/*
* Xen event channels
*
* Xen models interrupts with abstract event channels. Because each
* domain gets 1024 event channels, but NR_IRQ is not that large, we
* must dynamically map irqs<->event channels. The event channels
* interface with the rest of the kernel by defining a xen interrupt
* chip. When an event is received, it is mapped to an irq and sent
* through the normal interrupt processing path.
*
* There are four kinds of events which can be mapped to an event
* channel:
*
* 1. Inter-domain notifications. This includes all the virtual
* device events, since they're driven by front-ends in another domain
* (typically dom0).
* 2. VIRQs, typically used for timers. These are per-cpu events.
* 3. IPIs.
* 4. PIRQs - Hardware interrupts.
*
* Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
*/
#include <linux/linkage.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/bootmem.h>
#include <linux/slab.h>
#include <linux/irqnr.h>
#include <linux/pci.h>
#include <asm/desc.h>
#include <asm/ptrace.h>
#include <asm/irq.h>
#include <asm/idle.h>
#include <asm/io_apic.h>
#include <asm/sync_bitops.h>
#include <asm/xen/pci.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
#include <xen/xen.h>
#include <xen/hvm.h>
#include <xen/xen-ops.h>
#include <xen/events.h>
#include <xen/interface/xen.h>
#include <xen/interface/event_channel.h>
#include <xen/interface/hvm/hvm_op.h>
#include <xen/interface/hvm/params.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.
*/
static DEFINE_SPINLOCK(irq_mapping_update_lock);
static LIST_HEAD(xen_irq_list_head);
/* IRQ <-> VIRQ mapping. */
static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
/* 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 - vector, with MSB being "needs EIO", or physical IRQ of the HVM
* guest, or GSI (real passthrough IRQ) of the device.
* VIRQ - virq number
* IPI - IPI vector
* EVTCHN -
*/
struct irq_info
{
struct list_head list;
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 vector;
unsigned char flags;
} pirq;
} u;
};
#define PIRQ_NEEDS_EOI (1 << 0)
#define PIRQ_SHAREABLE (1 << 1)
static int *evtchn_to_irq;
static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG],
cpu_evtchn_mask);
/* Xen will never allocate port zero for any purpose. */
#define VALID_EVTCHN(chn) ((chn) != 0)
static struct irq_chip xen_dynamic_chip;
static struct irq_chip xen_percpu_chip;
static struct irq_chip xen_pirq_chip;
/* Get info for IRQ */
static struct irq_info *info_for_irq(unsigned irq)
{
return irq_get_handler_data(irq);
}
/* Constructors for packed IRQ information. */
static void xen_irq_info_common_init(struct irq_info *info,
unsigned irq,
enum xen_irq_type type,
unsigned short evtchn,
unsigned short cpu)
{
BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
info->type = type;
info->irq = irq;
info->evtchn = evtchn;
info->cpu = cpu;
evtchn_to_irq[evtchn] = irq;
}
static void xen_irq_info_evtchn_init(unsigned irq,
unsigned short evtchn)
{
struct irq_info *info = info_for_irq(irq);
xen_irq_info_common_init(info, irq, IRQT_EVTCHN, evtchn, 0);
}
static void xen_irq_info_ipi_init(unsigned cpu,
unsigned irq,
unsigned short evtchn,
enum ipi_vector ipi)
{
struct irq_info *info = info_for_irq(irq);
xen_irq_info_common_init(info, irq, IRQT_IPI, evtchn, 0);
info->u.ipi = ipi;
per_cpu(ipi_to_irq, cpu)[ipi] = irq;
}
static void xen_irq_info_virq_init(unsigned cpu,
unsigned irq,
unsigned short evtchn,
unsigned short virq)
{
struct irq_info *info = info_for_irq(irq);
xen_irq_info_common_init(info, irq, IRQT_VIRQ, evtchn, 0);
info->u.virq = virq;
per_cpu(virq_to_irq, cpu)[virq] = irq;
}
static void xen_irq_info_pirq_init(unsigned irq,
unsigned short evtchn,
unsigned short pirq,
unsigned short gsi,
unsigned short vector,
unsigned char flags)
{
struct irq_info *info = info_for_irq(irq);
xen_irq_info_common_init(info, irq, IRQT_PIRQ, evtchn, 0);
info->u.pirq.pirq = pirq;
info->u.pirq.gsi = gsi;
info->u.pirq.vector = vector;
info->u.pirq.flags = flags;
}
/*
* Accessors for packed IRQ information.
*/
static unsigned int evtchn_from_irq(unsigned irq)
{
if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
return 0;
return info_for_irq(irq)->evtchn;
}
unsigned irq_from_evtchn(unsigned int evtchn)
{
return evtchn_to_irq[evtchn];
}
EXPORT_SYMBOL_GPL(irq_from_evtchn);
static enum ipi_vector ipi_from_irq(unsigned irq)
{
struct irq_info *info = info_for_irq(irq);
BUG_ON(info == NULL);
BUG_ON(info->type != IRQT_IPI);
return info->u.ipi;
}
static unsigned virq_from_irq(unsigned irq)
{
struct irq_info *info = info_for_irq(irq);
BUG_ON(info == NULL);
BUG_ON(info->type != IRQT_VIRQ);
return info->u.virq;
}
static unsigned pirq_from_irq(unsigned irq)
{
struct irq_info *info = info_for_irq(irq);
BUG_ON(info == NULL);
BUG_ON(info->type != IRQT_PIRQ);
return info->u.pirq.pirq;
}
static enum xen_irq_type type_from_irq(unsigned irq)
{
return info_for_irq(irq)->type;
}
static unsigned cpu_from_irq(unsigned irq)
{
return info_for_irq(irq)->cpu;
}
static unsigned int cpu_from_evtchn(unsigned int evtchn)
{
int irq = evtchn_to_irq[evtchn];
unsigned ret = 0;
if (irq != -1)
ret = cpu_from_irq(irq);
return ret;
}
static bool pirq_needs_eoi(unsigned irq)
{
struct irq_info *info = info_for_irq(irq);
BUG_ON(info->type != IRQT_PIRQ);
return info->u.pirq.flags & PIRQ_NEEDS_EOI;
}
static inline unsigned long 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];
BUG_ON(irq == -1);
#ifdef CONFIG_SMP
cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
#endif
clear_bit(chn, per_cpu(cpu_evtchn_mask, cpu_from_irq(irq)));
set_bit(chn, per_cpu(cpu_evtchn_mask, cpu));
info_for_irq(irq)->cpu = cpu;
}
static void init_evtchn_cpu_bindings(void)
{
int i;
#ifdef CONFIG_SMP
struct irq_info *info;
/* By default all event channels notify CPU#0. */
list_for_each_entry(info, &xen_irq_list_head, list) {
struct irq_desc *desc = irq_to_desc(info->irq);
cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
}
#endif
for_each_possible_cpu(i)
memset(per_cpu(cpu_evtchn_mask, i),
(i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i)));
}
static inline void clear_evtchn(int port)
{
struct shared_info *s = HYPERVISOR_shared_info;
sync_clear_bit(port, &s->evtchn_pending[0]);
}
static inline void set_evtchn(int port)
{
struct shared_info *s = HYPERVISOR_shared_info;
sync_set_bit(port, &s->evtchn_pending[0]);
}
static inline int test_evtchn(int port)
{
struct shared_info *s = HYPERVISOR_shared_info;
return sync_test_bit(port, &s->evtchn_pending[0]);
}
/**
* notify_remote_via_irq - send event to remote end of event channel via irq
* @irq: irq of event channel to send event to
*
* Unlike notify_remote_via_evtchn(), this is safe to use across
* save/restore. Notifications on a broken connection are silently
* dropped.
*/
void notify_remote_via_irq(int irq)
{
int evtchn = evtchn_from_irq(irq);
if (VALID_EVTCHN(evtchn))
notify_remote_via_evtchn(evtchn);
}
EXPORT_SYMBOL_GPL(notify_remote_via_irq);
static void mask_evtchn(int port)
{
struct shared_info *s = HYPERVISOR_shared_info;
sync_set_bit(port, &s->evtchn_mask[0]);
}
static void unmask_evtchn(int port)
{
struct shared_info *s = HYPERVISOR_shared_info;
unsigned int cpu = get_cpu();
BUG_ON(!irqs_disabled());
/* Slow path (hypercall) if this is a non-local port. */
if (unlikely(cpu != cpu_from_evtchn(port))) {
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);
sync_clear_bit(port, &s->evtchn_mask[0]);
/*
* 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 (sync_test_bit(port, &s->evtchn_pending[0]) &&
!sync_test_and_set_bit(port / BITS_PER_LONG,
&vcpu_info->evtchn_pending_sel))
vcpu_info->evtchn_upcall_pending = 1;
}
put_cpu();
}
static void xen_irq_init(unsigned irq)
{
struct irq_info *info;
struct irq_desc *desc = irq_to_desc(irq);
#ifdef CONFIG_SMP
/* By default all event channels notify CPU#0. */
cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
#endif
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (info == NULL)
panic("Unable to allocate metadata for IRQ%d\n", irq);
info->type = IRQT_UNBOUND;
irq_set_handler_data(irq, info);
list_add_tail(&info->list, &xen_irq_list_head);
}
static int __must_check xen_allocate_irq_dynamic(void)
{
int first = 0;
int irq;
#ifdef CONFIG_X86_IO_APIC
/*
* For an HVM guest or domain 0 which see "real" (emulated or
* actual respectively) GSIs we allocate dynamic IRQs
* e.g. those corresponding to event channels or MSIs
* etc. from the range above those "real" GSIs to avoid
* collisions.
*/
if (xen_initial_domain() || xen_hvm_domain())
first = get_nr_irqs_gsi();
#endif
irq = irq_alloc_desc_from(first, -1);
xen_irq_init(irq);
return irq;
}
static int __must_check xen_allocate_irq_gsi(unsigned gsi)
{
int irq;
/*
* A PV guest has no concept of a GSI (since it has no ACPI
* nor access to/knowledge of the physical APICs). Therefore
* all IRQs are dynamically allocated from the entire IRQ
* space.
*/
if (xen_pv_domain() && !xen_initial_domain())
return xen_allocate_irq_dynamic();
/* Legacy IRQ descriptors are already allocated by the arch. */
if (gsi < NR_IRQS_LEGACY)
irq = gsi;
else
irq = irq_alloc_desc_at(gsi, -1);
xen_irq_init(irq);
return irq;
}
static void xen_free_irq(unsigned irq)
{
struct irq_info *info = irq_get_handler_data(irq);
list_del(&info->list);
irq_set_handler_data(irq, NULL);
kfree(info);
/* Legacy IRQ descriptors are managed by the arch. */
if (irq < NR_IRQS_LEGACY)
return;
irq_free_desc(irq);
}
static void pirq_unmask_notify(int irq)
{
struct physdev_eoi eoi = { .irq = pirq_from_irq(irq) };
if (unlikely(pirq_needs_eoi(irq))) {
int rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
WARN_ON(rc);
}
}
static void pirq_query_unmask(int irq)
{
struct physdev_irq_status_query irq_status;
struct irq_info *info = info_for_irq(irq);
BUG_ON(info->type != IRQT_PIRQ);
irq_status.irq = pirq_from_irq(irq);
if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
irq_status.flags = 0;
info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
if (irq_status.flags & XENIRQSTAT_needs_eoi)
info->u.pirq.flags |= PIRQ_NEEDS_EOI;
}
static bool probing_irq(int irq)
{
struct irq_desc *desc = irq_to_desc(irq);
return desc && desc->action == NULL;
}
static unsigned int __startup_pirq(unsigned int irq)
{
struct evtchn_bind_pirq bind_pirq;
struct irq_info *info = info_for_irq(irq);
int evtchn = evtchn_from_irq(irq);
int rc;
BUG_ON(info->type != IRQT_PIRQ);
if (VALID_EVTCHN(evtchn))
goto out;
bind_pirq.pirq = pirq_from_irq(irq);
/* NB. We are happy to share unless we are probing. */
bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
BIND_PIRQ__WILL_SHARE : 0;
rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
if (rc != 0) {
if (!probing_irq(irq))
printk(KERN_INFO "Failed to obtain physical IRQ %d\n",
irq);
return 0;
}
evtchn = bind_pirq.port;
pirq_query_unmask(irq);
evtchn_to_irq[evtchn] = irq;
bind_evtchn_to_cpu(evtchn, 0);
info->evtchn = evtchn;
out:
unmask_evtchn(evtchn);
pirq_unmask_notify(irq);
return 0;
}
static unsigned int startup_pirq(struct irq_data *data)
{
return __startup_pirq(data->irq);
}
static void shutdown_pirq(struct irq_data *data)
{
struct evtchn_close close;
unsigned int irq = data->irq;
struct irq_info *info = info_for_irq(irq);
int evtchn = evtchn_from_irq(irq);
BUG_ON(info->type != IRQT_PIRQ);
if (!VALID_EVTCHN(evtchn))
return;
mask_evtchn(evtchn);
close.port = evtchn;
if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
BUG();
bind_evtchn_to_cpu(evtchn, 0);
evtchn_to_irq[evtchn] = -1;
info->evtchn = 0;
}
static void enable_pirq(struct irq_data *data)
{
startup_pirq(data);
}
static void disable_pirq(struct irq_data *data)
{
}
static void ack_pirq(struct irq_data *data)
{
int evtchn = evtchn_from_irq(data->irq);
irq_move_irq(data);
if (VALID_EVTCHN(evtchn)) {
mask_evtchn(evtchn);
clear_evtchn(evtchn);
}
}
static int find_irq_by_gsi(unsigned gsi)
{
struct irq_info *info;
list_for_each_entry(info, &xen_irq_list_head, list) {
if (info->type != IRQT_PIRQ)
continue;
if (info->u.pirq.gsi == gsi)
return info->irq;
}
return -1;
}
int xen_allocate_pirq_gsi(unsigned gsi)
{
return gsi;
}
/*
* Do not make any assumptions regarding the relationship between the
* IRQ number returned here and the Xen pirq argument.
*
* Note: We don't assign an event channel until the irq actually started
* up. Return an existing irq if we've already got one for the gsi.
*/
int xen_bind_pirq_gsi_to_irq(unsigned gsi,
unsigned pirq, int shareable, char *name)
{
int irq = -1;
struct physdev_irq irq_op;
spin_lock(&irq_mapping_update_lock);
irq = find_irq_by_gsi(gsi);
if (irq != -1) {
printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
irq, gsi);
goto out; /* XXX need refcount? */
}
irq = xen_allocate_irq_gsi(gsi);
if (irq < 0)
goto out;
irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_level_irq,
name);
irq_op.irq = irq;
irq_op.vector = 0;
/* Only the privileged domain can do this. For non-priv, the pcifront
* driver provides a PCI bus that does the call to do exactly
* this in the priv domain. */
if (xen_initial_domain() &&
HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
xen_free_irq(irq);
irq = -ENOSPC;
goto out;
}
xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector,
shareable ? PIRQ_SHAREABLE : 0);
out:
spin_unlock(&irq_mapping_update_lock);
return irq;
}
#ifdef CONFIG_PCI_MSI
int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
{
int rc;
struct physdev_get_free_pirq op_get_free_pirq;
op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
WARN_ONCE(rc == -ENOSYS,
"hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
return rc ? -1 : op_get_free_pirq.pirq;
}
int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
int pirq, int vector, const char *name)
{
int irq, ret;
spin_lock(&irq_mapping_update_lock);
irq = xen_allocate_irq_dynamic();
if (irq == -1)
goto out;
irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_level_irq,
name);
xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, 0);
ret = irq_set_msi_desc(irq, msidesc);
if (ret < 0)
goto error_irq;
out:
spin_unlock(&irq_mapping_update_lock);
return irq;
error_irq:
spin_unlock(&irq_mapping_update_lock);
xen_free_irq(irq);
return -1;
}
#endif
int xen_destroy_irq(int irq)
{
struct irq_desc *desc;
struct physdev_unmap_pirq unmap_irq;
struct irq_info *info = info_for_irq(irq);
int rc = -ENOENT;
spin_lock(&irq_mapping_update_lock);
desc = irq_to_desc(irq);
if (!desc)
goto out;
if (xen_initial_domain()) {
unmap_irq.pirq = info->u.pirq.pirq;
unmap_irq.domid = DOMID_SELF;
rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
if (rc) {
printk(KERN_WARNING "unmap irq failed %d\n", rc);
goto out;
}
}
xen_free_irq(irq);
out:
spin_unlock(&irq_mapping_update_lock);
return rc;
}
int xen_irq_from_pirq(unsigned pirq)
{
int irq;
struct irq_info *info;
spin_lock(&irq_mapping_update_lock);
list_for_each_entry(info, &xen_irq_list_head, list) {
if (info == NULL || info->type != IRQT_PIRQ)
continue;
irq = info->irq;
if (info->u.pirq.pirq == pirq)
goto out;
}
irq = -1;
out:
spin_unlock(&irq_mapping_update_lock);
return irq;
}
int bind_evtchn_to_irq(unsigned int evtchn)
{
int irq;
spin_lock(&irq_mapping_update_lock);
irq = evtchn_to_irq[evtchn];
if (irq == -1) {
irq = xen_allocate_irq_dynamic();
if (irq == -1)
goto out;
irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
handle_fasteoi_irq, "event");
xen_irq_info_evtchn_init(irq, evtchn);
}
out:
spin_unlock(&irq_mapping_update_lock);
return irq;
}
EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
{
struct evtchn_bind_ipi bind_ipi;
int evtchn, irq;
spin_lock(&irq_mapping_update_lock);
irq = per_cpu(ipi_to_irq, cpu)[ipi];
if (irq == -1) {
irq = xen_allocate_irq_dynamic();
if (irq < 0)
goto out;
irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
handle_percpu_irq, "ipi");
bind_ipi.vcpu = cpu;
if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
&bind_ipi) != 0)
BUG();
evtchn = bind_ipi.port;
xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
bind_evtchn_to_cpu(evtchn, cpu);
}
out:
spin_unlock(&irq_mapping_update_lock);
return irq;
}
static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
unsigned int remote_port)
{
struct evtchn_bind_interdomain bind_interdomain;
int err;
bind_interdomain.remote_dom = remote_domain;
bind_interdomain.remote_port = remote_port;
err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
&bind_interdomain);
return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
}
int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
{
struct evtchn_bind_virq bind_virq;
int evtchn, irq;
spin_lock(&irq_mapping_update_lock);
irq = per_cpu(virq_to_irq, cpu)[virq];
if (irq == -1) {
irq = xen_allocate_irq_dynamic();
if (irq == -1)
goto out;
irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
handle_percpu_irq, "virq");
bind_virq.virq = virq;
bind_virq.vcpu = cpu;
if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
&bind_virq) != 0)
BUG();
evtchn = bind_virq.port;
xen_irq_info_virq_init(cpu, irq, evtchn, virq);
bind_evtchn_to_cpu(evtchn, cpu);
}
out:
spin_unlock(&irq_mapping_update_lock);
return irq;
}
static void unbind_from_irq(unsigned int irq)
{
struct evtchn_close close;
int evtchn = evtchn_from_irq(irq);
spin_lock(&irq_mapping_update_lock);
if (VALID_EVTCHN(evtchn)) {
close.port = evtchn;
if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
BUG();
switch (type_from_irq(irq)) {
case IRQT_VIRQ:
per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
[virq_from_irq(irq)] = -1;
break;
case IRQT_IPI:
per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
[ipi_from_irq(irq)] = -1;
break;
default:
break;
}
/* Closed ports are implicitly re-bound to VCPU0. */
bind_evtchn_to_cpu(evtchn, 0);
evtchn_to_irq[evtchn] = -1;
}
BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
xen_free_irq(irq);
spin_unlock(&irq_mapping_update_lock);
}
int bind_evtchn_to_irqhandler(unsigned int evtchn,
irq_handler_t handler,
unsigned long irqflags,
const char *devname, void *dev_id)
{
int irq, retval;
irq = bind_evtchn_to_irq(evtchn);
if (irq < 0)
return irq;
retval = request_irq(irq, handler, irqflags, devname, dev_id);
if (retval != 0) {
unbind_from_irq(irq);
return retval;
}
return irq;
}
EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
unsigned int remote_port,
irq_handler_t handler,
unsigned long irqflags,
const char *devname,
void *dev_id)
{
int irq, retval;
irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
if (irq < 0)
return irq;
retval = request_irq(irq, handler, irqflags, devname, dev_id);
if (retval != 0) {
unbind_from_irq(irq);
return retval;
}
return irq;
}
EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
irq_handler_t handler,
unsigned long irqflags, const char *devname, void *dev_id)
{
int irq, retval;
irq = bind_virq_to_irq(virq, cpu);
if (irq < 0)
return irq;
retval = request_irq(irq, handler, irqflags, devname, dev_id);
if (retval != 0) {
unbind_from_irq(irq);
return retval;
}
return irq;
}
EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
int bind_ipi_to_irqhandler(enum ipi_vector ipi,
unsigned int cpu,
irq_handler_t handler,
unsigned long irqflags,
const char *devname,
void *dev_id)
{
int irq, retval;
irq = bind_ipi_to_irq(ipi, cpu);
if (irq < 0)
return irq;
irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME;
retval = request_irq(irq, handler, irqflags, devname, dev_id);
if (retval != 0) {
unbind_from_irq(irq);
return retval;
}
return irq;
}
void unbind_from_irqhandler(unsigned int irq, void *dev_id)
{
free_irq(irq, dev_id);
unbind_from_irq(irq);
}
EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
{
int irq = per_cpu(ipi_to_irq, cpu)[vector];
BUG_ON(irq < 0);
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();
unsigned long *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*lx\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*lx%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*lx%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*lx%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_LONG)-1; i >= 0; i--)
printk("%0*lx%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--) {
unsigned long pending = sh->evtchn_pending[i]
& ~sh->evtchn_mask[i]
& cpu_evtchn[i];
printk("%0*lx%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, sh->evtchn_pending)) {
int word_idx = i / BITS_PER_LONG;
printk(" %d: event %d -> irq %d%s%s%s\n",
cpu_from_evtchn(i), i,
evtchn_to_irq[i],
sync_test_bit(word_idx, &v->evtchn_pending_sel)
? "" : " l2-clear",
!sync_test_bit(i, sh->evtchn_mask)
? "" : " globally-masked",
sync_test_bit(i, cpu_evtchn)
? "" : " locally-masked");
}
}
spin_unlock_irqrestore(&debug_lock, flags);
return IRQ_HANDLED;
}
static DEFINE_PER_CPU(unsigned, xed_nesting_count);
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 & ((~0UL) << i))
/*
* Search the CPUs 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.
*/
static void __xen_evtchn_do_upcall(void)
{
int start_word_idx, start_bit_idx;
int word_idx, bit_idx;
int i;
int cpu = get_cpu();
struct shared_info *s = HYPERVISOR_shared_info;
struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
unsigned count;
do {
unsigned long pending_words;
vcpu_info->evtchn_upcall_pending = 0;
if (__this_cpu_inc_return(xed_nesting_count) - 1)
goto out;
#ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
/* Clear master flag /before/ clearing selector flag. */
wmb();
#endif
pending_words = xchg(&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++) {
unsigned long pending_bits;
unsigned long 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 = __ffs(words);
pending_bits = active_evtchns(cpu, s, word_idx);
bit_idx = 0; /* usually scan entire word from start */
if (word_idx == start_word_idx) {
/* We scan the starting word in two parts */
if (i == 0)
/* 1st time: start in the middle */
bit_idx = start_bit_idx;
else
/* 2nd time: mask bits done already */
bit_idx &= (1UL << start_bit_idx) - 1;
}
do {
unsigned long bits;
int port, irq;
struct irq_desc *desc;
bits = MASK_LSBS(pending_bits, bit_idx);
/* If we masked out all events, move on. */
if (bits == 0)
break;
bit_idx = __ffs(bits);
/* Process port. */
port = (word_idx * BITS_PER_LONG) + bit_idx;
irq = evtchn_to_irq[port];
mask_evtchn(port);
clear_evtchn(port);
if (irq != -1) {
desc = irq_to_desc(irq);
if (desc)
generic_handle_irq_desc(irq, desc);
}
bit_idx = (bit_idx + 1) % BITS_PER_LONG;
/* Next caller starts at last processed + 1 */
__this_cpu_write(current_word_idx,
bit_idx ? word_idx :
(word_idx+1) % BITS_PER_LONG);
__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_LONG;
}
BUG_ON(!irqs_disabled());
count = __this_cpu_read(xed_nesting_count);
__this_cpu_write(xed_nesting_count, 0);
} while (count != 1 || vcpu_info->evtchn_upcall_pending);
out:
put_cpu();
}
void xen_evtchn_do_upcall(struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
exit_idle();
irq_enter();
__xen_evtchn_do_upcall();
irq_exit();
set_irq_regs(old_regs);
}
void xen_hvm_evtchn_do_upcall(void)
{
__xen_evtchn_do_upcall();
}
EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
/* Rebind a new event channel to an existing irq. */
void rebind_evtchn_irq(int evtchn, int irq)
{
struct irq_info *info = info_for_irq(irq);
/* Make sure the irq is masked, since the new event channel
will also be masked. */
disable_irq(irq);
spin_lock(&irq_mapping_update_lock);
/* After resume the irq<->evtchn mappings are all cleared out */
BUG_ON(evtchn_to_irq[evtchn] != -1);
/* Expect irq to have been bound before,
so there should be a proper type */
BUG_ON(info->type == IRQT_UNBOUND);
xen_irq_info_evtchn_init(irq, evtchn);
spin_unlock(&irq_mapping_update_lock);
/* new event channels are always bound to cpu 0 */
irq_set_affinity(irq, cpumask_of(0));
/* Unmask the event channel. */
enable_irq(irq);
}
/* Rebind an evtchn so that it gets delivered to a specific cpu */
static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
{
struct evtchn_bind_vcpu bind_vcpu;
int evtchn = evtchn_from_irq(irq);
if (!VALID_EVTCHN(evtchn))
return -1;
/*
* Events delivered via platform PCI interrupts are always
* routed to vcpu 0 and hence cannot be rebound.
*/
if (xen_hvm_domain() && !xen_have_vector_callback)
return -1;
/* Send future instances of this interrupt to other vcpu. */
bind_vcpu.port = evtchn;
bind_vcpu.vcpu = tcpu;
/*
* If this fails, it usually just indicates that we're dealing with a
* virq or IPI channel, which don't actually need to be rebound. Ignore
* it, but don't do the xenlinux-level rebind in that case.
*/
if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
bind_evtchn_to_cpu(evtchn, tcpu);
return 0;
}
static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
bool force)
{
unsigned tcpu = cpumask_first(dest);
return rebind_irq_to_cpu(data->irq, tcpu);
}
int resend_irq_on_evtchn(unsigned int irq)
{
int masked, evtchn = evtchn_from_irq(irq);
struct shared_info *s = HYPERVISOR_shared_info;
if (!VALID_EVTCHN(evtchn))
return 1;
masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
sync_set_bit(evtchn, s->evtchn_pending);
if (!masked)
unmask_evtchn(evtchn);
return 1;
}
static void enable_dynirq(struct irq_data *data)
{
int evtchn = evtchn_from_irq(data->irq);
if (VALID_EVTCHN(evtchn))
unmask_evtchn(evtchn);
}
static void disable_dynirq(struct irq_data *data)
{
int evtchn = evtchn_from_irq(data->irq);
if (VALID_EVTCHN(evtchn))
mask_evtchn(evtchn);
}
static void ack_dynirq(struct irq_data *data)
{
int evtchn = evtchn_from_irq(data->irq);
irq_move_masked_irq(data);
if (VALID_EVTCHN(evtchn))
unmask_evtchn(evtchn);
}
static int retrigger_dynirq(struct irq_data *data)
{
int evtchn = evtchn_from_irq(data->irq);
struct shared_info *sh = HYPERVISOR_shared_info;
int ret = 0;
if (VALID_EVTCHN(evtchn)) {
int masked;
masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
sync_set_bit(evtchn, sh->evtchn_pending);
if (!masked)
unmask_evtchn(evtchn);
ret = 1;
}
return ret;
}
static void restore_pirqs(void)
{
int pirq, rc, irq, gsi;
struct physdev_map_pirq map_irq;
struct irq_info *info;
list_for_each_entry(info, &xen_irq_list_head, list) {
if (info->type != IRQT_PIRQ)
continue;
pirq = info->u.pirq.pirq;
gsi = info->u.pirq.gsi;
irq = info->irq;
/* save/restore of PT devices doesn't work, so at this point the
* only devices present are GSI based emulated devices */
if (!gsi)
continue;
map_irq.domid = DOMID_SELF;
map_irq.type = MAP_PIRQ_TYPE_GSI;
map_irq.index = gsi;
map_irq.pirq = pirq;
rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
if (rc) {
printk(KERN_WARNING "xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
gsi, irq, pirq, rc);
xen_free_irq(irq);
continue;
}
printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
__startup_pirq(irq);
}
}
static void restore_cpu_virqs(unsigned int cpu)
{
struct evtchn_bind_virq bind_virq;
int virq, irq, evtchn;
for (virq = 0; virq < NR_VIRQS; virq++) {
if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
continue;
BUG_ON(virq_from_irq(irq) != virq);
/* Get a new binding from Xen. */
bind_virq.virq = virq;
bind_virq.vcpu = cpu;
if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
&bind_virq) != 0)
BUG();
evtchn = bind_virq.port;
/* Record the new mapping. */
xen_irq_info_virq_init(cpu, irq, evtchn, virq);
bind_evtchn_to_cpu(evtchn, cpu);
}
}
static void restore_cpu_ipis(unsigned int cpu)
{
struct evtchn_bind_ipi bind_ipi;
int ipi, irq, evtchn;
for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
continue;
BUG_ON(ipi_from_irq(irq) != ipi);
/* Get a new binding from Xen. */
bind_ipi.vcpu = cpu;
if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
&bind_ipi) != 0)
BUG();
evtchn = bind_ipi.port;
/* Record the new mapping. */
xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
bind_evtchn_to_cpu(evtchn, cpu);
}
}
/* Clear an irq's pending state, in preparation for polling on it */
void xen_clear_irq_pending(int irq)
{
int evtchn = evtchn_from_irq(irq);
if (VALID_EVTCHN(evtchn))
clear_evtchn(evtchn);
}
EXPORT_SYMBOL(xen_clear_irq_pending);
void xen_set_irq_pending(int irq)
{
int evtchn = evtchn_from_irq(irq);
if (VALID_EVTCHN(evtchn))
set_evtchn(evtchn);
}
bool xen_test_irq_pending(int irq)
{
int evtchn = evtchn_from_irq(irq);
bool ret = false;
if (VALID_EVTCHN(evtchn))
ret = test_evtchn(evtchn);
return ret;
}
/* Poll waiting for an irq to become pending with timeout. In the usual case,
* the irq will be disabled so it won't deliver an interrupt. */
void xen_poll_irq_timeout(int irq, u64 timeout)
{
evtchn_port_t evtchn = evtchn_from_irq(irq);
if (VALID_EVTCHN(evtchn)) {
struct sched_poll poll;
poll.nr_ports = 1;
poll.timeout = timeout;
set_xen_guest_handle(poll.ports, &evtchn);
if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
BUG();
}
}
EXPORT_SYMBOL(xen_poll_irq_timeout);
/* Poll waiting for an irq to become pending. In the usual case, the
* irq will be disabled so it won't deliver an interrupt. */
void xen_poll_irq(int irq)
{
xen_poll_irq_timeout(irq, 0 /* no timeout */);
}
void xen_irq_resume(void)
{
unsigned int cpu, evtchn;
struct irq_info *info;
init_evtchn_cpu_bindings();
/* New event-channel space is not 'live' yet. */
for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
mask_evtchn(evtchn);
/* No IRQ <-> event-channel mappings. */
list_for_each_entry(info, &xen_irq_list_head, list)
info->evtchn = 0; /* zap event-channel binding */
for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
evtchn_to_irq[evtchn] = -1;
for_each_possible_cpu(cpu) {
restore_cpu_virqs(cpu);
restore_cpu_ipis(cpu);
}
restore_pirqs();
}
static struct irq_chip xen_dynamic_chip __read_mostly = {
.name = "xen-dyn",
.irq_disable = disable_dynirq,
.irq_mask = disable_dynirq,
.irq_unmask = enable_dynirq,
.irq_eoi = ack_dynirq,
.irq_set_affinity = set_affinity_irq,
.irq_retrigger = retrigger_dynirq,
};
static struct irq_chip xen_pirq_chip __read_mostly = {
.name = "xen-pirq",
.irq_startup = startup_pirq,
.irq_shutdown = shutdown_pirq,
.irq_enable = enable_pirq,
.irq_unmask = enable_pirq,
.irq_disable = disable_pirq,
.irq_mask = disable_pirq,
.irq_ack = ack_pirq,
.irq_set_affinity = set_affinity_irq,
.irq_retrigger = retrigger_dynirq,
};
static struct irq_chip xen_percpu_chip __read_mostly = {
.name = "xen-percpu",
.irq_disable = disable_dynirq,
.irq_mask = disable_dynirq,
.irq_unmask = enable_dynirq,
.irq_ack = ack_dynirq,
};
int xen_set_callback_via(uint64_t via)
{
struct xen_hvm_param a;
a.domid = DOMID_SELF;
a.index = HVM_PARAM_CALLBACK_IRQ;
a.value = via;
return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
}
EXPORT_SYMBOL_GPL(xen_set_callback_via);
#ifdef CONFIG_XEN_PVHVM
/* Vector callbacks are better than PCI interrupts to receive event
* channel notifications because we can receive vector callbacks on any
* vcpu and we don't need PCI support or APIC interactions. */
void xen_callback_vector(void)
{
int rc;
uint64_t callback_via;
if (xen_have_vector_callback) {
callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
rc = xen_set_callback_via(callback_via);
if (rc) {
printk(KERN_ERR "Request for Xen HVM callback vector"
" failed.\n");
xen_have_vector_callback = 0;
return;
}
printk(KERN_INFO "Xen HVM callback vector for event delivery is "
"enabled\n");
/* in the restore case the vector has already been allocated */
if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
}
}
#else
void xen_callback_vector(void) {}
#endif
void __init xen_init_IRQ(void)
{
int i;
evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
GFP_KERNEL);
for (i = 0; i < NR_EVENT_CHANNELS; i++)
evtchn_to_irq[i] = -1;
init_evtchn_cpu_bindings();
/* No event channels are 'live' right now. */
for (i = 0; i < NR_EVENT_CHANNELS; i++)
mask_evtchn(i);
if (xen_hvm_domain()) {
xen_callback_vector();
native_init_IRQ();
/* pci_xen_hvm_init must be called after native_init_IRQ so that
* __acpi_register_gsi can point at the right function */
pci_xen_hvm_init();
} else {
irq_ctx_init(smp_processor_id());
if (xen_initial_domain())
xen_setup_pirqs();
}
}