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Diffstat (limited to 'arch/powerpc/lib/feature-fixups.c')
| -rw-r--r-- | arch/powerpc/lib/feature-fixups.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c new file mode 100644 index 00000000000..f6fd5d2ff10 --- /dev/null +++ b/arch/powerpc/lib/feature-fixups.c @@ -0,0 +1,56 @@ +/* + * Copyright (C) 2001 Ben. Herrenschmidt (benh@kernel.crashing.org) + * + * Modifications for ppc64: + * Copyright (C) 2003 Dave Engebretsen <engebret@us.ibm.com> + * + * Copyright 2008 Michael Ellerman, IBM Corporation. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/kernel.h> +#include <asm/cputable.h> +#include <asm/code-patching.h> + + +struct fixup_entry { + unsigned long mask; + unsigned long value; + long start_off; + long end_off; +}; + +static void patch_feature_section(unsigned long value, struct fixup_entry *fcur) +{ + unsigned int *pstart, *pend, *p; + + if ((value & fcur->mask) == fcur->value) + return; + + pstart = ((unsigned int *)fcur) + (fcur->start_off / 4); + pend = ((unsigned int *)fcur) + (fcur->end_off / 4); + + for (p = pstart; p < pend; p++) { + *p = PPC_NOP_INSTR; + asm volatile ("dcbst 0, %0" : : "r" (p)); + } + asm volatile ("sync" : : : "memory"); + for (p = pstart; p < pend; p++) + asm volatile ("icbi 0,%0" : : "r" (p)); + asm volatile ("sync; isync" : : : "memory"); +} + +void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end) +{ + struct fixup_entry *fcur, *fend; + + fcur = fixup_start; + fend = fixup_end; + + for (; fcur < fend; fcur++) + patch_feature_section(value, fcur); +} |