1 /* Copyright (C) 1999, 2000, 2001, 2004 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by David Mosberger-Tang <davidm@hpl.hp.com>.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library 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 GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
20 /* I/O access is restricted to ISA port space (ports 0..65535).
21 Modern devices hopefully are sane enough not to put any performance
22 critical registers in i/o space.
24 On the first call to ioperm() or iopl(), the entire (E)ISA port
25 space is mapped into the virtual address space at address io.base.
26 mprotect() calls are then used to enable/disable access to ports.
27 Per 4KB page, there are 4 I/O ports. */
36 #include <sys/types.h>
39 #define MAX_PORT 0x10000
42 * Memory fence w/accept. This should never be used in code that is
45 #define __ia64_mf_a() __asm__ __volatile__ ("mf.a" ::: "memory")
49 unsigned long int base
;
50 unsigned long int page_mask
;
54 __inline__
unsigned long int
55 io_offset (unsigned long int port
)
57 return ((port
>> 2) << 12) | (port
& 0xfff);
61 _ioperm (unsigned long int from
, unsigned long int num
, int turn_on
)
64 unsigned long int addr
, len
, base
;
66 unsigned long int base
;
69 /* this test isn't as silly as it may look like; consider overflows! */
70 if (from
>= MAX_PORT
|| from
+ num
> MAX_PORT
)
80 unsigned long phys_io_base
, len
;
83 io
.page_mask
= ~(__getpagesize() - 1);
85 /* get I/O base physical address from ar.k0 as per PRM: */
86 __asm__ ("mov %0=ar.k0" : "=r"(phys_io_base
));
88 /* The O_SYNC flag tells the /dev/mem driver to map the
90 fd
= __open ("/dev/mem", O_RDWR
| O_SYNC
);
94 len
= io_offset (MAX_PORT
);
96 /* see comment below */
97 base
= (unsigned long int) __mmap (0, len
, PROT_READ
| PROT_WRITE
, MAP_SHARED
,
100 base
= (unsigned long int) __mmap (0, len
, PROT_NONE
, MAP_SHARED
,
105 if ((long) base
== -1)
110 prot
= PROT_READ
| PROT_WRITE
;
115 return 0; /* never was turned on... */
120 /* We can't do mprotect because that would cause us to lose the
121 uncached flag that the /dev/mem driver turned on. A MAP_UNCACHED
122 flag seems so much cleaner... */
123 addr
= (io
.base
+ io_offset (from
)) & io
.page_mask
;
124 len
= io
.base
+ io_offset (from
+ num
) - addr
;
125 return mprotect ((void *) addr
, len
, prot
);
132 _iopl (unsigned int level
)
136 __set_errno (EINVAL
);
141 int retval
= _ioperm (0, MAX_PORT
, 1);
142 /* Match the documented error returns of the x86 version. */
143 if (retval
< 0 && errno
== EACCES
)
151 _inb (unsigned long int port
)
153 volatile unsigned char *addr
= (void *) io
.base
+ io_offset (port
);
162 _inw (unsigned long int port
)
164 volatile unsigned short *addr
= (void *) io
.base
+ io_offset (port
);
173 _inl (unsigned long int port
)
175 volatile unsigned int *addr
= (void *) io
.base
+ io_offset (port
);
184 _outb (unsigned char val
, unsigned long int port
)
186 volatile unsigned char *addr
= (void *) io
.base
+ io_offset (port
);
193 _outw (unsigned short val
, unsigned long int port
)
195 volatile unsigned short *addr
= (void *) io
.base
+ io_offset (port
);
202 _outl (unsigned int val
, unsigned long int port
)
204 volatile unsigned int *addr
= (void *) io
.base
+ io_offset (port
);
210 weak_alias (_ioperm
, ioperm
);
211 weak_alias (_iopl
, iopl
);
212 weak_alias (_inb
, inb
);
213 weak_alias (_inw
, inw
);
214 weak_alias (_inl
, inl
);
215 weak_alias (_outb
, outb
);
216 weak_alias (_outw
, outw
);
217 weak_alias (_outl
, outl
);