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Annotation of Gnu-Mach/i386/i386at/gpl/linux/linux_port.c, revision 1.1.1.1

1.1       root        1: /*
                      2:  * Linux I/O port management.
                      3:  * Copyright (C) 1995 Shantanu Goel.
                      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; either version 2, or (at your option)
                      8:  * any later version.
                      9:  *
                     10:  * This program is distributed in the hope that it will be useful,
                     11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
                     12:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     13:  * GNU General Public License for more details.
                     14:  *
                     15:  * You should have received a copy of the GNU General Public License
                     16:  * along with this program; if not, write to the Free Software
                     17:  * Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
                     18:  */
                     19: 
                     20: #include <linux/ioport.h>
                     21: 
                     22: #define NPORTS         65536
                     23: #define BITS_PER_WORD  32
                     24: #define NWORDS         (NPORTS / BITS_PER_WORD)
                     25: 
                     26: /*
                     27:  * This bitmap keeps track of all allocated ports.
                     28:  * A bit is set if the port has been allocated.
                     29:  */
                     30: static unsigned port_bitmap[NWORDS];
                     31: 
                     32: void snarf_region(unsigned, unsigned);
                     33: 
                     34: /*
                     35:  * Check if a region is available for use.
                     36:  */
                     37: int
                     38: check_region(unsigned port, unsigned size)
                     39: {
                     40:        unsigned i;
                     41: 
                     42:        for (i = port; i < port + size; i++)
                     43:                if (port_bitmap[i/BITS_PER_WORD] & (1 << (i%BITS_PER_WORD)))
                     44:                        return (1);
                     45:        return (0);
                     46: }
                     47: 
                     48: /*
                     49:  * Allocate a region.
                     50:  */
                     51: void
                     52: request_region(unsigned port, unsigned size, const char *name)
                     53: {
                     54:        unsigned i;
                     55: 
                     56:        for (i = port; i < port + size; i++)
                     57:                port_bitmap[i / BITS_PER_WORD] |= 1 << (i % BITS_PER_WORD);
                     58: }
                     59: 
                     60: /*
                     61:  * For compatibility with older kernels.
                     62:  */
                     63: void
                     64: snarf_region(unsigned port, unsigned size)
                     65: {
                     66:        request_region(port, size, 0);
                     67: }
                     68: 
                     69: /*
                     70:  * Deallocate a region.
                     71:  */
                     72: void
                     73: release_region(unsigned port, unsigned size)
                     74: {
                     75:        unsigned i;
                     76: 
                     77:        for (i = port; i < port + size; i++)
                     78:                port_bitmap[i / BITS_PER_WORD] &= ~(1 << (i % BITS_PER_WORD));
                     79: }

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