From 3d72808b73faa87378f84c26186f3de8bb198a81 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Tue, 22 Dec 1998 17:26:00 +0000 Subject: [PATCH] Implementation of inb, outb etc for ARM systems. --- sysdeps/unix/sysv/linux/arm/ioperm.c | 271 +++++++++++++++++++++++++++++++++++ 1 file changed, 271 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/arm/ioperm.c diff --git a/sysdeps/unix/sysv/linux/arm/ioperm.c b/sysdeps/unix/sysv/linux/arm/ioperm.c new file mode 100644 index 0000000..551fc97 --- /dev/null +++ b/sysdeps/unix/sysv/linux/arm/ioperm.c @@ -0,0 +1,271 @@ +/* Copyright (C) 1998 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. */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include + +#define PATH_ARM_SYSTYPE "/etc/arm_systype" +#define PATH_CPUINFO "/proc/cpuinfo" + +#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_BASE_FOOTBRIDGE 0x7c000000 +#define IO_SHIFT_FOOTBRIDGE 0 + +static struct platform { + const char *name; + unsigned long int io_base; + unsigned int shift; +} platform[] = { + /* All currently supported platforms are in fact the same. :-) */ + {"Chalice-CATS", IO_BASE_FOOTBRIDGE, IO_SHIFT_FOOTBRIDGE}, + {"DEC-EBSA285", IO_BASE_FOOTBRIDGE, IO_SHIFT_FOOTBRIDGE}, + {"Corel-NetWinder", IO_BASE_FOOTBRIDGE, IO_SHIFT_FOOTBRIDGE}, +}; + +#define IO_ADDR(port) (io.base + ((port) << io.shift)) + +/* + * Initialize I/O system. To determine what I/O system we're dealing + * with, we first try to read the value of symlink PATH_ARM_SYSTYPE, + * if that fails, we lookup the "system type" field in /proc/cpuinfo. + * If that fails as well, we give up. Other possible options might be + * to look at the ELF auxiliary vector or to add a special system call + * but there is probably no point. + * + * If the value received from PATH_ARM_SYSTYPE begins with a number, + * assume this is a previously unsupported system and the values encode, + * in order, ",". + */ + +static int +init_iosys (void) +{ + char systype[256]; + int i, n; + + n = readlink (PATH_ARM_SYSTYPE, systype, sizeof (systype) - 1); + if (n > 0) + { + systype[n] = '\0'; + if (isdigit (systype[0])) + { + if (sscanf (systype, "%li,%i", &io.io_base, &io.shift) == 2) + { + io.initdone = 1; + return 0; + } + /* else we're likely going to fail with the system match below */ + } + } + else + { + FILE * fp; + + fp = fopen (PATH_CPUINFO, "r"); + if (!fp) + return -1; + while ((n = fscanf (fp, "Hardware\t: %256[^\n]\n", systype)) + != EOF) + { + if (n == 1) + break; + else + fgets (systype, 256, fp); + } + fclose (fp); + + if (n == EOF) + { + /* this can happen if the format of /proc/cpuinfo changes... */ + fprintf (stderr, + "ioperm: Unable to determine system type.\n" + "\t(May need " PATH_ARM_SYSTYPE " symlink?)\n"); + __set_errno (ENODEV); + return -1; + } + } + + /* translate systype name into i/o system: */ + for (i = 0; i < sizeof (platform) / sizeof (platform[0]); ++i) + { + if (strcmp (platform[i].name, systype) == 0) + { + io.shift = platform[i].shift; + io.io_base = platform[i].io_base; + io.initdone = 1; + return 0; + } + } + + /* systype is not a known platform name... */ + __set_errno (EINVAL); + return -1; +} + +int +_ioperm (unsigned long int from, unsigned long int num, int turn_on) +{ + unsigned long int addr, len; + int prot; + + 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_NONE, + MAP_SHARED, fd, io.io_base); + close (fd); + if ((long) io.base == -1) + return -1; + } + prot = PROT_READ | PROT_WRITE; + } + else + { + if (!io.base) + return 0; /* never was turned on... */ + + /* turnoff access to relevant pages: */ + prot = PROT_NONE; + } + addr = (io.base + (from << io.shift)) & PAGE_MASK; + len = num << io.shift; + return mprotect ((void *) addr, len, prot); +} + + +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) +{ + if (port >= MAX_PORT) + return; + + *((volatile unsigned char *)(IO_ADDR (port))) = b; +} + + +void +_outw (unsigned short b, unsigned long int port) +{ + if (port >= MAX_PORT) + return; + + *((volatile unsigned short *)(IO_ADDR (port))) = b; +} + + +void +_outl (unsigned int b, unsigned long int port) +{ + if (port >= MAX_PORT) + return; + + *((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); -- 2.7.4