU(xen_ulong_t [NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD],

		      cpu_evtchn_mask);

void xen_evtchn_port_bind_to_cpu(struct irq_info *info, int cpu)

{

	clear_bit(info->evtchn, BM(per_cpu(cpu_evtchn_mask, info->cpu)));

	set_bit(info->evtchn, BM(per_cpu(cpu_evtchn_mask, cpu)));

}

void clear_evtchn(int port)

{

	struct shared_info *s = HYPERVISOR_shared_info;

	sync_clear_bit(port, BM(&s->evtchn_pending[0]));

}

void set_evtchn(int port)

{

	struct shared_info *s = HYPERVISOR_shared_info;

	sync_set_bit(port, BM(&s->evtchn_pending[0]));

}

int test_evtchn(int port)

{

	struct shared_info *s = HYPERVISOR_shared_info;

	return sync_test_bit(port, BM(&s->evtchn_pending[0]));

}

int test_and_set_mask(int port)

{

	struct shared_info *s = HYPERVISOR_shared_info;

	return sync_test_and_set_bit(port, BM(&s->evtchn_mask[0]));

}

void mask_evtchn(int port)

{

	struct shared_info *s = HYPERVISOR_shared_info;

	sync_set_bit(port, BM(&s->evtchn_mask[0]));

}

void unmask_evtchn(int port)

{

	struct shared_info *s = HYPERVISOR_shared_info;

	unsigned int cpu = get_cpu();

	int do_hypercall = 0, evtchn_pending = 0;

	BUG_ON(!irqs_disabled());

	if (unlikely((cpu != cpu_from_evtchn(port))))

		do_hypercall = 1;

	else {

		/*

		 * Need to clear the mask before checking pending to

		 * avoid a race with an event becoming pending.

		 *

		 * EVTCHNOP_unmask will only trigger an upcall if the

		 * mask bit was set, so if a hypercall is needed

		 * remask the event.

		 */

		sync_clear_bit(port, BM(&s->evtchn_mask[0]));

		evtchn_pending = sync_test_bit(port, BM(&s->evtchn_pending[0]));

		if (unlikely(evtchn_pending && xen_hvm_domain())) {

			sync_set_bit(port, BM(&s->evtchn_mask[0]));

			do_hypercall = 1;

		}

	}

	/* Slow path (hypercall) if this is a non-local port or if this is

	 * an hvm domain and an event is pending (hvm domains don't have

	 * their own implementation of irq_enable). */

	if (do_hypercall) {

		struct evtchn_unmask unmask = { .port = port };

		(void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);

	} else {

		struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);

		/*

		 * The following is basically the equivalent of

		 * 'hw_resend_irq'. Just like a real IO-APIC we 'lose

		 * the interrupt edge' if the channel is masked.

		 */

		if (evtchn_pending &&

		    !sync_test_and_set_bit(port / BITS_PER_EVTCHN_WORD,

					   BM(&vcpu_info->evtchn_pending_sel)))

			vcpu_info->evtchn_upcall_pending = 1;

	}

	put_cpu();

}

static DEFINE_PER_CPU(unsigned int, current_word_idx);

static DEFINE_PER_CPU(unsigned int, current_bit_idx);

/*

 * Mask out the i least significant bits of w

 */

#define MASK_LSBS(w, i) (w & ((~((xen_ulong_t)0UL)) << i))

static inline xen_ulong_t active_evtchns(unsigned int cpu,

					 struct shared_info *sh,

					 unsigned int idx)

{

	return sh->evtchn_pending[idx] &

		per_cpu(cpu_evtchn_mask, cpu)[idx] &

		~sh->evtchn_mask[idx];

}

/*

 * Search the CPU's pending events bitmasks.  For each one found, map

 * the event number to an irq, and feed it into do_IRQ() for handling.

 *

 * Xen uses a two-level bitmap to speed searching.  The first level is

 * a bitset of words which contain pending event bits.  The second

 * level is a bitset of pending events themselves.

 */

void xen_evtchn_handle_events(int cpu)

{

	int irq;

	xen_ulong_t pending_words;

	xen_ulong_t pending_bits;

	int start_word_idx, start_bit_idx;

	int word_idx, bit_idx;

	int i;

	struct irq_desc *desc;

	struct shared_info *s = HYPERVISOR_shared_info;

	struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);

	/* Timer interrupt has highest priority. */

	irq = irq_from_virq(cpu, VIRQ_TIMER);

	if (irq != -1) {

		unsigned int evtchn = evtchn_from_irq(irq);

		word_idx = evtchn / BITS_PER_LONG;

		bit_idx = evtchn % BITS_PER_LONG;

		if (active_evtchns(cpu, s, word_idx) & (1ULL << bit_idx)) {

			desc = irq_to_desc(irq);

			if (desc)

				generic_handle_irq_desc(irq, desc);

		}

	}

	/*

	 * Master flag must be cleared /before/ clearing

	 * selector flag. xchg_xen_ulong must contain an

	 * appropriate barrier.

	 */

	pending_words = xchg_xen_ulong(&vcpu_info->evtchn_pending_sel, 0);

	start_word_idx = __this_cpu_read(current_word_idx);

	start_bit_idx = __this_cpu_read(current_bit_idx);

	word_idx = start_word_idx;

	for (i = 0; pending_words != 0; i++) {

		xen_ulong_t words;

		words = MASK_LSBS(pending_words, word_idx);

		/*

		 * If we masked out all events, wrap to beginning.

		 */

		if (words == 0) {

			word_idx = 0;

			bit_idx = 0;

			continue;

		}

		word_idx = EVTCHN_FIRST_BIT(words);

		pending_bits = active_evtchns(cpu, s, word_idx);

		bit_idx = 0; /* usually scan entire word from start */

		/*

		 * We scan the starting word in two parts.

		 *

		 * 1st time: start in the middle, scanning the

		 * upper bits.

		 *

		 * 2nd time: scan the whole word (not just the

		 * parts skipped in the first pass) -- if an

		 * event in the previously scanned bits is

		 * pending again it would just be scanned on

		 * the next loop anyway.

		 */

		if (word_idx == start_word_idx) {

			if (i == 0)

				bit_idx = start_bit_idx;

		}

		do {

			xen_ulong_t bits;

			int port;

			bits = MASK_LSBS(pending_bits, bit_idx);

			/* If we masked out all events, move on. */

			if (bits == 0)

				break;

			bit_idx = EVTCHN_FIRST_BIT(bits);

			/* Process port. */

			port = (word_idx * BITS_PER_EVTCHN_WORD) + bit_idx;

			irq = evtchn_to_irq[port];

			if (irq != -1) {

				desc = irq_to_desc(irq);

				if (desc)

					generic_handle_irq_desc(irq, desc);

			}

			bit_idx = (bit_idx + 1) % BITS_PER_EVTCHN_WORD;

			/* Next caller starts at last processed + 1 */

			__this_cpu_write(current_word_idx,

					 bit_idx ? word_idx :

					 (word_idx+1) % BITS_PER_EVTCHN_WORD);

			__this_cpu_write(current_bit_idx, bit_idx);

		} while (bit_idx != 0);

		/* Scan start_l1i twice; all others once. */

		if ((word_idx != start_word_idx) || (i != 0))

			pending_words &= ~(1UL << word_idx);

		word_idx = (word_idx + 1) % BITS_PER_EVTCHN_WORD;

	}

}

irqreturn_t xen_debug_interrupt(int irq, void *dev_id)

{

	struct shared_info *sh = HYPERVISOR_shared_info;

	int cpu = smp_processor_id();

	xen_ulong_t *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);

	int i;

	unsigned long flags;

	static DEFINE_SPINLOCK(debug_lock);

	struct vcpu_info *v;

	spin_lock_irqsave(&debug_lock, flags);

	printk("\nvcpu %d\n  ", cpu);

	for_each_online_cpu(i) {

		int pending;

		v = per_cpu(xen_vcpu, i);

		pending = (get_irq_regs() && i == cpu)

			? xen_irqs_disabled(get_irq_regs())

			: v->evtchn_upcall_mask;

		printk("%d: masked=%d pending=%d event_sel %0*"PRI_xen_ulong"\n  ", i,

		       pending, v->evtchn_upcall_pending,

		       (int)(sizeof(v->evtchn_pending_sel)*2),

		       v->evtchn_pending_sel);

	}

	v = per_cpu(xen_vcpu, cpu);

	printk("\npending:\n   ");

	for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)

		printk("%0*"PRI_xen_ulong"%s",

		       (int)sizeof(sh->evtchn_pending[0])*2,

		       sh->evtchn_pending[i],

		       i % 8 == 0 ? "\n   " : " ");

	printk("\nglobal mask:\n   ");

	for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)

		printk("%0*"PRI_xen_ulong"%s",

		       (int)(sizeof(sh->evtchn_mask[0])*2),

		       sh->evtchn_mask[i],

		       i % 8 == 0 ? "\n   " : " ");

	printk("\nglobally unmasked:\n   ");

	for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)

		printk("%0*"PRI_xen_ulong"%s",

		       (int)(sizeof(sh->evtchn_mask[0])*2),

		       sh->evtchn_pending[i] & ~sh->evtchn_mask[i],

		       i % 8 == 0 ? "\n   " : " ");

	printk("\nlocal cpu%d mask:\n   ", cpu);

	for (i = (NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD)-1; i >= 0; i--)

		printk("%0*"PRI_xen_ulong"%s", (int)(sizeof(cpu_evtchn[0])*2),

		       cpu_evtchn[i],

		       i % 8 == 0 ? "\n   " : " ");

	printk("\nlocally unmasked:\n   ");

	for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {

		xen_ulong_t pending = sh->evtchn_pending[i]

			& ~sh->evtchn_mask[i]

			& cpu_evtchn[i];

		printk("%0*"PRI_xen_ulong"%s",

		       (int)(sizeof(sh->evtchn_mask[0])*2),

		       pending, i % 8 == 0 ? "\n   " : " ");

	}

	printk("\npending list:\n");

	for (i = 0; i < NR_EVENT_CHANNELS; i++) {

		if (sync_test_bit(i, BM(sh->evtchn_pending))) {

			int word_idx = i / BITS_PER_EVTCHN_WORD;

			printk("  %d: event %d -> irq %d%s%s%s\n",

			       cpu_from_evtchn(i), i,

			       evtchn_to_irq[i],

			       sync_test_bit(word_idx, BM(&v->evtchn_pending_sel))

			       ? "" : " l2-clear",

			       !sync_test_bit(i, BM(sh->evtchn_mask))

			       ? "" : " globally-masked",

			       sync_test_bit(i, BM(cpu_evtchn))

			       ? "" : " locally-masked");

		}

	}

	spin_unlock_irqrestore(&debug_lock, flags);

	return IRQ_HANDLED;

}

#include <xen/interface/vcpu.h>

#include <asm/hw_irq.h>

#include "events_internal.h"

/*

 * This lock protects updates to the following mapping and reference-count

 * arrays. The lock does not need to be acquired to read the mapping tables.

/* IRQ <-> IPI mapping */

static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};

/* Interrupt types. */

enum xen_irq_type {

	IRQT_UNBOUND = 0,

	IRQT_PIRQ,

	IRQT_VIRQ,

	IRQT_IPI,

	IRQT_EVTCHN

};

/*

 * Packed IRQ information:

 * type - enum xen_irq_type

 * event channel - irq->event channel mapping

 * cpu - cpu this event channel is bound to

 * index - type-specific information:

 *    PIRQ - physical IRQ, GSI, flags, and owner domain

 *    VIRQ - virq number

 *    IPI - IPI vector

 *    EVTCHN -

 */

struct irq_info {

	struct list_head list;

	int refcnt;

	enum xen_irq_type type;	/* type */

	unsigned irq;

	unsigned short evtchn;	/* event channel */

	unsigned short cpu;	/* cpu bound */

	union {

		unsigned short virq;

		enum ipi_vector ipi;

		struct {

			unsigned short pirq;

			unsigned short gsi;

			unsigned char flags;

			uint16_t domid;

		} pirq;

	} u;

};

#define PIRQ_NEEDS_EOI	(1 << 0)

#define PIRQ_SHAREABLE	(1 << 1)

static int *evtchn_to_irq;

int *evtchn_to_irq;

#ifdef CONFIG_X86

static unsigned long *pirq_eoi_map;

#endif

static bool (*pirq_needs_eoi)(unsigned irq);

/*

 * Note sizeof(xen_ulong_t) can be more than sizeof(unsigned long). Be

 * careful to only use bitops which allow for this (e.g

 * test_bit/find_first_bit and friends but not __ffs) and to pass

 * BITS_PER_EVTCHN_WORD as the bitmask length.

 */

#define BITS_PER_EVTCHN_WORD (sizeof(xen_ulong_t)*8)

/*

 * Make a bitmask (i.e. unsigned long *) of a xen_ulong_t

 * array. Primarily to avoid long lines (hence the terse name).

 */

#define BM(x) (unsigned long *)(x)

/* Find the first set bit in a evtchn mask */

#define EVTCHN_FIRST_BIT(w) find_first_bit(BM(&(w)), BITS_PER_EVTCHN_WORD)

static DEFINE_PER_CPU(xen_ulong_t [NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD],

		      cpu_evtchn_mask);

/* Xen will never allocate port zero for any purpose. */

#define VALID_EVTCHN(chn)	((chn) != 0)

static void disable_dynirq(struct irq_data *data);

/* Get info for IRQ */

static struct irq_info *info_for_irq(unsigned irq)

struct irq_info *info_for_irq(unsigned irq)

{

	return irq_get_handler_data(irq);

}

/*

 * Accessors for packed IRQ information.

 */

static unsigned int evtchn_from_irq(unsigned irq)

unsigned int evtchn_from_irq(unsigned irq)

{

	if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))

		return 0;

}

EXPORT_SYMBOL_GPL(irq_from_evtchn);

int irq_from_virq(unsigned int cpu, unsigned int virq)

{

	return per_cpu(virq_to_irq, cpu)[virq];

}

static enum ipi_vector ipi_from_irq(unsigned irq)

{

	struct irq_info *info = info_for_irq(irq);

	return info_for_irq(irq)->type;

}

static unsigned cpu_from_irq(unsigned irq)

unsigned cpu_from_irq(unsigned irq)

{

	return info_for_irq(irq)->cpu;

}

static unsigned int cpu_from_evtchn(unsigned int evtchn)

unsigned int cpu_from_evtchn(unsigned int evtchn)

{

	int irq = evtchn_to_irq[evtchn];

	unsigned ret = 0;

	return info->u.pirq.flags & PIRQ_NEEDS_EOI;

}

static inline xen_ulong_t active_evtchns(unsigned int cpu,

					 struct shared_info *sh,

					 unsigned int idx)

{

	return sh->evtchn_pending[idx] &

		per_cpu(cpu_evtchn_mask, cpu)[idx] &

		~sh->evtchn_mask[idx];

}

static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)

{

	int irq = evtchn_to_irq[chn];

	struct irq_info *info = info_for_irq(irq);

	BUG_ON(irq == -1);

#ifdef CONFIG_SMP

	cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));

#endif

	clear_bit(chn, BM(per_cpu(cpu_evtchn_mask, cpu_from_irq(irq))));

	set_bit(chn, BM(per_cpu(cpu_evtchn_mask, cpu)));

	info_for_irq(irq)->cpu = cpu;

}

static inline void clear_evtchn(int port)

{

	struct shared_info *s = HYPERVISOR_shared_info;

	sync_clear_bit(port, BM(&s->evtchn_pending[0]));

}

static inline void set_evtchn(int port)

{

	struct shared_info *s = HYPERVISOR_shared_info;

	sync_set_bit(port, BM(&s->evtchn_pending[0]));

}

static inline int test_evtchn(int port)

{

	struct shared_info *s = HYPERVISOR_shared_info;

	return sync_test_bit(port, BM(&s->evtchn_pending[0]));

}

	xen_evtchn_port_bind_to_cpu(info, cpu);

static inline int test_and_set_mask(int port)

{

	struct shared_info *s = HYPERVISOR_shared_info;

	return sync_test_and_set_bit(port, BM(&s->evtchn_mask[0]));

	info->cpu = cpu;

}

/**

 * notify_remote_via_irq - send event to remote end of event channel via irq

 * @irq: irq of event channel to send event to

}

EXPORT_SYMBOL_GPL(notify_remote_via_irq);

static void mask_evtchn(int port)

{

	struct shared_info *s = HYPERVISOR_shared_info;

	sync_set_bit(port, BM(&s->evtchn_mask[0]));

}

static void unmask_evtchn(int port)

{

	struct shared_info *s = HYPERVISOR_shared_info;

	unsigned int cpu = get_cpu();

	int do_hypercall = 0, evtchn_pending = 0;

	BUG_ON(!irqs_disabled());

	if (unlikely((cpu != cpu_from_evtchn(port))))

		do_hypercall = 1;

	else {

		/*

		 * Need to clear the mask before checking pending to

		 * avoid a race with an event becoming pending.

		 *

		 * EVTCHNOP_unmask will only trigger an upcall if the

		 * mask bit was set, so if a hypercall is needed

		 * remask the event.

		 */

		sync_clear_bit(port, BM(&s->evtchn_mask[0]));

		evtchn_pending = sync_test_bit(port, BM(&s->evtchn_pending[0]));

		if (unlikely(evtchn_pending && xen_hvm_domain())) {

			sync_set_bit(port, BM(&s->evtchn_mask[0]));

			do_hypercall = 1;

		}

	}

	/* Slow path (hypercall) if this is a non-local port or if this is

	 * an hvm domain and an event is pending (hvm domains don't have

	 * their own implementation of irq_enable). */

	if (do_hypercall) {

		struct evtchn_unmask unmask = { .port = port };

		(void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);

	} else {

		struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);

		/*

		 * The following is basically the equivalent of

		 * 'hw_resend_irq'. Just like a real IO-APIC we 'lose

		 * the interrupt edge' if the channel is masked.

		 */

		if (evtchn_pending &&

		    !sync_test_and_set_bit(port / BITS_PER_EVTCHN_WORD,

					   BM(&vcpu_info->evtchn_pending_sel)))

			vcpu_info->evtchn_upcall_pending = 1;

	}

	put_cpu();

}

static void xen_irq_init(unsigned irq)

{

	struct irq_info *info;

	notify_remote_via_irq(irq);

}

irqreturn_t xen_debug_interrupt(int irq, void *dev_id)

{

	struct shared_info *sh = HYPERVISOR_shared_info;

	int cpu = smp_processor_id();

	xen_ulong_t *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);

	int i;

	unsigned long flags;

	static DEFINE_SPINLOCK(debug_lock);

	struct vcpu_info *v;

	spin_lock_irqsave(&debug_lock, flags);

	printk("\nvcpu %d\n  ", cpu);

	for_each_online_cpu(i) {

		int pending;

		v = per_cpu(xen_vcpu, i);

		pending = (get_irq_regs() && i == cpu)

			? xen_irqs_disabled(get_irq_regs())

			: v->evtchn_upcall_mask;

		printk("%d: masked=%d pending=%d event_sel %0*"PRI_xen_ulong"\n  ", i,

		       pending, v->evtchn_upcall_pending,

		       (int)(sizeof(v->evtchn_pending_sel)*2),

		       v->evtchn_pending_sel);

	}

	v = per_cpu(xen_vcpu, cpu);

	printk("\npending:\n   ");

	for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)

		printk("%0*"PRI_xen_ulong"%s",

		       (int)sizeof(sh->evtchn_pending[0])*2,

		       sh->evtchn_pending[i],

		       i % 8 == 0 ? "\n   " : " ");

	printk("\nglobal mask:\n   ");

	for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)

		printk("%0*"PRI_xen_ulong"%s",

		       (int)(sizeof(sh->evtchn_mask[0])*2),

		       sh->evtchn_mask[i],

		       i % 8 == 0 ? "\n   " : " ");

	printk("\nglobally unmasked:\n   ");

	for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)

		printk("%0*"PRI_xen_ulong"%s",

		       (int)(sizeof(sh->evtchn_mask[0])*2),

		       sh->evtchn_pending[i] & ~sh->evtchn_mask[i],

		       i % 8 == 0 ? "\n   " : " ");

	printk("\nlocal cpu%d mask:\n   ", cpu);

	for (i = (NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD)-1; i >= 0; i--)

		printk("%0*"PRI_xen_ulong"%s", (int)(sizeof(cpu_evtchn[0])*2),

		       cpu_evtchn[i],

		       i % 8 == 0 ? "\n   " : " ");

	printk("\nlocally unmasked:\n   ");

	for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {

		xen_ulong_t pending = sh->evtchn_pending[i]

			& ~sh->evtchn_mask[i]

			& cpu_evtchn[i];

		printk("%0*"PRI_xen_ulong"%s",

		       (int)(sizeof(sh->evtchn_mask[0])*2),

		       pending, i % 8 == 0 ? "\n   " : " ");

	}

	printk("\npending list:\n");

	for (i = 0; i < NR_EVENT_CHANNELS; i++) {

		if (sync_test_bit(i, BM(sh->evtchn_pending))) {