diff options
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/Makefile | 1 | ||||
| -rw-r--r-- | virt/kvm/Kconfig | 3 | ||||
| -rw-r--r-- | virt/kvm/async_pf.c | 4 | ||||
| -rw-r--r-- | virt/kvm/eventfd.c | 187 | ||||
| -rw-r--r-- | virt/kvm/irqchip.c | 18 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 8 | ||||
| -rw-r--r-- | virt/lib/Kconfig | 2 | ||||
| -rw-r--r-- | virt/lib/Makefile | 1 | ||||
| -rw-r--r-- | virt/lib/irqbypass.c | 257 |
9 files changed, 376 insertions, 105 deletions
diff --git a/virt/Makefile b/virt/Makefile new file mode 100644 index 000000000000..be783472ac81 --- /dev/null +++ b/virt/Makefile @@ -0,0 +1 @@ +obj-y += lib/ diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index e2c876d5a03b..9f8014dda2cf 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -47,3 +47,6 @@ config KVM_GENERIC_DIRTYLOG_READ_PROTECT config KVM_COMPAT def_bool y depends on COMPAT && !S390 + +config HAVE_KVM_IRQ_BYPASS + bool diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c index 44660aee335f..77d42be6970e 100644 --- a/virt/kvm/async_pf.c +++ b/virt/kvm/async_pf.c @@ -94,6 +94,10 @@ static void async_pf_execute(struct work_struct *work) trace_kvm_async_pf_completed(addr, gva); + /* + * This memory barrier pairs with prepare_to_wait's set_current_state() + */ + smp_mb(); if (waitqueue_active(&vcpu->wq)) wake_up_interruptible(&vcpu->wq); diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index 79db45336e3a..e29fd2640709 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -23,6 +23,7 @@ #include <linux/kvm_host.h> #include <linux/kvm.h> +#include <linux/kvm_irqfd.h> #include <linux/workqueue.h> #include <linux/syscalls.h> #include <linux/wait.h> @@ -34,73 +35,20 @@ #include <linux/srcu.h> #include <linux/slab.h> #include <linux/seqlock.h> +#include <linux/irqbypass.h> #include <trace/events/kvm.h> #include <kvm/iodev.h> #ifdef CONFIG_HAVE_KVM_IRQFD -/* - * -------------------------------------------------------------------- - * irqfd: Allows an fd to be used to inject an interrupt to the guest - * - * Credit goes to Avi Kivity for the original idea. - * -------------------------------------------------------------------- - */ - -/* - * Resampling irqfds are a special variety of irqfds used to emulate - * level triggered interrupts. The interrupt is asserted on eventfd - * trigger. On acknowledgement through the irq ack notifier, the - * interrupt is de-asserted and userspace is notified through the - * resamplefd. All resamplers on the same gsi are de-asserted - * together, so we don't need to track the state of each individual - * user. We can also therefore share the same irq source ID. - */ -struct _irqfd_resampler { - struct kvm *kvm; - /* - * List of resampling struct _irqfd objects sharing this gsi. - * RCU list modified under kvm->irqfds.resampler_lock - */ - struct list_head list; - struct kvm_irq_ack_notifier notifier; - /* - * Entry in list of kvm->irqfd.resampler_list. Use for sharing - * resamplers among irqfds on the same gsi. - * Accessed and modified under kvm->irqfds.resampler_lock - */ - struct list_head link; -}; - -struct _irqfd { - /* Used for MSI fast-path */ - struct kvm *kvm; - wait_queue_t wait; - /* Update side is protected by irqfds.lock */ - struct kvm_kernel_irq_routing_entry irq_entry; - seqcount_t irq_entry_sc; - /* Used for level IRQ fast-path */ - int gsi; - struct work_struct inject; - /* The resampler used by this irqfd (resampler-only) */ - struct _irqfd_resampler *resampler; - /* Eventfd notified on resample (resampler-only) */ - struct eventfd_ctx *resamplefd; - /* Entry in list of irqfds for a resampler (resampler-only) */ - struct list_head resampler_link; - /* Used for setup/shutdown */ - struct eventfd_ctx *eventfd; - struct list_head list; - poll_table pt; - struct work_struct shutdown; -}; static struct workqueue_struct *irqfd_cleanup_wq; static void irqfd_inject(struct work_struct *work) { - struct _irqfd *irqfd = container_of(work, struct _irqfd, inject); + struct kvm_kernel_irqfd *irqfd = + container_of(work, struct kvm_kernel_irqfd, inject); struct kvm *kvm = irqfd->kvm; if (!irqfd->resampler) { @@ -121,12 +69,13 @@ irqfd_inject(struct work_struct *work) static void irqfd_resampler_ack(struct kvm_irq_ack_notifier *kian) { - struct _irqfd_resampler *resampler; + struct kvm_kernel_irqfd_resampler *resampler; struct kvm *kvm; - struct _irqfd *irqfd; + struct kvm_kernel_irqfd *irqfd; int idx; - resampler = container_of(kian, struct _irqfd_resampler, notifier); + resampler = container_of(kian, + struct kvm_kernel_irqfd_resampler, notifier); kvm = resampler->kvm; kvm_set_irq(kvm, KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID, @@ -141,9 +90,9 @@ irqfd_resampler_ack(struct kvm_irq_ack_notifier *kian) } static void -irqfd_resampler_shutdown(struct _irqfd *irqfd) +irqfd_resampler_shutdown(struct kvm_kernel_irqfd *irqfd) { - struct _irqfd_resampler *resampler = irqfd->resampler; + struct kvm_kernel_irqfd_resampler *resampler = irqfd->resampler; struct kvm *kvm = resampler->kvm; mutex_lock(&kvm->irqfds.resampler_lock); @@ -168,7 +117,8 @@ irqfd_resampler_shutdown(struct _irqfd *irqfd) static void irqfd_shutdown(struct work_struct *work) { - struct _irqfd *irqfd = container_of(work, struct _irqfd, shutdown); + struct kvm_kernel_irqfd *irqfd = + container_of(work, struct kvm_kernel_irqfd, shutdown); u64 cnt; /* @@ -191,6 +141,9 @@ irqfd_shutdown(struct work_struct *work) /* * It is now safe to release the object's resources */ +#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS + irq_bypass_unregister_consumer(&irqfd->consumer); +#endif eventfd_ctx_put(irqfd->eventfd); kfree(irqfd); } @@ -198,7 +151,7 @@ irqfd_shutdown(struct work_struct *work) /* assumes kvm->irqfds.lock is held */ static bool -irqfd_is_active(struct _irqfd *irqfd) +irqfd_is_active(struct kvm_kernel_irqfd *irqfd) { return list_empty(&irqfd->list) ? false : true; } @@ -209,7 +162,7 @@ irqfd_is_active(struct _irqfd *irqfd) * assumes kvm->irqfds.lock is held */ static void -irqfd_deactivate(struct _irqfd *irqfd) +irqfd_deactivate(struct kvm_kernel_irqfd *irqfd) { BUG_ON(!irqfd_is_active(irqfd)); @@ -218,13 +171,23 @@ irqfd_deactivate(struct _irqfd *irqfd) queue_work(irqfd_cleanup_wq, &irqfd->shutdown); } +int __attribute__((weak)) kvm_arch_set_irq( + struct kvm_kernel_irq_routing_entry *irq, + struct kvm *kvm, int irq_source_id, + int level, + bool line_status) +{ + return -EWOULDBLOCK; +} + /* * Called with wqh->lock held and interrupts disabled */ static int irqfd_wakeup(wait_queue_t *wait, unsigned mode, int sync, void *key) { - struct _irqfd *irqfd = container_of(wait, struct _irqfd, wait); + struct kvm_kernel_irqfd *irqfd = + container_of(wait, struct kvm_kernel_irqfd, wait); unsigned long flags = (unsigned long)key; struct kvm_kernel_irq_routing_entry irq; struct kvm *kvm = irqfd->kvm; @@ -241,7 +204,9 @@ irqfd_wakeup(wait_queue_t *wait, unsigned mode, int sync, void *key) if (irq.type == KVM_IRQ_ROUTING_MSI) kvm_set_msi(&irq, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1, false); - else + else if (kvm_arch_set_irq(&irq, kvm, + KVM_USERSPACE_IRQ_SOURCE_ID, 1, + false) == -EWOULDBLOCK) schedule_work(&irqfd->inject); srcu_read_unlock(&kvm->irq_srcu, idx); } @@ -274,37 +239,54 @@ static void irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh, poll_table *pt) { - struct _irqfd *irqfd = container_of(pt, struct _irqfd, pt); + struct kvm_kernel_irqfd *irqfd = + container_of(pt, struct kvm_kernel_irqfd, pt); add_wait_queue(wqh, &irqfd->wait); } /* Must be called under irqfds.lock */ -static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd) +static void irqfd_update(struct kvm *kvm, struct kvm_kernel_irqfd *irqfd) { struct kvm_kernel_irq_routing_entry *e; struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS]; - int i, n_entries; + int n_entries; n_entries = kvm_irq_map_gsi(kvm, entries, irqfd->gsi); write_seqcount_begin(&irqfd->irq_entry_sc); - irqfd->irq_entry.type = 0; - e = entries; - for (i = 0; i < n_entries; ++i, ++e) { - /* Only fast-path MSI. */ - if (e->type == KVM_IRQ_ROUTING_MSI) - irqfd->irq_entry = *e; - } + if (n_entries == 1) + irqfd->irq_entry = *e; + else + irqfd->irq_entry.type = 0; write_seqcount_end(&irqfd->irq_entry_sc); } +#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS +void __attribute__((weak)) kvm_arch_irq_bypass_stop( + struct irq_bypass_consumer *cons) +{ +} + +void __attribute__((weak)) kvm_arch_irq_bypass_start( + struct irq_bypass_consumer *cons) +{ +} + +int __attribute__((weak)) kvm_arch_update_irqfd_routing( + struct kvm *kvm, unsigned int host_irq, + uint32_t guest_irq, bool set) +{ + return 0; +} +#endif + static int kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args) { - struct _irqfd *irqfd, *tmp; + struct kvm_kernel_irqfd *irqfd, *tmp; struct fd f; struct eventfd_ctx *eventfd = NULL, *resamplefd = NULL; int ret; @@ -340,7 +322,7 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args) irqfd->eventfd = eventfd; if (args->flags & KVM_IRQFD_FLAG_RESAMPLE) { - struct _irqfd_resampler *resampler; + struct kvm_kernel_irqfd_resampler *resampler; resamplefd = eventfd_ctx_fdget(args->resamplefd); if (IS_ERR(resamplefd)) { @@ -428,6 +410,17 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args) * we might race against the POLLHUP */ fdput(f); +#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS + irqfd->consumer.token = (void *)irqfd->eventfd; + irqfd->consumer.add_producer = kvm_arch_irq_bypass_add_producer; + irqfd->consumer.del_producer = kvm_arch_irq_bypass_del_producer; + irqfd->consumer.stop = kvm_arch_irq_bypass_stop; + irqfd->consumer.start = kvm_arch_irq_bypass_start; + ret = irq_bypass_register_consumer(&irqfd->consumer); + if (ret) + pr_info("irq bypass consumer (token %p) registration fails: %d\n", + irqfd->consumer.token, ret); +#endif return 0; @@ -469,9 +462,18 @@ bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin) } EXPORT_SYMBOL_GPL(kvm_irq_has_notifier); -void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin) +void kvm_notify_acked_gsi(struct kvm *kvm, int gsi) { struct kvm_irq_ack_notifier *kian; + + hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list, + link) + if (kian->gsi == gsi) + kian->irq_acked(kian); +} + +void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin) +{ int gsi, idx; trace_kvm_ack_irq(irqchip, pin); @@ -479,10 +481,7 @@ void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin) idx = srcu_read_lock(&kvm->irq_srcu); gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin); if (gsi != -1) - hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list, - link) - if (kian->gsi == gsi) - kian->irq_acked(kian); + kvm_notify_acked_gsi(kvm, gsi); srcu_read_unlock(&kvm->irq_srcu, idx); } @@ -525,7 +524,7 @@ kvm_eventfd_init(struct kvm *kvm) static int kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd *args) { - struct _irqfd *irqfd, *tmp; + struct kvm_kernel_irqfd *irqfd, *tmp; struct eventfd_ctx *eventfd; eventfd = eventfd_ctx_fdget(args->fd); @@ -581,7 +580,7 @@ kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args) void kvm_irqfd_release(struct kvm *kvm) { - struct _irqfd *irqfd, *tmp; + struct kvm_kernel_irqfd *irqfd, *tmp; spin_lock_irq(&kvm->irqfds.lock); @@ -604,13 +603,23 @@ kvm_irqfd_release(struct kvm *kvm) */ void kvm_irq_routing_update(struct kvm *kvm) { - struct _irqfd *irqfd; + struct kvm_kernel_irqfd *irqfd; spin_lock_irq(&kvm->irqfds.lock); - list_for_each_entry(irqfd, &kvm->irqfds.items, list) + list_for_each_entry(irqfd, &kvm->irqfds.items, list) { irqfd_update(kvm, irqfd); +#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS + if (irqfd->producer) { + int ret = kvm_arch_update_irqfd_routing( + irqfd->kvm, irqfd->producer->irq, + irqfd->gsi, 1); + WARN_ON(ret); + } +#endif + } + spin_unlock_irq(&kvm->irqfds.lock); } @@ -914,9 +923,7 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args) return -EINVAL; /* ioeventfd with no length can't be combined with DATAMATCH */ - if (!args->len && - args->flags & (KVM_IOEVENTFD_FLAG_PIO | - KVM_IOEVENTFD_FLAG_DATAMATCH)) + if (!args->len && (args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH)) return -EINVAL; ret = kvm_assign_ioeventfd_idx(kvm, bus_idx, args); diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c index d7ea8e20dae4..f0b08a2a48ba 100644 --- a/virt/kvm/irqchip.c +++ b/virt/kvm/irqchip.c @@ -31,16 +31,6 @@ #include <trace/events/kvm.h> #include "irq.h" -struct kvm_irq_routing_table { - int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS]; - u32 nr_rt_entries; - /* - * Array indexed by gsi. Each entry contains list of irq chips - * the gsi is connected to. - */ - struct hlist_head map[0]; -}; - int kvm_irq_map_gsi(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *entries, int gsi) { @@ -154,11 +144,11 @@ static int setup_routing_entry(struct kvm_irq_routing_table *rt, /* * Do not allow GSI to be mapped to the same irqchip more than once. - * Allow only one to one mapping between GSI and MSI. + * Allow only one to one mapping between GSI and non-irqchip routing. */ hlist_for_each_entry(ei, &rt->map[ue->gsi], link) - if (ei->type == KVM_IRQ_ROUTING_MSI || - ue->type == KVM_IRQ_ROUTING_MSI || + if (ei->type != KVM_IRQ_ROUTING_IRQCHIP || + ue->type != KVM_IRQ_ROUTING_IRQCHIP || ue->u.irqchip.irqchip == ei->irqchip.irqchip) return r; @@ -231,6 +221,8 @@ int kvm_set_irq_routing(struct kvm *kvm, kvm_irq_routing_update(kvm); mutex_unlock(&kvm->irq_lock); + kvm_arch_irq_routing_update(kvm); + synchronize_srcu_expedited(&kvm->irq_srcu); new = old; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 7873d6daccb1..484079efea5b 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -230,6 +230,9 @@ int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) init_waitqueue_head(&vcpu->wq); kvm_async_pf_vcpu_init(vcpu); + vcpu->pre_pcpu = -1; + INIT_LIST_HEAD(&vcpu->blocked_vcpu_list); + page = alloc_page(GFP_KERNEL | __GFP_ZERO); if (!page) { r = -ENOMEM; @@ -2721,6 +2724,7 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg) case KVM_CAP_IRQFD: case KVM_CAP_IRQFD_RESAMPLE: #endif + case KVM_CAP_IOEVENTFD_ANY_LENGTH: case KVM_CAP_CHECK_EXTENSION_VM: return 1; #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING @@ -3344,7 +3348,7 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1) return -ENOSPC; - new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count + 1) * + new_bus = kmalloc(sizeof(*bus) + ((bus->dev_count + 1) * sizeof(struct kvm_io_range)), GFP_KERNEL); if (!new_bus) return -ENOMEM; @@ -3376,7 +3380,7 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, if (r) return r; - new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count - 1) * + new_bus = kmalloc(sizeof(*bus) + ((bus->dev_count - 1) * sizeof(struct kvm_io_range)), GFP_KERNEL); if (!new_bus) return -ENOMEM; diff --git a/virt/lib/Kconfig b/virt/lib/Kconfig new file mode 100644 index 000000000000..89a414f815d2 --- /dev/null +++ b/virt/lib/Kconfig @@ -0,0 +1,2 @@ +config IRQ_BYPASS_MANAGER + tristate diff --git a/virt/lib/Makefile b/virt/lib/Makefile new file mode 100644 index 000000000000..901228d1ffbc --- /dev/null +++ b/virt/lib/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_IRQ_BYPASS_MANAGER) += irqbypass.o diff --git a/virt/lib/irqbypass.c b/virt/lib/irqbypass.c new file mode 100644 index 000000000000..09a03b5a21ff --- /dev/null +++ b/virt/lib/irqbypass.c @@ -0,0 +1,257 @@ +/* + * IRQ offload/bypass manager + * + * Copyright (C) 2015 Red Hat, Inc. + * Copyright (c) 2015 Linaro Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Various virtualization hardware acceleration techniques allow bypassing or + * offloading interrupts received from devices around the host kernel. Posted + * Interrupts on Intel VT-d systems can allow interrupts to be received + * directly by a virtual machine. ARM IRQ Forwarding allows forwarded physical + * interrupts to be directly deactivated by the guest. This manager allows + * interrupt producers and consumers to find each other to enable this sort of + * bypass. + */ + +#include <linux/irqbypass.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/mutex.h> + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("IRQ bypass manager utility module"); + +static LIST_HEAD(producers); +static LIST_HEAD(consumers); +static DEFINE_MUTEX(lock); + +/* @lock must be held when calling connect */ +static int __connect(struct irq_bypass_producer *prod, + struct irq_bypass_consumer *cons) +{ + int ret = 0; + + if (prod->stop) + prod->stop(prod); + if (cons->stop) + cons->stop(cons); + + if (prod->add_consumer) + ret = prod->add_consumer(prod, cons); + + if (!ret) { + ret = cons->add_producer(cons, prod); + if (ret && prod->del_consumer) + prod->del_consumer(prod, cons); + } + + if (cons->start) + cons->start(cons); + if (prod->start) + prod->start(prod); + + return ret; +} + +/* @lock must be held when calling disconnect */ +static void __disconnect(struct irq_bypass_producer *prod, + struct irq_bypass_consumer *cons) +{ + if (prod->stop) + prod->stop(prod); + if (cons->stop) + cons->stop(cons); + + cons->del_producer(cons, prod); + + if (prod->del_consumer) + prod->del_consumer(prod, cons); + + if (cons->start) + cons->start(cons); + if (prod->start) + prod->start(prod); +} + +/** + * irq_bypass_register_producer - register IRQ bypass producer + * @producer: pointer to producer structure + * + * Add the provided IRQ producer to the list of producers and connect + * with any matching token found on the IRQ consumers list. + */ +int irq_bypass_register_producer(struct irq_bypass_producer *producer) +{ + struct irq_bypass_producer *tmp; + struct irq_bypass_consumer *consumer; + + might_sleep(); + + if (!try_module_get(THIS_MODULE)) + return -ENODEV; + + mutex_lock(&lock); + + list_for_each_entry(tmp, &producers, node) { + if (tmp->token == producer->token) { + mutex_unlock(&lock); + module_put(THIS_MODULE); + return -EBUSY; + } + } + + list_for_each_entry(consumer, &consumers, node) { + if (consumer->token == producer->token) { + int ret = __connect(producer, consumer); + if (ret) { + mutex_unlock(&lock); + module_put(THIS_MODULE); + return ret; + } + break; + } + } + + list_add(&producer->node, &producers); + + mutex_unlock(&lock); + + return 0; +} +EXPORT_SYMBOL_GPL(irq_bypass_register_producer); + +/** + * irq_bypass_unregister_producer - unregister IRQ bypass producer + * @producer: pointer to producer structure + * + * Remove a previously registered IRQ producer from the list of producers + * and disconnect it from any connected IRQ consumer. + */ +void irq_bypass_unregister_producer(struct irq_bypass_producer *producer) +{ + struct irq_bypass_producer *tmp; + struct irq_bypass_consumer *consumer; + + might_sleep(); + + if (!try_module_get(THIS_MODULE)) + return; /* nothing in the list anyway */ + + mutex_lock(&lock); + + list_for_each_entry(tmp, &producers, node) { + if (tmp->token != producer->token) + continue; + + list_for_each_entry(consumer, &consumers, node) { + if (consumer->token == producer->token) { + __disconnect(producer, consumer); + break; + } + } + + list_del(&producer->node); + module_put(THIS_MODULE); + break; + } + + mutex_unlock(&lock); + + module_put(THIS_MODULE); +} +EXPORT_SYMBOL_GPL(irq_bypass_unregister_producer); + +/** + * irq_bypass_register_consumer - register IRQ bypass consumer + * @consumer: pointer to consumer structure + * + * Add the provided IRQ consumer to the list of consumers and connect + * with any matching token found on the IRQ producer list. + */ +int irq_bypass_register_consumer(struct irq_bypass_consumer *consumer) +{ + struct irq_bypass_consumer *tmp; + struct irq_bypass_producer *producer; + + if (!consumer->add_producer || !consumer->del_producer) + return -EINVAL; + + might_sleep(); + + if (!try_module_get(THIS_MODULE)) + return -ENODEV; + + mutex_lock(&lock); + + list_for_each_entry(tmp, &consumers, node) { + if (tmp->token == consumer->token) { + mutex_unlock(&lock); + module_put(THIS_MODULE); + return -EBUSY; + } + } + + list_for_each_entry(producer, &producers, node) { + if (producer->token == consumer->token) { + int ret = __connect(producer, consumer); + if (ret) { + mutex_unlock(&lock); + module_put(THIS_MODULE); + return ret; + } + break; + } + } + + list_add(&consumer->node, &consumers); + + mutex_unlock(&lock); + + return 0; +} +EXPORT_SYMBOL_GPL(irq_bypass_register_consumer); + +/** + * irq_bypass_unregister_consumer - unregister IRQ bypass consumer + * @consumer: pointer to consumer structure + * + * Remove a previously registered IRQ consumer from the list of consumers + * and disconnect it from any connected IRQ producer. + */ +void irq_bypass_unregister_consumer(struct irq_bypass_consumer *consumer) +{ + struct irq_bypass_consumer *tmp; + struct irq_bypass_producer *producer; + + might_sleep(); + + if (!try_module_get(THIS_MODULE)) + return; /* nothing in the list anyway */ + + mutex_lock(&lock); + + list_for_each_entry(tmp, &consumers, node) { + if (tmp->token != consumer->token) + continue; + + list_for_each_entry(producer, &producers, node) { + if (producer->token == consumer->token) { + __disconnect(producer, consumer); + break; + } + } + + list_del(&consumer->node); + module_put(THIS_MODULE); + break; + } + + mutex_unlock(&lock); + + module_put(THIS_MODULE); +} +EXPORT_SYMBOL_GPL(irq_bypass_unregister_consumer); |