x86, doc: Documentation for early microcode loading

Documenation for early loading microcode methodology.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-2-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/microcode_intel.h: Define functions and macros for early loading ucode

Define some functions and macros that will be used in early loading ucode. Some
of them are moved from microcode_intel.c driver in order to be called in early
boot phase before module can be called.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-3-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/common.c: Make have_cpuid_p() a global function

Remove static declaration in have_cpuid_p() to make it a global function. The
function will be called in early loading microcode.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-4-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/common.c: load ucode in 64 bit or show loading ucode info in 32 bit on AP

In 64 bit, load ucode on AP in cpu_init().

In 32 bit, show ucode loading info on AP in cpu_init(). Microcode has been
loaded earlier before paging. Now it is safe to show the loading microcode
info on this AP.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-5-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/microcode_core_early.c: Define interfaces for early loading ucode

Define interfaces load_ucode_bsp() and load_ucode_ap() to load ucode on BSP and
AP in early boot time. These are generic interfaces. Internally they call
vendor specific implementations.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-6-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/microcode_intel_lib.c: Early update ucode on Intel's CPU

Define interfaces microcode_sanity_check() and get_matching_microcode(). They
are called both in early boot time and in microcode Intel driver.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-7-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/tlbflush.h: Define __native_flush_tlb_global_irq_disabled()

This function is called in __native_flush_tlb_global() and after
apply_microcode_early().

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-8-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/microcode_intel_early.c: Early update ucode on Intel's CPU

Implementation of early update ucode on Intel's CPU.

load_ucode_intel_bsp() scans ucode in initrd image file which is a cpio format
ucode followed by ordinary initrd image file. The binary ucode file is stored
in kernel/x86/microcode/GenuineIntel.bin in the cpio data. All ucode
patches with the same model as BSP are saved in memory. A matching ucode patch
is updated on BSP.

load_ucode_intel_ap() reads saved ucoded patches and updates ucode on AP.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-9-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/head_32.S: Early update ucode in 32-bit

This updates ucode in 32-bit kernel on BSP and AP. At this point, there is no
paging and no virtual address yet.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-10-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/head64.c: Early update ucode in 64-bit

This updates ucode on BSP in 64-bit mode. Paging and virtual address are
working now.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-11-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/mm/init.c: Copy ucode from initrd image to kernel memory

Before initrd image is freed, copy valid ucode patches from initrd image
to kernel memory. The saved ucode will be used to update AP in resume
or hotplug.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-12-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
x86/Kconfig: Make early microcode loading a configuration feature

MICROCODE_INTEL_LIB, MICROCODE_INTEL_EARLY, and MICROCODE_EARLY are three new
configurations to enable or disable the feature.

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1356075872-3054-13-git-send-email-fenghua.yu@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
locking/stat: Fix a typo

s/STATS/STAT

Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1359019365-23646-1-git-send-email-yuanhan.liu@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
lockdep: Rename print_unlock_inbalance_bug() to print_unlock_imbalance_bug()

Fix the typo in the function name (s/inbalance/imbalance)

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: rostedt@goodmis.org
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/20130108130547.32733.79507.stgit@srivatsabhat.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
watchdog: Use local_clock for get_timestamp()

The get_timestamp() function is always called with current cpu,
thus using local_clock() would be more appropriate and it makes
the code shorter and cleaner IMHO.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1356576585-28782-1-git-send-email-namhyung@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
lockdep: Silence warning if CONFIG_LOCKDEP isn't set

Since commit c9a4962881929df7f1ef6e63e1b9da304faca4dd ("nfsd:
make client_lock per net") compiling nfs4state.o without
CONFIG_LOCKDEP set, triggers this GCC warning:

    fs/nfsd/nfs4state.c: In function ‘free_client’:
    fs/nfsd/nfs4state.c:1051:19: warning: unused variable ‘nn’ [-Wunused-variable]

The cause of that warning is that lockdep_assert_held() compiles
away if CONFIG_LOCKDEP is not set. Silence this warning by using
the argument to lockdep_assert_held() as a nop if CONFIG_LOCKDEP
is not set.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Link: http://lkml.kernel.org/r/1359060797.1325.33.camel@x61.thuisdomein
Signed-off-by: Ingo Molnar <mingo@kernel.org>
--
 include/linux/lockdep.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
rwsem: Implement writer lock-stealing for better scalability

Commit 5a505085f043 ("mm/rmap: Convert the struct anon_vma::mutex
to an rwsem") changed struct anon_vma::mutex to an rwsem, which
caused aim7 fork_test performance to drop by 50%.

Yuanhan Liu did the following excellent analysis:

    https://lkml.org/lkml/2013/1/29/84

and found that the regression is caused by strict, serialized,
FIFO sequential write-ownership of rwsems. Ingo suggested
implementing opportunistic lock-stealing for the front writer
task in the waitqueue.

Yuanhan Liu implemented lock-stealing for spinlock-rwsems,
which indeed recovered much of the regression - confirming
the analysis that the main factor in the regression was the
FIFO writer-fairness of rwsems.

In this patch we allow lock-stealing to happen when the first
waiter is also writer. With that change in place the
aim7 fork_test performance is fully recovered on my
Intel NHM EP, NHM EX, SNB EP 2S and 4S test-machines.

Reported-by: lkp@linux.intel.com
Reported-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Signed-off-by: Alex Shi <alex.shi@intel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Anton Blanchard <anton@samba.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: paul.gortmaker@windriver.com
Link: https://lkml.org/lkml/2013/1/29/84
Link: http://lkml.kernel.org/r/1360069915-31619-1-git-send-email-alex.shi@intel.com
[ Small stylistic fixes, updated changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
lockdep: Print more info when MAX_LOCK_DEPTH is exceeded

This helps debug cases where a lock is acquired over and
over without being released.

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ben Greear <greearb@candelatech.com>
Cc: peterz@infradead.org
Link: http://lkml.kernel.org/r/1360176979-4421-1-git-send-email-greearb@candelatech.com
[ Changed the printout ordering. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
locking: Various static lock initializer fixes

The static lock initializers want to be fed the proper name of the
lock and not some random string. In mainline random strings are
obfuscating the readability of debug output, but for RT they prevent
the spinlock substitution. Fix it up.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
intel_idle: Convert i7300_idle_lock to raw_spinlock

24 core Intel box's first exposure to 3.0.12-rt30-rc3 didn't go well.

[   27.104159] i7300_idle: loaded v1.55
[   27.104192] BUG: scheduling while atomic: swapper/2/0/0x00000002
[   27.104309] Pid: 0, comm: swapper/2 Tainted: G           N  3.0.12-rt30-rc3-rt #1
[   27.104317] Call Trace:
[   27.104338]  [<ffffffff810046a5>] dump_trace+0x85/0x2e0
[   27.104372]  [<ffffffff8144eb00>] thread_return+0x12b/0x30b
[   27.104381]  [<ffffffff8144f1b9>] schedule+0x29/0xb0
[   27.104389]  [<ffffffff814506e5>] rt_spin_lock_slowlock+0xc5/0x240
[   27.104401]  [<ffffffffa01f818f>] i7300_idle_notifier+0x3f/0x360 [i7300_idle]
[   27.104415]  [<ffffffff814546c7>] notifier_call_chain+0x37/0x70
[   27.104426]  [<ffffffff81454748>] __atomic_notifier_call_chain+0x48/0x70
[   27.104439]  [<ffffffff81001a39>] cpu_idle+0x89/0xb0
[   27.104449] bad: scheduling from the idle thread!

This lock is taken from interrupt disabled context in the guts of
idle. Convert it to a raw_spinlock.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andy Henroid <andrew.d.henroid@intel.com>
Link: http://lkml.kernel.org/r/1323258522.5057.73.camel@marge.simson.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>