scif_ports.c
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/*
* Intel MIC Platform Software Stack (MPSS)
*
* Copyright(c) 2014 Intel Corporation.
*
* 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.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* Intel SCIF driver.
*
*/
#include <linux/idr.h>
#include "scif_main.h"
#define SCIF_PORT_COUNT 0x10000 /* Ports available */
struct idr scif_ports;
/*
* struct scif_port - SCIF port information
*
* @ref_cnt - Reference count since there can be multiple endpoints
* created via scif_accept(..) simultaneously using a port.
*/
struct scif_port {
int ref_cnt;
};
/**
* __scif_get_port - Reserve a specified port # for SCIF and add it
* to the global list.
* @port : port # to be reserved.
*
* @return : Allocated SCIF port #, or -ENOSPC if port unavailable.
* On memory allocation failure, returns -ENOMEM.
*/
static int __scif_get_port(int start, int end)
{
int id;
struct scif_port *port = kzalloc(sizeof(*port), GFP_ATOMIC);
if (!port)
return -ENOMEM;
spin_lock(&scif_info.port_lock);
id = idr_alloc(&scif_ports, port, start, end, GFP_ATOMIC);
if (id >= 0)
port->ref_cnt++;
spin_unlock(&scif_info.port_lock);
return id;
}
/**
* scif_rsrv_port - Reserve a specified port # for SCIF.
* @port : port # to be reserved.
*
* @return : Allocated SCIF port #, or -ENOSPC if port unavailable.
* On memory allocation failure, returns -ENOMEM.
*/
int scif_rsrv_port(u16 port)
{
return __scif_get_port(port, port + 1);
}
/**
* scif_get_new_port - Get and reserve any port # for SCIF in the range
* SCIF_PORT_RSVD + 1 to SCIF_PORT_COUNT - 1.
*
* @return : Allocated SCIF port #, or -ENOSPC if no ports available.
* On memory allocation failure, returns -ENOMEM.
*/
int scif_get_new_port(void)
{
return __scif_get_port(SCIF_PORT_RSVD + 1, SCIF_PORT_COUNT);
}
/**
* scif_get_port - Increment the reference count for a SCIF port
* @id : SCIF port
*
* @return : None
*/
void scif_get_port(u16 id)
{
struct scif_port *port;
if (!id)
return;
spin_lock(&scif_info.port_lock);
port = idr_find(&scif_ports, id);
if (port)
port->ref_cnt++;
spin_unlock(&scif_info.port_lock);
}
/**
* scif_put_port - Release a reserved SCIF port
* @id : SCIF port to be released.
*
* @return : None
*/
void scif_put_port(u16 id)
{
struct scif_port *port;
if (!id)
return;
spin_lock(&scif_info.port_lock);
port = idr_find(&scif_ports, id);
if (port) {
port->ref_cnt--;
if (!port->ref_cnt) {
idr_remove(&scif_ports, id);
kfree(port);
}
}
spin_unlock(&scif_info.port_lock);
}