| /* Copyright (C) 1998-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Phil Blundell, based on the Alpha version by |
| David Mosberger. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* I/O port access on the ARM is something of a fiction. What we do is to |
| map an appropriate area of /dev/mem into user space so that a program |
| can blast away at the hardware in such a way as to generate I/O cycles |
| on the bus. To insulate user code from dependencies on particular |
| hardware we don't allow calls to inb() and friends to be inlined, but |
| force them to come through code in here every time. Performance-critical |
| registers tend to be memory mapped these days so this should be no big |
| problem. */ |
| |
| /* Once upon a time this file used mprotect to enable and disable |
| access to particular areas of I/O space. Unfortunately the |
| mprotect syscall also has the side effect of enabling caching for |
| the area affected (this is a kernel limitation). So we now just |
| enable all the ports all of the time. */ |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stdio.h> |
| #include <ctype.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| |
| #include <sys/types.h> |
| #include <sys/mman.h> |
| |
| #include <sys/sysctl.h> |
| |
| #define MAX_PORT 0x10000 |
| |
| static struct { |
| unsigned long int base; |
| unsigned long int io_base; |
| unsigned int shift; |
| unsigned int initdone; /* since all the above could be 0 */ |
| } io; |
| |
| #define IO_ADDR(port) (io.base + ((port) << io.shift)) |
| |
| /* |
| * Initialize I/O system. The io_bae and port_shift values are fetched |
| * using sysctl (CTL_BUS, CTL_BUS_ISA, ISA_*). |
| */ |
| |
| static int |
| init_iosys (void) |
| { |
| static int iobase_name[] = { CTL_BUS, CTL_BUS_ISA, BUS_ISA_PORT_BASE }; |
| static int ioshift_name[] = { CTL_BUS, CTL_BUS_ISA, BUS_ISA_PORT_SHIFT }; |
| size_t len = sizeof(io.base); |
| |
| if (! __sysctl (iobase_name, 3, &io.io_base, &len, NULL, 0) |
| && ! __sysctl (ioshift_name, 3, &io.shift, &len, NULL, 0)) |
| { |
| io.initdone = 1; |
| return 0; |
| } |
| |
| /* sysctl has failed... */ |
| __set_errno (ENODEV); |
| return -1; |
| } |
| |
| int |
| _ioperm (unsigned long int from, unsigned long int num, int turn_on) |
| { |
| if (! io.initdone && init_iosys () < 0) |
| return -1; |
| |
| /* this test isn't as silly as it may look like; consider overflows! */ |
| if (from >= MAX_PORT || from + num > MAX_PORT) |
| { |
| __set_errno (EINVAL); |
| return -1; |
| } |
| |
| if (turn_on) |
| { |
| if (! io.base) |
| { |
| int fd; |
| |
| fd = __open ("/dev/mem", O_RDWR); |
| if (fd < 0) |
| return -1; |
| |
| io.base = |
| (unsigned long int) __mmap (0, MAX_PORT << io.shift, |
| PROT_READ | PROT_WRITE, |
| MAP_SHARED, fd, io.io_base); |
| __close (fd); |
| if ((long) io.base == -1) |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| |
| int |
| _iopl (unsigned int level) |
| { |
| if (level > 3) |
| { |
| __set_errno (EINVAL); |
| return -1; |
| } |
| if (level) |
| { |
| return _ioperm (0, MAX_PORT, 1); |
| } |
| return 0; |
| } |
| |
| |
| void |
| _outb (unsigned char b, unsigned long int port) |
| { |
| *((volatile unsigned char *)(IO_ADDR (port))) = b; |
| } |
| |
| |
| void |
| _outw (unsigned short b, unsigned long int port) |
| { |
| *((volatile unsigned short *)(IO_ADDR (port))) = b; |
| } |
| |
| |
| void |
| _outl (unsigned int b, unsigned long int port) |
| { |
| *((volatile unsigned long *)(IO_ADDR (port))) = b; |
| } |
| |
| |
| unsigned int |
| _inb (unsigned long int port) |
| { |
| return *((volatile unsigned char *)(IO_ADDR (port))); |
| } |
| |
| |
| unsigned int |
| _inw (unsigned long int port) |
| { |
| return *((volatile unsigned short *)(IO_ADDR (port))); |
| } |
| |
| |
| unsigned int |
| _inl (unsigned long int port) |
| { |
| return *((volatile unsigned long *)(IO_ADDR (port))); |
| } |
| |
| weak_alias (_ioperm, ioperm); |
| weak_alias (_iopl, iopl); |
| weak_alias (_inb, inb); |
| weak_alias (_inw, inw); |
| weak_alias (_inl, inl); |
| weak_alias (_outb, outb); |
| weak_alias (_outw, outw); |
| weak_alias (_outl, outl); |