linux-toradex.git/arch/x86/power, branch v3.14.52

nosave: consolidate __nosave_{begin,end} in

2015-05-06T19:59:21+00:00

commit 7f8998c7aef3ac9c5f3f2943e083dfa6302e90d0 upstream.

The different architectures used their own (and different) declarations:

    extern __visible const void __nosave_begin, __nosave_end;
    extern const void __nosave_begin, __nosave_end;
    extern long __nosave_begin, __nosave_end;

Consolidate them using the first variant in .

Signed-off-by: Geert Uytterhoeven 
Cc: Russell King 
Cc: Ralf Baechle 
Cc: Benjamin Herrenschmidt 
Cc: Martin Schwidefsky 
Cc: "David S. Miller" 
Cc: Guan Xuetao 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

x86, asmlinkage, power: Make various symbols used by the suspend asm code visible

2013-08-06T21:21:03+00:00

Signed-off-by: Andi Kleen 
Link: http://lkml.kernel.org/r/1375740170-7446-16-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin

x86, gdt, hibernate: Store/load GDT for hibernate path.

2013-05-02T18:27:35+00:00

The git commite7a5cd063c7b4c58417f674821d63f5eb6747e37
("x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path
is not needed.") assumes that for the hibernate path the booting
kernel and the resuming kernel MUST be the same. That is certainly
the case for a 32-bit kernel (see check_image_kernel and
CONFIG_ARCH_HIBERNATION_HEADER config option).

However for 64-bit kernels it is OK to have a different kernel
version (and size of the image) of the booting and resuming kernels.
Hence the above mentioned git commit introduces an regression.

This patch fixes it by introducing a 'struct desc_ptr gdt_desc'
back in the 'struct saved_context'. However instead of having in the
'save_processor_state' and 'restore_processor_state' the
store/load_gdt calls, we are only saving the GDT in the
save_processor_state.

For the restore path the lgdt operation is done in
hibernate_asm_[32|64].S in the 'restore_registers' path.

The apt reader of this description will recognize that only 64-bit
kernels need this treatment, not 32-bit. This patch adds the logic
in the 32-bit path to be more similar to 64-bit so that in the future
the unification process can take advantage of this.

[ hpa: this also reverts an inadvertent on-disk format change ]

Suggested-by: "H. Peter Anvin" 
Acked-by: "Rafael J. Wysocki" 
Signed-off-by: Konrad Rzeszutek Wilk 
Link: http://lkml.kernel.org/r/1367459610-9656-2-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin

Merge branch 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2013-04-30T15:41:21+00:00

Pull x86 paravirt update from Ingo Molnar:
 "Various paravirtualization related changes - the biggest one makes
  guest support optional via CONFIG_HYPERVISOR_GUEST"

* 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, wakeup, sleep: Use pvops functions for changing GDT entries
  x86, xen, gdt: Remove the pvops variant of store_gdt.
  x86-32, gdt: Store/load GDT for ACPI S3 or hibernation/resume path is not needed
  x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path is not needed.
  x86: Make Linux guest support optional
  x86, Kconfig: Move PARAVIRT_DEBUG into the paravirt menu

x86, wakeup, sleep: Use pvops functions for changing GDT entries

2013-04-11T22:41:15+00:00

We check the TSS descriptor before we try to dereference it.
Also we document what the value '9' actually means using the
AMD64 Architecture Programmer's Manual Volume 2, pg 90:
"Hex value 9: Available 64-bit TSS" and pg 91:
"The available 32-bit TSS (09h), which is redefined as the
available 64-bit TSS."

Without this, on Xen, where the GDT is available as R/O (to
protect the hypervisor from the guest modifying it), we end up
with a pagetable fault.

Signed-off-by: Konrad Rzeszutek Wilk 
Link: http://lkml.kernel.org/r/1365194544-14648-5-git-send-email-konrad.wilk@oracle.com
Cc: Rafael J. Wysocki 
Signed-off-by: H. Peter Anvin

x86-32, gdt: Store/load GDT for ACPI S3 or hibernation/resume path is not needed

2013-04-11T22:40:17+00:00

During the ACPI S3 suspend, we store the GDT in the wakup_header (see
wakeup_asm.s) field called 'pmode_gdt'.

Which is then used during the resume path and has the same exact
value as what the store/load_gdt do with the saved_context
(which is saved/restored via save/restore_processor_state()).

The flow during resume from ACPI S3 is simpler than the 64-bit
counterpart. We only use the early bootstrap once (wakeup_gdt) and
do various checks in real mode.

After the checks are completed, we load the saved GDT ('pmode_gdt') and
continue on with the resume (by heading to startup_32 in trampoline_32.S) -
which quickly jumps to what was saved in 'pmode_entry'
aka 'wakeup_pmode_return'.

The 'wakeup_pmode_return' restores the GDT (saved_gdt) again (which was
saved in do_suspend_lowlevel initially). After that it ends up calling
the 'ret_point' which calls 'restore_processor_state()'.

We have two opportunities to remove code where we restore the same GDT
twice.

Here is the call chain:
 wakeup_start
       |- lgdtl wakeup_gdt [the work-around broken BIOSes]
       |
       | - lgdtl pmode_gdt [the real one]
       |
       \-- startup_32 (in trampoline_32.S)
              \-- wakeup_pmode_return (in wakeup_32.S)
                       |- lgdtl saved_gdt [the real one]
                       \-- ret_point
                             |..
                             |- call restore_processor_state

The hibernate path is much simpler. During the saving of the hibernation
image we call save_processor_state() and save the contents of that
along with the rest of the kernel in the hibernation image destination.
We save the EIP of 'restore_registers' (restore_jump_address) and
cr3 (restore_cr3).

During hibernate resume, the 'restore_registers' (via the
'restore_jump_address) in hibernate_asm_32.S is invoked which
restores the contents of most registers. Naturally the resume path benefits
from already being in 32-bit mode, so it does not have to reload the GDT.

It only reloads the cr3 (from restore_cr3) and continues on. Note
that the restoration of the restore image page-tables is done prior to
this.

After the 'restore_registers' it returns and we end up called
restore_processor_state() - where we reload the GDT. The reload of
the GDT is not needed as bootup kernel has already loaded the GDT
which is at the same physical location as the the restored kernel.

Note that the hibernation path assumes the GDT is correct during its
'restore_registers'. The assumption in the code is that the restored
image is the same as saved - meaning we are not trying to restore
an different kernel in the virtual address space of a new kernel.

Signed-off-by: Konrad Rzeszutek Wilk 
Link: http://lkml.kernel.org/r/1365194544-14648-3-git-send-email-konrad.wilk@oracle.com
Cc: Rafael J. Wysocki 
Signed-off-by: H. Peter Anvin

x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path is not needed.

2013-04-11T22:39:38+00:00

During the ACPI S3 resume path the trampoline code handles it already.

During the ACPI S3 suspend phase (acpi_suspend_lowlevel) we set:
early_gdt_descr.address = (..)get_cpu_gdt_table(smp_processor_id());

which is then used during the resume path and has the same exact
value as what the store/load_gdt do with the saved_context
(which is saved/restored via save/restore_processor_state()).

The flow during resume is complex and for 64-bit kernels we use three GDTs
- one early bootstrap GDT (wakeup_igdt) that we load to workaround
broken BIOSes, an early Protected Mode to Long Mode transition one
(tr_gdt), and the final one - early_gdt_descr (which points to the real GDT).

The early ('wakeup_gdt') is loaded in 'trampoline_start' for working
around broken BIOSes, and then when we end up in Protected Mode in the
startup_32 (in trampoline_64.s, not head_32.s) we use the 'tr_gdt'
(still in trampoline_64.s). This 'tr_gdt' has a a 32-bit code segment,
64-bit code segment with L=1, and a 32-bit data segment.

Once we have transitioned from Protected Mode to Long Mode we then
set the GDT to 'early_gdt_desc' and then via an iretq emerge in
wakeup_long64 (set via 'initial_code' variable in acpi_suspend_lowlevel).

In the wakeup_long64 we end up restoring the %rip (which is set to
'resume_point') and jump there.

In 'resume_point' we call 'restore_processor_state' which does
the load_gdt on the saved context. This load_gdt is redundant as the
GDT loaded via early_gdt_desc is the same.

Here is the call-chain:
 wakeup_start
   |- lgdtl wakeup_gdt [the work-around broken BIOSes]
   |
   \-- trampoline_start (trampoline_64.S)
         |- lgdtl tr_gdt
         |
         \-- startup_32 (trampoline_64.S)
               |
               \-- startup_64 (trampoline_64.S)
                      |
                      \-- secondary_startup_64
                               |- lgdtl early_gdt_desc
                               | ...
                               |- movq initial_code(%rip), %eax
                               |-.. lretq
                               \-- wakeup_64
                                     |-- other registers are reloaded
                                     |-- call restore_processor_state

The hibernate path is much simpler. During the saving of the hibernation
image we call save_processor_state() and save the contents of that along
with the rest of the kernel in the hibernation image destination.
We save the EIP of 'restore_registers' (restore_jump_address) and cr3
(restore_cr3).

During hibernate resume, the 'restore_registers' (via the
'restore_jump_address) in hibernate_asm_64.S is invoked which restores
the contents of most registers. Naturally the resume path benefits from
already being in 64-bit mode, so it does not have to load the GDT.

It only reloads the cr3 (from restore_cr3) and continues on. Note that
the restoration of the restore image page-tables is done prior to this.

After the 'restore_registers' it returns and we end up called
restore_processor_state() - where we reload the GDT. The reload of
the GDT is not needed as bootup kernel has already loaded the GDT which
is at the same physical location as the the restored kernel.

Note that the hibernation path assumes the GDT is correct during its
'restore_registers'. The assumption in the code is that the restored
image is the same as saved - meaning we are not trying to restore
an different kernel in the virtual address space of a new kernel.

Signed-off-by: Konrad Rzeszutek Wilk 
Link: http://lkml.kernel.org/r/1365194544-14648-2-git-send-email-konrad.wilk@oracle.com
Cc: Rafael J. Wysocki 
Signed-off-by: H. Peter Anvin

perf,x86: fix kernel crash with PEBS/BTS after suspend/resume

2013-03-15T16:26:35+00:00

This patch fixes a kernel crash when using precise sampling (PEBS)
after a suspend/resume. Turns out the CPU notifier code is not invoked
on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly
by the kernel and keeps it power-on/resume value of 0 causing any PEBS
measurement to crash when running on CPU0.

The workaround is to add a hook in the actual resume code to restore
the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0,
the DS_AREA will be restored twice but this is harmless.

Reported-by: Linus Torvalds 
Signed-off-by: Stephane Eranian 
Signed-off-by: Linus Torvalds

Merge remote-tracking branch 'origin/x86/mm' into x86/mm2

2013-02-01T10:28:36+00:00

Explicitly merging these two branches due to nontrivial conflicts and
to allow further work.

Resolved Conflicts:
	arch/x86/kernel/head32.c
	arch/x86/kernel/head64.c
	arch/x86/mm/init_64.c
	arch/x86/realmode/init.c

Signed-off-by: H. Peter Anvin

x86-32, mm: Remove reference to resume_map_numa_kva()

2013-01-31T22:12:30+00:00

Remove reference to removed function resume_map_numa_kva().

Signed-off-by: H. Peter Anvin 
Cc: Dave Hansen 
Cc: 
Link: http://lkml.kernel.org/r/20130131005616.1C79F411@kernel.stglabs.ibm.com