* Solve issues described in 6f66cbc630
in a way that doesn't resort to set_cpus_allowed();
* in fact, only collect_cpu_info and apply_microcode callbacks
must run on a target cpu, others will do just fine on any other.
smp_call_function_single() (as suggested by Ingo) is used to run
these callbacks on a target cpu.
* cleanup of synchronization logic of the 'microcode_core' part
The generic 'microcode_core' part guarantees that only a single cpu
(be it a full-fledged cpu, one of the cores or HT)
is being updated at any particular moment of time.
In general, there is no need for any additional sync. mechanism in
arch-specific parts (the patch removes existing spinlocks).
See also the "Synchronization" section in microcode_core.c.
* return -EINVAL instead of -1 (which is translated into -EPERM) in
microcode_write(), reload_cpu() and mc_sysdev_add(). Other suggestions
for an error code?
* use 'enum ucode_state' as return value of request_microcode_{fw, user}
to gain more flexibility by distinguishing between real error cases
and situations when an appropriate ucode was not found (which is not an
error per-se).
* some minor cleanups
Thanks a lot to Hugh Dickins for review/suggestions/testing!
Reference: http://marc.info/?l=linux-kernel&m=124025889012541&w=2
[ Impact: refactor and clean up microcode driver locking code ]
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Peter Oruba <peter.oruba@amd.com>
Cc: Arjan van de Ven <arjan@infradead.org>
LKML-Reference: <1242078507.5560.9.camel@earth>
[ did some more cleanups ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/include/asm/microcode.h | 25 ++
arch/x86/kernel/microcode_amd.c | 58 ++----
arch/x86/kernel/microcode_core.c | 326 +++++++++++++++++++++-----------------
arch/x86/kernel/microcode_intel.c | 92 +++-------
4 files changed, 261 insertions(+), 240 deletions(-)
(~20 new comment lines)
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: fix microcode driver newly spewing warnings
x86, PAT: Remove page granularity tracking for vm_insert_pfn maps
x86: disable X86_PTRACE_BTS for now
x86, documentation: kernel-parameters replace X86-32,X86-64 with X86
x86: pci-swiotlb.c swiotlb_dma_ops should be static
x86, PAT: Remove duplicate memtype reserve in devmem mmap
x86, PAT: Consolidate code in pat_x_mtrr_type() and reserve_memtype()
x86, PAT: Changing memtype to WC ensuring no WB alias
x86, PAT: Handle faults cleanly in set_memory_ APIs
x86, PAT: Change order of cpa and free in set_memory_wb
x86, CPA: Change idmap attribute before ioremap attribute setup
Jeff Garzik reported this WARN_ON() noise:
> Kernel: 2.6.30-rc1-00306-g8371f87
> Hardware: ICH10 x86-64
>
> This is a regression from 2.6.29. Microcode spews the following WARNING
> multiple times during boot:
>
> ------------[ cut here ]------------
> WARNING: at fs/sysfs/group.c:138 sysfs_remove_group+0xeb/0xf0()
> Hardware name: sysfs group ffffffffa0209700 not found for
> kobject 'cpu0'
Keep sysfs files around for cpus even when we failed to locate
microcode for them at the moment of module loading. The appropriate
microcode firmware can become available later on.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Revert part of af5c820a31 ("x86: cpumask:
use work_on_cpu in arch/x86/kernel/microcode_core.c")
That change is causing only one Intel CPU's microcode to be updated e.g.
microcode: CPU3 updated from revision 0x9 to 0x17, date = 2005-04-22
where before it announced that also for CPU0 and CPU1 and CPU2.
We cannot use work_on_cpu() in the CONFIG_MICROCODE_OLD_INTERFACE code,
because Intel's request_microcode_user() involves a copy_from_user() from
/sbin/microcode_ctl, which therefore needs to be on that CPU at the time.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: don't play with current's cpumask
Straightforward indirection through work_on_cpu(). One change is
that the error code from microcode_update_cpu() is now actually
plumbed back to microcode_init_cpu(), so now we printk if it fails
on cpu hotplug.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Cc: Peter Oruba <peter.oruba@amd.com>
LKML-Reference: <200903111632.37279.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix deadlock
This is in response to the following bug report:
Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=12100
Subject : resume (S2R) broken by Intel microcode module, on A110L
Submitter : Andreas Mohr <andi@lisas.de>
Date : 2008-11-25 08:48 (19 days old)
Handled-By : Dmitry Adamushko <dmitry.adamushko@gmail.com>
[ The deadlock scenario has been discovered by Andreas Mohr ]
I think I might have a logical explanation why the system:
(http://bugzilla.kernel.org/show_bug.cgi?id=12100)
might hang upon resuming, OTOH it should have likely hanged each and every time.
(1) possible deadlock in microcode_resume_cpu() if either 'if' section is
taken;
(2) now, I don't see it in spec. and can't experimentally verify it (newer
ucodes don't seem to be available for my Core2duo)... but logically-wise, I'd
think that when read upon resuming, the 'microcode revision' (MSR 0x8B) should
be back to its original one (we need to reload ucode anyway so it doesn't seem
logical if a cpu doesn't drop the version)... if so, the comparison with
memcmp() for the full 'struct cpu_signature' is wrong... and that's how one of
the aforementioned 'if' sections might have been triggered - leading to a
deadlock.
Obviously, in my tests I simulated loading/resuming with the ucode of the same
version (just to see that the file is loaded/re-loaded upon resuming) so this
issue has never popped up.
I'd appreciate if someone with an appropriate system might give a try to the
2nd patch (titled "fix a comparison && deadlock...").
In any case, the deadlock situation is a must-have fix.
Reported-by: Andreas Mohr <andi@lisas.de>
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Tested-by: Andreas Mohr <andi@lisas.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: make global variables and a function static
Fix following sparse warnings:
arch/x86/kernel/microcode_core.c:102:22: warning: symbol
'microcode_ops' was not declared. Should it be static?
arch/x86/kernel/microcode_core.c:206:24: warning: symbol
'microcode_pdev' was not declared. Should it be static?
arch/x86/kernel/microcode_core.c:322:6: warning: symbol
'microcode_update_cpu' was not declared. Should it be static?
arch/x86/kernel/microcode_intel.c:468:22: warning: symbol
'microcode_intel_ops' was not declared. Should it be static?
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Combine both generic and arch-specific parts of microcode into a
single module (arch-specific parts are config-dependent).
Also while we are at it, move arch-specific parts from microcode.h
into their respective arch-specific .c files.
Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Cc: "Peter Oruba" <peter.oruba@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-23 12:21:42 +02:00
Renamed from arch/x86/kernel/microcode.c (Browse further)
