1/*
  2 * Intel MIC Platform Software Stack (MPSS)
  3 *
  4 * Copyright(c) 2014 Intel Corporation.
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License, version 2, as
  8 * published by the Free Software Foundation.
  9 *
 10 * This program is distributed in the hope that it will be useful, but
 11 * WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 13 * General Public License for more details.
 14 *
 15 * Intel SCIF driver.
 16 *
 17 */
 18#include <linux/idr.h>
 19
 20#include "scif_main.h"
 21
 22#define SCIF_PORT_COUNT	0x10000	/* Ports available */
 23
 24struct idr scif_ports;
 25
 26/*
 27 * struct scif_port - SCIF port information
 28 *
 29 * @ref_cnt - Reference count since there can be multiple endpoints
 30 *		created via scif_accept(..) simultaneously using a port.
 31 */
 32struct scif_port {
 33	int ref_cnt;
 34};
 35
 36/**
 37 * __scif_get_port - Reserve a specified port # for SCIF and add it
 38 * to the global list.
 39 * @port : port # to be reserved.
 40 *
 41 * @return : Allocated SCIF port #, or -ENOSPC if port unavailable.
 42 *		On memory allocation failure, returns -ENOMEM.
 43 */
 44static int __scif_get_port(int start, int end)
 45{
 46	int id;
 47	struct scif_port *port = kzalloc(sizeof(*port), GFP_ATOMIC);
 48
 49	if (!port)
 50		return -ENOMEM;
 51	spin_lock(&scif_info.port_lock);
 52	id = idr_alloc(&scif_ports, port, start, end, GFP_ATOMIC);
 53	if (id >= 0)
 54		port->ref_cnt++;
 55	spin_unlock(&scif_info.port_lock);
 56	return id;
 57}
 58
 59/**
 60 * scif_rsrv_port - Reserve a specified port # for SCIF.
 61 * @port : port # to be reserved.
 62 *
 63 * @return : Allocated SCIF port #, or -ENOSPC if port unavailable.
 64 *		On memory allocation failure, returns -ENOMEM.
 65 */
 66int scif_rsrv_port(u16 port)
 67{
 68	return __scif_get_port(port, port + 1);
 69}
 70
 71/**
 72 * scif_get_new_port - Get and reserve any port # for SCIF in the range
 73 *			SCIF_PORT_RSVD + 1 to SCIF_PORT_COUNT - 1.
 74 *
 75 * @return : Allocated SCIF port #, or -ENOSPC if no ports available.
 76 *		On memory allocation failure, returns -ENOMEM.
 77 */
 78int scif_get_new_port(void)
 79{
 80	return __scif_get_port(SCIF_PORT_RSVD + 1, SCIF_PORT_COUNT);
 81}
 82
 83/**
 84 * scif_get_port - Increment the reference count for a SCIF port
 85 * @id : SCIF port
 86 *
 87 * @return : None
 88 */
 89void scif_get_port(u16 id)
 90{
 91	struct scif_port *port;
 92
 93	if (!id)
 94		return;
 95	spin_lock(&scif_info.port_lock);
 96	port = idr_find(&scif_ports, id);
 97	if (port)
 98		port->ref_cnt++;
 99	spin_unlock(&scif_info.port_lock);
100}
101
102/**
103 * scif_put_port - Release a reserved SCIF port
104 * @id : SCIF port to be released.
105 *
106 * @return : None
107 */
108void scif_put_port(u16 id)
109{
110	struct scif_port *port;
111
112	if (!id)
113		return;
114	spin_lock(&scif_info.port_lock);
115	port = idr_find(&scif_ports, id);
116	if (port) {
117		port->ref_cnt--;
118		if (!port->ref_cnt) {
119			idr_remove(&scif_ports, id);
120			kfree(port);
121		}
122	}
123	spin_unlock(&scif_info.port_lock);
124}