From 96d4c5881806ebb993a3d84991af9c96fa9cd576 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Mon, 18 Mar 2013 15:50:17 +0000 Subject: [PATCH] xen/events: allow setup of irq_info to fail The FIFO-based event ABI requires additional setup of newly bound events (it may need to expand the event array) and this setup may fail. xen_irq_info_common_init() is a useful place to put this setup so allow this call to fail. This call and the other similar calls are renamed to be *_setup() to reflect that they may now fail. This failure can only occur with new event channels not on rebind. Signed-off-by: David Vrabel Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Boris Ostrovsky --- drivers/xen/events/events_base.c | 156 +++++++++++++++++++++++---------------- 1 file changed, 91 insertions(+), 65 deletions(-) diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 7c7b744cd13d..4f7d94abe82c 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -99,7 +99,7 @@ struct irq_info *info_for_irq(unsigned irq) } /* Constructors for packed IRQ information. */ -static void xen_irq_info_common_init(struct irq_info *info, +static int xen_irq_info_common_setup(struct irq_info *info, unsigned irq, enum xen_irq_type type, unsigned short evtchn, @@ -116,45 +116,47 @@ static void xen_irq_info_common_init(struct irq_info *info, evtchn_to_irq[evtchn] = irq; irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN); + + return 0; } -static void xen_irq_info_evtchn_init(unsigned irq, +static int xen_irq_info_evtchn_setup(unsigned irq, unsigned short evtchn) { struct irq_info *info = info_for_irq(irq); - xen_irq_info_common_init(info, irq, IRQT_EVTCHN, evtchn, 0); + return xen_irq_info_common_setup(info, irq, IRQT_EVTCHN, evtchn, 0); } -static void xen_irq_info_ipi_init(unsigned cpu, +static int xen_irq_info_ipi_setup(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; + + return xen_irq_info_common_setup(info, irq, IRQT_IPI, evtchn, 0); } -static void xen_irq_info_virq_init(unsigned cpu, +static int xen_irq_info_virq_setup(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; + + return xen_irq_info_common_setup(info, irq, IRQT_VIRQ, evtchn, 0); } -static void xen_irq_info_pirq_init(unsigned irq, +static int xen_irq_info_pirq_setup(unsigned irq, unsigned short evtchn, unsigned short pirq, unsigned short gsi, @@ -163,12 +165,12 @@ static void xen_irq_info_pirq_init(unsigned irq, { 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.domid = domid; info->u.pirq.flags = flags; + + return xen_irq_info_common_setup(info, irq, IRQT_PIRQ, evtchn, 0); } /* @@ -521,6 +523,47 @@ int xen_irq_from_gsi(unsigned gsi) } EXPORT_SYMBOL_GPL(xen_irq_from_gsi); +static void __unbind_from_irq(unsigned int irq) +{ + struct evtchn_close close; + 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)) { + 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); +} + /* * Do not make any assumptions regarding the relationship between the * IRQ number returned here and the Xen pirq argument. @@ -536,6 +579,7 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi, { int irq = -1; struct physdev_irq irq_op; + int ret; mutex_lock(&irq_mapping_update_lock); @@ -563,8 +607,13 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi, goto out; } - xen_irq_info_pirq_init(irq, 0, pirq, gsi, DOMID_SELF, + 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 @@ -624,7 +673,9 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc, irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_edge_irq, name); - xen_irq_info_pirq_init(irq, 0, pirq, 0, domid, 0); + ret = xen_irq_info_pirq_setup(irq, 0, pirq, 0, domid, 0); + if (ret < 0) + goto error_irq; ret = irq_set_msi_desc(irq, msidesc); if (ret < 0) goto error_irq; @@ -632,8 +683,8 @@ out: mutex_unlock(&irq_mapping_update_lock); return irq; error_irq: + __unbind_from_irq(irq); mutex_unlock(&irq_mapping_update_lock); - xen_free_irq(irq); return ret; } #endif @@ -703,9 +754,11 @@ 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; mutex_lock(&irq_mapping_update_lock); @@ -719,7 +772,12 @@ int bind_evtchn_to_irq(unsigned int evtchn) irq_set_chip_and_handler_name(irq, &xen_dynamic_chip, handle_edge_irq, "event"); - xen_irq_info_evtchn_init(irq, evtchn); + ret = xen_irq_info_evtchn_setup(irq, evtchn); + if (ret < 0) { + __unbind_from_irq(irq); + irq = ret; + goto out; + } } else { struct irq_info *info = info_for_irq(irq); WARN_ON(info == NULL || info->type != IRQT_EVTCHN); @@ -736,6 +794,7 @@ 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); @@ -755,8 +814,12 @@ static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu) BUG(); evtchn = bind_ipi.port; - xen_irq_info_ipi_init(cpu, irq, evtchn, ipi); - + 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); @@ -835,7 +898,12 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu) evtchn = ret; } - xen_irq_info_virq_init(cpu, irq, evtchn, virq); + 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 { @@ -851,50 +919,8 @@ out: static void unbind_from_irq(unsigned int irq) { - struct evtchn_close close; - int evtchn = evtchn_from_irq(irq); - struct irq_info *info = irq_get_handler_data(irq); - - if (WARN_ON(!info)) - return; - mutex_lock(&irq_mapping_update_lock); - - if (info->refcnt > 0) { - info->refcnt--; - if (info->refcnt != 0) - goto done; - } - - 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); - - done: + __unbind_from_irq(irq); mutex_unlock(&irq_mapping_update_lock); } @@ -1142,7 +1168,7 @@ void rebind_evtchn_irq(int evtchn, int irq) so there should be a proper type */ BUG_ON(info->type == IRQT_UNBOUND); - xen_irq_info_evtchn_init(irq, evtchn); + (void)xen_irq_info_evtchn_setup(irq, evtchn); mutex_unlock(&irq_mapping_update_lock); @@ -1317,7 +1343,7 @@ static void restore_cpu_virqs(unsigned int cpu) evtchn = bind_virq.port; /* Record the new mapping. */ - xen_irq_info_virq_init(cpu, irq, evtchn, virq); + (void)xen_irq_info_virq_setup(cpu, irq, evtchn, virq); bind_evtchn_to_cpu(evtchn, cpu); } } @@ -1341,7 +1367,7 @@ static void restore_cpu_ipis(unsigned int cpu) evtchn = bind_ipi.port; /* Record the new mapping. */ - xen_irq_info_ipi_init(cpu, irq, evtchn, ipi); + (void)xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi); bind_evtchn_to_cpu(evtchn, cpu); } } -- 2.11.0