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Diffstat (limited to 'libc/sysdeps/linux/arm/ioperm.c')
| -rw-r--r-- | libc/sysdeps/linux/arm/ioperm.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/arm/ioperm.c b/libc/sysdeps/linux/arm/ioperm.c new file mode 100644 index 000000000..d67c04d3b --- /dev/null +++ b/libc/sysdeps/linux/arm/ioperm.c @@ -0,0 +1,147 @@ +/* Copyright (C) 1998, 1999 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 Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +/* 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 <string.h> +#include <unistd.h> + +#include <sys/types.h> +#include <sys/mman.h> + +#include <asm/page.h> +#include <sys/sysctl.h> + + +#define IO_BASE 0x7c000000 +#define IO_SHIFT 0 +#define IO_ADDR(port) (IO_BASE + ((port) << IO_SHIFT)) + + +#if 0 +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 MAX_PORT 0x10000 +int ioperm(unsigned long int from, unsigned long int num, int turn_on) +{ + /* 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; +} +#endif + +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))); +} + |