Commit Graph

30 Commits

Author SHA1 Message Date
H. Peter Anvin 1396adc3c2 x86, suspend: Correct the restore of CR4, EFER; skip computing EFLAGS.ID
The patch:

    73201dbe x86, suspend: On wakeup always initialize cr4 and EFER

... was incorrectly committed in an intermediate (unfinished) form.

- We need to test CF, not ZF, for a bit test with btl.
- We don't actually need to compute the existence of EFLAGS.ID,
  since we set a flag at suspend time if CR4 should be restored.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Link: http://lkml.kernel.org/r/1348529239-17943-1-git-send-email-hpa@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-10-02 08:42:31 +02:00
H. Peter Anvin 73201dbec6 x86, suspend: On wakeup always initialize cr4 and EFER
We already have a flag word to indicate the existence of MISC_ENABLES,
so use the same flag word to indicate existence of cr4 and EFER, and
always restore them if they exist.  That way if something passes a
nonzero value when the value *should* be zero, we will still
initialize it.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Link: http://lkml.kernel.org/r/1348529239-17943-1-git-send-email-hpa@linux.intel.com
2012-09-26 15:06:22 -07:00
Andrew Boie 484d90eec8 x86, build: Globally set -fno-pic
GCC built with nonstandard options can enable -fpic by default.
We never want this for 32-bit kernels and it will break the build.

[ hpa: Notably the Android toolchain apparently does this. ]

Change-Id: Iaab7d66e598b1c65ac4a4f0229eca2cd3d0d2898
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Link: http://lkml.kernel.org/r/1344624546-29691-1-git-send-email-andrew.p.boie@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-08-10 16:12:30 -07:00
H. Peter Anvin 9751d76275 x86-64, reboot: Be more paranoid in 64-bit reboot=bios
Be a bit more paranoid in the transition back to 16-bit mode.  In
particular, in case the kernel is residing above the 4 GiB mark,
switch to the trampoline GDT, and make the jump after turning off
paging a far jump.  In theory, none of this should matter, but it is
exactly the kind of things that broken SMM or virtualization software
could trip up on.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/tip-jopx7y6g6dbcx4tpal8q0jlr@git.kernel.org
2012-06-21 10:25:03 -07:00
H. Peter Anvin 650513979a x86-64, reboot: Allow reboot=bios and reboot-cpu override on x86-64
With the revamped realmode trampoline code, it is trivial to extend
support for reboot=bios to x86-64.  Furthermore, while we are at it,
remove the restriction that only we can only override the reboot CPU
on 32 bits.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-jopx7y6g6dbcx4tpal8q0jlr@git.kernel.org
2012-06-17 10:51:01 -07:00
H. Peter Anvin 61f5446169 x86, realmode: Move end signature into header.S
The end signature was defined in wakeup_asm.S as it originally came
from the ACPI wakeup code.  However, we rely on the existence of the
.signature section to expand .bss, otherwise we would have to include
code to explicitly zero the .bss depending on the configuration.
Since the expanded .bss is just in .init.data anyway, it's easier to
always have it expanded.

This fixes failures when compiled without CONFIG_ACPI_SLEEP.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
2012-05-21 00:02:45 -07:00
H. Peter Anvin 638d957b51 x86, realmode: Change EFER to a single u64 field
Change EFER to be a single u64 field instead of two u32 fields; change
the order to maintain alignment.  Note that on x86-64 cr4 is really
also a 64-bit quantity, although we can only set the low 32 bits from
the trampoline code since it is still executing in 32-bit mode at that
point.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
2012-05-16 14:02:05 -07:00
H. Peter Anvin 1371270188 x86, realmode: Move kernel/realmode.c to realmode/init.c
Keep all the realmode code together, including initialization (only
the rm/ subdirectory is actually built as real-mode code, anyway.)

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
2012-05-16 13:49:10 -07:00
H. Peter Anvin 51edbe6a2f x86, realmode: Move not-common bits out of trampoline_common.S
Move the bits that aren't actually common out of trampoline_common.S
and into the arch-specific files.  Furthermore, make sure the page
directory is first in the .bss section for trampoline_64.S in order to
not waste an entire page of memory.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
2012-05-16 13:44:10 -07:00
Jarkko Sakkinen 34d0b02e08 x86, realmode: Fix no cache bits test in reboot_32.S
Before the new real-mode code infrastructure %edx was
used for testing CD and NW bits with andl in order to
decide whether to flush the processor caches or not.
The value of cr0 was also stored in %eax, which was
later used to set cr0 after masking out lower byte
(except TS bit) in order to enter real-mode.

In the new real-mode code infrastructure we wanted to
keep input parameter in %eax so we are using %edx for
both cr0 cases. This has caused regression since andl
overwrites the value of %edx.

This patch fixes the issue by replacing andl with testl,
which is essentially andl without writing result to the
register.

Special thanks to Paolo Bonzini for noting this and
proposing a fix.

Reported-and-tested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336633898-23743-1-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-10 19:31:22 -07:00
H. Peter Anvin 0f6f11eb00 x86, realmode: Make sure all generated files are listed in targets
Kbuild expects all generated files to be listed in the targets
variable.  If it isn't, weird things happen.

Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336595106-21135-1-git-send-email-jarkko.sakkinen@intel.com
2012-05-09 14:53:01 -07:00
Jarkko Sakkinen c5403aed04 x86, realmode: build fix: remove duplicate build
Real-mode binary was built twice. This patch fixes
the issue by making realmode.relocs as target for
realmode.bin.

[ hpa: removed the direct dependency on realmode.relocs in
  arch/x86/realmode/Makefile ]

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336595106-21135-1-git-send-email-jarkko.sakkinen@intel.com
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-09 13:32:17 -07:00
Jarkko Sakkinen cda846f101 x86, realmode: read cr4 and EFER from kernel for 64-bit trampoline
This patch changes 64-bit trampoline so that CR4 and
EFER are provided by the kernel instead of using fixed
values.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-24-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-08 15:04:27 -07:00
Jarkko Sakkinen f2604c141a x86, realmode: move relocs from scripts/ to arch/x86/tools
Moved relocs tool from scripts/ to arch/x86/tools because
it is architecture specific script. Added new target archscripts
that can be used to build scripts needed building an architecture.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-22-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Michal Marek <mmarek@suse.cz>
2012-05-08 15:03:35 -07:00
Jarkko Sakkinen f37240f16b x86, realmode: header for trampoline code
Added header for trampoline code that can be used to supply
input data to it. This makes interface between real mode code
and kernel cleaner and simpler. Replaced two confusing pointers
to level4 pgt in trampoline_64.S with a single pointer to the
beginning of the page table.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-21-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-08 11:48:45 -07:00
Jarkko Sakkinen c4845474a0 x86, realmode: flattened rm hierachy
Simplified hierarchy under rm directory to a flat
directory because it is not anymore really justified
to have own directory for wakeup code. It only adds
more complexity.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-20-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-08 11:48:45 -07:00
Jarkko Sakkinen b429dbf6e8 x86, realmode: don't copy real_mode_header
Replaced copying of real_mode_header with a pointer
to beginning of RM memory.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-19-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-08 11:48:45 -07:00
Jarkko Sakkinen 8e029fcdd8 x86, realmode: fix 64-bit wakeup sequence
There were number of issues in wakeup sequence:

- Wakeup stack was placed in hardcoded address.
- NX bit in EFER was not enabled.
- Initialization incorrectly set physical address
of secondary_startup_64.
- Some alignment issues.

This patch fixes these issues and in addition:

- Unifies coding conventions in .S files.
- Sets alignments of code and data right.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-18-git-send-email-jarkko.sakkinen@intel.com
Originally-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-08 11:48:11 -07:00
H. Peter Anvin 6feb592dce x86, realmode: Fix always-zero test in reboot_32.S
A test instruction is an "and", and an and with zero is always zero.
This would cause us to always take the BIOS path, not the APM path, in
case anyone actually cares...

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-17-git-send-email-jarkko.sakkinen@intel.com
2012-05-08 11:48:04 -07:00
H. Peter Anvin be60828920 x86, realmode: Move trampoline_*.S early in the link order
Move trampoline_*.S earlier in the link order so it ends up being
first in the text segment; since the SIPI vector requires 4K alignment
it otherwise ends up padding the .text segment with that much
completely unnecessarily.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-16-git-send-email-jarkko.sakkinen@intel.com
2012-05-08 11:48:03 -07:00
H. Peter Anvin e5684ec438 x86, realmode: Replace open-coded ljmpw with a macro
We cannot code an ljmpw to the real-mode segment directly, because gas
refuses to assemble an ljmp with a symbolic segment.  Instead of
open-coding it everywhere, define a macro and use it for this case.

This is specifically an ljmpw from a 16-bit segment.  This is okay, as
one should never enter real mode from a 32-bit segment: if one do, the
CPU ends up in a bizarre (and useless) mode sometimes called "unreal
mode" where segments behave like real mode but the default address and
operand sizes is 32 bits.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-15-git-send-email-jarkko.sakkinen@intel.com
2012-05-08 11:48:03 -07:00
H. Peter Anvin 968ff9ee56 x86, realmode: Remove indirect jumps in trampoline_32 and wakeup_asm
Remove indirect jumps in trampoline_32.S and the 32-bit part of
wakeup_asm.S.  There exist systems which are known to do weird
things if an SMI comes in right after a mode switch, and the
safest way to deal with it is to always follow with a simple
absolute far jump.  In the 64-bit code we then to a register
indirect near jump; follow that pattern for the 32-bit code.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-14-git-send-email-jarkko.sakkinen@intel.com
2012-05-08 11:48:03 -07:00
H. Peter Anvin 056a43a6d3 x86, realmode: Remove indirect jumps in trampoline_64.S
Remove indirect jumps in trampoline_64.S which are no longer
necessary: the realmode code can relocate the absolute jumps
correctly from the start.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-13-git-send-email-jarkko.sakkinen@intel.com
2012-05-08 11:48:03 -07:00
H. Peter Anvin f7436a9da9 x86, realmode: Align .data section in trampoline_32.S
Specify the alignment of the .data section in trampoline_32.S.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-12-git-send-email-jarkko.sakkinen@intel.com
2012-05-08 11:48:03 -07:00
H. Peter Anvin 0247428611 x86, realmode: Move bits to the proper sections in trampoline_64.S
Move various bits to the sections they really belong in in
trampoline_64.S.  Use GLOBAL() rather than ENTRY() for data objects:
ENTRY() should only be used with code and forces alignment to 16
bytes.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-11-git-send-email-jarkko.sakkinen@intel.com
2012-05-08 11:48:03 -07:00
H. Peter Anvin 487f50ffeb x86, realmode: Add .text64 section, make barrier symbols absolute
Add a .text64 section.  The purpose of this is to keep 16-, 32- and
64-bit code segregated into separate sections, mainly to keep
disassembly sane.

Move barrier symbols out of sections to avoid the "symbol in empty
section" problem in some versions of GNU ld.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-10-git-send-email-jarkko.sakkinen@intel.com
2012-05-08 11:47:18 -07:00
Jarkko Sakkinen c9b77ccb52 x86, realmode: Move ACPI wakeup to unified realmode code
Migrated ACPI wakeup code to the real-mode blob.
Code existing in .x86_trampoline  can be completely
removed. Static descriptor table in wakeup_asm.S is
courtesy of H. Peter Anvin.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-7-git-send-email-jarkko.sakkinen@intel.com
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-08 11:46:05 -07:00
Jarkko Sakkinen 48927bbb97 x86, realmode: Move SMP trampoline to unified realmode code
Migrated SMP trampoline code to the real mode blob.
SMP trampoline code is not yet removed from
.x86_trampoline because it is needed by the wakeup
code.

[ hpa: always enable compiling startup_32_smp in head_32.S... it is
  only a few instructions which go into .init on UP builds, and it makes
  the rest of the code less #ifdef ugly. ]

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-6-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-08 11:41:51 -07:00
Jarkko Sakkinen 5a8c9aebe0 x86, realmode: Move reboot_32.S to unified realmode code
Migrated reboot_32.S from x86_trampoline to the real-mode
blob.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-5-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-08 11:41:50 -07:00
Jarkko Sakkinen b3266bd6ff x86, realmode: realmode.bin infrastructure
Create realmode.bin and realmode.relocs files. Piggy
pack them into relocatable object that will be included
into .init.data section of the main kernel image.

The first file includes binary image of the real-mode code.
The latter file includes all relocations. The layout of the
binary image is specified in realmode.lds.S. The makefile
generates pa_ prefixed symbols for each exported global.
These are used in 32-bit code and in realmode header to
define symbols that need to be relocated.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-3-git-send-email-jarkko.sakkinen@intel.com
Originally-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-05-08 11:41:48 -07:00