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authorEric Andersen <andersen@codepoet.org>2001-09-27 07:20:27 +0000
committerEric Andersen <andersen@codepoet.org>2001-09-27 07:20:27 +0000
commita8f281fb479299c388a4c3c5c406ddb6f6c0e323 (patch)
treec44d741f1e214b30fa2d75d6f61054273ed1f365 /libc/sysdeps/linux
parent6ef2a08dbf5648e6df1479ae7e3014fb9500e546 (diff)
Add inb, outb and friends,
Diffstat (limited to 'libc/sysdeps/linux')
-rw-r--r--libc/sysdeps/linux/arm/Makefile2
-rw-r--r--libc/sysdeps/linux/arm/ioperm.c147
2 files changed, 148 insertions, 1 deletions
diff --git a/libc/sysdeps/linux/arm/Makefile b/libc/sysdeps/linux/arm/Makefile
index 965a636db..482d84497 100644
--- a/libc/sysdeps/linux/arm/Makefile
+++ b/libc/sysdeps/linux/arm/Makefile
@@ -36,7 +36,7 @@ CRT0_OBJ=$(patsubst %.S,%.o, $(CRT0))
SSRC=longjmp.S setjmp.S vfork.S
SOBJS=$(patsubst %.S,%.o, $(SSRC))
-CSRC=
+CSRC=ioperm.c
COBJS=$(patsubst %.c,%.o, $(CSRC))
OBJS=$(SOBJS) $(MOBJ) $(COBJS)
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)));
+}
+