/* $XFree86: xc/programs/Xserver/hw/xfree86/os-support/shared/bios_mmap.c,v 1.9 2001/05/23 14:46:05 alanh Exp $ */
/*
 * Copyright 1993 by David Wexelblat <dwex@goblin.org>
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of David Wexelblat not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission.  David Wexelblat makes no representations
 * about the suitability of this software for any purpose.  It is provided
 * "as is" without express or implied warranty.
 *
 * DAVID WEXELBLAT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL DAVID WEXELBLAT BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 *
 */
/* $XConsortium: bios_V4mmap.c /main/4 1996/02/21 17:54:27 kaleb $ */

#include "X.h"

#include "xf86.h"
#include "xf86Priv.h"
#include "xf86_OSlib.h"

#ifndef MAP_FAILED
#define MAP_FAILED ((void *)-1)
#endif

/*
 * Read BIOS via mmap()ing DEV_MEM
 */

#ifndef __alpha__
int
xf86ReadBIOS(unsigned long Base, unsigned long Offset, unsigned char *Buf,
	     int Len)
{
	int fd;
	unsigned char *ptr;
	int psize;
	int mlen;

	if ((fd = open(DEV_MEM, O_RDONLY)) < 0)
	{
		xf86Msg(X_WARNING, "xf86ReadBIOS: Failed to open %s (%s)\n",
			DEV_MEM, strerror(errno));
		return(-1);
	}
	psize = xf86getpagesize();
	Offset += Base & (psize - 1);
	Base &= ~(psize - 1);
	mlen = (Offset + Len + psize - 1) & ~(psize - 1);
	ptr = (unsigned char *)mmap((caddr_t)0, mlen, PROT_READ,
					MAP_SHARED, fd, (off_t)Base);
	if (ptr == MAP_FAILED)
	{
		xf86Msg(X_WARNING, "xf86ReadBIOS: %s mmap failed (%s)\n",
			DEV_MEM, strerror(errno));
		close(fd);
		return(-1);
	}
#ifdef DEBUG
	ErrorF("xf86ReadBIOS: BIOS at 0x%08x has signature 0x%04x\n",
		Base, ptr[0] | (ptr[1] << 8));
#endif
	(void)memcpy(Buf, (void *)(ptr + Offset), Len);
	(void)munmap((caddr_t)ptr, mlen);
	(void)close(fd);
	return(Len);
}

#else /* __alpha__ */

  /*
   *  We trick "mmap" into mapping BUS memory for us via BUS_BASE,
   *  which is the KSEG address of the start of the DENSE memory
   *  area.
   */

  /*
   * NOTE: there prolly ought to be more validity checks and all
   *  re: boundaries and sizes and such...
   */

/*
 * The Jensen lacks dense memory, thus we have to address the bus via
 * the sparse addressing scheme.
 *
 * Martin Ostermann (ost@comnets.rwth-aachen.de) - Apr.-Sep. 1996
 */

#ifdef linux

#ifdef TEST_JENSEN_CODE /* define to test the Sparse addressing on a non-Jensen */
#define SPARSE (5)
#define isJensen (1)
#else
#define isJensen (!_bus_base())
#define SPARSE (7)
#endif

extern unsigned long _bus_base(void);
extern unsigned long _bus_base_sparse(void);
#define BUS_BASE (isJensen ? _bus_base_sparse() : _bus_base())
#define JENSEN_SHIFT(x) (isJensen ? ((long)x<<SPARSE) : (long)x)

#else

extern u_int64_t dense_base(void);
#define BUS_BASE dense_base()
#define JENSEN_SHIFT(x) ((long) x)

#endif

int
xf86ReadBIOS(unsigned long Base, unsigned long Offset, unsigned char *Buf,
	     int Len)
{
	caddr_t base;
 	int fd;
	int psize;
	int mlen;

	if ((fd = open(DEV_MEM, O_RDONLY)) < 0)
	{
		xf86Msg(X_WARNING, "xf86ReadBIOS: Failed to open %s (%s)\n",
			DEV_MEM, strerror(errno));
		return(-1);
	}

	psize = xf86getpagesize();
	Offset += Base & (psize - 1);
	Base &= ~(psize - 1);
	mlen = (Offset + Len + psize - 1) & ~(psize - 1);
	base = mmap((caddr_t)0, JENSEN_SHIFT(mlen), PROT_READ,
		    MAP_SHARED, fd, (off_t)(JENSEN_SHIFT(Base) + BUS_BASE));

	if (base == MAP_FAILED)
	{
		xf86Msg(X_WARNING, "xf86ReadBIOS: Failed to mmap %s (%s)\n",
			DEV_MEM, strerror(errno));
		return(-1);
	}

	xf86SlowBCopyFromBus((unsigned char *)(base+JENSEN_SHIFT(Offset)), 
								    Buf, Len);

	munmap((caddr_t)JENSEN_SHIFT(base), JENSEN_SHIFT(mlen));
	close(fd);
	return(Len);
}

#endif /* __alpha__ */
