linux-toradex.git/arch/s390/kernel/cache.c, branch v4.9.54

s390/cpuinfo: show dynamic and static cpu mhz

2016-06-13T13:58:17+00:00

Show the dynamic and static cpu mhz of each cpu. Since these values
are per cpu this requires a fundamental extension of the format of
/proc/cpuinfo.

Historically we had only a single line per cpu and a summary at the
top of the file. This format is hardly extendible if we want to add
more per cpu information.

Therefore this patch adds per cpu blocks at the end of /proc/cpuinfo:

cpu             : 0
cpu Mhz dynamic : 5504
cpu Mhz static  : 5504

cpu             : 1
cpu Mhz dynamic : 5504
cpu Mhz static  : 5504

cpu             : 2
cpu Mhz dynamic : 5504
cpu Mhz static  : 5504

cpu             : 3
cpu Mhz dynamic : 5504
cpu Mhz static  : 5504

Right now each block contains only the dynamic and static cpu mhz,
but it can be easily extended like on every other architecture.

This extension is supposed to be compatible with the old format.

Signed-off-by: Heiko Carstens 
Acked-by: Sascha Silbe 
Signed-off-by: Martin Schwidefsky

s390/cache: remove superfluous locking

2016-05-10T11:24:49+00:00

With "s390/cpuinfo: simplify locking and skip offline cpus early" we
prevent already that cpus will go away. The additional
get_online_cpus() / put_online_cpus() within show_cacheinfo() is not
needed anymore.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/cachinfo: add missing facility check to init_cache_level()

2015-07-28T06:54:42+00:00

Stephen Powell reported the following crash on a z890 machine:

Kernel BUG at 00000000001219d0 [verbose debug info unavailable]
illegal operation: 0001 ilc:3 [#1] SMP
Krnl PSW : 0704e00180000000 00000000001219d0 (init_cache_level+0x38/0xe0)
	   R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 EA:3
Krnl Code: 00000000001219c2: a7840056		brc	8,121a6e
	   00000000001219c6: a7190000		lghi	%r1,0
	  #00000000001219ca: eb101000004c	ecag	%r1,%r0,0(%r1)
	  >00000000001219d0: a7390000		lghi	%r3,0
	   00000000001219d4: e310f0a00024	stg	%r1,160(%r15)
	   00000000001219da: a7080000		lhi	%r0,0
	   00000000001219de: a7b9f000		lghi	%r11,-4096
	   00000000001219e2: c0a0002899d9	larl	%r10,634d94
Call Trace:
 [<0000000000478ee2>] detect_cache_attributes+0x2a/0x2b8
 [<000000000097c9b0>] cacheinfo_sysfs_init+0x60/0xc8
 [<00000000001001c0>] do_one_initcall+0x98/0x1c8
 [<000000000094fdc2>] kernel_init_freeable+0x212/0x2d8
 [<000000000062352e>] kernel_init+0x26/0x118
 [<000000000062fd2e>] kernel_thread_starter+0x6/0xc

The illegal operation was executed because of a missing facility check,
which should have made sure that the ECAG execution would only be executed
on machines which have the general-instructions-extension facility
installed.

Reported-and-tested-by: Stephen Powell 
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/cacheinfo: add missing facility check

2015-04-13T08:46:16+00:00

Git commit d97d929f06d0 ("s390: move cacheinfo sysfs to generic cacheinfo
infrastructure") removed the general-instructions-extension availability
check before the ecag instruction is executed.
Without this check this may lead to crashes on machines without this facility.
Therefore add the check again where needed.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/cacheinfo: coding style changes

2015-02-12T08:37:24+00:00

Just some minor coding style changes, while I had to look at the code.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/cacheinfo: fix shared cpu masks

2015-02-12T08:37:24+00:00

When testing Sudeep Holla's cache info rework I didn't realize that the
shared cpu masks are broken (all have the same cpu set).
Let's fix this.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/cacheinfo: don't use smp_processor_id() in preemptible context

2015-02-10T09:15:57+00:00

show_cacheinfo() needs to access the cacheinfo structure of any online
cpu. This was done with using smp_processor_id() as in index while in
preemtible context.
This means the cpu could be offline and the data be gone when it would
be accessed.
Better use any online cpu address and protect the data by get_online_cpus()
and put_online_cpus().

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390: move cacheinfo sysfs to generic cacheinfo infrastructure

2015-01-08T09:02:54+00:00

This patch removes the redundant sysfs cacheinfo code by reusing
the newly introduced generic cacheinfo infrastructure through the
commit 246246cbde5e ("drivers: base: support cpu cache information
interface to userspace via sysfs")

Signed-off-by: Sudeep Holla 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390, cacheinfo: Fix CPU hotplug callback registration

2014-03-20T12:43:41+00:00

Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:

	get_online_cpus();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	register_cpu_notifier(&foobar_cpu_notifier);

	put_online_cpus();

This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).

Instead, the correct and race-free way of performing the callback
registration is:

	cpu_notifier_register_begin();

	for_each_online_cpu(cpu)
		init_cpu(cpu);

	/* Note the use of the double underscored version of the API */
	__register_cpu_notifier(&foobar_cpu_notifier);

	cpu_notifier_register_done();

Fix the cacheinfo code in s390 by using this latter form of callback
registration.

Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Ingo Molnar 
Signed-off-by: Srivatsa S. Bhat 
Signed-off-by: Rafael J. Wysocki

s390/cache: get rid of compile warning

2013-10-24T15:17:06+00:00

Get rid of this one:

arch/s390/kernel/cache.c: In function 'cache_build_info':
arch/s390/kernel/cache.c:144: warning: 'private' may be used uninitialized
in this function

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky