51c52e8669
The logic to patch CPU feature sections lives in cputable.c, but these days it's used for CPU features as well as firmware features. Move it into it's own file for neatness and as preparation for some additions. While we're moving the code, we pull the loop body logic into a separate routine, and remove a comment which doesn't apply anymore. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
57 lines
1.4 KiB
C
57 lines
1.4 KiB
C
/*
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* Copyright (C) 2001 Ben. Herrenschmidt (benh@kernel.crashing.org)
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*
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* Modifications for ppc64:
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* Copyright (C) 2003 Dave Engebretsen <engebret@us.ibm.com>
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*
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* Copyright 2008 Michael Ellerman, IBM Corporation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/kernel.h>
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#include <asm/cputable.h>
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#include <asm/code-patching.h>
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struct fixup_entry {
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unsigned long mask;
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unsigned long value;
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long start_off;
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long end_off;
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};
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static void patch_feature_section(unsigned long value, struct fixup_entry *fcur)
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{
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unsigned int *pstart, *pend, *p;
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if ((value & fcur->mask) == fcur->value)
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return;
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pstart = ((unsigned int *)fcur) + (fcur->start_off / 4);
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pend = ((unsigned int *)fcur) + (fcur->end_off / 4);
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for (p = pstart; p < pend; p++) {
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*p = PPC_NOP_INSTR;
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asm volatile ("dcbst 0, %0" : : "r" (p));
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}
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asm volatile ("sync" : : : "memory");
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for (p = pstart; p < pend; p++)
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asm volatile ("icbi 0,%0" : : "r" (p));
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asm volatile ("sync; isync" : : : "memory");
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}
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void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
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{
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struct fixup_entry *fcur, *fend;
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fcur = fixup_start;
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fend = fixup_end;
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for (; fcur < fend; fcur++)
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patch_feature_section(value, fcur);
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}
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