linux-stable.git/arch/x86/kernel/reboot.c, branch linux-3.7.y

efi: Make 'efi_enabled' a function to query EFI facilities

2013-02-04T00:27:05+00:00

commit 83e68189745ad931c2afd45d8ee3303929233e7f upstream.

Originally 'efi_enabled' indicated whether a kernel was booted from
EFI firmware. Over time its semantics have changed, and it now
indicates whether or not we are booted on an EFI machine with
bit-native firmware, e.g. 64-bit kernel with 64-bit firmware.

The immediate motivation for this patch is the bug report at,

    https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557

which details how running a platform driver on an EFI machine that is
designed to run under BIOS can cause the machine to become
bricked. Also, the following report,

    https://bugzilla.kernel.org/show_bug.cgi?id=47121

details how running said driver can also cause Machine Check
Exceptions. Drivers need a new means of detecting whether they're
running on an EFI machine, as sadly the expression,

    if (!efi_enabled)

hasn't been a sufficient condition for quite some time.

Users actually want to query 'efi_enabled' for different reasons -
what they really want access to is the list of available EFI
facilities.

For instance, the x86 reboot code needs to know whether it can invoke
the ResetSystem() function provided by the EFI runtime services, while
the ACPI OSL code wants to know whether the EFI config tables were
mapped successfully. There are also checks in some of the platform
driver code to simply see if they're running on an EFI machine (which
would make it a bad idea to do BIOS-y things).

This patch is a prereq for the samsung-laptop fix patch.

Signed-off-by: Matt Fleming 
Cc: David Airlie 
Cc: Corentin Chary 
Cc: Matthew Garrett 
Cc: Dave Jiang 
Cc: Olof Johansson 
Cc: Peter Jones 
Cc: Colin Ian King 
Cc: Steve Langasek 
Cc: Tony Luck 
Cc: Konrad Rzeszutek Wilk 
Cc: Rafael J. Wysocki 
Signed-off-by: H. Peter Anvin 
Signed-off-by: Greg Kroah-Hartman

x86/reboot: Remove quirk entry for SBC FITPC

2012-10-04T10:22:32+00:00

Remove the quirk for the SBC FITPC. It seems ot have been
required when the default was kbd reboot, but no longer required
now that the default is acpi reboot. Furthermore, BIOS reboot no
longer works for this board as of 2.6.39 or any of the 3.x
kernels.

Signed-off-by: David Hooper 
Signed-off-by: Alan Cox 
Link: http://lkml.kernel.org/r/20121002142635.17403.59959.stgit@localhost.localdomain
Signed-off-by: Ingo Molnar

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

2012-07-22T19:25:47+00:00

Pull x86/reboot changes from Ingo Molnar:
 "Now that the revampted x86 real-mode trampoline code is upstream and
  seems to be working well, we can extend the 64-bit reboot code to be
  as capable as the 32-bit one."

* 'x86-reboot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86-64, reboot: Be more paranoid in 64-bit reboot=bios
  x86, reboot: Drop redundant write of reboot_mode
  x86-64, reboot: Allow reboot=bios and reboot-cpu override on x86-64

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

2012-07-22T19:04:44+00:00

Pull debug-for-linus git tree from Ingo Molnar.

Fix up trivial conflict in arch/x86/kernel/cpu/perf_event_intel.c due to
a printk() having changed to a pr_info() differently in the two branches.

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Move call to print_modules() out of show_regs()
  x86/mm: Mark free_initrd_mem() as __init
  x86/microcode: Mark microcode_id[] as __initconst
  x86/nmi: Clean up register_nmi_handler() usage
  x86: Save cr2 in NMI in case NMIs take a page fault (for i386)
  x86: Remove cmpxchg from i386 NMI nesting code
  x86: Save cr2 in NMI in case NMIs take a page fault
  x86/debug: Add KERN_ to bare printks, convert printks to pr_

Merge branches 'acpi_pad-bugzilla-42981', 'apei-bugzilla-43282', 'video-bugzilla-43168', 'bugzilla-40002' and 'bugfix-misc' into release

2012-06-30T04:53:50+00:00

bug fixes

x86, reboot: Drop redundant write of reboot_mode

2012-06-21T04:18:14+00:00

We write reboot_mode to BIOS location 0x472 in
native_machine_emergency_restart() (reboot.c:542) already, there is no
need to then write it again in machine_real_restart().

This means nothing gets written there for MRR_APM, but the APM call is
a poweroff call and doesn't use this memory location.

Link: http://lkml.kernel.org/n/tip-3i0pfh44c1e3jv5lab0cf7sc@git.kernel.org
Signed-off-by: H. Peter Anvin

Merge commit 'v3.5-rc3' into x86/debug

2012-06-20T12:22:34+00:00

Merge it in to pick up a fix that we are going to clean up in this
branch.

Signed-off-by: Ingo Molnar

x86-64, reboot: Allow reboot=bios and reboot-cpu override on x86-64

2012-06-17T17:51:01+00:00

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 
Link: http://lkml.kernel.org/n/tip-jopx7y6g6dbcx4tpal8q0jlr@git.kernel.org

x86/reboot: Fix a warning message triggered by stop_other_cpus()

2012-06-06T10:03:23+00:00

When rebooting our 24 CPU Westmere servers with 3.4-rc6, we
always see this warning msg:

Restarting system.
machine restart
------------[ cut here ]------------
WARNING: at arch/x86/kernel/smp.c:125
native_smp_send_reschedule+0x74/0xa7() Hardware name: X8DTN
Modules linked in: igb [last unloaded: scsi_wait_scan]
Pid: 1, comm: systemd-shutdow Not tainted 3.4.0-rc6+ #22
Call Trace:
   [] warn_slowpath_common+0x7e/0x96
 [] warn_slowpath_null+0x15/0x17
 [] native_smp_send_reschedule+0x74/0xa7
 [] trigger_load_balance+0x279/0x2a6
 [] scheduler_tick+0xe0/0xe9
 [] update_process_times+0x60/0x70
 [] tick_sched_timer+0x68/0x92
 [] __run_hrtimer+0xb3/0x13c
 [] ? tick_nohz_handler+0xd0/0xd0
 [] hrtimer_interrupt+0xdb/0x198
 [] smp_apic_timer_interrupt+0x81/0x94
 [] apic_timer_interrupt+0x67/0x70
   [] ? default_send_IPI_mask_allbutself_phys+0xb4/0xc4
 [] physflat_send_IPI_allbutself+0x12/0x14
 [] native_nmi_stop_other_cpus+0x8a/0xd6
 [] native_machine_shutdown+0x50/0x67
 [] machine_shutdown+0xa/0xc
 [] native_machine_restart+0x20/0x32
 [] machine_restart+0xa/0xc
 [] kernel_restart+0x47/0x4c
 [] sys_reboot+0x13e/0x17c
 [] ? _raw_spin_unlock_bh+0x10/0x12
 [] ? bdi_queue_work+0xcf/0xd8
 [] ? __bdi_start_writeback+0xae/0xb7
 [] ? iterate_supers+0xa3/0xb7
 [] system_call_fastpath+0x16/0x1b
---[ end trace 320af5cb1cb60c5b ]---

The root cause seems to be the
default_send_IPI_mask_allbutself_phys() takes quite some time (I
measured it could be several ms) to complete sending NMIs to all
the other 23 CPUs, and for HZ=250/1000 system, the time is long
enough for a timer interrupt to happen, which will in turn
trigger to kick load balance to a stopped CPU and cause this
warning in native_smp_send_reschedule().

So disabling the local irq before stop_other_cpu() can fix this
problem (tested 25 times reboot ok), and it is fine as there
should be nobody caring the timer interrupt in such reboot
stage.

The latest 3.4 kernel slightly changes this behavior by sending
REBOOT_VECTOR first and only send NMI_VECTOR if the REBOOT_VCTOR
fails, and this patch is still needed to prevent the problem.

Signed-off-by: Feng Tang 
Acked-by: Don Zickus 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20120530231541.4c13433a@feng-i7
Signed-off-by: Ingo Molnar

x86/debug: Add KERN_ to bare printks, convert printks to pr_

2012-06-06T07:17:22+00:00

Use a more current logging style:

 - Bare printks should have a KERN_ for consistency's sake
 - Add pr_fmt where appropriate
 - Neaten some macro definitions
 - Convert some Ok output to OK
 - Use "%s: ", __func__ in pr_fmt for summit
 - Convert some printks to pr_

Message output is not identical in all cases.

Signed-off-by: Joe Perches 
Cc: levinsasha928@gmail.com
Link: http://lkml.kernel.org/r/1337655007.24226.10.camel@joe2Laptop
[ merged two similar patches, tidied up the changelog ]
Signed-off-by: Ingo Molnar