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/* ----------------------------------------------------------------------- *
*
* Copyright 2010 Intel Corporation; author: H. Peter Anvin
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston MA 02110-1301, USA; either version 2 of the License, or
* (at your option) any later version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
#include <stdint.h>
#include <stdbool.h>
#include <netinet/in.h>
#include "pxe.h"
/* Port number bitmap - port numbers 49152 (0xc000) to 57343 (0xefff) */
#define PORT_NUMBER_BASE 49152
#define PORT_NUMBER_COUNT 8192 /* Power of 2, please */
static uint32_t port_number_bitmap[PORT_NUMBER_COUNT/32];
static uint16_t first_port_number /* = 0 */;
/*
* Bitmap functions
*/
static bool test_bit(const uint32_t *bitmap, int32_t index)
{
uint8_t st;
asm("btl %2,%1 ; setc %0" : "=qm" (st) : "m" (*bitmap), "r" (index));
return st;
}
static void set_bit(uint32_t *bitmap, int32_t index)
{
asm volatile("btsl %1,%0" : "+m" (*bitmap) : "r" (index) : "memory");
}
static void clr_bit(uint32_t *bitmap, int32_t index)
{
asm volatile("btcl %1,%0" : "+m" (*bitmap) : "r" (index) : "memory");
}
/*
* Get and free a port number (host byte order)
*/
uint16_t get_port(void)
{
uint16_t port;
do {
port = first_port_number++;
first_port_number &= PORT_NUMBER_COUNT - 1;
} while (test_bit(port_number_bitmap, port));
set_bit(port_number_bitmap, port);
return htons(port + PORT_NUMBER_BASE);
}
void free_port(uint16_t port)
{
port = ntohs(port) - PORT_NUMBER_BASE;
if (port >= PORT_NUMBER_COUNT)
return;
clr_bit(port_number_bitmap, port);
}
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