numam-spdk/include/spdk/io_channel.h
Ben Walker d969ac445a io_channel: Remove per-channel priority
This wasn't used anywhere and we currently believe there
are superior software-only techniques for controlling
quality of service.

Change-Id: Icdadd5870ed0629b338c307d2619bbc242c3e7a3
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/362065
Reviewed-by: Jim Harris <james.r.harris@intel.com>
2017-05-26 13:42:19 -04:00

112 lines
4.4 KiB
C

/*-
* BSD LICENSE
*
* Copyright (c) Intel Corporation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** \file
* IO channel
*/
#ifndef SPDK_IO_CHANNEL_H_
#define SPDK_IO_CHANNEL_H_
#include "spdk/stdinc.h"
#include "spdk/queue.h"
struct spdk_io_channel;
typedef int (*io_channel_create_cb_t)(void *io_device, void *ctx_buf);
typedef void (*io_channel_destroy_cb_t)(void *io_device, void *ctx_buf);
/**
* \brief Initializes the calling thread for I/O channel allocation.
*/
void spdk_allocate_thread(void);
/**
* \brief Releases any resources related to the calling thread for I/O channel allocation.
*
* All I/O channel references related to the calling thread must be released using
* spdk_put_io_channel() prior to calling this function.
*/
void spdk_free_thread(void);
/**
* \brief Register the opaque io_device context as an I/O device.
*
* After an I/O device is registered, it can return I/O channels using the
* spdk_get_io_channel() function. create_cb is the callback function invoked
* to allocate any resources required for a new I/O channel. destroy_cb is the
* callback function invoked to release the resources for an I/O channel. ctx_size
* is the size of the context buffer allocated to store references to allocated I/O
* channel resources.
*/
void spdk_io_device_register(void *io_device, io_channel_create_cb_t create_cb,
io_channel_destroy_cb_t destroy_cb, uint32_t ctx_size);
/**
* \brief Unregister the opaque io_device context as an I/O device.
*
* Callers must ensure they release references to any I/O channel related to this
* device before calling this function.
*/
void spdk_io_device_unregister(void *io_device);
/**
* \brief Gets an I/O channel for the specified io_device to be used by the calling thread.
*
* The io_device context pointer specified must have previously been registered using
* spdk_io_device_register(). If an existing I/O channel does not exist yet for the given
* io_device on the calling thread, it will allocate an I/O channel and invoke the create_cb
* function pointer specified in spdk_io_device_register(). If an I/O channel already
* exists for the given io_device on the calling thread, its reference is returned rather
* than creating a new I/O channel.
*/
struct spdk_io_channel *spdk_get_io_channel(void *io_device);
/**
* \brief Releases a reference to an I/O channel.
*
* Must be called from the same thread that called spdk_get_io_channel() for the specified
* I/O channel. If this releases the last reference to the I/O channel, The destroy_cb
* function specified in spdk_io_device_register() will be invoked to release any
* associated resources.
*/
void spdk_put_io_channel(struct spdk_io_channel *ch);
/**
* \brief Returns the context buffer associated with an I/O channel.
*/
void *spdk_io_channel_get_ctx(struct spdk_io_channel *ch);
#endif /* SPDK_IO_CHANNEL_H_ */