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/* Copyright (C) 1999-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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
<https://www.gnu.org/licenses/>. */
/* I/O access is restricted to ISA port space (ports 0..65535).
Modern devices hopefully are sane enough not to put any performance
critical registers in i/o space.
On the first call to ioperm() or iopl(), the entire (E)ISA port
space is mapped into the virtual address space at address io.base.
mprotect() calls are then used to enable/disable access to ports.
Per 4KB page, there are 4 I/O ports. */
#include <errno.h>
#include <fcntl.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h>
#define MAX_PORT 0x10000
/*
* Memory fence w/accept. This should never be used in code that is
* not IA-64 specific.
*/
#define __ia64_mf_a() __asm__ __volatile__ ("mf.a" ::: "memory")
static struct
{
unsigned long int base;
unsigned long int page_mask;
}
io;
__inline__ unsigned long int
io_offset (unsigned long int port)
{
return ((port >> 2) << 12) | (port & 0xfff);
}
int
_ioperm (unsigned long int from, unsigned long int num, int turn_on)
{
unsigned long int base;
/* 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)
{
unsigned long phys_io_base, len;
int fd;
io.page_mask = ~(__getpagesize() - 1);
/* get I/O base physical address from ar.k0 as per PRM: */
__asm__ ("mov %0=ar.k0" : "=r"(phys_io_base));
/* The O_SYNC flag tells the /dev/mem driver to map the
memory uncached: */
fd = __open ("/dev/mem", O_RDWR | O_SYNC);
if (fd < 0)
return -1;
len = io_offset (MAX_PORT);
/* see comment below */
base = (unsigned long int) __mmap (0, len, PROT_READ | PROT_WRITE, MAP_SHARED,
fd, phys_io_base);
__close (fd);
if ((long) base == -1)
return -1;
io.base = base;
}
}
else
{
if (!io.base)
return 0; /* never was turned on... */
}
/* We can't do mprotect because that would cause us to lose the
uncached flag that the /dev/mem driver turned on. A MAP_UNCACHED
flag seems so much cleaner...
See the history of this file for a version that tried mprotect. */
return 0;
}
int
_iopl (unsigned int level)
{
if (level > 3)
{
__set_errno (EINVAL);
return -1;
}
if (level)
{
int retval = _ioperm (0, MAX_PORT, 1);
/* Match the documented error returns of the x86 version. */
if (retval < 0 && errno == EACCES)
__set_errno (EPERM);
return retval;
}
return 0;
}
unsigned int
_inb (unsigned long int port)
{
volatile unsigned char *addr = (void *) io.base + io_offset (port);
unsigned char ret;
ret = *addr;
__ia64_mf_a();
return ret;
}
unsigned int
_inw (unsigned long int port)
{
volatile unsigned short *addr = (void *) io.base + io_offset (port);
unsigned short ret;
ret = *addr;
__ia64_mf_a();
return ret;
}
unsigned int
_inl (unsigned long int port)
{
volatile unsigned int *addr = (void *) io.base + io_offset (port);
unsigned int ret;
ret = *addr;
__ia64_mf_a();
return ret;
}
void
_outb (unsigned char val, unsigned long int port)
{
volatile unsigned char *addr = (void *) io.base + io_offset (port);
*addr = val;
__ia64_mf_a();
}
void
_outw (unsigned short val, unsigned long int port)
{
volatile unsigned short *addr = (void *) io.base + io_offset (port);
*addr = val;
__ia64_mf_a();
}
void
_outl (unsigned int val, unsigned long int port)
{
volatile unsigned int *addr = (void *) io.base + io_offset (port);
*addr = val;
__ia64_mf_a();
}
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);
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