linux/arch/mips/lib/uncached.c

81 lines
2.0 KiB
C
Raw Normal View History

/*
* 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 <asm/addrspace.h>
#include <asm/bug.h>
#include <asm/cacheflush.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.
*/
MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code commit 3747069b25e419f6b51395f48127e9812abc3596 upstream. The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit -- so if we remove the __cpuinit from the arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit related content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. Here, we remove all the MIPS __cpuinit from C code and __CPUINIT from asm files. MIPS is interesting in this respect, because there are also uasm users hiding behind their own renamed versions of the __cpuinit macros. [1] https://lkml.org/lkml/2013/5/20/589 [ralf@linux-mips.org: Folded in Paul's followup fix.] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5494/ Patchwork: https://patchwork.linux-mips.org/patch/5495/ Patchwork: https://patchwork.linux-mips.org/patch/5509/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-06-18 21:38:59 +08:00
unsigned long 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);
#ifdef CONFIG_64BIT
else if ((long long)sp >= (long long)PHYS_TO_XKPHYS(0, 0) &&
(long long)sp < (long long)PHYS_TO_XKPHYS(8, 0))
usp = PHYS_TO_XKPHYS(K_CALG_UNCACHED,
XKPHYS_TO_PHYS((long long)sp));
#endif
else {
BUG();
usp = sp;
}
if (lfunc >= (long)CKSEG0 && lfunc < (long)CKSEG2)
ufunc = CKSEG1ADDR(lfunc);
#ifdef CONFIG_64BIT
else if ((long long)lfunc >= (long long)PHYS_TO_XKPHYS(0, 0) &&
(long long)lfunc < (long long)PHYS_TO_XKPHYS(8, 0))
ufunc = PHYS_TO_XKPHYS(K_CALG_UNCACHED,
XKPHYS_TO_PHYS((long long)lfunc));
#endif
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;
}