linux-toradex.git/arch/x86/kernel/microcode_core.c, branch v3.2.34

x86, microcode: Sanitize per-cpu microcode reloading interface

2012-08-02T13:37:44+00:00

commit c9fc3f778a6a215ace14ee556067c73982b6d40f upstream.

Microcode reloading in a per-core manner is a very bad idea for both
major x86 vendors. And the thing is, we have such interface with which
we can end up with different microcode versions applied on different
cores of an otherwise homogeneous wrt (family,model,stepping) system.

So turn off the possibility of doing that per core and allow it only
system-wide.

This is a minimal fix which we'd like to see in stable too thus the
more-or-less arbitrary decision to allow system-wide reloading only on
the BSP:

$ echo 1 > /sys/devices/system/cpu/cpu0/microcode/reload
...

and disable the interface on the other cores:

$ echo 1 > /sys/devices/system/cpu/cpu23/microcode/reload
-bash: echo: write error: Invalid argument

Also, allowing the reload only from one CPU (the BSP in
that case) doesn't allow the reload procedure to degenerate
into an O(n^2) deal when triggering reloads from all
/sys/devices/system/cpu/cpuX/microcode/reload sysfs nodes
simultaneously.

A more generic fix will follow.

Cc: Henrique de Moraes Holschuh 
Cc: Peter Zijlstra 
Signed-off-by: Borislav Petkov 
Link: http://lkml.kernel.org/r/1340280437-7718-2-git-send-email-bp@amd64.org
Signed-off-by: H. Peter Anvin 
Signed-off-by: Ben Hutchings

x86, microcode: microcode_core.c simple_strtoul cleanup

2012-08-02T13:37:44+00:00

commit e826abd523913f63eb03b59746ffb16153c53dc4 upstream.

Change reload_for_cpu() in kernel/microcode_core.c to call kstrtoul()
instead of calling obsoleted simple_strtoul().

Signed-off-by: Shuah Khan 
Reviewed-by: Borislav Petkov 
Link: http://lkml.kernel.org/r/1336324264.2897.9.camel@lorien2
Signed-off-by: H. Peter Anvin 
Signed-off-by: Ben Hutchings

x86, microcode: Fix sysfs warning during module unload on unsupported CPUs

2012-05-11T12:14:31+00:00

commit a956bd6f8583326b18348ab1452b4686778f785d upstream.

Loading the microcode driver on an unsupported CPU and subsequently
unloading the driver causes

 WARNING: at fs/sysfs/group.c:138 mc_device_remove+0x5f/0x70 [microcode]()
 Hardware name: 01972NG
 sysfs group ffffffffa00013d0 not found for kobject 'cpu0'
 Modules linked in: snd_hda_codec_hdmi snd_hda_codec_conexant snd_hda_intel btusb snd_hda_codec bluetooth thinkpad_acpi rfkill microcode(-) [last unloaded: cfg80211]
 Pid: 4560, comm: modprobe Not tainted 3.4.0-rc2-00002-g258f742 #5
 Call Trace:
  [] ? warn_slowpath_common+0x7b/0xc0
  [] ? warn_slowpath_fmt+0x45/0x50
  [] ? sysfs_remove_group+0x34/0x120
  [] ? mc_device_remove+0x5f/0x70 [microcode]
  [] ? subsys_interface_unregister+0x69/0xa0
  [] ? mutex_lock+0x16/0x40
  [] ? microcode_exit+0x50/0x92 [microcode]
  [] ? sys_delete_module+0x16d/0x260
  [] ? wait_iff_congested+0x45/0x110
  [] ? page_fault+0x1f/0x30
  [] ? system_call_fastpath+0x16/0x1b

on recent kernels.

This is due to commit 8a25a2fd126c ("cpu: convert 'cpu' and
'machinecheck' sysdev_class to a regular subsystem") which renders
commit 6c53cbfced04 ("x86, microcode: Correct sysdev_add error path")
useless.

See http://marc.info/?l=linux-kernel&m=133416246406478

Avoid above warning by restoring the old driver behaviour before
6c53cbfced04 ("x86, microcode: Correct sysdev_add error path").

Cc: Tigran Aivazian 
Signed-off-by: Andreas Herrmann 
Acked-by: Greg Kroah-Hartman 
Link: http://lkml.kernel.org/r/20120411163849.GE4794@alberich.amd.com
Signed-off-by: Borislav Petkov 
[bwh: Backported to 3.2: deleted line uses sys_dev, not dev]
Signed-off-by: Ben Hutchings

x86, microcode: Fix the failure path of microcode update driver init code

2011-12-05T13:21:01+00:00

The microcode update driver's initialization code does not handle
failures correctly. This patch fixes this issue.

Signed-off-by: Jan Beulich 
Signed-off-by: Srivatsa S. Bhat 
Link: http://lkml.kernel.org/r/20111107123530.12164.31227.stgit@srivatsabhat.in.ibm.com
Link: http://lkml.kernel.org/r/4ED8E2270200007800065120@nat28.tlf.novell.com
Signed-off-by: Borislav Petkov

x86, microcode: Don't request microcode from userspace unnecessarily

2011-10-13T14:20:35+00:00

Requesting the microcode from userspace *every time* when onlining CPUs
(during a CPU hotplug operation) is unnecessary. Thus, ensure that
once the kernel gets the microcode after booting, it is not freed nor
invalidated when a CPU goes offline, so that it can be reused when that
CPU comes back online, without requesting userspace for it again. As a
result, the CPU hotplug operations become faster as well.

Signed-off-by: Srivatsa S. Bhat 
Acked-by: Rafael J. Wysocki 
Acked-by: Andreas Herrmann 
Link: http://lkml.kernel.org/r/4E91F908.5010006@linux.vnet.ibm.com
Signed-off-by: Borislav Petkov

x86, microcode: Unregister syscore_ops after microcode unloaded

2011-03-29T09:12:04+00:00

Currently, microcode doesn't unregister syscore_ops after it's
unloaded. So if we modprobe then rmmod microcode, the stale
microcode syscore_ops info will stay on syscore_ops_list.

Later when we're trying to reboot/halt/shutdown the machine, kernel
will panic on syscore_shutdown().

With the patch applied, I can reboot/halt/shutdown my machine successfully.

Signed-off-by: Xiaotian Feng 
Cc: Tigran Aivazian 
Cc: Rafael J. Wysocki 
LKML-Reference: <1301387672-23661-1-git-send-email-dfeng@redhat.com>
Signed-off-by: Ingo Molnar

x86: Use syscore_ops instead of sysdev classes and sysdevs

2011-03-23T21:15:54+00:00

Some subsystems in the x86 tree need to carry out suspend/resume and
shutdown operations with one CPU on-line and interrupts disabled and
they define sysdev classes and sysdevs or sysdev drivers for this
purpose.  This leads to unnecessarily complicated code and excessive
memory usage, so switch them to using struct syscore_ops objects for
this purpose instead.

Generally, there are three categories of subsystems that use
sysdevs for implementing PM operations: (1) subsystems whose
suspend/resume callbacks ignore their arguments entirely (the
majority), (2) subsystems whose suspend/resume callbacks use their
struct sys_device argument, but don't really need to do that,
because they can be implemented differently in an arguably simpler
way (io_apic.c), and (3) subsystems whose suspend/resume callbacks
use their struct sys_device argument, but the value of that argument
is always the same and could be ignored (microcode_core.c).  In all
of these cases the subsystems in question may be readily converted to
using struct syscore_ops objects for power management and shutdown.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Thomas Gleixner 
Acked-by: Ingo Molnar

x86, microcode: Correct sysdev_add error path

2011-02-09T15:05:31+00:00

When we encounter an error while initting the microcode driver on a CPU,
we must undo the previously added sysfs group.

Cc: Tigran Aivazian 
Signed-off-by: Borislav Petkov 
Acked-by: Andreas Herrmann

Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2010-10-24T20:41:39+00:00

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  Update broken web addresses in arch directory.
  Update broken web addresses in the kernel.
  Revert "drivers/usb: Remove unnecessary return's from void functions" for musb gadget
  Revert "Fix typo: configuation => configuration" partially
  ida: document IDA_BITMAP_LONGS calculation
  ext2: fix a typo on comment in ext2/inode.c
  drivers/scsi: Remove unnecessary casts of private_data
  drivers/s390: Remove unnecessary casts of private_data
  net/sunrpc/rpc_pipe.c: Remove unnecessary casts of private_data
  drivers/infiniband: Remove unnecessary casts of private_data
  drivers/gpu/drm: Remove unnecessary casts of private_data
  kernel/pm_qos_params.c: Remove unnecessary casts of private_data
  fs/ecryptfs: Remove unnecessary casts of private_data
  fs/seq_file.c: Remove unnecessary casts of private_data
  arm: uengine.c: remove C99 comments
  arm: scoop.c: remove C99 comments
  Fix typo configue => configure in comments
  Fix typo: configuation => configuration
  Fix typo interrest[ing|ed] => interest[ing|ed]
  Fix various typos of valid in comments
  ...

Fix up trivial conflicts in:
	drivers/char/ipmi/ipmi_si_intf.c
	drivers/usb/gadget/rndis.c
	net/irda/irnet/irnet_ppp.c

Update broken web addresses in arch directory.

2010-10-18T09:03:21+00:00

The patch below updates broken web addresses in the arch directory.

Signed-off-by: Justin P. Mattock 
Signed-off-by: Maciej W. Rozycki 
Cc: Finn Thain 
Cc: Randy Dunlap 
Reviewed-by: Finn Thain 
Signed-off-by: Jiri Kosina