77 lines
2.0 KiB
C
77 lines
2.0 KiB
C
/*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive
|
|
* for more details.
|
|
*
|
|
* Copyright (C) 2005 Thiemo Seufer
|
|
* Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved.
|
|
* Author: Maciej W. Rozycki <macro@mips.com>
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
|
|
#include <asm/addrspace.h>
|
|
#include <asm/bug.h>
|
|
|
|
#ifndef CKSEG2
|
|
#define CKSEG2 CKSSEG
|
|
#endif
|
|
#ifndef TO_PHYS_MASK
|
|
#define TO_PHYS_MASK -1
|
|
#endif
|
|
|
|
/*
|
|
* FUNC is executed in one of the uncached segments, depending on its
|
|
* original address as follows:
|
|
*
|
|
* 1. If the original address is in CKSEG0 or CKSEG1, then the uncached
|
|
* segment used is CKSEG1.
|
|
* 2. If the original address is in XKPHYS, then the uncached segment
|
|
* used is XKPHYS(2).
|
|
* 3. Otherwise it's a bug.
|
|
*
|
|
* The same remapping is done with the stack pointer. Stack handling
|
|
* works because we don't handle stack arguments or more complex return
|
|
* values, so we can avoid sharing the same stack area between a cached
|
|
* and the uncached mode.
|
|
*/
|
|
unsigned long __init run_uncached(void *func)
|
|
{
|
|
register long sp __asm__("$sp");
|
|
register long ret __asm__("$2");
|
|
long lfunc = (long)func, ufunc;
|
|
long usp;
|
|
|
|
if (sp >= (long)CKSEG0 && sp < (long)CKSEG2)
|
|
usp = CKSEG1ADDR(sp);
|
|
else if ((long long)sp >= (long long)PHYS_TO_XKPHYS(0LL, 0) &&
|
|
(long long)sp < (long long)PHYS_TO_XKPHYS(8LL, 0))
|
|
usp = PHYS_TO_XKPHYS((long long)K_CALG_UNCACHED,
|
|
XKPHYS_TO_PHYS((long long)sp));
|
|
else {
|
|
BUG();
|
|
usp = sp;
|
|
}
|
|
if (lfunc >= (long)CKSEG0 && lfunc < (long)CKSEG2)
|
|
ufunc = CKSEG1ADDR(lfunc);
|
|
else if ((long long)lfunc >= (long long)PHYS_TO_XKPHYS(0LL, 0) &&
|
|
(long long)lfunc < (long long)PHYS_TO_XKPHYS(8LL, 0))
|
|
ufunc = PHYS_TO_XKPHYS((long long)K_CALG_UNCACHED,
|
|
XKPHYS_TO_PHYS((long long)lfunc));
|
|
else {
|
|
BUG();
|
|
ufunc = lfunc;
|
|
}
|
|
|
|
__asm__ __volatile__ (
|
|
" move $16, $sp\n"
|
|
" move $sp, %1\n"
|
|
" jalr %2\n"
|
|
" move $sp, $16"
|
|
: "=r" (ret)
|
|
: "r" (usp), "r" (ufunc)
|
|
: "$16", "$31");
|
|
|
|
return ret;
|
|
}
|