![Eric W. Biederman](/assets/img/avatar_default.png)
This reverts commit c9ccf30d77
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Entering the kernel at startup_32 without passing our real mode data in
%esi, and without guaranteeing that physical and virtual addresses are
identity mapped makes head.S impossible to maintain.
The only user of this infrastructure is lguest which is not merged so
nothing we currently support will break by removing this over designed
nightmare, and only the pending lguest patches will be affected. The
pending Xen patches have a different entry point that they use.
We are currently discussing what Xen and lguest need to do to boot the
kernel in a more normal fashion so using startup_32 in this weird manner is
clearly not their long term direction.
So let's remove this code in head.S before it causes brain damage to people
trying to maintain head.S
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Zachary Amsden <zach@vmware.com>
CC: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
348 lines
8.7 KiB
C
348 lines
8.7 KiB
C
/* Paravirtualization interfaces
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Copyright (C) 2006 Rusty Russell IBM Corporation
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/errno.h>
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#include <linux/module.h>
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#include <linux/efi.h>
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#include <linux/bcd.h>
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#include <linux/highmem.h>
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#include <asm/bug.h>
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#include <asm/paravirt.h>
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#include <asm/desc.h>
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#include <asm/setup.h>
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#include <asm/arch_hooks.h>
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#include <asm/time.h>
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#include <asm/irq.h>
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#include <asm/delay.h>
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#include <asm/fixmap.h>
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#include <asm/apic.h>
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#include <asm/tlbflush.h>
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#include <asm/timer.h>
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/* nop stub */
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void _paravirt_nop(void)
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{
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}
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static void __init default_banner(void)
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{
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printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
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paravirt_ops.name);
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}
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char *memory_setup(void)
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{
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return paravirt_ops.memory_setup();
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}
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/* Simple instruction patching code. */
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#define DEF_NATIVE(name, code) \
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extern const char start_##name[], end_##name[]; \
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asm("start_" #name ": " code "; end_" #name ":")
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DEF_NATIVE(irq_disable, "cli");
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DEF_NATIVE(irq_enable, "sti");
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DEF_NATIVE(restore_fl, "push %eax; popf");
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DEF_NATIVE(save_fl, "pushf; pop %eax");
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DEF_NATIVE(iret, "iret");
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DEF_NATIVE(irq_enable_sysexit, "sti; sysexit");
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DEF_NATIVE(read_cr2, "mov %cr2, %eax");
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DEF_NATIVE(write_cr3, "mov %eax, %cr3");
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DEF_NATIVE(read_cr3, "mov %cr3, %eax");
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DEF_NATIVE(clts, "clts");
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DEF_NATIVE(read_tsc, "rdtsc");
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DEF_NATIVE(ud2a, "ud2a");
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static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len)
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{
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const unsigned char *start, *end;
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unsigned ret;
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switch(type) {
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#define SITE(x) case PARAVIRT_PATCH(x): start = start_##x; end = end_##x; goto patch_site
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SITE(irq_disable);
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SITE(irq_enable);
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SITE(restore_fl);
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SITE(save_fl);
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SITE(iret);
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SITE(irq_enable_sysexit);
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SITE(read_cr2);
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SITE(read_cr3);
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SITE(write_cr3);
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SITE(clts);
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SITE(read_tsc);
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#undef SITE
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patch_site:
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ret = paravirt_patch_insns(insns, len, start, end);
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break;
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case PARAVIRT_PATCH(make_pgd):
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case PARAVIRT_PATCH(make_pte):
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case PARAVIRT_PATCH(pgd_val):
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case PARAVIRT_PATCH(pte_val):
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#ifdef CONFIG_X86_PAE
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case PARAVIRT_PATCH(make_pmd):
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case PARAVIRT_PATCH(pmd_val):
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#endif
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/* These functions end up returning exactly what
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they're passed, in the same registers. */
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ret = paravirt_patch_nop();
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break;
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default:
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ret = paravirt_patch_default(type, clobbers, insns, len);
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break;
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}
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return ret;
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}
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unsigned paravirt_patch_nop(void)
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{
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return 0;
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}
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unsigned paravirt_patch_ignore(unsigned len)
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{
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return len;
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}
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unsigned paravirt_patch_call(void *target, u16 tgt_clobbers,
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void *site, u16 site_clobbers,
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unsigned len)
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{
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unsigned char *call = site;
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unsigned long delta = (unsigned long)target - (unsigned long)(call+5);
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if (tgt_clobbers & ~site_clobbers)
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return len; /* target would clobber too much for this site */
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if (len < 5)
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return len; /* call too long for patch site */
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*call++ = 0xe8; /* call */
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*(unsigned long *)call = delta;
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return 5;
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}
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unsigned paravirt_patch_jmp(void *target, void *site, unsigned len)
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{
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unsigned char *jmp = site;
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unsigned long delta = (unsigned long)target - (unsigned long)(jmp+5);
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if (len < 5)
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return len; /* call too long for patch site */
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*jmp++ = 0xe9; /* jmp */
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*(unsigned long *)jmp = delta;
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return 5;
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}
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unsigned paravirt_patch_default(u8 type, u16 clobbers, void *site, unsigned len)
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{
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void *opfunc = *((void **)¶virt_ops + type);
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unsigned ret;
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if (opfunc == NULL)
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/* If there's no function, patch it with a ud2a (BUG) */
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ret = paravirt_patch_insns(site, len, start_ud2a, end_ud2a);
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else if (opfunc == paravirt_nop)
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/* If the operation is a nop, then nop the callsite */
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ret = paravirt_patch_nop();
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else if (type == PARAVIRT_PATCH(iret) ||
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type == PARAVIRT_PATCH(irq_enable_sysexit))
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/* If operation requires a jmp, then jmp */
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ret = paravirt_patch_jmp(opfunc, site, len);
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else
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/* Otherwise call the function; assume target could
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clobber any caller-save reg */
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ret = paravirt_patch_call(opfunc, CLBR_ANY,
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site, clobbers, len);
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return ret;
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}
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unsigned paravirt_patch_insns(void *site, unsigned len,
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const char *start, const char *end)
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{
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unsigned insn_len = end - start;
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if (insn_len > len || start == NULL)
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insn_len = len;
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else
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memcpy(site, start, insn_len);
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return insn_len;
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}
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void init_IRQ(void)
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{
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paravirt_ops.init_IRQ();
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}
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static void native_flush_tlb(void)
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{
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__native_flush_tlb();
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}
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/*
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* Global pages have to be flushed a bit differently. Not a real
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* performance problem because this does not happen often.
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*/
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static void native_flush_tlb_global(void)
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{
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__native_flush_tlb_global();
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}
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static void native_flush_tlb_single(unsigned long addr)
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{
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__native_flush_tlb_single(addr);
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}
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/* These are in entry.S */
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extern void native_iret(void);
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extern void native_irq_enable_sysexit(void);
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static int __init print_banner(void)
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{
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paravirt_ops.banner();
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return 0;
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}
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core_initcall(print_banner);
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struct paravirt_ops paravirt_ops = {
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.name = "bare hardware",
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.paravirt_enabled = 0,
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.kernel_rpl = 0,
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.shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */
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.patch = native_patch,
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.banner = default_banner,
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.arch_setup = paravirt_nop,
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.memory_setup = machine_specific_memory_setup,
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.get_wallclock = native_get_wallclock,
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.set_wallclock = native_set_wallclock,
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.time_init = hpet_time_init,
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.init_IRQ = native_init_IRQ,
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.cpuid = native_cpuid,
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.get_debugreg = native_get_debugreg,
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.set_debugreg = native_set_debugreg,
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.clts = native_clts,
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.read_cr0 = native_read_cr0,
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.write_cr0 = native_write_cr0,
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.read_cr2 = native_read_cr2,
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.write_cr2 = native_write_cr2,
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.read_cr3 = native_read_cr3,
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.write_cr3 = native_write_cr3,
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.read_cr4 = native_read_cr4,
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.read_cr4_safe = native_read_cr4_safe,
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.write_cr4 = native_write_cr4,
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.save_fl = native_save_fl,
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.restore_fl = native_restore_fl,
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.irq_disable = native_irq_disable,
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.irq_enable = native_irq_enable,
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.safe_halt = native_safe_halt,
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.halt = native_halt,
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.wbinvd = native_wbinvd,
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.read_msr = native_read_msr_safe,
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.write_msr = native_write_msr_safe,
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.read_tsc = native_read_tsc,
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.read_pmc = native_read_pmc,
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.get_scheduled_cycles = native_read_tsc,
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.get_cpu_khz = native_calculate_cpu_khz,
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.load_tr_desc = native_load_tr_desc,
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.set_ldt = native_set_ldt,
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.load_gdt = native_load_gdt,
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.load_idt = native_load_idt,
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.store_gdt = native_store_gdt,
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.store_idt = native_store_idt,
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.store_tr = native_store_tr,
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.load_tls = native_load_tls,
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.write_ldt_entry = write_dt_entry,
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.write_gdt_entry = write_dt_entry,
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.write_idt_entry = write_dt_entry,
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.load_esp0 = native_load_esp0,
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.set_iopl_mask = native_set_iopl_mask,
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.io_delay = native_io_delay,
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#ifdef CONFIG_X86_LOCAL_APIC
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.apic_write = native_apic_write,
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.apic_write_atomic = native_apic_write_atomic,
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.apic_read = native_apic_read,
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.setup_boot_clock = setup_boot_APIC_clock,
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.setup_secondary_clock = setup_secondary_APIC_clock,
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.startup_ipi_hook = paravirt_nop,
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#endif
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.set_lazy_mode = paravirt_nop,
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.pagetable_setup_start = native_pagetable_setup_start,
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.pagetable_setup_done = native_pagetable_setup_done,
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.flush_tlb_user = native_flush_tlb,
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.flush_tlb_kernel = native_flush_tlb_global,
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.flush_tlb_single = native_flush_tlb_single,
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.flush_tlb_others = native_flush_tlb_others,
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.alloc_pt = paravirt_nop,
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.alloc_pd = paravirt_nop,
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.alloc_pd_clone = paravirt_nop,
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.release_pt = paravirt_nop,
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.release_pd = paravirt_nop,
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.set_pte = native_set_pte,
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.set_pte_at = native_set_pte_at,
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.set_pmd = native_set_pmd,
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.pte_update = paravirt_nop,
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.pte_update_defer = paravirt_nop,
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#ifdef CONFIG_HIGHPTE
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.kmap_atomic_pte = kmap_atomic,
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#endif
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#ifdef CONFIG_X86_PAE
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.set_pte_atomic = native_set_pte_atomic,
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.set_pte_present = native_set_pte_present,
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.set_pud = native_set_pud,
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.pte_clear = native_pte_clear,
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.pmd_clear = native_pmd_clear,
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.pmd_val = native_pmd_val,
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.make_pmd = native_make_pmd,
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#endif
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.pte_val = native_pte_val,
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.pgd_val = native_pgd_val,
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.make_pte = native_make_pte,
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.make_pgd = native_make_pgd,
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.irq_enable_sysexit = native_irq_enable_sysexit,
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.iret = native_iret,
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.dup_mmap = paravirt_nop,
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.exit_mmap = paravirt_nop,
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.activate_mm = paravirt_nop,
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};
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EXPORT_SYMBOL(paravirt_ops);
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