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Diffstat (limited to 'include/linux/irqbypass.h')
| -rw-r--r-- | include/linux/irqbypass.h | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/include/linux/irqbypass.h b/include/linux/irqbypass.h new file mode 100644 index 000000000000..1551b5b2f4c2 --- /dev/null +++ b/include/linux/irqbypass.h @@ -0,0 +1,90 @@ +/* + * 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. + */ +#ifndef IRQBYPASS_H +#define IRQBYPASS_H + +#include <linux/list.h> + +struct irq_bypass_consumer; + +/* + * Theory of operation + * + * The IRQ bypass manager is a simple set of lists and callbacks that allows + * IRQ producers (ex. physical interrupt sources) to be matched to IRQ + * consumers (ex. virtualization hardware that allows IRQ bypass or offload) + * via a shared token (ex. eventfd_ctx). Producers and consumers register + * independently. When a token match is found, the optional @stop callback + * will be called for each participant. The pair will then be connected via + * the @add_* callbacks, and finally the optional @start callback will allow + * any final coordination. When either participant is unregistered, the + * process is repeated using the @del_* callbacks in place of the @add_* + * callbacks. Match tokens must be unique per producer/consumer, 1:N pairings + * are not supported. + */ + +/** + * struct irq_bypass_producer - IRQ bypass producer definition + * @node: IRQ bypass manager private list management + * @token: opaque token to match between producer and consumer + * @irq: Linux IRQ number for the producer device + * @add_consumer: Connect the IRQ producer to an IRQ consumer (optional) + * @del_consumer: Disconnect the IRQ producer from an IRQ consumer (optional) + * @stop: Perform any quiesce operations necessary prior to add/del (optional) + * @start: Perform any startup operations necessary after add/del (optional) + * + * The IRQ bypass producer structure represents an interrupt source for + * participation in possible host bypass, for instance an interrupt vector + * for a physical device assigned to a VM. + */ +struct irq_bypass_producer { + struct list_head node; + void *token; + int irq; + int (*add_consumer)(struct irq_bypass_producer *, + struct irq_bypass_consumer *); + void (*del_consumer)(struct irq_bypass_producer *, + struct irq_bypass_consumer *); + void (*stop)(struct irq_bypass_producer *); + void (*start)(struct irq_bypass_producer *); +}; + +/** + * struct irq_bypass_consumer - IRQ bypass consumer definition + * @node: IRQ bypass manager private list management + * @token: opaque token to match between producer and consumer + * @add_producer: Connect the IRQ consumer to an IRQ producer + * @del_producer: Disconnect the IRQ consumer from an IRQ producer + * @stop: Perform any quiesce operations necessary prior to add/del (optional) + * @start: Perform any startup operations necessary after add/del (optional) + * + * The IRQ bypass consumer structure represents an interrupt sink for + * participation in possible host bypass, for instance a hypervisor may + * support offloads to allow bypassing the host entirely or offload + * portions of the interrupt handling to the VM. + */ +struct irq_bypass_consumer { + struct list_head node; + void *token; + int (*add_producer)(struct irq_bypass_consumer *, + struct irq_bypass_producer *); + void (*del_producer)(struct irq_bypass_consumer *, + struct irq_bypass_producer *); + void (*stop)(struct irq_bypass_consumer *); + void (*start)(struct irq_bypass_consumer *); +}; + +int irq_bypass_register_producer(struct irq_bypass_producer *); +void irq_bypass_unregister_producer(struct irq_bypass_producer *); +int irq_bypass_register_consumer(struct irq_bypass_consumer *); +void irq_bypass_unregister_consumer(struct irq_bypass_consumer *); + +#endif /* IRQBYPASS_H */ |