444 строки
13 KiB
C
444 строки
13 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/types.h>
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#include <linux/jump_label.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/init.h>
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#include <linux/sched/mm.h>
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#include <asm/cputable.h>
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#include <asm/code-patching.h>
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#include <asm/page.h>
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#include <asm/sections.h>
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#include <asm/setup.h>
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#include <asm/firmware.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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long alt_start_off;
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long alt_end_off;
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};
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static unsigned int *calc_addr(struct fixup_entry *fcur, long offset)
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{
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/*
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* We store the offset to the code as a negative offset from
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* the start of the alt_entry, to support the VDSO. This
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* routine converts that back into an actual address.
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*/
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return (unsigned int *)((unsigned long)fcur + offset);
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}
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static int patch_alt_instruction(unsigned int *src, unsigned int *dest,
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unsigned int *alt_start, unsigned int *alt_end)
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{
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unsigned int instr;
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instr = *src;
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if (instr_is_relative_branch(*src)) {
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unsigned int *target = (unsigned int *)branch_target(src);
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/* Branch within the section doesn't need translating */
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if (target < alt_start || target >= alt_end) {
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instr = translate_branch(dest, src);
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if (!instr)
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return 1;
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}
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}
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patch_instruction(dest, instr);
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return 0;
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}
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static int patch_feature_section(unsigned long value, struct fixup_entry *fcur)
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{
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unsigned int *start, *end, *alt_start, *alt_end, *src, *dest;
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start = calc_addr(fcur, fcur->start_off);
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end = calc_addr(fcur, fcur->end_off);
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alt_start = calc_addr(fcur, fcur->alt_start_off);
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alt_end = calc_addr(fcur, fcur->alt_end_off);
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if ((alt_end - alt_start) > (end - start))
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return 1;
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if ((value & fcur->mask) == fcur->value)
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return 0;
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src = alt_start;
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dest = start;
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for (; src < alt_end; src++, dest++) {
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if (patch_alt_instruction(src, dest, alt_start, alt_end))
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return 1;
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}
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for (; dest < end; dest++)
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patch_instruction(dest, PPC_INST_NOP);
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return 0;
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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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if (patch_feature_section(value, fcur)) {
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WARN_ON(1);
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printk("Unable to patch feature section at %p - %p" \
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" with %p - %p\n",
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calc_addr(fcur, fcur->start_off),
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calc_addr(fcur, fcur->end_off),
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calc_addr(fcur, fcur->alt_start_off),
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calc_addr(fcur, fcur->alt_end_off));
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}
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}
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}
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void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end)
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{
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long *start, *end;
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unsigned int *dest;
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if (!(value & CPU_FTR_LWSYNC))
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return ;
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start = fixup_start;
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end = fixup_end;
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for (; start < end; start++) {
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dest = (void *)start + *start;
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patch_instruction(dest, PPC_INST_LWSYNC);
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}
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}
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static void do_final_fixups(void)
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{
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#if defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE)
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int *src, *dest;
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unsigned long length;
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if (PHYSICAL_START == 0)
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return;
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src = (int *)(KERNELBASE + PHYSICAL_START);
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dest = (int *)KERNELBASE;
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length = (__end_interrupts - _stext) / sizeof(int);
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while (length--) {
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patch_instruction(dest, *src);
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src++;
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dest++;
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}
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#endif
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}
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static unsigned long __initdata saved_cpu_features;
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static unsigned int __initdata saved_mmu_features;
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#ifdef CONFIG_PPC64
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static unsigned long __initdata saved_firmware_features;
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#endif
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void __init apply_feature_fixups(void)
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{
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struct cpu_spec *spec = PTRRELOC(*PTRRELOC(&cur_cpu_spec));
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*PTRRELOC(&saved_cpu_features) = spec->cpu_features;
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*PTRRELOC(&saved_mmu_features) = spec->mmu_features;
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/*
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* Apply the CPU-specific and firmware specific fixups to kernel text
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* (nop out sections not relevant to this CPU or this firmware).
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*/
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do_feature_fixups(spec->cpu_features,
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PTRRELOC(&__start___ftr_fixup),
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PTRRELOC(&__stop___ftr_fixup));
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do_feature_fixups(spec->mmu_features,
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PTRRELOC(&__start___mmu_ftr_fixup),
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PTRRELOC(&__stop___mmu_ftr_fixup));
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do_lwsync_fixups(spec->cpu_features,
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PTRRELOC(&__start___lwsync_fixup),
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PTRRELOC(&__stop___lwsync_fixup));
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#ifdef CONFIG_PPC64
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saved_firmware_features = powerpc_firmware_features;
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do_feature_fixups(powerpc_firmware_features,
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&__start___fw_ftr_fixup, &__stop___fw_ftr_fixup);
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#endif
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do_final_fixups();
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}
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void __init setup_feature_keys(void)
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{
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/*
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* Initialise jump label. This causes all the cpu/mmu_has_feature()
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* checks to take on their correct polarity based on the current set of
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* CPU/MMU features.
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*/
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jump_label_init();
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cpu_feature_keys_init();
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mmu_feature_keys_init();
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}
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static int __init check_features(void)
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{
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WARN(saved_cpu_features != cur_cpu_spec->cpu_features,
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"CPU features changed after feature patching!\n");
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WARN(saved_mmu_features != cur_cpu_spec->mmu_features,
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"MMU features changed after feature patching!\n");
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#ifdef CONFIG_PPC64
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WARN(saved_firmware_features != powerpc_firmware_features,
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"Firmware features changed after feature patching!\n");
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#endif
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return 0;
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}
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late_initcall(check_features);
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#ifdef CONFIG_FTR_FIXUP_SELFTEST
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#define check(x) \
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if (!(x)) printk("feature-fixups: test failed at line %d\n", __LINE__);
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/* This must be after the text it fixes up, vmlinux.lds.S enforces that atm */
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static struct fixup_entry fixup;
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static long calc_offset(struct fixup_entry *entry, unsigned int *p)
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{
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return (unsigned long)p - (unsigned long)entry;
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}
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static void test_basic_patching(void)
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{
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extern unsigned int ftr_fixup_test1[];
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extern unsigned int end_ftr_fixup_test1[];
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extern unsigned int ftr_fixup_test1_orig[];
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extern unsigned int ftr_fixup_test1_expected[];
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int size = end_ftr_fixup_test1 - ftr_fixup_test1;
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fixup.value = fixup.mask = 8;
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fixup.start_off = calc_offset(&fixup, ftr_fixup_test1 + 1);
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fixup.end_off = calc_offset(&fixup, ftr_fixup_test1 + 2);
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fixup.alt_start_off = fixup.alt_end_off = 0;
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/* Sanity check */
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check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
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/* Check we don't patch if the value matches */
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patch_feature_section(8, &fixup);
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check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
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/* Check we do patch if the value doesn't match */
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patch_feature_section(0, &fixup);
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check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0);
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/* Check we do patch if the mask doesn't match */
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memcpy(ftr_fixup_test1, ftr_fixup_test1_orig, size);
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check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0);
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patch_feature_section(~8, &fixup);
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check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0);
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}
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static void test_alternative_patching(void)
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{
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extern unsigned int ftr_fixup_test2[];
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extern unsigned int end_ftr_fixup_test2[];
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extern unsigned int ftr_fixup_test2_orig[];
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extern unsigned int ftr_fixup_test2_alt[];
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extern unsigned int ftr_fixup_test2_expected[];
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int size = end_ftr_fixup_test2 - ftr_fixup_test2;
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fixup.value = fixup.mask = 0xF;
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fixup.start_off = calc_offset(&fixup, ftr_fixup_test2 + 1);
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fixup.end_off = calc_offset(&fixup, ftr_fixup_test2 + 2);
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fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test2_alt);
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fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test2_alt + 1);
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/* Sanity check */
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check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
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/* Check we don't patch if the value matches */
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patch_feature_section(0xF, &fixup);
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check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
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/* Check we do patch if the value doesn't match */
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patch_feature_section(0, &fixup);
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check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0);
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/* Check we do patch if the mask doesn't match */
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memcpy(ftr_fixup_test2, ftr_fixup_test2_orig, size);
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check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0);
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patch_feature_section(~0xF, &fixup);
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check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0);
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}
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static void test_alternative_case_too_big(void)
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{
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extern unsigned int ftr_fixup_test3[];
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extern unsigned int end_ftr_fixup_test3[];
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extern unsigned int ftr_fixup_test3_orig[];
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extern unsigned int ftr_fixup_test3_alt[];
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int size = end_ftr_fixup_test3 - ftr_fixup_test3;
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fixup.value = fixup.mask = 0xC;
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fixup.start_off = calc_offset(&fixup, ftr_fixup_test3 + 1);
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fixup.end_off = calc_offset(&fixup, ftr_fixup_test3 + 2);
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fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test3_alt);
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fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test3_alt + 2);
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/* Sanity check */
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check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
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/* Expect nothing to be patched, and the error returned to us */
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check(patch_feature_section(0xF, &fixup) == 1);
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check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
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check(patch_feature_section(0, &fixup) == 1);
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check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
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check(patch_feature_section(~0xF, &fixup) == 1);
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check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0);
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}
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static void test_alternative_case_too_small(void)
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{
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extern unsigned int ftr_fixup_test4[];
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extern unsigned int end_ftr_fixup_test4[];
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extern unsigned int ftr_fixup_test4_orig[];
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extern unsigned int ftr_fixup_test4_alt[];
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extern unsigned int ftr_fixup_test4_expected[];
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int size = end_ftr_fixup_test4 - ftr_fixup_test4;
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unsigned long flag;
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/* Check a high-bit flag */
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flag = 1UL << ((sizeof(unsigned long) - 1) * 8);
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fixup.value = fixup.mask = flag;
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fixup.start_off = calc_offset(&fixup, ftr_fixup_test4 + 1);
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fixup.end_off = calc_offset(&fixup, ftr_fixup_test4 + 5);
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fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test4_alt);
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fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test4_alt + 2);
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/* Sanity check */
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check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
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/* Check we don't patch if the value matches */
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patch_feature_section(flag, &fixup);
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check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
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/* Check we do patch if the value doesn't match */
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patch_feature_section(0, &fixup);
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check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0);
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/* Check we do patch if the mask doesn't match */
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memcpy(ftr_fixup_test4, ftr_fixup_test4_orig, size);
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check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0);
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patch_feature_section(~flag, &fixup);
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check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0);
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}
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static void test_alternative_case_with_branch(void)
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{
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extern unsigned int ftr_fixup_test5[];
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extern unsigned int end_ftr_fixup_test5[];
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extern unsigned int ftr_fixup_test5_expected[];
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int size = end_ftr_fixup_test5 - ftr_fixup_test5;
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check(memcmp(ftr_fixup_test5, ftr_fixup_test5_expected, size) == 0);
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}
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static void test_alternative_case_with_external_branch(void)
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{
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extern unsigned int ftr_fixup_test6[];
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extern unsigned int end_ftr_fixup_test6[];
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extern unsigned int ftr_fixup_test6_expected[];
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int size = end_ftr_fixup_test6 - ftr_fixup_test6;
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check(memcmp(ftr_fixup_test6, ftr_fixup_test6_expected, size) == 0);
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}
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static void test_cpu_macros(void)
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{
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extern u8 ftr_fixup_test_FTR_macros[];
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extern u8 ftr_fixup_test_FTR_macros_expected[];
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unsigned long size = ftr_fixup_test_FTR_macros_expected -
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ftr_fixup_test_FTR_macros;
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/* The fixups have already been done for us during boot */
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check(memcmp(ftr_fixup_test_FTR_macros,
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ftr_fixup_test_FTR_macros_expected, size) == 0);
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}
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static void test_fw_macros(void)
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{
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#ifdef CONFIG_PPC64
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extern u8 ftr_fixup_test_FW_FTR_macros[];
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extern u8 ftr_fixup_test_FW_FTR_macros_expected[];
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unsigned long size = ftr_fixup_test_FW_FTR_macros_expected -
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ftr_fixup_test_FW_FTR_macros;
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/* The fixups have already been done for us during boot */
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check(memcmp(ftr_fixup_test_FW_FTR_macros,
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ftr_fixup_test_FW_FTR_macros_expected, size) == 0);
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#endif
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}
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static void test_lwsync_macros(void)
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{
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extern u8 lwsync_fixup_test[];
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extern u8 end_lwsync_fixup_test[];
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extern u8 lwsync_fixup_test_expected_LWSYNC[];
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extern u8 lwsync_fixup_test_expected_SYNC[];
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unsigned long size = end_lwsync_fixup_test -
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lwsync_fixup_test;
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/* The fixups have already been done for us during boot */
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if (cur_cpu_spec->cpu_features & CPU_FTR_LWSYNC) {
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check(memcmp(lwsync_fixup_test,
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lwsync_fixup_test_expected_LWSYNC, size) == 0);
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} else {
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check(memcmp(lwsync_fixup_test,
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lwsync_fixup_test_expected_SYNC, size) == 0);
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}
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}
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static int __init test_feature_fixups(void)
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{
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printk(KERN_DEBUG "Running feature fixup self-tests ...\n");
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test_basic_patching();
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test_alternative_patching();
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test_alternative_case_too_big();
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test_alternative_case_too_small();
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test_alternative_case_with_branch();
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test_alternative_case_with_external_branch();
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test_cpu_macros();
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test_fw_macros();
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test_lwsync_macros();
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return 0;
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}
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late_initcall(test_feature_fixups);
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#endif /* CONFIG_FTR_FIXUP_SELFTEST */
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