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linux/drivers/xen/events/events_base.c

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/*
* 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
*/
#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 <linux/string.h>
#include <linux/bootmem.h>
#include <linux/slab.h>
#include <linux/irqnr.h>
#include <linux/pci.h>
#ifdef CONFIG_X86
#include <asm/desc.h>
#include <asm/ptrace.h>
#include <asm/irq.h>
#include <asm/idle.h>
#include <asm/io_apic.h>
#include <asm/i8259.h>
#include <asm/xen/pci.h>
#endif
#include <asm/sync_bitops.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
#include <xen/page.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>
#include <xen/interface/physdev.h>
#include <xen/interface/sched.h>
#include <xen/interface/vcpu.h>
#include <asm/hw_irq.h>
#include "events_internal.h"
const struct evtchn_ops *evtchn_ops;
/*
* 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_MUTEX(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};
int **evtchn_to_irq;
#ifdef CONFIG_X86
static unsigned long *pirq_eoi_map;
#endif
static bool (*pirq_needs_eoi)(unsigned irq);
#define EVTCHN_ROW(e) (e / (PAGE_SIZE/sizeof(**evtchn_to_irq)))
#define EVTCHN_COL(e) (e % (PAGE_SIZE/sizeof(**evtchn_to_irq)))
#define EVTCHN_PER_ROW (PAGE_SIZE / sizeof(**evtchn_to_irq))
/* 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;
static void enable_dynirq(struct irq_data *data);
static void disable_dynirq(struct irq_data *data);
static void clear_evtchn_to_irq_row(unsigned row)
{
unsigned col;
for (col = 0; col < EVTCHN_PER_ROW; col++)
evtchn_to_irq[row][col] = -1;
}
static void clear_evtchn_to_irq_all(void)
{
unsigned row;
for (row = 0; row < EVTCHN_ROW(xen_evtchn_max_channels()); row++) {
if (evtchn_to_irq[row] == NULL)
continue;
clear_evtchn_to_irq_row(row);
}
}
static int set_evtchn_to_irq(unsigned evtchn, unsigned irq)
{
unsigned row;
unsigned col;
if (evtchn >= xen_evtchn_max_channels())
return -EINVAL;
row = EVTCHN_ROW(evtchn);
col = EVTCHN_COL(evtchn);
if (evtchn_to_irq[row] == NULL) {
/* Unallocated irq entries return -1 anyway */
if (irq == -1)
return 0;
evtchn_to_irq[row] = (int *)get_zeroed_page(GFP_KERNEL);
if (evtchn_to_irq[row] == NULL)
return -ENOMEM;
clear_evtchn_to_irq_row(row);
}
evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)] = irq;
return 0;
}
int get_evtchn_to_irq(unsigned evtchn)
{
if (evtchn >= xen_evtchn_max_channels())
return -1;
if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL)
return -1;
return evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)];
}
/* Get info for IRQ */
struct irq_info *info_for_irq(unsigned irq)
{
return irq_get_handler_data(irq);
}
/* Constructors for packed IRQ information. */
static int xen_irq_info_common_setup(struct irq_info *info,
unsigned irq,
enum xen_irq_type type,
unsigned evtchn,
unsigned short cpu)
{
int ret;
BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
info->type = type;
info->irq = irq;
info->evtchn = evtchn;
info->cpu = cpu;
ret = set_evtchn_to_irq(evtchn, irq);
if (ret < 0)
return ret;
irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);
return xen_evtchn_port_setup(info);
}
static int xen_irq_info_evtchn_setup(unsigned irq,
unsigned evtchn)
{
struct irq_info *info = info_for_irq(irq);
return xen_irq_info_common_setup(info, irq, IRQT_EVTCHN, evtchn, 0);
}
static int xen_irq_info_ipi_setup(unsigned cpu,
unsigned irq,
unsigned evtchn,
enum ipi_vector ipi)
{
struct irq_info *info = info_for_irq(irq);
info->u.ipi = ipi;
per_cpu(ipi_to_irq, cpu)[ipi] = irq;
return xen_irq_info_common_setup(info, irq, IRQT_IPI, evtchn, 0);
}
static int xen_irq_info_virq_setup(unsigned cpu,
unsigned irq,
unsigned evtchn,
unsigned virq)
{
struct irq_info *info = info_for_irq(irq);
info->u.virq = virq;
per_cpu(virq_to_irq, cpu)[virq] = irq;
return xen_irq_info_common_setup(info, irq, IRQT_VIRQ, evtchn, 0);
}
static int xen_irq_info_pirq_setup(unsigned irq,
unsigned evtchn,
unsigned pirq,
unsigned gsi,
uint16_t domid,
unsigned char flags)
{
struct irq_info *info = info_for_irq(irq);
info->u.pirq.pirq = pirq;
info->u.pirq.gsi = gsi;
info->u.pirq.domid = domid;
info->u.pirq.flags = flags;
return xen_irq_info_common_setup(info, irq, IRQT_PIRQ, evtchn, 0);
}
static void xen_irq_info_cleanup(struct irq_info *info)
{
set_evtchn_to_irq(info->evtchn, -1);
info->evtchn = 0;
}
/*
* Accessors for packed IRQ information.
*/
unsigned int evtchn_from_irq(unsigned irq)
{
if (unlikely(WARN(irq >= nr_irqs, "Invalid irq %d!\n", irq)))
return 0;
return info_for_irq(irq)->evtchn;
}
unsigned irq_from_evtchn(unsigned int evtchn)
{
return get_evtchn_to_irq(evtchn);
}
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);
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;
}
unsigned cpu_from_irq(unsigned irq)
{
return info_for_irq(irq)->cpu;
}
unsigned int cpu_from_evtchn(unsigned int evtchn)
{
int irq = get_evtchn_to_irq(evtchn);
unsigned ret = 0;
if (irq != -1)
ret = cpu_from_irq(irq);
return ret;
}
#ifdef CONFIG_X86
static bool pirq_check_eoi_map(unsigned irq)
{
return test_bit(pirq_from_irq(irq), pirq_eoi_map);
}
#endif
static bool pirq_needs_eoi_flag(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 void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
{
int irq = get_evtchn_to_irq(chn);
struct irq_info *info = info_for_irq(irq);
BUG_ON(irq == -1);
#ifdef CONFIG_SMP
cpumask_copy(irq_get_affinity_mask(irq), cpumask_of(cpu));
#endif
xen_evtchn_port_bind_to_cpu(info, cpu);
info->cpu = cpu;
}
static void xen_evtchn_mask_all(void)
{
unsigned int evtchn;
for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++)
mask_evtchn(evtchn);
}
/**
* 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 xen_irq_init(unsigned irq)
{
struct irq_info *info;
#ifdef CONFIG_SMP
/* By default all event channels notify CPU#0. */
cpumask_copy(irq_get_affinity_mask(irq), 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;
info->refcnt = -1;
irq_set_handler_data(irq, info);
list_add_tail(&info->list, &xen_irq_list_head);
}
static int __must_check xen_allocate_irqs_dynamic(int nvec)
{
int i, irq = irq_alloc_descs(-1, 0, nvec, -1);
if (irq >= 0) {
for (i = 0; i < nvec; i++)
xen_irq_init(irq + i);
}
return irq;
}
static inline int __must_check xen_allocate_irq_dynamic(void)
{
return xen_allocate_irqs_dynamic(1);
}
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_legacy_irqs())
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);
if (WARN_ON(!info))
return;
list_del(&info->list);
irq_set_handler_data(irq, NULL);
WARN_ON(info->refcnt > 0);
kfree(info);
/* Legacy IRQ descriptors are managed by the arch. */
if (irq < nr_legacy_irqs())
return;
irq_free_desc(irq);
}
static void xen_evtchn_close(unsigned int port)
{
struct evtchn_close close;
close.port = port;
if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
BUG();
}
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 void eoi_pirq(struct irq_data *data)
{
int evtchn = evtchn_from_irq(data->irq);
struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
int rc = 0;
irq_move_irq(data);
if (VALID_EVTCHN(evtchn))
clear_evtchn(evtchn);
if (pirq_needs_eoi(data->irq)) {
rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
WARN_ON(rc);
}
}
static void mask_ack_pirq(struct irq_data *data)
{
disable_dynirq(data);
eoi_pirq(data);
}
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) {
pr_warn("Failed to obtain physical IRQ %d\n", irq);
return 0;
}
evtchn = bind_pirq.port;
pirq_query_unmask(irq);
rc = set_evtchn_to_irq(evtchn, irq);
if (rc)
goto err;
info->evtchn = evtchn;
bind_evtchn_to_cpu(evtchn, 0);
rc = xen_evtchn_port_setup(info);
if (rc)
goto err;
out:
unmask_evtchn(evtchn);
eoi_pirq(irq_get_irq_data(irq));
return 0;
err:
pr_err("irq%d: Failed to set port to irq mapping (%d)\n", irq, rc);
xen_evtchn_close(evtchn);
return 0;
}
static unsigned int startup_pirq(struct irq_data *data)
{
return __startup_pirq(data->irq);
}
static void shutdown_pirq(struct irq_data *data)
{
unsigned int irq = data->irq;
struct irq_info *info = info_for_irq(irq);
unsigned evtchn = evtchn_from_irq(irq);
BUG_ON(info->type != IRQT_PIRQ);
if (!VALID_EVTCHN(evtchn))
return;
mask_evtchn(evtchn);
xen_evtchn_close(evtchn);
xen_irq_info_cleanup(info);
}
static void enable_pirq(struct irq_data *data)
{
startup_pirq(data);
}
static void disable_pirq(struct irq_data *data)
{
disable_dynirq(data);
}
int xen_irq_from_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;
}
EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
static void __unbind_from_irq(unsigned int irq)
{
int evtchn = evtchn_from_irq(irq);
struct irq_info *info = irq_get_handler_data(irq);
if (info->refcnt > 0) {
info->refcnt--;
if (info->refcnt != 0)
return;
}
if (VALID_EVTCHN(evtchn)) {
unsigned int cpu = cpu_from_irq(irq);
xen_evtchn_close(evtchn);
switch (type_from_irq(irq)) {
case IRQT_VIRQ:
per_cpu(virq_to_irq, cpu)[virq_from_irq(irq)] = -1;
break;
case IRQT_IPI:
per_cpu(ipi_to_irq, cpu)[ipi_from_irq(irq)] = -1;
break;
default:
break;
}
xen_irq_info_cleanup(info);
}
BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
xen_free_irq(irq);
}
/*
* 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.
*
* Shareable implies level triggered, not shareable implies edge
* triggered here.
*/
int xen_bind_pirq_gsi_to_irq(unsigned gsi,
unsigned pirq, int shareable, char *name)
{
int irq = -1;
struct physdev_irq irq_op;
int ret;
mutex_lock(&irq_mapping_update_lock);
irq = xen_irq_from_gsi(gsi);
if (irq != -1) {
pr_info("%s: returning irq %d for gsi %u\n",
__func__, irq, gsi);
goto out;
}
irq = xen_allocate_irq_gsi(gsi);
if (irq < 0)
goto out;
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;
}
ret = xen_irq_info_pirq_setup(irq, 0, pirq, gsi, DOMID_SELF,
shareable ? PIRQ_SHAREABLE : 0);
if (ret < 0) {
__unbind_from_irq(irq);
irq = ret;
goto out;
}
pirq_query_unmask(irq);
/* We try to use the handler with the appropriate semantic for the
* type of interrupt: if the interrupt is an edge triggered
* interrupt we use handle_edge_irq.
*
* On the other hand if the interrupt is level triggered we use
* handle_fasteoi_irq like the native code does for this kind of
* interrupts.
*
* Depending on the Xen version, pirq_needs_eoi might return true
* not only for level triggered interrupts but for edge triggered
* interrupts too. In any case Xen always honors the eoi mechanism,
* not injecting any more pirqs of the same kind if the first one
* hasn't received an eoi yet. Therefore using the fasteoi handler
* is the right choice either way.
*/
if (shareable)
irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
handle_fasteoi_irq, name);
else
irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
handle_edge_irq, name);
out:
mutex_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 nvec, const char *name, domid_t domid)
{
int i, irq, ret;
mutex_lock(&irq_mapping_update_lock);
irq = xen_allocate_irqs_dynamic(nvec);
if (irq < 0)
goto out;
for (i = 0; i < nvec; i++) {
irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name);
ret = xen_irq_info_pirq_setup(irq + i, 0, pirq + i, 0, domid,
i == 0 ? 0 : PIRQ_MSI_GROUP);
if (ret < 0)
goto error_irq;
}
ret = irq_set_msi_desc(irq, msidesc);
if (ret < 0)
goto error_irq;
out:
mutex_unlock(&irq_mapping_update_lock);
return irq;
error_irq:
for (; i >= 0; i--)
__unbind_from_irq(irq + i);
mutex_unlock(&irq_mapping_update_lock);
return ret;
}
#endif
int xen_destroy_irq(int irq)
{
struct physdev_unmap_pirq unmap_irq;
struct irq_info *info = info_for_irq(irq);
int rc = -ENOENT;
mutex_lock(&irq_mapping_update_lock);
/*
* If trying to remove a vector in a MSI group different
* than the first one skip the PIRQ unmap unless this vector
* is the first one in the group.
*/
if (xen_initial_domain() && !(info->u.pirq.flags & PIRQ_MSI_GROUP)) {
unmap_irq.pirq = info->u.pirq.pirq;
unmap_irq.domid = info->u.pirq.domid;
rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
/* If another domain quits without making the pci_disable_msix
* call, the Xen hypervisor takes care of freeing the PIRQs
* (free_domain_pirqs).
*/
if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
pr_info("domain %d does not have %d anymore\n",
info->u.pirq.domid, info->u.pirq.pirq);
else if (rc) {
pr_warn("unmap irq failed %d\n", rc);
goto out;
}
}
xen_free_irq(irq);
out:
mutex_unlock(&irq_mapping_update_lock);
return rc;
}
int xen_irq_from_pirq(unsigned pirq)
{
int irq;
struct irq_info *info;
mutex_lock(&irq_mapping_update_lock);
list_for_each_entry(info, &xen_irq_list_head, list) {
if (info->type != IRQT_PIRQ)
continue;
irq = info->irq;
if (info->u.pirq.pirq == pirq)
goto out;
}
irq = -1;
out:
mutex_unlock(&irq_mapping_update_lock);
return irq;
}
int xen_pirq_from_irq(unsigned irq)
{
return pirq_from_irq(irq);
}
EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
int bind_evtchn_to_irq(unsigned int evtchn)
{
int irq;
int ret;
if (evtchn >= xen_evtchn_max_channels())
return -ENOMEM;
mutex_lock(&irq_mapping_update_lock);
irq = get_evtchn_to_irq(evtchn);
if (irq == -1) {
irq = xen_allocate_irq_dynamic();
if (irq < 0)
goto out;
irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
handle_edge_irq, "event");
ret = xen_irq_info_evtchn_setup(irq, evtchn);
if (ret < 0) {
__unbind_from_irq(irq);
irq = ret;
goto out;
}
/* New interdomain events are bound to VCPU 0. */
bind_evtchn_to_cpu(evtchn, 0);
} else {
struct irq_info *info = info_for_irq(irq);
WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
}
out:
mutex_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;
int ret;
mutex_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;
ret = xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
if (ret < 0) {
__unbind_from_irq(irq);
irq = ret;
goto out;
}
bind_evtchn_to_cpu(evtchn, cpu);
} else {
struct irq_info *info = info_for_irq(irq);
WARN_ON(info == NULL || info->type != IRQT_IPI);
}
out:
mutex_unlock(&irq_mapping_update_lock);
return irq;
}
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);
}
EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq);
static int find_virq(unsigned int virq, unsigned int cpu)
{
struct evtchn_status status;
int port, rc = -ENOENT;
memset(&status, 0, sizeof(status));
for (port = 0; port < xen_evtchn_max_channels(); port++) {
status.dom = DOMID_SELF;
status.port = port;
rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
if (rc < 0)
continue;
if (status.status != EVTCHNSTAT_virq)
continue;
if (status.u.virq == virq && status.vcpu == cpu) {
rc = port;
break;
}
}
return rc;
}
/**
* xen_evtchn_nr_channels - number of usable event channel ports
*
* This may be less than the maximum supported by the current
* hypervisor ABI. Use xen_evtchn_max_channels() for the maximum
* supported.
*/
unsigned xen_evtchn_nr_channels(void)
{
return evtchn_ops->nr_channels();
}
EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
{
struct evtchn_bind_virq bind_virq;
int evtchn, irq, ret;
mutex_lock(&irq_mapping_update_lock);
irq = per_cpu(virq_to_irq, cpu)[virq];
if (irq == -1) {
irq = xen_allocate_irq_dynamic();
if (irq < 0)
goto out;
if (percpu)
irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
handle_percpu_irq, "virq");
else
irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
handle_edge_irq, "virq");
bind_virq.virq = virq;
bind_virq.vcpu = cpu;
ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
&bind_virq);
if (ret == 0)
evtchn = bind_virq.port;
else {
if (ret == -EEXIST)
ret = find_virq(virq, cpu);
BUG_ON(ret < 0);
evtchn = ret;
}
ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
if (ret < 0) {
__unbind_from_irq(irq);
irq = ret;
goto out;
}
bind_evtchn_to_cpu(evtchn, cpu);
} else {
struct irq_info *info = info_for_irq(irq);
WARN_ON(info == NULL || info->type != IRQT_VIRQ);
}
out:
mutex_unlock(&irq_mapping_update_lock);
return irq;
}
static void unbind_from_irq(unsigned int irq)
{
mutex_lock(&irq_mapping_update_lock);
__unbind_from_irq(irq);
mutex_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, irqflags & IRQF_PERCPU);
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 | IRQF_EARLY_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)
{
struct irq_info *info = irq_get_handler_data(irq);
if (WARN_ON(!info))
return;
free_irq(irq, dev_id);
unbind_from_irq(irq);
}
EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
/**
* xen_set_irq_priority() - set an event channel priority.
* @irq:irq bound to an event channel.
* @priority: priority between XEN_IRQ_PRIORITY_MAX and XEN_IRQ_PRIORITY_MIN.
*/
int xen_set_irq_priority(unsigned irq, unsigned priority)
{
struct evtchn_set_priority set_priority;
set_priority.port = evtchn_from_irq(irq);
set_priority.priority = priority;
return HYPERVISOR_event_channel_op(EVTCHNOP_set_priority,
&set_priority);
}
EXPORT_SYMBOL_GPL(xen_set_irq_priority);
int evtchn_make_refcounted(unsigned int evtchn)
{
int irq = get_evtchn_to_irq(evtchn);
struct irq_info *info;
if (irq == -1)
return -ENOENT;
info = irq_get_handler_data(irq);
if (!info)
return -ENOENT;
WARN_ON(info->refcnt != -1);
info->refcnt = 1;
return 0;
}
EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
int evtchn_get(unsigned int evtchn)
{
int irq;
struct irq_info *info;
int err = -ENOENT;
if (evtchn >= xen_evtchn_max_channels())
return -EINVAL;
mutex_lock(&irq_mapping_update_lock);
irq = get_evtchn_to_irq(evtchn);
if (irq == -1)
goto done;
info = irq_get_handler_data(irq);
if (!info)
goto done;
err = -EINVAL;
if (info->refcnt <= 0)
goto done;
info->refcnt++;
err = 0;
done:
mutex_unlock(&irq_mapping_update_lock);
return err;
}
EXPORT_SYMBOL_GPL(evtchn_get);
void evtchn_put(unsigned int evtchn)
{
int irq = get_evtchn_to_irq(evtchn);
if (WARN_ON(irq == -1))
return;
unbind_from_irq(irq);
}
EXPORT_SYMBOL_GPL(evtchn_put);
void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
{
int irq;
#ifdef CONFIG_X86
if (unlikely(vector == XEN_NMI_VECTOR)) {
int rc = HYPERVISOR_vcpu_op(VCPUOP_send_nmi, cpu, NULL);
if (rc < 0)
printk(KERN_WARNING "Sending nmi to CPU%d failed (rc:%d)\n", cpu, rc);
return;
}
#endif
irq = per_cpu(ipi_to_irq, cpu)[vector];
BUG_ON(irq < 0);
notify_remote_via_irq(irq);
}
static DEFINE_PER_CPU(unsigned, xed_nesting_count);
static void __xen_evtchn_do_upcall(void)
{
struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
int cpu = get_cpu();
unsigned count;
do {
vcpu_info->evtchn_upcall_pending = 0;
if (__this_cpu_inc_return(xed_nesting_count) - 1)
goto out;
xen_evtchn_handle_events(cpu);
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);
irq_enter();
#ifdef CONFIG_X86
exit_idle();
inc_irq_stat(irq_hv_callback_count);
#endif
__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);
if (WARN_ON(!info))
return;
/* Make sure the irq is masked, since the new event channel
will also be masked. */
disable_irq(irq);
mutex_lock(&irq_mapping_update_lock);
/* After resume the irq<->evtchn mappings are all cleared out */
BUG_ON(get_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);
(void)xen_irq_info_evtchn_setup(irq, evtchn);
mutex_unlock(&irq_mapping_update_lock);
bind_evtchn_to_cpu(evtchn, info->cpu);
/* This will be deferred until interrupt is processed */
irq_set_affinity(irq, cpumask_of(info->cpu));
/* 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);
int masked;
if (!VALID_EVTCHN(evtchn))
return -1;
if (!xen_support_evtchn_rebind())
return -1;
/* Send future instances of this interrupt to other vcpu. */
bind_vcpu.port = evtchn;
bind_vcpu.vcpu = tcpu;
/*
* Mask the event while changing the VCPU binding to prevent
* it being delivered on an unexpected VCPU.
*/
masked = test_and_set_mask(evtchn);
/*
* 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);
if (!masked)
unmask_evtchn(evtchn);
return 0;
}
static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
bool force)
{
unsigned tcpu = cpumask_first_and(dest, cpu_online_mask);
return rebind_irq_to_cpu(data->irq, tcpu);
}
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_irq(data);
if (VALID_EVTCHN(evtchn))
clear_evtchn(evtchn);
}
static void mask_ack_dynirq(struct irq_data *data)
{
disable_dynirq(data);
ack_dynirq(data);
}
static int retrigger_dynirq(struct irq_data *data)
{
unsigned int evtchn = evtchn_from_irq(data->irq);
int masked;
if (!VALID_EVTCHN(evtchn))
return 0;
masked = test_and_set_mask(evtchn);
set_evtchn(evtchn);
if (!masked)
unmask_evtchn(evtchn);
return 1;
}
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) {
pr_warn("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. */
(void)xen_irq_info_virq_setup(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. */
(void)xen_irq_info_ipi_setup(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 */);
}
/* Check whether the IRQ line is shared with other guests. */
int xen_test_irq_shared(int irq)
{
struct irq_info *info = info_for_irq(irq);
struct physdev_irq_status_query irq_status;
if (WARN_ON(!info))
return -ENOENT;
irq_status.irq = info->u.pirq.pirq;
if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
return 0;
return !(irq_status.flags & XENIRQSTAT_shared);
}
EXPORT_SYMBOL_GPL(xen_test_irq_shared);
void xen_irq_resume(void)
{
unsigned int cpu;
struct irq_info *info;
/* New event-channel space is not 'live' yet. */
xen_evtchn_mask_all();
xen_evtchn_resume();
/* No IRQ <-> event-channel mappings. */
list_for_each_entry(info, &xen_irq_list_head, list)
info->evtchn = 0; /* zap event-channel binding */
clear_evtchn_to_irq_all();
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_ack = ack_dynirq,
.irq_mask_ack = mask_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_disable = disable_pirq,
.irq_mask = disable_dynirq,
.irq_unmask = enable_dynirq,
.irq_ack = eoi_pirq,
.irq_eoi = eoi_pirq,
.irq_mask_ack = mask_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(HYPERVISOR_CALLBACK_VECTOR);
rc = xen_set_callback_via(callback_via);
if (rc) {
pr_err("Request for Xen HVM callback vector failed\n");
xen_have_vector_callback = 0;
return;
}
pr_info("Xen HVM callback vector for event delivery is enabled\n");
/* in the restore case the vector has already been allocated */
if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
xen_hvm_callback_vector);
}
}
#else
void xen_callback_vector(void) {}
#endif
#undef MODULE_PARAM_PREFIX
#define MODULE_PARAM_PREFIX "xen."
static bool fifo_events = true;
module_param(fifo_events, bool, 0);
void __init xen_init_IRQ(void)
{
int ret = -EINVAL;
if (fifo_events)
ret = xen_evtchn_fifo_init();
if (ret < 0)
xen_evtchn_2l_init();
evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
sizeof(*evtchn_to_irq), GFP_KERNEL);
BUG_ON(!evtchn_to_irq);
/* No event channels are 'live' right now. */
xen_evtchn_mask_all();
pirq_needs_eoi = pirq_needs_eoi_flag;
#ifdef CONFIG_X86
if (xen_pv_domain()) {
irq_ctx_init(smp_processor_id());
if (xen_initial_domain())
pci_xen_initial_domain();
}
if (xen_feature(XENFEAT_hvm_callback_vector))
xen_callback_vector();
if (xen_hvm_domain()) {
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 {
int rc;
struct physdev_pirq_eoi_gmfn eoi_gmfn;
pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
eoi_gmfn.gmfn = virt_to_gfn(pirq_eoi_map);
rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn);
/* TODO: No PVH support for PIRQ EOI */
if (rc != 0) {
free_page((unsigned long) pirq_eoi_map);
pirq_eoi_map = NULL;
} else
pirq_needs_eoi = pirq_check_eoi_map;
}
#endif
}
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