diff options
Diffstat (limited to 'drivers/xen/events/events_base.c')
| -rw-r--r-- | drivers/xen/events/events_base.c | 1693 |
1 files changed, 1693 insertions, 0 deletions
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c new file mode 100644 index 00000000000..c919d3d5c84 --- /dev/null +++ b/drivers/xen/events/events_base.c @@ -0,0 +1,1693 @@ +/* + * 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/xen/page.h> +#include <asm/xen/pci.h> +#endif +#include <asm/sync_bitops.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> +#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 < 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 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_irq_data(irq)->affinity, 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_irq_data(irq)->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; + 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_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); + + 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_IRQS_LEGACY) + 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 != 0) { + pr_err("irq%d: Failed to set port to irq mapping (%d)\n", + irq, rc); + xen_evtchn_close(evtchn); + return 0; + } + bind_evtchn_to_cpu(evtchn, 0); + info->evtchn = evtchn; + +out: + unmask_evtchn(evtchn); + eoi_pirq(irq_get_irq_data(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) +{ + 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; +} + +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); +} + +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) +{ + 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; + + irq_set_chip_and_handler_name(irq, &xen_percpu_chip, + handle_percpu_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); + 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); + + /* 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); + int masked; + + 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; + + /* + * 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_mfn(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 +} |