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freebsd-dev/sys/amd64/acpica/acpi_wakecode.S
Konstantin Belousov bd101a6648 Ensure that resume path on amd64 only accesses page tables for normal 
operation after processor is configured to allow all required
features.

In particular, NX must be enabled in EFER, otherwise load of page
table element with nx bit set causes reserved bit page fault.  Since
malloc uses direct mapping for small allocations, in particular for
the suspension pcbs, and DMAP is nx after r316767, this commit tripped
fault on resume path.

Restore complete state of EFER while wakeup code is still executing
with custom page table, before calling resumectx, instead of trying to
guess which features might be needed before resumectx restored EFER on
its own.

Bisected and tested by:	trasz
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2017-05-15 20:52:43 +00:00

286 lines
8.1 KiB
ArmAsm
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/*-
* Copyright (c) 2001 Takanori Watanabe <takawata@jp.freebsd.org>
* Copyright (c) 2001 Mitsuru IWASAKI <iwasaki@jp.freebsd.org>
* Copyright (c) 2003 Peter Wemm
* Copyright (c) 2008-2012 Jung-uk Kim <jkim@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <machine/asmacros.h>
#include <machine/ppireg.h>
#include <machine/specialreg.h>
#include <machine/timerreg.h>
#include "assym.s"
/*
* Resume entry point for real mode.
*
* If XFirmwareWakingVector is zero and FirmwareWakingVector is non-zero
* in FACS, the BIOS enters here in real mode after POST with CS set to
* (FirmwareWakingVector >> 4) and IP set to (FirmwareWakingVector & 0xf).
* Depending on the previous sleep state, we may need to initialize more
* of the system (i.e., S3 suspend-to-RAM vs. S4 suspend-to-disk).
*
* Note: If XFirmwareWakingVector is non-zero, it should disable address
* translation/paging and interrupts, load all segment registers with
* a flat 4 GB address space, and set EFLAGS.IF to zero. Currently
* this mode is not supported by this code.
*/
.data /* So we can modify it */
ALIGN_TEXT
.code16
wakeup_start:
/*
* Set up segment registers for real mode, a small stack for
* any calls we make, and clear any flags.
*/
cli /* make sure no interrupts */
mov %cs, %ax /* copy %cs to %ds. Remember these */
mov %ax, %ds /* are offsets rather than selectors */
mov %ax, %ss
movw $PAGE_SIZE, %sp
xorw %ax, %ax
pushw %ax
popfw
/* To debug resume hangs, beep the speaker if the user requested. */
testb $~0, resume_beep - wakeup_start
jz 1f
movb $0, resume_beep - wakeup_start
/* Set PIC timer2 to beep. */
movb $(TIMER_SEL2 | TIMER_SQWAVE | TIMER_16BIT), %al
outb %al, $TIMER_MODE
/* Turn on speaker. */
inb $IO_PPI, %al
orb $PIT_SPKR, %al
outb %al, $IO_PPI
/* Set frequency. */
movw $0x4c0, %ax
outb %al, $TIMER_CNTR2
shrw $8, %ax
outb %al, $TIMER_CNTR2
1:
/* Re-initialize video BIOS if the reset_video tunable is set. */
testb $~0, reset_video - wakeup_start
jz 1f
movb $0, reset_video - wakeup_start
lcall $0xc000, $3
/* When we reach here, int 0x10 should be ready. Hide cursor. */
movb $0x01, %ah
movb $0x20, %ch
int $0x10
/* Re-start in case the previous BIOS call clobbers them. */
jmp wakeup_start
1:
/*
* Find relocation base and patch the gdt descript and ljmp targets
*/
xorl %ebx, %ebx
mov %cs, %bx
sall $4, %ebx /* %ebx is now our relocation base */
/*
* Load the descriptor table pointer. We'll need it when running
* in 16-bit protected mode.
*/
lgdtl bootgdtdesc - wakeup_start
/* Enable protected mode */
movl $CR0_PE, %eax
mov %eax, %cr0
/*
* Now execute a far jump to turn on protected mode. This
* causes the segment registers to turn into selectors and causes
* %cs to be loaded from the gdt.
*
* The following instruction is:
* ljmpl $bootcode32 - bootgdt, $wakeup_32 - wakeup_start
* but gas cannot assemble that. And besides, we patch the targets
* in early startup and its a little clearer what we are patching.
*/
wakeup_sw32:
.byte 0x66 /* size override to 32 bits */
.byte 0xea /* opcode for far jump */
.long wakeup_32 - wakeup_start /* offset in segment */
.word bootcode32 - bootgdt /* index in gdt for 32 bit code */
/*
* At this point, we are running in 32 bit legacy protected mode.
*/
ALIGN_TEXT
.code32
wakeup_32:
mov $bootdata32 - bootgdt, %eax
mov %ax, %ds
/* Turn on the PAE bit for when paging is enabled */
mov %cr4, %eax
orl $CR4_PAE, %eax
mov %eax, %cr4
/*
* Enable EFER.LME so that we get long mode when all the prereqs are
* in place. In this case, it turns on when CR0_PG is finally enabled.
* Also it picks up a few other EFER bits that we'll use need we're
* here, like SYSCALL and NX enable.
*/
movl $MSR_EFER, %ecx
movl wakeup_efer - wakeup_start(%ebx), %eax
movl wakeup_efer + 4 - wakeup_start(%ebx), %edx
wrmsr
/*
* Point to the embedded page tables for startup. Note that this
* only gets accessed after we're actually in 64 bit mode, however
* we can only set the bottom 32 bits of %cr3 in this state. This
* means we are required to use a temporary page table that is below
* the 4GB limit. %ebx is still our relocation base. We could just
* subtract 3 * PAGE_SIZE, but that would be too easy.
*/
leal wakeup_pagetables - wakeup_start(%ebx), %eax
movl (%eax), %eax
mov %eax, %cr3
/*
* Finally, switch to long bit mode by enabling paging. We have
* to be very careful here because all the segmentation disappears
* out from underneath us. The spec says we can depend on the
* subsequent pipelined branch to execute, but *only if* everything
* is still identity mapped. If any mappings change, the pipeline
* will flush.
*/
mov %cr0, %eax
orl $CR0_PG, %eax
mov %eax, %cr0
/*
* At this point paging is enabled, and we are in "compatibility" mode.
* We do another far jump to reload %cs with the 64 bit selector.
* %cr3 points to a 4-level page table page.
* We cannot yet jump all the way to the kernel because we can only
* specify a 32 bit linear address. So, yet another trampoline.
*
* The following instruction is:
* ljmp $bootcode64 - bootgdt, $wakeup_64 - wakeup_start
* but gas cannot assemble that. And besides, we patch the targets
* in early startup and its a little clearer what we are patching.
*/
wakeup_sw64:
.byte 0xea /* opcode for far jump */
.long wakeup_64 - wakeup_start /* offset in segment */
.word bootcode64 - bootgdt /* index in gdt for 64 bit code */
/*
* Yeehar! We're running in 64-bit mode! We can mostly ignore our
* segment registers, and get on with it.
* Note that we are running at the correct virtual address, but with
* a 1:1 1GB mirrored mapping over entire address space. We had better
* switch to a real %cr3 promptly so that we can get to the direct map
* space. Remember that jmp is relative and that we've been relocated,
* so use an indirect jump.
*/
ALIGN_TEXT
.code64
wakeup_64:
mov $bootdata64 - bootgdt, %eax
mov %ax, %ds
/* Restore arguments. */
movq wakeup_pcb - wakeup_start(%rbx), %rdi
movq wakeup_ret - wakeup_start(%rbx), %rax
/* Restore GDT. */
lgdt wakeup_gdt - wakeup_start(%rbx)
/* Jump to return address. */
jmp *%rax
.data
resume_beep:
.byte 0
reset_video:
.byte 0
ALIGN_DATA
bootgdt:
.long 0x00000000
.long 0x00000000
.long 0x00000000
.long 0x00000000
.long 0x00000000
.long 0x00000000
.long 0x00000000
.long 0x00000000
bootcode64:
.long 0x0000ffff
.long 0x00af9b00
bootdata64:
.long 0x0000ffff
.long 0x00af9300
bootcode32:
.long 0x0000ffff
.long 0x00cf9b00
bootdata32:
.long 0x0000ffff
.long 0x00cf9300
bootgdtend:
wakeup_pagetables:
.long 0
bootgdtdesc:
.word bootgdtend - bootgdt /* Length */
.long bootgdt - wakeup_start /* Offset plus %ds << 4 */
ALIGN_DATA
wakeup_pcb:
.quad 0
wakeup_ret:
.quad 0
wakeup_efer:
.quad 0
wakeup_gdt:
.word 0
.quad 0
dummy:
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