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