mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-31 08:28:13 +00:00
4aec216b93
All these are functions which are invoked from elsewhere but they are not typical C functions. So annotate them using the new SYM_CODE_START. All these were not balanced with any END, so mark their ends by SYM_CODE_END appropriately too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> [xen bits] Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [power mgmt] Cc: Andy Shevchenko <andy@infradead.org> Cc: Cao jin <caoj.fnst@cn.fujitsu.com> Cc: Darren Hart <dvhart@infradead.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: linux-arch@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: Pavel Machek <pavel@ucw.cz> Cc: Pingfan Liu <kernelfans@gmail.com> Cc: platform-driver-x86@vger.kernel.org Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Huang <wei@redhat.com> Cc: x86-ml <x86@kernel.org> Cc: xen-devel@lists.xenproject.org Cc: Xiaoyao Li <xiaoyao.li@linux.intel.com> Link: https://lkml.kernel.org/r/20191011115108.12392-23-jslaby@suse.cz
157 lines
4.2 KiB
ArmAsm
157 lines
4.2 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#include <linux/linkage.h>
|
|
#include <asm/segment.h>
|
|
#include <asm/page_types.h>
|
|
#include <asm/processor-flags.h>
|
|
#include <asm/msr-index.h>
|
|
#include "realmode.h"
|
|
|
|
/*
|
|
* The following code and data reboots the machine by switching to real
|
|
* mode and jumping to the BIOS reset entry point, as if the CPU has
|
|
* really been reset. The previous version asked the keyboard
|
|
* controller to pulse the CPU reset line, which is more thorough, but
|
|
* doesn't work with at least one type of 486 motherboard. It is easy
|
|
* to stop this code working; hence the copious comments.
|
|
*
|
|
* This code is called with the restart type (0 = BIOS, 1 = APM) in
|
|
* the primary argument register (%eax for 32 bit, %edi for 64 bit).
|
|
*/
|
|
.section ".text32", "ax"
|
|
.code32
|
|
SYM_CODE_START(machine_real_restart_asm)
|
|
|
|
#ifdef CONFIG_X86_64
|
|
/* Switch to trampoline GDT as it is guaranteed < 4 GiB */
|
|
movl $__KERNEL_DS, %eax
|
|
movl %eax, %ds
|
|
lgdtl pa_tr_gdt
|
|
|
|
/* Disable paging to drop us out of long mode */
|
|
movl %cr0, %eax
|
|
andl $~X86_CR0_PG, %eax
|
|
movl %eax, %cr0
|
|
ljmpl $__KERNEL32_CS, $pa_machine_real_restart_paging_off
|
|
|
|
SYM_INNER_LABEL(machine_real_restart_paging_off, SYM_L_GLOBAL)
|
|
xorl %eax, %eax
|
|
xorl %edx, %edx
|
|
movl $MSR_EFER, %ecx
|
|
wrmsr
|
|
|
|
movl %edi, %eax
|
|
|
|
#endif /* CONFIG_X86_64 */
|
|
|
|
/* Set up the IDT for real mode. */
|
|
lidtl pa_machine_real_restart_idt
|
|
|
|
/*
|
|
* Set up a GDT from which we can load segment descriptors for real
|
|
* mode. The GDT is not used in real mode; it is just needed here to
|
|
* prepare the descriptors.
|
|
*/
|
|
lgdtl pa_machine_real_restart_gdt
|
|
|
|
/*
|
|
* Load the data segment registers with 16-bit compatible values
|
|
*/
|
|
movl $16, %ecx
|
|
movl %ecx, %ds
|
|
movl %ecx, %es
|
|
movl %ecx, %fs
|
|
movl %ecx, %gs
|
|
movl %ecx, %ss
|
|
ljmpw $8, $1f
|
|
SYM_CODE_END(machine_real_restart_asm)
|
|
|
|
/*
|
|
* This is 16-bit protected mode code to disable paging and the cache,
|
|
* switch to real mode and jump to the BIOS reset code.
|
|
*
|
|
* The instruction that switches to real mode by writing to CR0 must be
|
|
* followed immediately by a far jump instruction, which set CS to a
|
|
* valid value for real mode, and flushes the prefetch queue to avoid
|
|
* running instructions that have already been decoded in protected
|
|
* mode.
|
|
*
|
|
* Clears all the flags except ET, especially PG (paging), PE
|
|
* (protected-mode enable) and TS (task switch for coprocessor state
|
|
* save). Flushes the TLB after paging has been disabled. Sets CD and
|
|
* NW, to disable the cache on a 486, and invalidates the cache. This
|
|
* is more like the state of a 486 after reset. I don't know if
|
|
* something else should be done for other chips.
|
|
*
|
|
* More could be done here to set up the registers as if a CPU reset had
|
|
* occurred; hopefully real BIOSs don't assume much. This is not the
|
|
* actual BIOS entry point, anyway (that is at 0xfffffff0).
|
|
*
|
|
* Most of this work is probably excessive, but it is what is tested.
|
|
*/
|
|
.text
|
|
.code16
|
|
|
|
.balign 16
|
|
machine_real_restart_asm16:
|
|
1:
|
|
xorl %ecx, %ecx
|
|
movl %cr0, %edx
|
|
andl $0x00000011, %edx
|
|
orl $0x60000000, %edx
|
|
movl %edx, %cr0
|
|
movl %ecx, %cr3
|
|
movl %cr0, %edx
|
|
testl $0x60000000, %edx /* If no cache bits -> no wbinvd */
|
|
jz 2f
|
|
wbinvd
|
|
2:
|
|
andb $0x10, %dl
|
|
movl %edx, %cr0
|
|
LJMPW_RM(3f)
|
|
3:
|
|
andw %ax, %ax
|
|
jz bios
|
|
|
|
apm:
|
|
movw $0x1000, %ax
|
|
movw %ax, %ss
|
|
movw $0xf000, %sp
|
|
movw $0x5307, %ax
|
|
movw $0x0001, %bx
|
|
movw $0x0003, %cx
|
|
int $0x15
|
|
/* This should never return... */
|
|
|
|
bios:
|
|
ljmpw $0xf000, $0xfff0
|
|
|
|
.section ".rodata", "a"
|
|
|
|
.balign 16
|
|
SYM_DATA_START(machine_real_restart_idt)
|
|
.word 0xffff /* Length - real mode default value */
|
|
.long 0 /* Base - real mode default value */
|
|
SYM_DATA_END(machine_real_restart_idt)
|
|
|
|
.balign 16
|
|
SYM_DATA_START(machine_real_restart_gdt)
|
|
/* Self-pointer */
|
|
.word 0xffff /* Length - real mode default value */
|
|
.long pa_machine_real_restart_gdt
|
|
.word 0
|
|
|
|
/*
|
|
* 16-bit code segment pointing to real_mode_seg
|
|
* Selector value 8
|
|
*/
|
|
.word 0xffff /* Limit */
|
|
.long 0x9b000000 + pa_real_mode_base
|
|
.word 0
|
|
|
|
/*
|
|
* 16-bit data segment with the selector value 16 = 0x10 and
|
|
* base value 0x100; since this is consistent with real mode
|
|
* semantics we don't have to reload the segments once CR0.PE = 0.
|
|
*/
|
|
.quad GDT_ENTRY(0x0093, 0x100, 0xffff)
|
|
SYM_DATA_END(machine_real_restart_gdt)
|