1 /* ----------------------------------------------------------------------- *
2 *
3 * Copyright 2010 Intel Corporation; author: H. Peter Anvin
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
8 * Boston MA 02110-1301, USA; either version 2 of the License, or
9 * (at your option) any later version; incorporated herein by reference.
10 *
11 * ----------------------------------------------------------------------- */
12
13 #include <stdint.h>
14 #include <stdbool.h>
15 #include <netinet/in.h>
16 #include "pxe.h"
17
18 /* Port number bitmap - port numbers 49152 (0xc000) to 57343 (0xefff) */
19 #define PORT_NUMBER_BASE 49152
20 #define PORT_NUMBER_COUNT 8192 /* Power of 2, please */
21 static uint32_t port_number_bitmap[PORT_NUMBER_COUNT/32];
22 static uint16_t first_port_number /* = 0 */;
23
24 /*
25 * Bitmap functions
26 */
test_bit(const uint32_t * bitmap,int32_t index)27 static bool test_bit(const uint32_t *bitmap, int32_t index)
28 {
29 uint8_t st;
30 asm("btl %2,%1 ; setc %0" : "=qm" (st) : "m" (*bitmap), "r" (index));
31 return st;
32 }
33
set_bit(uint32_t * bitmap,int32_t index)34 static void set_bit(uint32_t *bitmap, int32_t index)
35 {
36 asm volatile("btsl %1,%0" : "+m" (*bitmap) : "r" (index) : "memory");
37 }
38
clr_bit(uint32_t * bitmap,int32_t index)39 static void clr_bit(uint32_t *bitmap, int32_t index)
40 {
41 asm volatile("btcl %1,%0" : "+m" (*bitmap) : "r" (index) : "memory");
42 }
43
44 /*
45 * Get and free a port number (host byte order)
46 */
get_port(void)47 uint16_t get_port(void)
48 {
49 uint16_t port;
50
51 do {
52 port = first_port_number++;
53 first_port_number &= PORT_NUMBER_COUNT - 1;
54 } while (test_bit(port_number_bitmap, port));
55
56 set_bit(port_number_bitmap, port);
57 return htons(port + PORT_NUMBER_BASE);
58 }
59
free_port(uint16_t port)60 void free_port(uint16_t port)
61 {
62 port = ntohs(port) - PORT_NUMBER_BASE;
63
64 if (port >= PORT_NUMBER_COUNT)
65 return;
66
67 clr_bit(port_number_bitmap, port);
68 }
69